tag:blogger.com,1999:blog-55752659383739021142024-03-19T04:15:56.017-05:00Minnesota Crop NewsUnknownnoreply@blogger.comBlogger1360125tag:blogger.com,1999:blog-5575265938373902114.post-59481021784743717662024-03-18T10:47:00.001-05:002024-03-18T10:47:57.929-05:00Strategic Farming: Let's talk crops focused on corn insect pestsLiz Stahl, Extension educator – crops and Fei Yang, Extension corn entomologist <br /><br /><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGzArOOjw6BfV5PRTzIIFFPlLsIsJne4ZLrvcFE8GfYyFwuWJzbuL1R7aPrITFBX8AsU9-JPPfJb0yt34WmhQlr7Cg2Urh-_41_Ry-3DZgF82R1fm6OylJj9KiWlgEehDyWZgEar6BxtHQmAkFcxqxrH_ea45PaiMPHyugCVsSaz0tGiE4IS-qfDfaPnf2/s400/overwintering-ecb-larva-potter.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="400" data-original-width="300" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGzArOOjw6BfV5PRTzIIFFPlLsIsJne4ZLrvcFE8GfYyFwuWJzbuL1R7aPrITFBX8AsU9-JPPfJb0yt34WmhQlr7Cg2Urh-_41_Ry-3DZgF82R1fm6OylJj9KiWlgEehDyWZgEar6BxtHQmAkFcxqxrH_ea45PaiMPHyugCVsSaz0tGiE4IS-qfDfaPnf2/s320/overwintering-ecb-larva-potter.jpg" width="240" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Overwintering European corn borer<br /> larva and its feeding damage within<br /> the lower stalk. Photo: Bruce Potter</td></tr></tbody></table>Although European corn borer (ECB) populations dropped dramatically after widespread adoption of Bt-corn hybrids, the discovery of Bt-resistant populations reminds us to not let our guard down on this pest. Corn rootworm (CRW) is another major corn pest in Minnesota where resistance to Bt traits has led to management challenges. ECB and CRW were the topic of discussion on the March 13th, Strategic Farming: Let’s Talk Crops program with Dr. Fei Yang, Extension Entomologist with University of Minnesota Extension. <br /><h2 style="text-align: left;">European corn borer (ECB) </h2>European corn borer, specifically the larva, caused significant yield losses and economic damage throughout the U.S. Corn Belt prior to the introduction of Bt hybrids. Injury from ECB can lead to stalk breakage, ear droppage, stalk rots, ear rots, mycotoxins, and ultimately yield losses. Control was particularly challenged in MN by the existence of two biotypes, the univoltine biotype, which has only one generation in a year, and the multivoltine biotype, which has at least two generations each year. <br /><br />Because ECB larvae burrow into the stalks and ears of corn, timing an insecticide application for effective control is challenging. Transgenic Bt corn replaced the use of insecticides for ECB control in many fields, providing excellent control of ECB for almost 27 years in the U.S. <br /><h3 style="text-align: left;">ECB resistance to the Bt technology </h3>Practical resistance in ECB to Bt corn (Cry1F) was first found in four fields in Nova Scotia, Canada in 2018. Since then, practical resistance to Cry1F and other Bt proteins has been documented to widely expand in other locations in Canada, and in 2023 practical resistance in ECB to Bt sweet corn (Cry1A.105 + Cry2Ab2) was found in the U.S. in Connecticut. Although resistance in ECB to Bt corn is still rare in the U.S., insect resistance to Bt proteins poses a significant threat to the long-term sustainability of this technology. <br /><br />The close proximity of the Canadian populations to MN is concerning as ECB moths can migrate long distances. Monitoring for resistance, use of a high dose/refuge strategy, and pyramiding or stacking traits in hybrids have been effective so far at fending off and slowing down resistance. <br /><br />University of MN Extension surveyed fields across MN in 2023 for ECB in research supported by the MN Corn Research and Promotion Council. Overall ECB populations were very low. In one non-Bt field in Crookston MN, however, approximately 30 to 35% of the corn plants had been damaged by ECB. ECB larvae were collected, then reared and tested in the lab for resistance. Fortunately, resistance was not detected to any of the Cry Bt proteins currently on the market for control of ECB. Continued monitoring is needed, however, and Dr. Yang requests anyone who sees a problem developing in a field to contact him either using this <a href="https://docs.google.com/forms/d/e/1FAIpQLSdJbrF5vrFrSEM089ppk4tviAaZZU8M_GiS2Y2M0SZmRn6UYA/viewform?vc=0&c=0&w=1&flr=0">online report form</a> or email at <a href="mailto:yang8905@umn.edu">yang8905@umn.edu</a>. <br /><h2 style="text-align: left;">Corn rootworm (CRW) </h2>As with ECB, the larval stage of CRW causes the most damage to corn, but in this case by feeding on corn roots. Root feeding can hurt corn yield since injured roots take up less water and nutrients, and when severe, can result in root lodging, which can hinder photosynthesis, pollination and harvestability. Feeding wounds can also create entry points for root and crown rot pathogens. Adult CRW beetles can also injure corn by feeding on silks, which can hinder pollination. This feeding can also create an entry point for sap beetles and ear molds. <br /><br />There are two main species of CRW in Minnesota: The western corn rootworm (WCR) and northern corn rootworm (NCR). WCR tends to be the dominant species in southern MN, while the balance shifts to NCR as you move further north in state. One reason for this shift is the increased cold tolerance of NCR eggs compared to WCR eggs. <br /><br />Since WCR eggs hatch the following year, problems with WCR are most significant in continuous corn. The WCR variant that lays eggs in soybean fields has not been detected in MN. As a result, rotation is still the number one way to manage WCR. Control of volunteer corn in soybean, however, is important for this strategy to work as WCR beetles will be attracted to volunteer corn in soybean fields, laying their eggs in the volunteer corn. <br /><br />The first evidence of field-evolved resistance in WCR to Bt-corn (Cry3Bb) was in 2009, six years after commercialization. Resistance to Cry3 and Cry34/35 Bt proteins has since been detected in states throughout the Corn Belt including MN, IA, NE, and ND. <br /><h3 style="text-align: left;">Northern corn rootworm (NCR) </h3>After staying generally low since 2005, populations of NCR are on the rise in Minnesota. Although a portion of NCR eggs will hatch the following year, NCR exhibits extended diapause, where a significant portion of the egg population will hatch two or more years after being laid. This complicates the management of CRW since rotating to soybean every other year can still result in injury from CRW when corn is grown in the rotation. There are many unknowns around extended diapause, and it is currently unclear how many populations show this trait in the state. <br /><br />Resistance to Bt proteins (Cry3 and Cry 34/35) in North Dakota in NCR was reported in 2019 from a population collected in 2016. Resistance in NCR to these same proteins in Minnesota was reported in 2023 from a population collected in 2019. <br /><h3 style="text-align: left;">The quest to better understand CRW </h3>There are currently many gaps in our understanding of the biology, ecology, genetics and resistance to Bt proteins in NCR and WCR. A better understanding of extended diapause in NCR could also help in the management of this pest. <br /><br />Dr. Yang has started a greenhouse trial to evaluate the interactions and population dynamics of WCR and NCR. Initial results indicate that WCR tends to out-compete NCR in most conditions, although many factors influence the relationship between these two species. A study conducted two decades ago showed that at 0.5 F, you can see 100% mortality of WCR but only 20 to 50% mortality of NCR. However, given the ongoing changes in climate and the adaptive evolution of insect pests, it's plausible that the biological traits of these species, such as their supercooling and cold hardiness abilities, have significantly evolved. Consequently, current research is focusing on the effects of cold temperatures on WCR and NCR mortality to better predict their population densities and geographical distributions. <br /><h3 style="text-align: left;">Management strategies: </h3>Scout fields to assess the potential for CRW issues the next time corn will be planted in the field. This can be done by using yellow sticky traps to monitor adult corn rootworm beetle populations and/or by digging roots during mid-late July to check for feeding. <br /><br />Crop rotation is the still the number one tactic to help manage CRW. Check what Bt traits are in the hybrids you plant, rotating effective sources when feasible, and consider pyramid stacks and the use of an insecticide at planting in fields where you anticipate heavy CRW pressure. Rarely would adult CRW beetle control be called for in field corn in Minnesota, and insecticide resistance in CRW has limited the effectiveness of this practice where it has been historically used. <br /><br />Dr. Yang noted that RNAi offers a different mode of action, or way of controlling CRW, than the proteins in Bt hybrids, but it takes longer to kill CRW than an effective Bt trait. This technology must also be managed with resistance in mind.<br /><h2 style="text-align: left;">Join the webinar series </h2>Join us next week when we welcome Dr. Kiersten Wise, plant pathologist at the University of Kentucky to discuss “Efficacy matters: Fungicides for managing specific corn and soybean diseases”. <br /><br />University of Minnesota’s Strategic Farming: Let’s talk crops! webinar series, offered Wednesdays through March, features discussions with specialists to provide up-to-date, research-based information to help farmers and ag professionals optimize crop management strategies for 2024. For more information and to register, visit <a href="http://z.umn.edu/strategic-farming">z.umn.edu/strategic-farming</a>. <br /><br /><b><i>Thanks to the Soybean Research and Promotion Council and the Corn Research and Promotion Council for their generous support of this program. </i></b><br /><h2 style="text-align: left;">References and Resources: </h2><a href="https://blog-crop-news.extension.umn.edu/2024/02/european-corn-borer-new-pest-old.html">European corn borer: Old pest, new problems</a> <br /><br /><a href="https://blog-crop-news.extension.umn.edu/2023/07/northern-corn-rootworm-and-extended.html">Northern corn rootworm and extended diapause problems increase in areas of Minnesota</a> <br /><br /><a href="https://www.texasinsects.org/uploads/4/9/3/0/49304017/24_bttraittable_march2024.pdf">Handy Bt Trait Table for 2024</a>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-90569470948735748042024-03-14T09:56:00.000-05:002024-03-14T09:56:06.278-05:00Soil test pH and liming: Common questions and answers<div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjVv4LeoW2hznsx5WZXFRY0Dw28YW9kBEz1rSVKGN0jjJDFyf4g-TvYAtAMg_em_EROg6xXYVGU5tTwdcICzzpwu9Q9fC9HcReyvvK4Fmmq_VdBQgnoWxyUmniGg2G39UAcI7oDGudNCBhZ4WPRXIpyDPpbNWGH_DJC0nxN_v9ii_fnTcWDcjMyWS_vdu7M/s2184/soil%20liming.jpg" style="text-align: center;"><img alt="lime ready to be added to soil" border="0" data-original-height="1439" data-original-width="2184" height="422" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjVv4LeoW2hznsx5WZXFRY0Dw28YW9kBEz1rSVKGN0jjJDFyf4g-TvYAtAMg_em_EROg6xXYVGU5tTwdcICzzpwu9Q9fC9HcReyvvK4Fmmq_VdBQgnoWxyUmniGg2G39UAcI7oDGudNCBhZ4WPRXIpyDPpbNWGH_DJC0nxN_v9ii_fnTcWDcjMyWS_vdu7M/w640-h422/soil%20liming.jpg" title="lime ready to be added to soil" width="640" /></a></div><p>By: Dan Kaiser, Extension nutrient management specialist</p><div class="separator" style="clear: both; text-align: left;"><div class="separator" style="clear: both;">When it comes to soil tests, I commonly receive questions about pH and liming. Below are some common questions I get and my answers.</div><h3 style="clear: both; text-align: left;">What exactly is the buffer pH? </h3><div class="separator" style="clear: both;">Soils are routinely analyzed for water pH where equal weights of water and soil are mixed, and a pH electrode is used to determine the pH of the solution. The water pH represents what we call the “active” pH of the soil. When the water pH drops below a certain point, most labs will then run a buffer pH on the soil, which is used to determine the amount of limestone needed to raise the water pH to a desired value. Buffer pH methods use various extraction solutions and are meant to measure both the active and reserve acidity of the soil, which provides a better indication of how the active acidity will change when limestone is applied. The two tests will not return the same value and it is common for the buffer pH value to be higher than the water pH in nearly all soils. </div><h3 style="clear: both; text-align: left;">If I have a water pH value, but no buffer pH value, can I still determine how much lime I need?</h3><div class="separator" style="clear: both;">While having a buffer pH value is best for determining lime needs, the University of Minnesota does have suggested rates of lime based solely on water pH. In fact, for organic or peat soils, there is no suggestion that uses a buffer pH to determine lime requirement. Organic or peat soils differ from mineral soils in that they tend to be more acidic and the current <a href="https://extension.umn.edu/liming/lime-needs-minnesota" target="_blank">Minnesota guidelines for liming</a> only suggest raising these soils to a pH of 5.5. For mineral soils, it is suggested to raise soil pH to 6.0 or 6.5, depending on the crop. It is important to know what crops you are growing and what their optimal pH is to determine how much lime your soil requires.</div><h3 style="clear: both; text-align: left;">Would raising my soil to a pH of 7.0 be better?</h3><div class="separator" style="clear: both;">Some states may suggest liming soils to a pH of 7.0, which is considered to be neutral pH. However, crops like corn and soybean tend to show positive yield benefits to lime only when the soil pH is below 6.0. For alfalfa, yield may be impacted when pH is less than 6.5. Raising your soil pH to 7.0 may help to increase the time between lime applications but there is generally no economic justification to do so for most crops. It should be noted that there are separate lime guidelines in the state of Minnesota for western versus eastern Minnesota. This is because there are higher levels of soil carbonates near the soil surface in western Minnesota, where leaching has resulted in the carbonate layers being deeper in the soil profile than in eastern Minnesota. </div><h3 style="clear: both; text-align: left;">I have multiple options for lime. Which one should I choose?</h3><div class="separator" style="clear: both;">Effective neutralizing power, or ENP, can be used to assess differences in liming sources. The ENP rating should provide a level playing field to determine the overall economics of different sources of limestone. An ENP rating is made on a per ton of material basis. So, if you want to look at costs, you can take your suggested application rate of ENP per acre and divide it by the ENP rating per ton of material. This will give you the total cost when comparing materials. However, the ENP ratings do not factor in how easy it is to spread certain materials. Lime needs to be spread evenly to have the greatest impact and materials high in moisture can form large clumps, which can make it difficult to spread evenly across a field. This should be taken into account when deciding on the best material to use.</div><h3 style="clear: both; text-align: left;">Is it possible to over-lime a field?</h3><div class="separator" style="clear: both;">Excessive lime application can result in soil pH values that may cause some issues for crops such as soybean. We do know that nutrient availability in soils is impacted by pH and that high pH soils can present challenges when it comes to phosphorus acquisition. Also, for soybean, high pH soils can impact the acquisition of iron, causing <a href="https://extension.umn.edu/crop-specific-needs/managing-iron-deficiency-chlorosis-soybean" target="_blank">iron deficiency chlorosis</a>. The maximum pH that typically can be achieved with liming sources is around 8.4 to 8.5. While it is possible to find soils with even higher pH values, those soils typically have other issues, such as high salts or high sodium content, which are separate issues. </div><h3 style="clear: both; text-align: left;">Can I acidify high pH soils?</h3><div class="separator" style="clear: both;">While it would be possible to acidify a soil where too much lime was applied, there is no economically feasible way to acidify soils natively high in lime, such as those in western Minnesota. The layers of carbonates in soils in western Minnesota can go from the soil surface to several feet deep in the soil profile. Acidification in the upper soil surface would only be temporary and have a very minimal impact on crops. In these types of soils, it is better to deal with the high lime in other ways and not fall for any of the misinformation on using elemental sulfur or AMS to acidify natively high pH soils.</div><h3 style="clear: both; text-align: left;">Additional resources:</h3><div class="separator" style="clear: both;">•<span style="white-space: pre;"> </span><a href="https://extension.umn.edu/liming/lime-needs-minnesota" target="_blank">Lime needs in Minnesota</a></div><div class="separator" style="clear: both;">•<span style="white-space: pre;"> </span><a href="https://extension.umn.edu/liming/liming-materials-minnesota-soils" target="_blank">Liming materials for Minnesota soils</a></div><div class="separator" style="clear: both;">•<span style="white-space: pre;"> </span><a href="https://extension.umn.edu/testing-and-analysis/understanding-soil-test-report" target="_blank">Understanding the soil test report</a></div><div class="separator" style="clear: both;">•<span style="white-space: pre;"> </span><a href="https://blog-crop-news.extension.umn.edu/2020/10/what-to-know-about-liming.html" target="_blank">Nutrient Management Podcast episode: What to know about liming (Oct. 2020)</a></div></div><div><br /></div>---<br /><br />For the latest nutrient management information, subscribe to the <a href="https://nutrientmanagement.transistor.fm/subscribe" target="_blank">Nutrient Management Podcast</a> wherever you listen and never miss an episode! And don't forget to subscribe to the <a href="https://pub.s6.exacttarget.com/k0nz2zsg2m4" target="_blank">Minnesota Crop News</a> daily or weekly email newsletter, subscribe to our <a href="https://youtube.com/playlist?list=PLOPc3IDYKqybHLzKb5j1tOIl_Yeii_ofn" target="_blank">YouTube</a> channel, like UMN Extension Nutrient Management on <a href="https://www.facebook.com/UMNNutrientMgmt/" target="_blank">Facebook</a>, follow us on <a href="https://twitter.com/UMNNutrientMgmt" target="_blank">Twitter</a>, and visit our <a href="https://extension.umn.edu/crop-production#nutrient-management" target="_blank">website</a>.<br /><br />If you have questions or comments, please email us at <a href="mailto:nutmgmt@umn.edu?subject=Response to your blog post">nutmgmt@umn.edu.</a> Jack Wilcoxhttp://www.blogger.com/profile/14996004057706995837noreply@blogger.com2tag:blogger.com,1999:blog-5575265938373902114.post-186097157285583032024-03-11T11:19:00.002-05:002024-03-11T11:19:22.098-05:00Did My Winter Wheat and Winter Rye Survive the Last Cold Snap?<p>Temperatures keep gyrating back and forth between hard freezes and very mild conditions. I had received several reports that winter wheat and winter rye had started to green up before last week's return to freezing temperatures. You may be wondering whether the fields survived this last cold snap.</p><p>The month of March truly is the 'witching hour' for winter wheat and winter rye. The crowns are aging and as a result, are less winterhardy than they were in December and January. I also explained in an <a href="https://blog-crop-news.extension.umn.edu/2024/02/a-midwinters-thaw-nightmare.html" target="_blank">earlier article</a> that the crop is not able to return to the same level of winterhardiness if warm weather allows the crop to break dormancy. , </p><p>To evaluate whether your winter wheat survived the last cold snap, I suggest you do the following: dig up several seedlings across the field and cut them longitudinal (lengthwise) with a very sharp knife or a safety razor blade. If the crowns look white/yellow to light green, they are healthy and will continue to grow. If you find that the crown has turned tan to brown and soft, it did not survive the cold weather. </p><p>In addition, you can check whether seedlings will grow by trimming the roots and leaves down to about ¼ to ½ ” above and below the crown. Place these seedlings on a wet paper towel and place the towel in a Ziploc bag or plastic container that can be sealed. Place the container at room temperature and check for regrowth in 24-48 hours. Viable seedlings will show regrowth almost immediately (Photo 1). It will take longer than usual, but as long as the crown is healthy, a stand will be established.</p><p><br /></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhq9UmJKn1Du5XW9rE06WfB2KKexQZz1lF-UrayrcYVSZjBPyrhyphenhyphenm3QeiTkZiCPZm4d9YVOOaRyyVfQyCc-WJhRKjdXJpbRsilfvQt7DS7OzbR6Wo6zs7hhIm_ld43qfGRTVp2TlGFRHoykBewoHabnu9lM_wzTaF1xOO-efoLcwTXXzLpXL2E_goOmjxs/s2304/24%20Winter%20Wheat%20Seedling%20Test.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1296" data-original-width="2304" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhq9UmJKn1Du5XW9rE06WfB2KKexQZz1lF-UrayrcYVSZjBPyrhyphenhyphenm3QeiTkZiCPZm4d9YVOOaRyyVfQyCc-WJhRKjdXJpbRsilfvQt7DS7OzbR6Wo6zs7hhIm_ld43qfGRTVp2TlGFRHoykBewoHabnu9lM_wzTaF1xOO-efoLcwTXXzLpXL2E_goOmjxs/w640-h360/24%20Winter%20Wheat%20Seedling%20Test.jpg" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Photo 1 - Regrowth on winter crowns after 48 hrs at room temperature. <br />Note the cut marks on the old leaves and the new growth. </td></tr></tbody></table><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><br /><p><br /></p><p> </p><p><br /></p><p><br /></p>Jochum Wiersmahttp://www.blogger.com/profile/12077401423747385722noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-29009634448557232102024-03-11T08:57:00.000-05:002024-03-11T08:57:15.399-05:00Strategic Farming: Let's talk crops focused on getting your best fertilizer ROIPhyllis Bongard, Extension content development and communications specialist, Dan Kaiser, Extension nutrient management specialist, and Jeff Vetsch, Researcher, Southern Research and Outreach Center <br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSkYwBc7o9SrmK6hsY3YYfxldjGdguljTd-OjJIToAinFIxQE33o7e1-joUDHbVcITjEoSF6-9unnQayluz3Mk2ziAYuDCjrcwDSpsIrZDsMraRSrwlMM_LNi8XSSu-DtU7a7liBiDOTHMd-M2gdNqoIN7kwp_aCNG5hcS6r_HWVUU3easPqUxWVqoGuF1/s5472/anhydrous-application.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="3648" data-original-width="5472" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSkYwBc7o9SrmK6hsY3YYfxldjGdguljTd-OjJIToAinFIxQE33o7e1-joUDHbVcITjEoSF6-9unnQayluz3Mk2ziAYuDCjrcwDSpsIrZDsMraRSrwlMM_LNi8XSSu-DtU7a7liBiDOTHMd-M2gdNqoIN7kwp_aCNG5hcS6r_HWVUU3easPqUxWVqoGuF1/s320/anhydrous-application.JPG" width="320" /></a></div>Dry conditions and the winter that wasn’t is accelerating nutrient management decisions. Should fertilizer be applied now? How can you get the best return on your fertilizer investment given current prices and costs? Ryan Miller, Extension educator – crops, steered this wide-ranging discussion with Dan Kaiser, Extension nutrient management specialist, and Jeff Vetsch, Researcher at the Southern Research and Outreach Center, to address these and other nutrient management questions in the March 6 <b>Strategic Farming: Let’s talk crops</b> session. <br /><h2 style="text-align: left;">Early spring fertilizer application </h2>Current field conditions are pushing early fertilizer application decisions. If phosphorus, potassium, or lime didn’t get applied last fall, this could be a good time to get that done. Without any rainfall, however, the fertilizer will just sit on the soil surface. Since it needs time to dissolve, there is some risk of loss involved. <br /><br />Anhydrous ammonia applications might also be considered at this time. Nitrification inhibitors (NIs), such as N-Serve, could help prevent nitrogen loss, particularly in south central Minnesota. As we approach planting, the advantage for NIs with anhydrous decreases. <br /><br />What about urea? The thought of applying urea right now concerns Kaiser, even if it was applied with a urease inhibitor like Agrotain. Since the lifespan of a urease inhibitor is roughly two weeks, the potential for volatility losses would significantly increase as the inhibitor degraded. In addition, there might be enough moisture to start hydrolysis in our dry conditions, but not enough to incorporate it. Data from the West looked at 80 pounds of surface-applied urea at three different application times: December 1, early February, and April 1. Researchers saw volatility losses of 30% with the December 1 application and a range of 10 to 15% with the April application. Due to the high potential for N loss and added costs, a March application of urea is not recommended. Anhydrous ammonia would make more sense at this point and would be a safer bet for an early application. <br /><br />For more information, see <a href="https://blog-crop-news.extension.umn.edu/2024/03/thinking-of-getting-early-start-on.html">Thinking of getting an early start on fertilizer applications? Here are a few things to consider</a>, <a href="https://extension.umn.edu/nitrogen/fertilizer-urea">Fertilizer urea</a>, and <a href="https://blog-crop-news.extension.umn.edu/2016/05/the-three-biggies-urea-anhydrous.html">The three biggies: Urea, anhydrous ammonia, and UAN</a>. <br /><h2 style="text-align: left;">Nitrogen </h2><h3 style="text-align: left;">Variable rate technology opportunities </h3>How can variable rate technologies incorporate UMN’s N rate recommendations when the maximum return to nitrogen (MRTN) is a single number? The corresponding economic optimum N rate provides a range, but no guidelines on how to use the range. Kaiser suggests that the MRTN is a target. If actual application rates were within 10 to 15 pounds in our highly variable fields, that would be a major success. Other researchers suggest that plus or minus 40 pounds is a good range. What they all agree on is that the N cycle is complex and managing N to optimize production and minimize environmental impacts is key. <br /><br />Field variability contributes to the complexity of managing N and is a given. Delta yield - the yield difference between optimum N and no or near zero N – measures the crop response to N. It seems logical that N application rates would be tied closely to yields; in fact, the relationship between recommended N rates and yield level is quite poor. Kaiser admits that this is a challenging concept. The relationship is more about the field environment and the nitrogen-producing ability of the soil at that location than yield. Since the MRTN is focused on the return on investment per pound of N and not maximum productivity, poorer areas in the field may be the ones with higher nitrogen use efficiencies (NUE). In contrast, other areas of the field may have better characteristics going for them - higher organic matter mineralization, N contributions from the soil, etc. - that make them highly productive may have lower NUE. An ongoing, long-term study is comparing plots with no additional nitrogen to those with above optimal rates to get at these soil contribution questions. <br /><br />Where do variable rate technologies like drone and aerial imagery fit in? In general, Minnesota’s fine-textured soils carry enough residual N that Kaiser doesn’t tend to see differences until it’s too late to make an application decision. For Vetsch, delta yield has been a good indicator of sites that needed a higher N rate for corn following soybeans, but by the time those differences were noticed, the risk for delayed applications was high. <br /><br />In-season sensing, either with the drone or remote sensing, may be most practical for rescue treatments. While the past couple of years have been dry, there have been areas of the state over the years that have gotten too much rainfall in the spring. By June and July, deficient areas start to show up. Sensing tools may help identify those areas and determine whether the entire field or just portions of it require supplemental N. <br /><br />For more information, see <a href="file:///C:/Users/jvetsch/Downloads/For%20more%20information,%20see%20Variable%20rate%20technology:%20How%20should%20farmers%20evaluatet%20outcomes%3f">Variable rate technology: How should farmers evaluate outcomes?</a>, <a href="https://blog-crop-news.extension.umn.edu/2022/05/q-with-dan-kaiser-on-minnesotas-updated.html">Making sense of Minnesota’s corn fertilizer guidelines: Frequently asked questions and answers</a>, <a href="https://extension.umn.edu/crop-specific-needs/fertilizing-corn-minnesota">Fertilizing corn in Minnesota</a>, and <a href="https://apps.extension.umn.edu/agriculture/nutrient-management/crop-calculators/corn-calculator-popup.html">Supplemental N corn calculator</a>. <br /><h3 style="text-align: left;">PPNT and PSNT soil tests </h3>The preplant nitrate test (PPNT) is a tool that can help make fertilizer application decisions upfront. Samples are taken to a 2-foot depth before planting and any nitrogen applications. The PPNT is recommended in western Minnesota, due to its drier climate. In south-central, southeastern, and east-central Minnesota, the PPNT is recommended if conditions favor residual N. A guide for making that decision is available in <a href="https://extension.umn.edu/crop-specific-needs/fertilizing-corn-minnesota#use-of-a-soil-nitrate-test-encouraged-2237064">Fertilizing corn</a>. <br /><br />The pre-sidedress nitrate test (PSNT) is taken to a 1-foot depth in late May to early June before corn is 12-inches tall to determine if enough N is available for the crop. According to Dr. Fernandez’s work, the critical level seems to be between 20 and 26 ppm, but the amount of N to apply below the critical range is still a question. If a sidedress application decision is made, the N should be applied by V10 or earlier if conditions are dry. <br /><br />Sampling for the PSNT is challenging when N has been banded either as anhydrous ammonia, injected manure, or a starter band. Try to avoid those hotspots since they will skew results. Vetsch has also seen skewed results in dry years, so he suggests using the test in years with normal spring rainfall when N is more normally distributed through the soil profile. <br /><br />What about N residual after a manure application and a failed crop due to drought? This scenario of taking the PPNT in early April could be effective in determining residual N. If levels are elevated, a small amount of starter could be applied with the planter, then residual N reassessed with the PSNT. If the PSNT comes back greater than Iowa State University's critical value of 25, there should be enough nitrogen to carry the crop through the season. <br /><br />Similarly, the PPNT could also be useful in a corn – corn situation after two dry years, especially if the crop was poor. Vetsch and Kaiser both agree that the PPNT is not effective in corn following soybeans unless manure had been applied. <br /><br />For more information, see <a href="https://blog-crop-news.extension.umn.edu/2023/02/for-second-year-in-row-taking-pre-plant.html">For second year in a row, taking a preplant soil nitrate test this spring could pay big</a> (2022). <br /><h3 style="text-align: left;">ESN and other N sources </h3>ESN is a polymer-coated, controlled release nitrogen fertilizer that protects N against both volatilization and nitrification. It’s more expensive than urea, so is often blended at a one-third to two-thirds ratio. Treated urea may have had either a nitrification inhibitor – like N-Serve – or urease inhibitor – like NBPT – or both applied to the prill. Urease inhibitors are important to protect surface-applied urea from volatilization losses when it doesn’t get incorporated within 2 to 3 days. Nitrification inhibitors, on the other hand, slow the conversion from ammonium to nitrate, and thus reduce leaching potential. <br /><br />The best fit for ESN, according to Vetsch, is on medium- and fine-textured, poorly drained soils as an alternative to split applications. If used in a preplant blend, the ESN would protect some of that N from denitrification through mid-June. Split-applications of urea or UAN will probably be as effective at a lower cost if time and equipment are available.<br /><br />In the karst region of southeastern Minnesota, preplant applications of urea and anhydrous are effective most years on the finer-textured soils. On the occasional coarse-textured soils, blends containing ESN and urea applied preplant may be an alternative to split applications. <br /><br />For more information, see <a href="https://blog-crop-news.extension.umn.edu/2022/03/high-nitrogen-fertilizer-prices-is-now.html">High nitrogen fertilizer prices: Is now the time to try polymer-coated urea?</a> <br /><h3 style="text-align: left;">Cover crops and N release </h3>Cereal rye can be a very good scavenger of soil nitrate when grown as a cover crop. However, nitrogen release to the following cash crop hasn’t been seen in most of the Minnesota data. A grass, like cereal rye, has a high carbon to nitrogen ratio, so the nitrogen in the residue is more likely to be tied up and unavailable to the following crop. <br /><br />For more information, see <a href="https://blog-crop-news.extension.umn.edu/2023/09/why-did-cover-crops-cause-issues-in.html">Why did cover crops cause issues in Minnesota the last two years and what should growers do going forward?</a> and <a href="https://blog-crop-news.extension.umn.edu/2024/02/cover-crops-in-minnesota-recent.html">Cover crops in Minnesota: Recent challenges and future solutions</a>. <br /><h2 style="text-align: left;">Potassium </h2>Potassium (K) soil test levels fluctuate over the cropping season as much as 80 to 100 ppm, due in part to crop demand. In drier years, the variability is related to the amount of K that’s being leached out of the residue. If there’s moisture, water moving through the residue will leach some of the potassium out, but that differs by crop. Iowa data showed that even in wet years, only about 50% of the roughly 200 pounds of K in corn residue would be available by May. Soybeans release the K in their residue much faster. <br /><br />It's a dynamic system, much like nitrogen, which can be frustrating as K values decline during dry conditions. Kaiser predicts that we’ll see some recovery in soil test values with wetter years. The bottom line is to trust your soil test and try to sample at the same time because of its seasonal variability. <br /><br />What about K base saturation? Not necessary to factor in, according to Kaiser. If the soil test value is 200 ppm or above, there shouldn’t be an issue with potassium. <br /><br />For more information, see <a href="https://extension.umn.edu/phosphorus-and-potassium/potassium-crop-production">Potassium for Minnesota crops</a>. <br /><h2 style="text-align: left;">Tillage </h2>Strip-till presents some challenges for nitrogen applications. Vetsch has had several studies looking at this over the years at Waseca. Any combinations of planting and coulter injected UAN, urea and UAN preplant and all split applications with UAN and urea with a urease inhibitor worked well. Two treatments did not work well: fall anhydrous, with or without an NI, and 40 pounds of N applied in a surface dribble band at planting. Vetsch cautions that 20 pounds of N in the dribble band is a better rate and the balance can be sidedressed or split-applied. Coarse-textured soils will probably require more than two split applications in this system. <br /><br />What about deep banding in strip-till? Vetsch doesn’t recommend reducing the band rates for potassium. However, recent data showed that band and broadcast rates can be reduced by as much as a third or more for phosphorus in neutral pH soils, since current UMN fertilizer guidelines and crop removal rates usually build soil test P. This allows for a reduced fertilizer P rate at maximized yield while maintaining soil test P concentrations. Getting an accurate soil test can be a challenge with deep banding since the knife injects fertilizer deeper than the normal 6-inch sampling depth. If you’re not sampling in that range, soil test values will seem to decline quickly. <br /><br />Vetsch recommends banding P and K in strip-till and no-till in alternate years since there may be a slightly higher return on investment. However, his data also shows that buying equipment for the sole purpose of band applying P and K is unlikely to pay. <br /><br />Application options are limited for no-till systems. Broadcasting P without incorporation probably won’t impact crop uptake, but it can lead to environmental concerns. Broadcasting K without incorporation can lead to nutrient stratification, particularly in dry years. Deep banding once every 4 to 6 years would be helpful to get K placed deeper in the soil profile. <br /><br />Liquid fertilizer options applied with the planter are 2 to 3 times more expensive on a per unit basis versus broadcast. In the final analysis, it comes down to whether there are enough nutrients for the crop to optimize yield. <br /><h2 style="text-align: left;">Join the webinar series </h2>Join us next week when we welcome Dr. Fei Yang, Extension corn entomologist to address “Are we smarter than the average European corn borer and corn rootworm.” <br /><br />University of Minnesota’s Strategic Farming: Let’s talk crops! webinar series, offered Wednesdays through March, features discussions with specialists to provide up-to-date, research-based information to help farmers and ag professionals optimize crop management strategies for 2024. For more information and to register, visit <a href="https://z.umn.edu/strategic-farming">z.umn.edu/strategic-farming</a>. <br /><br /><b><i>Thanks to the Soybean Research and Promotion Council and the Corn Research and Promotion Council for their generous support of this program. </i></b><br /><br /><div style="mso-element: comment-list;"><div style="mso-element: comment;"><div class="msocomtxt" id="_com_5" language="JavaScript">
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</div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-15710335560387716402024-03-08T20:16:00.002-06:002024-03-08T20:49:24.214-06:00What does a record-warm winter mean for 2024 insect forecasts?<p><i>Dr. Anthony Hanson, </i><i>Regional Extension Educator - Field Crops Integrated Pest Management</i></p><p>Cold winters help prevent many potential pest insects from establishing in Minnesota or require species that cannot survive our winters to migrate up from southern states each year. Extreme cold can also knock back species that are established here. The cold can be a welcome event for farmers from a pest management perspective, but the record-warm winter has left many farmers wondering if 2024 will be a severe year for insects, especially now that meteorological winter is over.</p><p>Each year, I try to get a rough snapshot of how winter may have helped us out with reducing pest insect populations by using temperatures on the coldest night of the year. So far for most of the state, Jan. 20 had been the coldest night during winter 2023-24 with morning low air temperatures near -15 °F in the central portion of the state and below -20 °F farther north (Fig. 1). NOAA and the US National Phenology Network provide 1.6 square-mile resolution daily temperature data used in Fig. 1 that helps give a region-wide picture of daily high and low temperatures. This interpolated data is generally within a couple degrees of individual weather stations. Here at the U of M's <a href="https://wcroc.cfans.umn.edu/weather" target="_blank">West Central Research and Outreach Center</a> in Morris, the morning low was -16 °F on Jan. 20, and we had a string of subzero nights Jan. 10-21. However, four inches below the soil surface, temperatures around this time were still only barely below freezing at 27 to 28 °F. </p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-oABb4u_PyusfVVp6EvpCZuvqoQQ_16ojyZ0oSsa5BX-WcKii7DPME7r9JaCbmovv0xGOeStKMihEJvNzxwVbthC7MJQiVejUgFJ29fi3H7MjI2czu1lTy4V-5_2BJbHUZnAKNgr79Zq17F0JAzwv3j-IUNXbN4-_nafJgjFlqldCANiCvh0iy34OsVX2/s3507/mintemp2024.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2480" data-original-width="3507" height="452" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-oABb4u_PyusfVVp6EvpCZuvqoQQ_16ojyZ0oSsa5BX-WcKii7DPME7r9JaCbmovv0xGOeStKMihEJvNzxwVbthC7MJQiVejUgFJ29fi3H7MjI2czu1lTy4V-5_2BJbHUZnAKNgr79Zq17F0JAzwv3j-IUNXbN4-_nafJgjFlqldCANiCvh0iy34OsVX2/w640-h452/mintemp2024.png" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Figure 1. Morning lows on Jan. 20, 2024; temperature data produced by NOAA obtained from U.S. National Phenology Network.</td></tr></tbody></table><br /><h3 style="text-align: left;">Insect Cold Tolerance</h3><div>
For the most part, insects match the temperature of their surrounding environment, making them "cold-blooded." Unlike warm-blooded animals, wind chill doesn't affect insects, but air temperature does. Even so, many insects can survive temperatures well-below freezing due to antifreeze compounds like glycerol that lower the freezing point of water in their bodies similar to antifreeze in a car. For many insects, like soybean aphid, we can forecast mortality based on when ice does form in their body. The minimum winter air temperature each year can help forecast insect freeze mortality, which is similar to how USDA plant hardiness zone maps are used. <h3 style="text-align: left;">Soybean aphid</h3><p class="MsoNormal">Soybean aphid overwintering predictions are a little easier to make with air temperature alone because they overwinter as eggs on buckthorn buds where there is little protection from cold exposure unless small plants are under insulating snow cover. Eggs will freeze between -25 and -35 °F with most freezing around -29 °F. Some egg mortality can also occur above freezing due to dehydration and late-fall cold snaps. This year, very little mortality for soybean aphid is expected anywhere in the region excluding a few very small pockets in Northwest Minnesota (Fig. 2). <br /> </p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7IKBIAE_1EbQ4MbRxy3WKECvISb80ffeN-PJp1y4iwJNzGp4UMDcz4G3gSYxXt36tK0-g-cRJ-Cq636G1JOmMj9m7X0Vq7gmGbveYzqHhYRX0wvoaUaKY4-ERvvNQw1JdeZVvb18rW3aQ2hZm64YzYM3KdhGomE1O7s1nxLEDVTXr3A2UIpphcQjPU4HY/s3507/sbamortality2024.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2480" data-original-width="3507" height="452" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7IKBIAE_1EbQ4MbRxy3WKECvISb80ffeN-PJp1y4iwJNzGp4UMDcz4G3gSYxXt36tK0-g-cRJ-Cq636G1JOmMj9m7X0Vq7gmGbveYzqHhYRX0wvoaUaKY4-ERvvNQw1JdeZVvb18rW3aQ2hZm64YzYM3KdhGomE1O7s1nxLEDVTXr3A2UIpphcQjPU4HY/w640-h452/sbamortality2024.png" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Figure 2. Predicted soybean aphid cold-exposure mortality on Jan. 20, 2024 based on average the freezing point of overwintering eggs at -29º F (std. dev.: 3.4) and minimum air temperature. Only areas in Northwest Minnesota that reached approximately -25ºF had detectable mortality (above 5%).</td></tr></tbody></table><br /><p></p>
<p></p><p class="MsoNormal">For comparison in 2019, there was significant soybean aphid mortality throughout the state. This was the year we had a strong polar vortex that
<a href="https://blog-crop-news.extension.umn.edu/2019/03/insects-and-polar-vortex-how-will.html" target="_blank">brought temperatures near -30ºF</a> to central Minnesota.
That year was a very stark comparison for soybean aphid forecasts (Fig. 3) compared
to this extremely mild winter of 2024 (Fig. 2). Those few areas with predicted mortality in 2024 show just how much difference even a few degrees difference can make for insect overwintering where temperatures just barely reaching -25ºF caused perhaps near 10% aphid mortality. Meanwhile, widespread 2019 temperatures colder than -30ºF caused near 90% mortality in the northern half of the state. Those two years document different extremes in winter temperatures, but even only a few degrees for a winter low can have significant impacts on insect overwintering ability.<br /></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiZAtlxn8i1B-oftFwT_4mJmuHoETTPjNiY7x0-4l3uaqynhhAAyZxgmc4PI3GLq7pd0yEqVip6kAjpVRN0P9dmnYiEx8jx6aoPsp5F1vO6n4VcWMlS6wwXXZBwXRIPFN56eNksG-TePYQkSHRyDyUThw0txDAriyKKAeieRw1OfkvTlI5solkRgGMZlqNZ/s3507/soybeaaphidmortality2019.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2480" data-original-width="3507" height="452" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiZAtlxn8i1B-oftFwT_4mJmuHoETTPjNiY7x0-4l3uaqynhhAAyZxgmc4PI3GLq7pd0yEqVip6kAjpVRN0P9dmnYiEx8jx6aoPsp5F1vO6n4VcWMlS6wwXXZBwXRIPFN56eNksG-TePYQkSHRyDyUThw0txDAriyKKAeieRw1OfkvTlI5solkRgGMZlqNZ/w640-h452/soybeaaphidmortality2019.png" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Figure 3. Predicted soybean aphid cold-exposure mortality on Jan. 31, <u>2019</u> based on average the freezing point of overwintering eggs at -29º F (std. dev.: 3.4) and minimum air temperature.</td></tr></tbody></table>
<p></p><p class="MsoNormal">Since soybean aphid populations were starting to be more
abundant during 2023 after years of relatively low populations, this winter may
set up the 2024 growing season to be at higher risk for soybean aphid issues.
Overwintering is only one piece of the puzzle for affecting pest populations,
so it’s possible other factors like beneficial insects and pathogens might help suppress aphid
populations. Even with increased aphid risk, this does not mean there will be a benefit
to preventative insecticide use. Insecticidal seed treatments generally <a href="https://extension.umn.edu/soybean-pest-management/soybean-aphid" target="_blank">aren’t effective for soybean aphid</a> as the seed treatment loses efficacy after about
40 days after planting, and aphids typically move from buckthorn to soybeans
after this time. Instead, be proactive about scouting this year. <span style="mso-spacerun: yes;"> </span>This may also be a good year to consider <a href="https://extension.umn.edu/soybean-variety-selection/aphid-resistant-soybean-varieties-minnesota" target="_blank">aphid-resistant varieties</a>
if available in your area. </p>
<h3 class="MsoNormal" style="text-align: left;">Corn rootworm</h3>
<p class="MsoNormal">Where insects overwinter also affects mortality, so insects
like soybean aphid that are primarily exposed to air temperatures during winter
are a bit more straightforward to forecast. Western corn rootworm forecasting
though is a bit more complicated.<span style="mso-spacerun: yes;"> </span>Their
eggs overwinter in the soil where they are protected from temperature
extremes
by the soil's insulation, especially last winter with deep snow cover.
That's why accurate soil temperatures are needed to predict
overwintering for these insects.<br /></p>
<p class="MsoNormal">This winter, there was potential to have some soil-dwelling insect
mortality with little to no snow cover if we ever had sustained cold
temperatures. A majority of overwintering corn rootworm eggs will die
after at
least two weeks of exposure to 18.5 °F or colder. However, even with an
extended
period of subzero air temperature during January, four-inch depth soil
temperatures at Morris remained near 30 °F most of the winter with a brief dip near
the upper-20s. There likely won't be much rootworm
cold mortality this year despite the lack of snow cover.</p>
<h3 class="MsoNormal" style="text-align: left;">Alfalfa weevil</h3>
<p class="MsoNormal"><a href="https://blog-crop-news.extension.umn.edu/2023/05/updated-alfalfa-weevil-management.html" target="_blank">Alfalfa weevil</a> has been a resurgent pest for alfalfa growers
in recent years. It overwinters as an adult in leaf litter or stubble in
alfalfa fields or nearby protected grassy areas. During the winter of 2023, weevils were well-protected and insulated by snow cover from temperatures that would
cause it to freeze. As a tradeoff, that same insulation also protects <a href="https://blog-crop-news.extension.umn.edu/2024/03/predicting-alfalfa-winter-survival.html" target="_blank">alfalfa from winterkill</a>
as long as the plants don't go through too many freeze-thaw cycles in spring.</p>
<p class="MsoNormal">It takes exposure around 13 °F at the soil surface to reach
20-30% alfalfa weevil mortality with a small subset able to survive down to
around 1 °F. It is difficult to get accurate widespread estimates of temperature
just at the soil surface due to variation in vegetative cover and other insulating
effects of the soil, but I would expect to see some minor to moderate alfalfa weevil mortality
this year in exposed areas that may slightly reduce weevil issues in some
fields. However, I would still plan to scout heavily for it in fields that have had weevil
problems in previous years.</p>
<h3 class="MsoNormal" style="text-align: left;">Migratory crop pests</h3>
<p class="MsoNormal">Potato leafhopper affects crops such as soybeans, edible beans,
alfalfa, and potatoes, though it typically has to migrate up from states bordering the Gulf of Mexico
each year. It only overwinters in areas with at least 260-270 frost-free days
and is usually no longer found in Minnesota once temperatures reach 20 °F in the fall.
Other migratory pests such as black cutworm and true armyworm cannot survive
winters with persistent freezing temperatures, so this record winter still
would not allow these pests to survive our winter. The problem to watch though
is that populations may be larger and start the season farther north than previous years, so monitoring
for moth migration will be important this year, such as the <a href="https://swroc.cfans.umn.edu/research/ipm/bcw-network" target="_blank">UMN Black Cutworm Reporting Network</a>. </p>
<h3 class="MsoNormal" style="text-align: left;">Emerald ash borer</h3>
<p class="MsoNormal">While it's not a field crop pest, I often get questions if winter will cut back on emerald ash borer (EAB) populations. EAB overwinters a couple inches underneath the bark of ash trees, which adds 2 – 6 °F insulation to morning low air temperatures below 15 °F. Mortality starts to be noticeable around actual exposure temperatures of -22 °F, around half freeze at -24.5 °F, and a small percentage can even survive brief exposure near -40 °F. Larger diameter parts of trees can provide more insulation; smaller trees will be closer to air temperature. This year, don't expect much if any EAB overwintering mortality (Fig. 4). Only a few areas of north-central Minnesota would even experience 10% EAB cold mortality this year, though EAB has <a href="https://gisdata.mn.gov/dataset/emerald-ash-borer" target="_blank">not been found</a> in many of these counties, yet.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRLZlatYrk0zNvZHJRywkmcMEgboqcYizEcCW11b-DFINPuk9C0MvKEOGTJ_AV_eibytWSj0YwGio0EzVJ78uvOcpbAoCDAl3C6ksjv24T92MfksANotK-Fj0ao208oMTTNttvDhC9gz7tehdcDWYh6qSyNuVkXf3uaxH5J7b2b4OMj5Sh0iYUP4y6rlPp/s3507/eabmortality2024.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2480" data-original-width="3507" height="452" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRLZlatYrk0zNvZHJRywkmcMEgboqcYizEcCW11b-DFINPuk9C0MvKEOGTJ_AV_eibytWSj0YwGio0EzVJ78uvOcpbAoCDAl3C6ksjv24T92MfksANotK-Fj0ao208oMTTNttvDhC9gz7tehdcDWYh6qSyNuVkXf3uaxH5J7b2b4OMj5Sh0iYUP4y6rlPp/w640-h452/eabmortality2024.png" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Figure 4. Predicted emerald ash borer (EAB) cold-exposure mortality on Jan. 20, 2024 based on average freezing point -24.5 °F (std. dev.: 6.6), minimum air temperature, and added average insulation between green and black ash species at 4.6 ft height.</td></tr></tbody></table> <p></p>
<h3 class="MsoNormal" style="text-align: left;">Growing season outlook</h3>
<p>In short, it's not a surprise that our record-breaking winter didn't get cold enough significantly affect some of our common overwintering field crop insects, though just getting below freezing still prevents of some of our "snowbird" insect pests from having even larger populations during the growing season. It is concerning though to see just how widespread the effects of this warm winter have been for increasing the chances of insect issues.<br /></p><p>Warm winter temperatures don't only indicate that more insects survive the winter, but a warm spring will also lead to insects showing up earlier this year. How early remains to be seen for Minnesota, but some estimates at the time of this posting were showing measures like <a href="https://www.usanpn.org/data/maps/spring" target="_blank">first leaf emergence</a> being 20+ days earlier than normal in states such as Missouri and Iowa. Some of those locations are showing the earliest emergence on record for these spring indicators. Pest emergence will likely be much earlier than normal if current weather trends continue to hold. University of Minnesota Extension also tracks <a href="https://vegedge.umn.edu/degree-day-models-select-insect-pests-midwest-region" target="_blank">temperature-based forecasts for insect pests</a> of field and specialty crops, so more updates will be coming this spring.<br /></p>
<p>Read more about insect overwintering at <a href="https://drive.google.com/file/d/1W8aKBoQG2656RwTBnMEx74aWmdgnvk2T/view" target="_blank"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: major-fareast;">Tough Buggers: Insect strategies to
survive winter in Minnesota</span></a> or contact Anthony Hanson at <a href="mailto:hans4022@umn.edu"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: major-fareast;">hans4022@umn.edu</span></a>.</p></div>Anthony Hansonhttp://www.blogger.com/profile/13583194000646140319noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-84639623689317683482024-03-07T10:12:00.008-06:002024-03-07T13:21:27.399-06:00Thinking of getting an early start on fertilizer applications? Here are a few things to consider.<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhht7O4OvTngHfBxKY5G9TSGY5d2CmM4rdzEDU0IX0vwxqY4bYoCtS40_mtIvTfEauxUYVaJ5duxxf6Onw_hJO4EgAwoEs38EsrqRsNIb3JEdaTKEvmorYHVGq70FgkbO-Y_9oHTsQ6UQjVn7mfIyQLi4qJF39XZ7G6p7B2slFGrtr3XqYM1C0E4zUoyBA/s1920/TerraGator%20(8).jpg" style="margin-left: 1em; margin-right: 1em; text-align: center;"><img alt="nitrogen fertilizer minnesota urea" border="0" data-original-height="1080" data-original-width="1920" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhht7O4OvTngHfBxKY5G9TSGY5d2CmM4rdzEDU0IX0vwxqY4bYoCtS40_mtIvTfEauxUYVaJ5duxxf6Onw_hJO4EgAwoEs38EsrqRsNIb3JEdaTKEvmorYHVGq70FgkbO-Y_9oHTsQ6UQjVn7mfIyQLi4qJF39XZ7G6p7B2slFGrtr3XqYM1C0E4zUoyBA/w640-h360/TerraGator%20(8).jpg" title="nitrogen fertilizer minnesota urea" width="640" /></a><br /><br />By: Dan Kaiser, Extension nutrient management specialist; Fabian Fernandez, Extension nitrogen management specialist; & Jeff Vetsch, U of M SROC researcher<br /><br />The record warm winter has been raising questions about early spring fertilizer applications. With soils not frozen, yet fit enough for fieldwork, what are the risks of early fertilizer application? <br /><br />Most fertilizers are water-soluble and will dissolve readily at this point. If a soil is not frozen, any fertilizer that dissolves will react with the soil and stay where it was applied. Therefore, applications of phosphate and potash fertilizers present little risk for loss if they are not incorporated in the soil, unless excessive quantities of water are running off the soil surface. In addition, because the nitrogen in MAP, DAP, and AMS is in the ammonium form, it is not subject to volatility. <br /><br />In cold soils (less than 50°F), the accumulation of nitrate nitrogen from fertilizers is low. Nitrification is still possible if soils are not frozen, but the amount of nitrate accumulation should be minimal as this is a microbial-driven process. Similarly, denitrification, which is one of the processes by which nitrate can be lost, is low in cold soils because it is done by microbes. On the other hand, while N loss from nitrate might be low at this point, nitrogen loss through ammonia volatilization is a bigger concern because it occurs readily even at cooler soil temperatures.<br /><h2 style="text-align: left;">Is early urea application a bad idea?</h2>Volatilization of ammonia is greatest with urea that is not incorporated. Urea molecules undergo a process called hydrolysis that splits the urea into ammonia gas and carbon dioxide. If this process occurs near the soil surface, the soil might not be able to retain ammonia and it would be lost via volatilization. Incorporation of urea to a depth of at least three inches within four days of application is suggested to limit volatilization. There is research showing that the risk of ammonia volatilization is greater when urea is surface-applied in early or late winter compared to late April or early May. While soil seems dry, there is enough moisture to dissolve (hydrolyze) the urea granules and start ammonia volatilization. <br /><br />Liquid forms of N such as 28% or 32% UAN should also not be applied too early. Urea ammonium nitrate solutions contain half of the N as urea so volatility can be an issue. A larger problem is that a quarter of the N in UAN is already in the nitrate form at application, and nitrate is subject to loss if there is excess water. <br /><br />While urease inhibitors are effective to reduce ammonia volatilization for up to 14 days, they will not be effective long enough if urea is applied in March and left on the soil surface. It takes about a quarter-inch of rainfall to incorporate urea left on the soil surface deep enough into the soil to protect it from volatilization. So, a urease inhibitor is effective only if it lasts long enough for urea to get incorporated. It should also be noted that nitrification inhibitors such as DCD and Instinct will have no effect on ammonia loss because ammonia is produced before nitrification can even occur.<h2 style="text-align: left;">What about anhydrous ammonia?</h2>Since anhydrous is knifed into the soil, the risk for volatilization loss is substantially less. However, application in March may warrant a nitrification inhibitor. Since soils are still cool, the overall effect of the nitrification inhibitor will be great compared to application closer to planting. This is because of two reasons: first, the inhibitor last longer because degradation is slower at cooler temperatures now compared to closer to planting, and second, the time between application and nitrogen uptake by the crop is longer now, so there is a longer window of time for nitrogen loss to occur.<br /><h2 style="text-align: left;">Other considerations</h2>With our current field conditions, it would be a good idea to consider soil testing in fields that haven’t been tested or where you think you might have carryover nitrate. In continuous corn or fields with a manure history, a two-foot soil sample analyzed for nitrate might provide some insight into fields where some nitrate can be credited for this year’s crop. It would also be a good time to consider other things like lime application if you have been putting it off. <br /><br />The main thing to avoid right now is application of urea or UAN as there is greater risk for loss with those fertilizers when we still have two months before there is a crop in the field growing enough to utilize these nutrients. One thing about urea and UAN is there is a lot of flexibility with when these fertilizers can be applied after planting. There is still plenty of time for N fertilizer application this spring, so there is no need to jump the gun and apply too early. Also, this is a year where, because of the low nitrogen loss potential so far, there might be more nitrogen already in the soil than is typical. So, crops will have all the nitrogen they need for a while after planting, which should give you more time into the growing season to make your nitrogen application.<div><h2 style="text-align: left;">Additional resources:</h2><div><ul style="text-align: left;"><li><a href="https://blog-crop-news.extension.umn.edu/2024/03/spring-fertilizer-outlook-key-decisions.html" target="_blank">2024 Spring fertilizer outlook podcast: Key decisions after a warm winter</a></li><li><a href="https://extension.umn.edu/crop-specific-needs/fertilizing-corn-minnesota" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #7a0019; cursor: pointer;" target="_blank">Corn fertilizer guidelines</a></li><li><a href="https://extension.umn.edu/crop-specific-needs/soybean-fertilizer-guidelines" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #7a0019; cursor: pointer;" target="_blank">Soybean fertilizer guidelines</a></li><li><a href="https://extension.umn.edu/nutrient-management/nitrogen" target="_blank">Extension nitrogen management web pages</a></li><li><a href="https://extension.umn.edu/courses-and-events/nitrogen-smart" target="_blank">Nitrogen Smart online course</a></li></ul></div>---<br /><br />For the latest nutrient management information, subscribe to the <a href="https://nutrientmanagement.transistor.fm/subscribe">Nutrient Management Podcast</a> wherever you listen and never miss an episode! And don't forget to subscribe to the <a href="https://pub.s6.exacttarget.com/k0nz2zsg2m4">Minnesota Crop News</a> daily or weekly email newsletter, subscribe to our <a href="https://youtube.com/playlist?list=PLOPc3IDYKqybHLzKb5j1tOIl_Yeii_ofn">YouTube</a> channel, like UMN Extension Nutrient Management on <a href="https://www.facebook.com/UMNNutrientMgmt/">Facebook</a>, follow us on <a href="https://twitter.com/UMNNutrientMgmt">X (formerly Twitter)</a>, and visit our <a href="https://extension.umn.edu/crop-production#nutrient-management">website</a>.<br /><br />If you have questions or comments, please email us at <a href="mailto:nutmgmt@umn.edu?subject=Response%20to%20your%20blog%20post">nutmgmt@umn.edu.</a></div>Paul McDivitthttp://www.blogger.com/profile/10662129298502128426noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-84138817236603187352024-03-06T18:50:00.004-06:002024-03-08T09:57:38.705-06:00Spring fertilizer outlook: Key decisions after a warm winter<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDF8PSgw72nw7tkFPKTpzUGm4nc13qqVBV7NXl6xspT47muWd7RaJQj2VesI8LDfSa3NKrIgfjhXpIIVPIxBn9sq64FbpXv9tHJZ6T36KqKNzGfyB6QBPMhRrPd70Xwk7Lw2cZSFHHKcJmTdCeOjav6BGUjeMqg4rLKWNJEGYIs0SjdoEgIDmy9vLzXhuV/s5363/Fertilizer%20tractor%202.JPG" style="margin-left: 1em; margin-right: 1em;"><img alt="fertilizer being applied to corn field" border="0" data-original-height="2375" data-original-width="5363" height="284" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDF8PSgw72nw7tkFPKTpzUGm4nc13qqVBV7NXl6xspT47muWd7RaJQj2VesI8LDfSa3NKrIgfjhXpIIVPIxBn9sq64FbpXv9tHJZ6T36KqKNzGfyB6QBPMhRrPd70Xwk7Lw2cZSFHHKcJmTdCeOjav6BGUjeMqg4rLKWNJEGYIs0SjdoEgIDmy9vLzXhuV/w640-h284/Fertilizer%20tractor%202.JPG" title="fertilizer being applied to corn field" width="640" /></a></div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;">This episode of the Nutrient Management Podcast is our annual spring fertilizer outlook. What are the field conditions our panelists are seeing across the state? What options for early fertilizer application should Minnesota growers consider? What practices should be avoided-and why? Should growers be concerned about nitrogen carryover? What economic practices should growers keep in mind as the season begins?</div><div class="separator" style="clear: both; text-align: left;"><br /></div><div>
<iframe frameborder="no" height="180" scrolling="no" seamless="" src="https://share.transistor.fm/e/ce62cf22" width="100%"></iframe><br /><h3 style="text-align: left;"><a href="https://docs.google.com/document/d/e/2PACX-1vRgMzUoOxohFkjllnsQ-iDZ1Z7BJvpXiBvDb-gcSZG7CIzwXVj9tzxeoBJf7-UQgqjSLkKuHIOgn3Uf/pub" target="_blank">TRANSCRIPT</a></h3><div><h3 style="text-align: left;">Guests:</h3><ul style="text-align: left;"><li>Daniel Kaiser, Extension nutrient management specialist (St. Paul)</li><li>Fabian Fernandez, Extension nutrient management specialist (St. Paul)</li><li>Lindsay Pease, Extension nutrient and water management specialist (Crookston)</li><li>Brad Carlson, Extension educator (Mankato)</li></ul><h3 style="text-align: left;">Additional resources:</h3><a href="https://extension.umn.edu/crop-specific-needs/fertilizing-corn-minnesota"></a><ul style="text-align: left;"><a href="https://extension.umn.edu/crop-specific-needs/fertilizing-corn-minnesota"></a><li><a href="https://extension.umn.edu/crop-specific-needs/fertilizing-corn-minnesota"></a><a href="https://extension.umn.edu/crop-specific-needs/fertilizing-corn-minnesota" target="_blank">Corn fertilizer guidelines</a></li><li><a href="https://extension.umn.edu/crop-specific-needs/soybean-fertilizer-guidelines" target="_blank">Soybean fertilizer guidelines</a></li><li><a href="https://finbin.umn.edu/" target="_blank">FINBIN - The Farm Financial Management Database</a></li><li><a href="https://extension.umn.edu/courses-and-events/nitrogen-smart" target="_blank">Nitrogen Smart online course</a></li></ul>---<br /><br />For the latest nutrient management information, <a href="https://nutrientmanagement.transistor.fm/subscribe" target="_blank">subscribe to the Nutrient Management Podcast</a> wherever you listen and never miss an episode! And don't forget to <a href="https://pub.s6.exacttarget.com/k0nz2zsg2m4" target="_blank">subscribe</a> to the Minnesota Crop News daily or weekly email newsletter, subscribe to our <a href="https://youtube.com/playlist?list=PLOPc3IDYKqybHLzKb5j1tOIl_Yeii_ofn" target="_blank">YouTube</a> channel, like UMN Extension Nutrient Management on <a href="https://www.facebook.com/UMNNutrientMgmt/" target="_blank">Facebook</a>, follow us on <a href="https://twitter.com/UMNNutrientMgmt" target="_blank">Twitter</a>, and visit our <a href="https://extension.umn.edu/crop-production#nutrient-management" target="_blank">website</a>.<br /><br />If you have questions or comments, please email us at <a href="nutmgmt@umn.edu?subject=Response to your podcast episode" target="_blank">nutmgmt@umn.edu.</a><br /><br />Support for the Nutrient Management Podcast is provided by Minnesota's fertilizer tonnage fee through the Agricultural Fertilizer Research & Education Council (AFREC). Learn more at <a href="http://mnsoilfertility.com/" target="_blank">MNsoilfertility.com</a>.</div></div>Jack Wilcoxhttp://www.blogger.com/profile/14996004057706995837noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-66174221205429819872024-03-06T09:03:00.001-06:002024-03-06T09:03:51.626-06:00Register now for the Midwest Soybean Gall Midge Research Update webinar<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhIbJKTvql-seo2KUfF9MK4t5-RvRfhC6oi9qlLlPQuWphDNBpRws1wZ3_iHLT9JBz-RY76NHQ6PqP4bZjYenRboM5LJ3hi8_QPif2SEXn4j2ogWoBylmwXGYk0xrlUVXVR2wj4BrZ1qPsh1oejiCMpM6fdtLglhXxB3TocT9zyZ3fXUtD9MredKC3_qKEq/s1005/soybean-gall-midge-larvae.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="666" data-original-width="1005" height="212" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhIbJKTvql-seo2KUfF9MK4t5-RvRfhC6oi9qlLlPQuWphDNBpRws1wZ3_iHLT9JBz-RY76NHQ6PqP4bZjYenRboM5LJ3hi8_QPif2SEXn4j2ogWoBylmwXGYk0xrlUVXVR2wj4BrZ1qPsh1oejiCMpM6fdtLglhXxB3TocT9zyZ3fXUtD9MredKC3_qKEq/s320/soybean-gall-midge-larvae.jpg" width="320" /></a></div>Join Extension entomologists from four universities for the 2024 Midwest Soybean Gall Midge Research webinar on <b>April 5th from 9 to 11 am CST</b>. <div><br /></div><div>This webinar will feature several short presentations on recent developments in its biology, ecology, and management strategies. The session will offer plenty of time for questions and discussion. Two CCA CEUs have been applied for. </div><h3 style="text-align: left;"><a href="https://z.umn.edu/SGM24">Register now</a></h3><div>The webinar is free, but you must be registered to attend. For more information, visit <a href="https://extension.umn.edu/courses-and-events/midwest-soybean-gall-midge-research-update">Midwest Soybean Gall Midge Research Update</a> (<a href="https://z.umn.edu/MidwestSGM2024">z.umn.edu/Midwest SGM2024</a>)</div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-83198063753697169662024-03-05T10:25:00.001-06:002024-03-05T10:25:55.088-06:00Optimizing soybean management: The Impact of planting dates on Minnesota farmsAnibal Cerrudo, UMN visiting professor, Department of Agronomy and Plant Genetics, and Seth Naeve, Extension soybean agronomist<br /><br /><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKITeT4ZRD3csKPTmL9zoUYcwUNCcWUXCvXEjqqWHs7P3zYVEjEsqQtcbPErNriN8J5uXWLF3aVhyphenhyphenBj7EGHdhdx7IWKb4qN3NqSFd_9aG7k4MGYn4jcW_fj7MRC3GrqRIq6YaMLGPwR6Neq33T0w2o7kiHfenZADvRtOluvmpKPvn4T3pp0zL2RDatqG_S/s800/strip-till-jodi.jpg" style="clear: right; margin-bottom: 1em; margin-left: 1em; margin-right: auto;"><img border="0" data-original-height="600" data-original-width="800" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKITeT4ZRD3csKPTmL9zoUYcwUNCcWUXCvXEjqqWHs7P3zYVEjEsqQtcbPErNriN8J5uXWLF3aVhyphenhyphenBj7EGHdhdx7IWKb4qN3NqSFd_9aG7k4MGYn4jcW_fj7MRC3GrqRIq6YaMLGPwR6Neq33T0w2o7kiHfenZADvRtOluvmpKPvn4T3pp0zL2RDatqG_S/s320/strip-till-jodi.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Photo: Jodi DeJong-Hughes</td></tr></tbody></table>Early soybean planting in Minnesota maximizes yield by optimizing resource utilization. However, risks that lead to poor stands and situations that require replanting must be managed. In addition, water stress can impact planting date effects, emphasizing the need for informed decisions to optimize yield. <br /><br />This report aims to explore the significance of planting dates in determining soybean yield among Minnesota farmers. Through the presentation of locally generated and modeled data, we seek to underscore the importance of early planting, address the risks associated with replanting, and examine the impact of water stress on planting date decisions. <br /><h2 style="text-align: left;">The Impact of Planting Date on Yield</h2> Research consistently demonstrates that the timing of soybean planting influences soybean yield. Early planting offers a distinct advantage, resulting in higher yields compared to delayed planting. This advantage is attributed to resource capture and utilization. <div><br /></div><div>As planting is delayed from the earliest possible date, the more critical reproductive stages are shortened and exposed to a reduced incident radiation (Figure 1a), resulting in reduced radiation capture. Temperatures during these stages are also lower as we delay planting (Figure 1a) that in turn reduces the efficiency to transform radiation in growth. Consequently, as we delay planting date, both reduced radiation and efficiency in radiation utilization impact crop growth during these critical stages, affecting yield. </div><div><br /></div><div>To illustrate these concepts, we can use some modeled data for St Paul for the 2000-2023 period in Figure 1b. A progressive yield loss is observed, with reductions ranging from 0.4 bushel per acre per day of planting delay during May to 1.0 bushel per acre per day of planting delay during June. For instance, a 10-day delay in May may result in a yield depression close to 4 bushel per acre, while the same delay in June may lead to a 10 bushel per acre yield depression. In this way, advancing planting dates can increases yield without any extra cost.</div><div><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3p0WIYdClIn35ezdho2jRgFTZ6OjatH7s3z2QMBMgbn0voWXfh3IsNs09JqT0KbL8BiAopsTqjX91wbOGOrCoTdkRzpUWhdrPATjnXi0acQ5NPz8R2JSBEplwyTTuk_Dx0cKQb3ealItVsnnwpIXQtJ3CL2OkkeopOqKOGVHgh2Dvz-k9GKaqywLiy4C4/s994/soybean-season-length.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="467" data-original-width="994" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3p0WIYdClIn35ezdho2jRgFTZ6OjatH7s3z2QMBMgbn0voWXfh3IsNs09JqT0KbL8BiAopsTqjX91wbOGOrCoTdkRzpUWhdrPATjnXi0acQ5NPz8R2JSBEplwyTTuk_Dx0cKQb3ealItVsnnwpIXQtJ3CL2OkkeopOqKOGVHgh2Dvz-k9GKaqywLiy4C4/s16000/soybean-season-length.png" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><b style="font-size: small;">Figure 1a </b><span style="font-size: small;">(left) Schematic representation of the impact of planting dates on resource capture and utilization. Illustrates how the duration of the reproductive stages (orange) is shortened as the crop is exposed to lowered radiation and temperature as planting is delayed throughout the season, departing from the earliest planting date. </span><b style="font-size: small;">1b.</b><span style="font-size: small;"><b> (right)</b> Relationship between modeled potential soybean yield (yield under no water, nutrient, or pest limitations) and planting date for St. Paul, MN. Cropgro (DSSAT) validated with local data (mean absolute error=2.4 bu ac-1) was used to simulate planting date effect from 2000 to 2023; the average (line) and the standard deviation (shadow) are presented. During May, each day of delay resulted in an average of 0.4 bu per acre per day of planting delay; this yield depression increased to 1 bu per acre per day during June.</span></td></tr></tbody></table><h2 style="text-align: left;">Considerations for risk management</h2>While early planting offers yield advantages, it's crucial to assess potential risks such as frost events or adverse soil conditions affecting crop establishment, which may necessitate replanting. For instance, advancing the planting date by a week in early May (Figure 2) could lead to almost a 3 bu/ac yield increase (7 days x 0.4 bu/ac day = 2.8 bu/ac). However, if replanting is required due to poor stand conditions and occurs three weeks after planting, a yield loss close to 6 bu/ac is expected compared to a farmer who did not advance the planting date (14 days x 0.4 bu/ac day = 5.6 bu/ac). Replanting also incurs additional costs, including seed and labor expenses, which may amount to up to 7 bu/ac. Thus, while early planting is advantageous, it's crucial to mitigate the risk of conditions that lead to poor stands and replanting to avoid a yield loss that can even exceed the initial intended advantage.<div><br /></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAR4poU5T2tVQsLRfrXc8FYyjn0Vi6L3eWuOnMvFjerSrOFfnw0J3KHrguSIdFlJoHDguR7r9HVxTC_Dozu0IgpOiuEYQA3XwSOLC8tsnpWFy93rXhZMf5ZBK29PD0r0Tl2uGQuswzKQI8E6tBih63cxDeZNBY1L7ICilfMc9UIQC4QpsOeRdhFoMfF9Do/s975/plant-replant-scenarios.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="385" data-original-width="975" height="252" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAR4poU5T2tVQsLRfrXc8FYyjn0Vi6L3eWuOnMvFjerSrOFfnw0J3KHrguSIdFlJoHDguR7r9HVxTC_Dozu0IgpOiuEYQA3XwSOLC8tsnpWFy93rXhZMf5ZBK29PD0r0Tl2uGQuswzKQI8E6tBih63cxDeZNBY1L7ICilfMc9UIQC4QpsOeRdhFoMfF9Do/w640-h252/plant-replant-scenarios.png" width="640" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;"><b>Figure 2. </b>Hypothetical effect of different planting/replanting scenarios on yield, considering the expected depression in yield estimated for Figure 1b of 0.4 bushels per acre per day of delay in planting date during May<b>. </b></td></tr></tbody></table><h3 style="text-align: left;"> Addressing water stress</h3>It is important to acknowledge that planting date effects may vary under conditions of water stress. While radiation and temperature play pivotal roles in yield determination in the absence of stress, water stress emerges as a crucial factor under low water availability conditions. To illustrate this point, we present data from Waseca's 2023 season, characterized by reduced rainfall and evident water stress. Despite variation in planting dates, no significant differences in yield were observed, highlighting the overriding influence of water availability on soybean yield under such environmental conditions.<div> <br /><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5b9xOIucVx1mnVDXp6MFwOaoDNQDuV_LSXBjq7M26XS1PCwDjaFFmtXBkjXUETnOz17-Vhve-6xUqm55mbetjFIs3G4deGpn70IK3Ovl0ggweEuc4Hs6sb_cvA3v9xvtxkVvsJqwaZXctbfI_35Ex8FioQvZHUaWIuOvHJkHpHSxuPtOwvTd3nNHVHMnz/s975/2023-precip-soybean-yields-waseca.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="500" data-original-width="975" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5b9xOIucVx1mnVDXp6MFwOaoDNQDuV_LSXBjq7M26XS1PCwDjaFFmtXBkjXUETnOz17-Vhve-6xUqm55mbetjFIs3G4deGpn70IK3Ovl0ggweEuc4Hs6sb_cvA3v9xvtxkVvsJqwaZXctbfI_35Ex8FioQvZHUaWIuOvHJkHpHSxuPtOwvTd3nNHVHMnz/s16000/2023-precip-soybean-yields-waseca.png" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;font-size:small;"><b>Figure 3a</b>. (left) ) Historic (hist) and 2023 season monthly rains at Waseca, indicating a relatively low amount of precipitation for June, July, and August in 2023,which is in accordance with the observed water stress symptoms by soybean. <b>3b. (right)</b> Soybean yield for three planting dates at Waseca (Southern Research and Outreach Center) during 2023. Each bar shows the average of four replications. No differences in soybean yield were found among planting dates</td></tr></tbody></table></div><h2>Conclusion</h2>Soybean planting stands as one of the most critical management practices for farmers in Minnesota. Early planting offers distinct yield advantages but necessitates careful consideration of associated risks, particularly under conditions of water stress. By understanding the interplay between planting dates, radiation, temperature, and water availability, farmers can make informed decisions to optimize soybean yield and ensure sustainable agricultural practices for the future.</div></div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-88617731211809128992024-03-05T09:29:00.000-06:002024-03-05T09:29:20.841-06:00Introducing ManureDB: A new way to view manure variability and trends<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlKi_sthWjQKZMoi1uDa_s5u24zkuCoJIfNhbZNVm3sls20RKB-J5fY5X-hwQu1mCWzEBz3_7OcRSKxXJsvEFyllSTsYanFFGjNAkkQSvwIU9WXl-y28PxMhqf4MHCeaT1_arsZYR5kT3ICTcGgPzpnRU5K9qYgBBBpjU2Hk344bQoCIdjCYHsmABdjfER/s1803/Header.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="847" data-original-width="1803" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlKi_sthWjQKZMoi1uDa_s5u24zkuCoJIfNhbZNVm3sls20RKB-J5fY5X-hwQu1mCWzEBz3_7OcRSKxXJsvEFyllSTsYanFFGjNAkkQSvwIU9WXl-y28PxMhqf4MHCeaT1_arsZYR5kT3ICTcGgPzpnRU5K9qYgBBBpjU2Hk344bQoCIdjCYHsmABdjfER/w640-h300/Header.png" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><p class="MsoNormal"><span style="font-family: "Calibri",sans-serif;">Figure 1.
Screenshot of ManureDB website home page.<o:p></o:p></span></p></td></tr></tbody></table><div class="separator" style="clear: both; text-align: left;">By: Nancy Bohl Bormann, Graduate research assistant</div><br />Manure is used as an organic fertilizer source on approximately 31 million United States (U.S.) acres, equating to 10% of US cultivated land the Conservation Effects Assessment Project (CEAP) II survey of practices from 2013-2016 estimates (USDA NRCS, 2022). Manure book values, approximate nutrient concentrations, are used for developing manure management plans, designing manure storages, creating best management practices for manure land application, and agricultural modeling. They show a range of nutrient values that can be expected from typical manure storages and encourage farmers to test their manure often. However, current book values are several decades old and may not reflect current production practices. Recent laboratory data from the Midwest indicated manure nutrient data has changed compared to published Midwest Plan Service (MWPS) book values (Bohl Bormann, 2022; Lorimor et al., 2004). Different animal diets, treatments, genetics, housing, and manure storage and handling practices can impact these manure nutrient values.<br /><br /> Researchers at the University of Minnesota received Agriculture and Food Research Initiative (AFRI) National Institute of Food and Agriculture (NIFA) grant funding in 2020 to create a manure nutrient database called ManureDB using FAIR principles (Findable, Accessible, Interoperable, and Reusable) in collaboration with the <a href="https://www.msi.umn.edu/" target="_blank">Minnesota Supercomputing Institute</a>. This project partners with laboratories and universities that analyze manure for business and/or research. A project team comprised of commercial manure laboratories, livestock commodity groups, regulatory and agency staff, agriculture professionals, researchers, engineers, and alternative energy groups guides the development process. <br /><br /> This project highly values data privacy. A data use agreement gets signed between the participating laboratory and the University of Minnesota. Laboratories can share past manure data and annual data going forward with no customer names or addresses shared to avoid privacy concerns. Only the state or first three digits of a ZIP code are entered into the database. The ZIP codes and laboratory identities will not be included in the public-facing database. At least five samples per year from a state or region will be needed to show up in public summaries. <br /><br />As one can imagine, all the laboratories report their results in many ways and producing a standardized template was a high priority. The database only requires the year the sample was analyzed but offers many other reporting options and sample notes. A manure type, animal or other amendment type, manure treatment, if agitated, bedding type, storage type, length of storage, and application method options can be selected if known. The template offers a wide selection of analyte options from macronutrients, micronutrients, and other metals and ratios. For each analyte reported the analytical method, units reported, and wet or dry basis is selected. The project based the analytical method selections off of the recently updated <a href="D:\My Drive\Presentations\z.umn.edu\Manure-analysis-methods" target="_blank">Recommended Methods of Manure Analysis</a> (Wilson et al., 2022), the AgGateway Modus Agricultural Lab Test Data Standard (AgGateway, 2023), and interviews with laboratories. A spreadsheet validation step ensures the data conforms to the template parameters prior to uploading to the database. Once uploaded, each sample is given a unique ManureDB identifier and conversion equations are used to display data in consistent units.<br /><br /> The public facing ManureDB database launched in summer 2023 at <a href="http://ManureDB.umn.edu" target="_blank">ManureDB.umn.edu</a> and recently released a data download feature in January 2024. See Figure 1 for a screenshot of the homepage. New features and improvements continue to roll out. Sign up for the email list<span style="background-color: white;"> at<span> <a href="http://z.umn.edu/ManureDB-signup" target="_blank">z.umn.edu/ManureDB-signup</a></span> to be notified of updates. The database interface offers data aggreg</span>ation with preliminary filters and provides some overview statistics. As of February 2024, ManureDB includes >490,000 samples from 49 states, 14 laboratories, over 65 animal types, and 18 organic amendments. With other data use agreements signed and some pending, the database will continue to grow with additional datasets and annual data additions from participating laboratories. The team continues to refine and build features in ManureDB, with plans to add data visualization displays, make the website mobile-friendly, and streamline the annual data update process. Eventually a log-in feature is planned for laboratories to view their lab-specific data relative to the aggregated database. The team plans to archive data on an annual basis in the USDA National Agricultural Library’s <a href="https://data.nal.usda.gov/" target="_blank">Ag Data Commons</a>. We continue to seek out laboratory, university, and consultant data collaborators; if interested in learning more, please email manure@umn.edu.<br /><h3 style="text-align: left;">What are the steps to submit data in ManureDB?</h3><ol style="text-align: left;"><li>Contact <a href="mailto:manure@umn.edu" target="_blank">manure@umn.edu</a> or one of the project leaders</li><li>We can set up an initial meeting to learn more about the manure database project and your laboratory</li><li>Send out the data use agreement for signatures</li><li>Once signed by the lab, University of Minnesota will sign and return the fully executed agreement</li><li>We can meet again to review the lab’s methods, analytes, column names if needed</li><li>Send a spreadsheet of your lab’s data, as far back as you wish to go</li><li>We work through the spreadsheet validation process and may have a few questions for the lab as we go</li><li>Import into ManureDB!</li></ol>While this manure database resource will give better manure nutrient estimates, the wide variability should also encourage farmers to test their manure more frequently. Tight margins make utilizing manure nutrients where they get the most value economically important. Having a better idea and confidence in manure’s nutrient value will ensure crops get the required amount of nutrients for full economic optimum yield potential. That knowledge should reduce manure overapplication, which would lessen the environmental risk of nutrient loss. If plants cannot use all the nutrients applied, there is a greater probability of environmental contamination. <br /><br />With many states working on nutrient reduction strategies for water quality improvements, knowing more about manure characteristics can improve those strategic plans. Animal feeding operation regulations could be improved with updated manure book values by having better estimates of how much land would be required for new animal feeding operation construction. A new barn location could be compared to available land for manure application to prevent manure overapplication in a specific area. Knowledge of what are appropriate manure application rates for agronomic and environmental reasons can assist environmental regulators in farmer education and relevant nutrient management policy for their region. This database can also show improved estimates of other less studied manure components such as carbon and chloride. Regional comparisons between animal types (Table 1), comparisons between different manure types (Table 2), and manure trends over time (Table 3) are some examples of what can be done with this new data resource. With the largest manure dataset of its kind, this manure database is poised to be a valuable resource for understanding manure trends and variability into the future.<div><br /></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi10h3wDPSiWLOCaO7jHuH-yYLVz0ljkv0kA5C9_NqseO1ukGuXy46LDX1xs42CDC8h0-kCDl3yN92xSSj3aJUKchCSK7V9SU8aD6S0p7Ssu04g2EB5nWnSmCErnbn4fIBgciLkV4uGEQIAQrenPJq2jS8s1nsAil0StWWsQ_HiSPW8Pz2NX5RZtvdV3cWM/s1600/Table%201.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="900" data-original-width="1600" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi10h3wDPSiWLOCaO7jHuH-yYLVz0ljkv0kA5C9_NqseO1ukGuXy46LDX1xs42CDC8h0-kCDl3yN92xSSj3aJUKchCSK7V9SU8aD6S0p7Ssu04g2EB5nWnSmCErnbn4fIBgciLkV4uGEQIAQrenPJq2jS8s1nsAil0StWWsQ_HiSPW8Pz2NX5RZtvdV3cWM/w640-h360/Table%201.png" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><p class="MsoNormal"><span style="font-family: "Calibri",sans-serif; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Table
1. Comparison of nutrient contents in poultry samples between regions from
1998-2023. <o:p></o:p></span></p></td></tr></tbody></table><br /><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFLmYnbFBneZiKqLzaa5US1OeQdDIZZ5at0tsoZYyoHDRg7p2O5Se28pFBL5EWz0y7Kutz-Mmqr1Fe9qV22wd83MUYB16jIgMcmXPXA8EOvRpUGxzjS6RUlF-Rwh6WJls6rLSs4lbFJbeFCTlxqcv62rsoe6cGz_Xh7cEgpNXQb-wc2b_7sJJgC3fATH-z/s800/Table%202.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><i><img border="0" data-original-height="450" data-original-width="800" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFLmYnbFBneZiKqLzaa5US1OeQdDIZZ5at0tsoZYyoHDRg7p2O5Se28pFBL5EWz0y7Kutz-Mmqr1Fe9qV22wd83MUYB16jIgMcmXPXA8EOvRpUGxzjS6RUlF-Rwh6WJls6rLSs4lbFJbeFCTlxqcv62rsoe6cGz_Xh7cEgpNXQb-wc2b_7sJJgC3fATH-z/w640-h360/Table%202.png" width="640" /></i></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><p class="MsoNormal"><span style="font-family: "Calibri",sans-serif; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Table
2. Nutrient comparisons between dairy manure types from 1998-2022. <o:p></o:p></span></p></td></tr></tbody></table><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEisYQJaDbZlj_Mr0up47y7s6pylNxHkojcdzGd_sL0JIdsJa_VWQTUZc9hxdZSZGewgbm13XLco0HY6j6bZlaC6hiH4jn4-TYBaIiZdjUsGz1K3vsUOYinJHYXchx1trIbmhcenRZ59ji4EqJCjqhcOdK8c6hRiPqNCYaPgPDGoDh12QlWSX37z5f7Gsw5y/s1651/Table%203.png" imageanchor="1" style="margin-left: auto; margin-right: auto; text-align: center;"><img border="0" data-original-height="924" data-original-width="1651" height="358" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEisYQJaDbZlj_Mr0up47y7s6pylNxHkojcdzGd_sL0JIdsJa_VWQTUZc9hxdZSZGewgbm13XLco0HY6j6bZlaC6hiH4jn4-TYBaIiZdjUsGz1K3vsUOYinJHYXchx1trIbmhcenRZ59ji4EqJCjqhcOdK8c6hRiPqNCYaPgPDGoDh12QlWSX37z5f7Gsw5y/w640-h358/Table%203.png" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><p class="MsoNormal"><span style="font-family: "Calibri",sans-serif;">Table 3.
Liquid manure P<sub>2</sub>O<sub>5</sub> medians for samples labeled
swine-finisher in the Midwest Region of IA, IL, IN, MI, MN, MO, OH, and WI from
2001-2023. <o:p></o:p></span></p></td></tr></tbody></table><i><br /></i></div><div><i>This article first appeared in the November 2023 issue of the <a href="https://jofnm.com/article-299-Introducing-ManureDB-A-new-way-to-view-manure-variability-and-trends.html" target="_blank">Journal of Nutrient Management</a> and has been republished here with permission.<br /></i><h3 style="text-align: left;">Additional resources:</h3><ul style="text-align: left;"><li><a href="https://youtu.be/5EAas7602d8?si=uepBG6EmOBDjndta" target="_blank">Video: Presentation on best practices for manure sampling & ManureDB update - February 2024 Nutrient Management Conference</a></li><li><a href="https://www.youtube.com/@UMNmanure" target="_blank">UMN Manure YouTube channel</a></li></ul><h3 style="text-align: left;">Acknowledgments</h3>I would like to recognize the Minnesota ManureDB team of Melissa Wilson, Associate Professor, Erin Cortus, Associate Professor and Extension Engineer, Kevin Janni, Extension Engineer (retired), and Kevin Silverstein, Scientific Lead Informatics Analyst, all from the University of Minnesota, and Larry Gunderson, Pesticide & Fertilizer Management, Minnesota Department of Agriculture, along with the ManureDB Stakeholder Committee and participating laboratories. This work is supported by the AFRI Foundational and Applied Science Program [grant no. 2020-67021-32465] from the USDA National Institute of Food and Agriculture, the University of Minnesota College of Food, Agricultural and Natural Resource Sciences, Minnesota Supercomputing Institute, and the Hueg-Harrison Fellowship.<br /><h3 style="text-align: left;">References</h3>AgGateway. (2023). Modus Agricultural Lab Test Data Standard. Modus Agricultural Lab Test Data Standard. https://aggateway.atlassian.net/wiki/spaces/MOD/overview<div><br />Bohl Bormann, N., & Other. (2022). How is manure changing over time? Trends in Midwest manure sample data. https://blog-crop-news.extension.umn.edu/2022/07/how-is-manure-changing-over-time-trends.html<br /><br />Lorimor, J., Powers, W., & Sutton, A. (2004). Manure Characteristics. MidWest Plan Service, Iowa State University, Ames, IA.<br /><br />USDA NRCS. (2022). Conservation Practices on Cultivated Cropland A Comparison of CEAP I and CEAP II Survey Data and Modeling. Conservation Effects Assessment Project. https://nrcs.usda.gov/sites/default/files/2022-09/CEAP-Croplands-ConservationPracticesonCultivatedCroplands-Report-March2022.pdf<br /><br />Wilson, M. L., Cortus, S., Brimmer, R., Floren, J., Gunderson, L., Hicks, K., Hoerner, T., Lessl, J., Meinen, R. J., Miller, R. O., Mowrer, J., Porter, J., Spargo, J. T., Thayer, B., & Vocasek, F. (2022). Recommended Methods of Manure Analysis, Second Edition. University of Minnesota Libraries Publishing. http://conservancy.umn.edu/handle/11299/227650<br /><br />---<br /><br />For the latest nutrient management information, subscribe to the <a href="https://nutrientmanagement.transistor.fm/subscribe" target="_blank">Nutrient Management Podcast</a> wherever you listen and never miss an episode! And don't forget to subscribe to the <a href="https://pub.s6.exacttarget.com/k0nz2zsg2m4" target="_blank">Minnesota Crop News</a> daily or weekly email newsletter, subscribe to our <a href="https://youtube.com/playlist?list=PLOPc3IDYKqybHLzKb5j1tOIl_Yeii_ofn" target="_blank">YouTube</a> channel, like UMN Extension Nutrient Management on <a href="https://www.facebook.com/UMNNutrientMgmt/" target="_blank">Facebook</a>, follow us on <a href="https://twitter.com/UMNNutrientMgmt" target="_blank">Twitter</a>, and visit our <a href="https://extension.umn.edu/crop-production#nutrient-management" target="_blank">website</a>.<br /><br />If you have questions or comments, please email us at <a href="mailto:nutmgmt@umn.edu?subject=Response to your blog post">nutmgmt@umn.edu.</a></div></div>Jack Wilcoxhttp://www.blogger.com/profile/14996004057706995837noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-30454965929685806922024-03-04T15:59:00.003-06:002024-03-06T07:44:13.997-06:00Harvesting corn stoverCraig Sheaffer, Extension Agronomist; John Lamb, Nutrient Management Extension Specialist (Emeritus) and Carl Rosen, Extension Soil Scientist <br /><br /><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhUPr_lIOjGPAauUo4MBGmTiNiQah-7WD0QU6sVaWwRA354q0Y6ZwQ4gfUbFLvq1BndK-FSGSMX7GzJeoygkqikCa8a7AEKN-Ekzdb-4zHSMGOzbtN-IcFzdlEMwVEe4aTqeuoEqhjC1TbylVuHkIMVOZCiKmR3_tunc4ORd-MvBoau4LMfT_utV7Qpg7al/s1430/corn-stover-round-bale.jpg" style="clear: right; margin-bottom: 1em; margin-left: 1em; margin-right: auto;"><img border="0" data-original-height="1073" data-original-width="1430" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhUPr_lIOjGPAauUo4MBGmTiNiQah-7WD0QU6sVaWwRA354q0Y6ZwQ4gfUbFLvq1BndK-FSGSMX7GzJeoygkqikCa8a7AEKN-Ekzdb-4zHSMGOzbtN-IcFzdlEMwVEe4aTqeuoEqhjC1TbylVuHkIMVOZCiKmR3_tunc4ORd-MvBoau4LMfT_utV7Qpg7al/s320/corn-stover-round-bale.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Harvesting corn stover. Photo: C Sheaffer</td></tr></tbody></table>Corn stover remaining in the field following grain harvest is a valuable resource providing significant benefits to soil conservation and soil health. In addition, the nutrients in incorporated corn stover are recycled and used by the following crop. Harvest of corn stover for livestock feed or bedding reduces its beneficial effects on soil. <br /><h2 style="text-align: left;">Soil conservation </h2>Stover left on the soil surface or partially incorporated provides residue that can reduce soil erosion by wind and water. Incorporation of stover improves soil health by increasing soil carbon and tilth, water infiltration. Of course, the impacts of corn stover on these attributes is dependent on the amount of stover produced and left on the field. Because corn grain and stover yields are related (typically a 1:1 ratio), as grain yields increase so does stover production. In our research over several locations in Minnesota, we found the corn stover production ranged from 3.2 to 4.0 tons/acre and on average 3.8 ton/acre. An average of 0.8 ton/acre of corn cobs were produced (Tables 1 and 2). However, because of differences in cropping systems, tillage, soil erosion potential, and harvest methods, farmers typically only harvest a part of the stover residue. Minnesota Extension provides a decision support tool for deciding the amount of corn residue to harvest for various crop rotations, tillage systems and yield levels. <br /><br />For more information, see <a href="https://extension.psu.edu/predicting-soil-loss-with-rusle2">Predicting soil loss with RUSLE2</a> (Penn State) and <a href="https://extension.umn.edu/corn-harvest/crop-residue-management">Crop residue management</a>.<div><br /></div><div><b>Table 1.</b> Quantities of grain and stover, nitrogen (N), potash (K<sub>2</sub>O), phosphate (P<sub>2</sub>O<sub>5</sub>), and sulfur (S), with stover when corn was harvested at the agronomically optimum N rate at four locations.*</div>
<table style="width: 100%;">
<thead>
<tr bgcolor="#b2babb">
<th>Location</th>
<th>Grain</th>
<th>Stover</th>
<th>N</th>
<th>K<sub>2</sub>0</th>
<th>P<sub>2</sub>O<sub>5</sub></th>
<th>S</th>
</tr>
</thead>
<tbody>
<tr>
<td></td>
<td>bu/acre</td>
<td>T/acre</td>
<td>lb/acre</td>
<td>lb/acre</td>
<td>lb/acre</td>
<td>lb/acre</td>
</tr>
<tr>
<td>Becker</td>
<td>210</td>
<td>4.0</td>
<td>46</td>
<td>158</td>
<td>9.2</td>
<td>4.1</td>
</tr>
<tr bgcolor="#e5e8e8">
<td>Hastings</td>
<td>243</td>
<td>3.5</td>
<td>42</td>
<td>105</td>
<td>8.2</td>
<td>3.3</td>
</tr>
<tr>
<td>Lamberton</td>
<td>160</td>
<td>3.7</td>
<td>50</td>
<td>49</td>
<td>4.1</td>
<td>3.2</td>
</tr>
<tr bgcolor="#e5e8e8">
<td>Red Lake Falls</td>
<td>164</td>
<td>3.2</td>
<td>57</td>
<td>56</td>
<td>6.2</td>
<td>3.8</td>
</tr>
<tr>
<td><b>Mean</b></td>
<td><b>194</b></td>
<td><b>3.8</b></td>
<td><b>48</b></td>
<td><b>92</b></td>
<td><b>6.9</b></td>
<td><b>3.6</b></td>
</tr>
<tr bgcolor="#e5e8e8">
<td><b>lb/ton</b></td>
<td></td>
<td></td>
<td><b>13</b></td>
<td><b>24</b></td>
<td><b>1.8</b></td>
<td><b>0.9</b><br /></td>
</tr>
</tbody>
</table>
<div><b>*</b>Results are averaged for two years at each location. For experimental details, see Sindelar et al., 2012 and 2013. Becker and Hastings were irrigated sites while the others were rainfed.</div><div><br /></div><div><b>Table 2.</b> Quantities of grain, cob, nitrogen (N), potash (K<sub>2</sub>O), phosphate (P<sub>2</sub>O<sub>5</sub>), and sulfur (S), removed with cob when corn was harvested at the agronomically optimum N rate at four locations.*</div>
<table style="width: 100%;">
<thead>
<tr bgcolor="#b2babb">
<th>Location</th>
<th>Cob</th>
<th>Stover</th>
<th>N</th>
<th>K<sub>2</sub>0</th>
<th>P<sub>2</sub>O<sub>5</sub></th>
<th>S</th>
</tr>
</thead>
<tbody>
<tr>
<td></td>
<td>bu/acre</td>
<td>T/acre</td>
<td>lb/acre</td>
<td>lb/acre</td>
<td>lb/acre</td>
<td>lb/acre</td>
</tr>
<tr>
<td>Becker</td>
<td>210</td>
<td>0.8</td>
<td>6.8</td>
<td>9.2</td>
<td>1.0</td>
<td>0.4</td>
</tr>
<tr bgcolor="#e5e8e8">
<td>Hastings</td>
<td>243</td>
<td>0.8</td>
<td>6.4</td>
<td>11.6</td>
<td>0.9</td>
<td>0.4</td>
</tr>
<tr>
<td>Lamberton</td>
<td>160</td>
<td>0.6</td>
<td>5.3</td>
<td>10.2</td>
<td>0.7</td>
<td>0.4</td>
</tr>
<tr bgcolor="#e5e8e8">
<td>Red Lake Falls</td>
<td>164</td>
<td>0.8</td>
<td>6.8</td>
<td>8.6</td>
<td>0.7</td>
<td>0.4</td>
</tr>
<tr>
<td><b>Mean</b></td>
<td><b>194</b></td>
<td><b>0.8</b></td>
<td><b>6.3</b></td>
<td><b>9.9</b></td>
<td><b>0.8</b></td>
<td><b>0.4</b></td>
</tr>
</tbody>
</table>
*Results are averaged for two years at each location. For experimental details see Sindelar et al., 2012.<div><h2 style="text-align: left;">Livestock feed and bedding </h2>Corn stover is used as livestock feed and bedding. Corn stover is low in nutritive value. It contains about 5% crude protein, 70% NDF concentration, and 50% dry matter digestibility. It is often used in maintenance rations of non-lactating beef cows. Supplementation with energy and protein are required if corn stover is the primary ingredient in rations for growing and lactating animals. </div><div><br /></div><div>Grazing is a cost-effective on-site approach to stover utilization and cattle can be more selective and eat the higher quality leaves and grain lost in combining. (Felix, 2023). Grazing livestock also deposits manure nutrients as they move over the field and through hoof traffic increases decay of stover. Baled corn stover is often lower in quality than grazed stover because of field harvesting losses which include chopping, shredding, and raking. Dried corn stover can be used as livestock bedding and will absorb 2.5 times its weight in water compared to 2.1 for wheat straw.</div><div><br /></div><div>For more information, see <a href="https://extension.psu.edu/grazing-corn-stalks-with-beef-cattle">Grazing corn stalks with beef cattle</a>. <br /><h2 style="text-align: left;">Corn stover nutrients </h2>An economic consequence of corn stover removal is the loss of plant nutrients. In our research, we found an average of 13, 24, 1.8, and 0.9 lb of N, K<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub>, and S removed per ton of stover. At a retail price of $0.60, 0.30 and 0.30, and 0.50 per lb of, N P<sub>2</sub>O<sub>5</sub>, and K<sub>2</sub>O, and S, respectively, the value of nutrient removal in 3.8 tons of stover per acre would be $61 or $16 per ton. However, there was considerable range in nutrient content of stover, and we found that increasing N fertilization rate increased N, K2O and S removal.</div><div><br />Stover removal will result in an accelerated depletion of soil nutrients beyond those nutrients removed by grain harvest. Soil analysis following corn stover removal is recommended to provide location specific fertilizer recommendations as nutrient returns by corn stover are affected by stover yield and harvest losses. There was significantly less removed by only cob removal and if a cob harvest system is used, nutrient removal would be less. </div><h2 style="text-align: left;">What about cellulosic ethanol?</h2>There was considerable national interest in cellulosic ethanol production from corn stover following the passage of the Energy Independence and Security Act and development of the Federal Renewable Fuel Standards in 2007. An initial goal was to produce 16 billion gallons of cellulosic ethanol by 2022. This led to construction of several large-scale process ethanol production plants in the Midwest with potential to produce about 130 gal of ethanol per ton of corn stover. In our research, ethanol yields from corn stover ranged from 303 to 410 gal/acre. <br /><br />However, there are no ethanol producing plants operational today and it does not appear that a viable cellulosic ethanol industry will develop. This development is related to several factors. These include the challenges of conversion of cellulosic energy to ethanol and as well as variation in quality of product due to contamination with soil. Also, unlike corn grain, which is the primary feedstock for ethanol production, corn stover is bulky and challenging to transport and store. <br /><h2 style="text-align: left;">Acknowledgement </h2>Research on corn grain, stover and cob nutrient composition and conversion to ethanol was funded by the Minnesota Corn Growers Research and Promotion Council. <br /><h2 style="text-align: left;">References for this publication </h2>D. Kramer. 2022. Whatever happened to cellulosic ethanol? Physics Today 75: 22–24. <a href="https://doi.org/10.1063/PT.3.5036">https://doi.org/10.1063/PT.3.5036</a> <br /><br />T. Felix, 2023. Penn State Extension. Grazing corn stalks with beef cattle. <a href="https://extension.psu.edu/grazing-corn-stalks-with-beef-cattle">https://extension.psu.edu/grazing-corn-stalks-with-beef-cattle</a> <br /><br />J. DeJong-Hughes and J. Coulter. Crop residue management. Minnesota Extension. <a href="https://extension.umn.edu/corn-harvest/crop-residue-management">https://extension.umn.edu/corn-harvest/crop-residue-management</a> <br /><br />C. Wortmann, R. Klein, and C. Shapiro. 2012. <a href="http://extensionpublications.unl.edu/assets/html/g1846/build/g1846.htm">Harvesting crop residues</a>, Nebraska Extension. <a href="https://extensionpubs.unl.edu/publication/g1846/pdf/view/g1846-2012.pdf">https://extensionpubs.unl.edu/publication/g1846/pdf/view/g1846-2012.pdf</a> <br /><br />W. Edwards. 2020, Estimating a value for corn stover. Iowa State Extension. <a href="https://www.extension.iastate.edu/agdm/crops/pdf/a1-70.pdf">https://www.extension.iastate.edu/agdm/crops/pdf/a1-70.pdf</a> <br /><br />A. Sindelar, J. Lamb, C. Sheaffer, H. Jung, and C. Rosen. 2012. Response of corn grain, cellulosic biomass, and ethanol yield to nitrogen fertilization. Agron. J. 104: 363-366. <a href="https://doi.org/10.2134/agronj2011.0279">https://doi.org/10.2134/agronj2011.0279</a> <br /><br />A. Sindelar, J. Lamb, C. Sheaffer, C. Rosen and H.G. Jung. 2013. Fertilizer rate effects on nutrient removal by corn stover and cobs. Agron. J. 105:43-445. <a href="https://doi.org/10.2134/agronj2012.0240">https://doi.org/10.2134/agronj2012.0240</a> <br /><br /><div>J. Hartschuh. 2019. What are your bedding options? Ohio State Extension.<br /><a href="https://u.osu.edu/sheep/2019/04/23/bedding-options/">https://u.osu.edu/sheep/2019/04/23/bedding-options/</a></div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-81999387553497237672024-03-04T11:17:00.000-06:002024-03-04T11:17:12.449-06:00Predicting alfalfa winter survival?Craig Sheaffer, Extension forage agronomist <br /><br /><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEYVoJ5asyFcA6tOh62WD1Qh9K2Covhyphenhyphen2wyBjS3Dq7N1vIu2aYd5poLE8i5Fpk5Fl4aJa0Qn5Bj7yn5lrGehWmx1QKIBxywfcw4tvzH3KF9NPGshNngaBf02ESF3g4Yt7agKkrztDVHGNN7HpWcm3rfm60PjDI8y3GGwUH9vnbSlk-1VxGP3eDNZfdYA-v/s576/alfalfa-variety-trials.jpg" style="clear: right; margin-bottom: 1em; margin-left: 1em; margin-right: auto;"><img border="0" data-original-height="378" data-original-width="576" height="210" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEYVoJ5asyFcA6tOh62WD1Qh9K2Covhyphenhyphen2wyBjS3Dq7N1vIu2aYd5poLE8i5Fpk5Fl4aJa0Qn5Bj7yn5lrGehWmx1QKIBxywfcw4tvzH3KF9NPGshNngaBf02ESF3g4Yt7agKkrztDVHGNN7HpWcm3rfm60PjDI8y3GGwUH9vnbSlk-1VxGP3eDNZfdYA-v/s320/alfalfa-variety-trials.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Alfalfa variety trials showing varying levels of<br /> winter survival.</td></tr></tbody></table>This winter has been remarkable in many ways. In contrast to the 2022-2023 winter, much of the state has received 50% or less of the normal snowfall, and each month we have had record high air temperatures. There have also been wide swings in air temperatures. <br /><br />But most importantly for alfalfa, the 2-4 inch soil temperatures have been in the mid- 20’s to mid-30’s throughout the winter. Even on 28 February, when morning air temperatures plunged to near 0 F, 2- 4 inch soil temperatures were near 30 F, nowhere near the temperatures of 5-15 F that can injure alfalfa. <div><br /></div><div>For more details on Minnesota weather and soil temperatures, visit </div><div><ul style="text-align: left;"><li><a href="https://climateapps.dnr.state.mn.us/index.htm">Minnesota State Climatology office</a> </li><li><a href="https://gis.mda.state.mn.us/mda-soiltemp/">MDA soil temperature network</a> </li></ul><h2 style="text-align: left;">Alfalfa winterinjury </h2>A diversity of winter conditions can cause a significant risk to alfalfa persistence. We have therefore over time written several articles about winter injury and its effects. This includes an article written in 2023 where we raved about the importance of snow cover for alfalfa winter survival. But that was last year, and this year is really different. For more insight on winter injury and its evaluation see:</div><div><ul style="text-align: left;"><li><a href="https://extension.umn.edu/growing-forages/alfalfa-winter-injury-weather-and-management-effects">Alfalfa winter injury: Weather and management effects </a></li><ul><li><a href="https://z.umn.edu/alfalfawinterinjurycalculator">Winter injury risk calculator</a></li></ul><li><a href="https://blog-crop-news.extension.umn.edu/2023/02/winter-damages-to-forages-ice-sheets.html">Winter damage to forages: Ice sheets</a> - 2023</li><li><a href="https://blog-crop-news.extension.umn.edu/2023/01/let-it-snow.html">Let it snow!</a> - 2023</li><li><a href="https://blog-crop-news.extension.umn.edu/2023/05/spring-alfalfa-stand-assessment-could.html">Spring alfalfa stand assessment could yield benefits</a></li><li><a href="https://blog-crop-news.extension.umn.edu/2022/05/winterkilled-alfalfa.html">Winterkilled alfalfa?</a> - 2022</li></ul><h2 style="text-align: left;">How’s alfalfa doing this winter? </h2>Energy reserves and cold resistance of winterhardy alfalfa varieties are normally greatest in December to January and then slowly decrease till March when dormancy is broken as soil temperatures climb. Several days of soil temperatures of 41F and above are required for dormancy to break. Once broken, overwintering crown buds that formed become vegetative and elongate. We typically begin to see regrowth during April. <br /><br />This is a different year, and we will likely see alfalfa shoots by mid-March. Some south facing stands that warm up sooner will like to emerge earlier. But so far alfalfa should be in great shape throughout most the state. There are several factors to consider: <br /><ul style="text-align: left;"><li>Alfalfa had a long fall dormancy reaction period that lasted from September to nearly December. During this time, until air temperatures reached >22F for several days, some small leaves were visible near the soil surface and the plant had potential to continue to store energy. </li><li>Dry soils during the fall and winter in major producing regions decrease free water in the plant and enhanced winterhardiness.</li><li>Soil temperature in the top 2-4 inches remained in the 20- 30’s for most of the winter. Even with warm air temperatures, soil temperatures in the top 2-4 inches have not reached 41 F in many parts of the state. Because of the day-night fluctuations, we have not accumulated enough growing degree days or heat units above 41 F to break dormancy and awaken crown buds.</li></ul><h2 style="text-align: left;">The biggest risk to alfalfa winter survival: fluctuating air temperatures. </h2>If warming air temperature trends continue and alfalfa breaks dormancy, there is a risk of significant frost damage, should we have minimum air temperatures of 24 F or less. New regrowth would then need to come from newly formed buds. Spring damage to alfalfa is described in <a href="https://blog-crop-news.extension.umn.edu/2020/05/frosted-alfalfa.html">Frosted alfalfa</a>.<br /><br />Another risk associated with fluctuating temperatures is from heaving of the roots and crowns of alfalfa’s tap root. Heaving is a volumetric expansion of the soil caused by the segregation and expansion of frozen water (ice) in the soils. Heaving injury results in breaking of the tap root, shearing of lateral roots, and exposure of crowns above ground. For more details, see <a href="https://blog-crop-news.extension.umn.edu/2023/03/winter-hazards-to-forages-heaving.html">Winter hazards to forages: Heaving</a> <br /><h2 style="text-align: left;">Decreasing risks of winter injury: </h2>There are several management strategies applied in 2023 that reduce the risk of winterinjury this spring. These are detailed at:</div><div><ul style="text-align: left;"><li><a href="https://extension.umn.edu/growing-forages/alfalfa-winter-injury-weather-and-management-effects">Alfalfa winter injury: Weather and management effects </a></li><li><a href="https://blog-crop-news.extension.umn.edu/2023/09/fall-cutting-of-alfalfa-in-2023.html">Fall cutting of alfalfa in 2023</a> </li></ul>The most important of these this year are fall cutting and variety selection.<br /><ul style="text-align: left;"><li><b>Unharvested stubble</b>. Alfalfa stems and leaves remaining in the field are valuable to buffer the soil against winter soil warmup when air temperatures rise. In recent measurements we have taken, soil temperatures under unharvested stubble were 5 F less than bare soil where fall harvests occurred. This is beneficial in delaying premature breaking of dormancy. </li><li><b>Variety winterhardiness and fall dormancy</b>. Varieties are characterized for winterhardiness, fall dormancy and disease resistance. Varieties grown in Minnesota should have a winterhardiness of 1 or 2. This year fall dormancy reaction may be especially important in protecting alfalfa from late season winterkill because varieties with greater fall dormancy are slower to emerge from dormancy in late winter than less dormant varieties. Therefore, although some marketed varieties are FD5, there is less risk with varieties of FD2, FD3, FD4. For information on alfalfa varieties see the National Alfalfa & Forage Alliance's: <a href="https://www.alfalfa.org/varietyratings.php">Alfalfa variety ratings</a>.</li></ul><h2 style="text-align: left;">Should we do early spring seedings this year? </h2>With the higher-than-normal air temperatures and dry soil conditions, there may be opportunities to seed earlier than normal this year. We have been proponents of early spring seedings to maximize seeding year forage yields. Early planting allows seedlings to take advantage of spring moisture conditions, compete better with weeds, and provides a longer growing season with the possibility of three harvests in the seeding year. Seedlings from cotyledon to unifoliolate leaf stage are tolerant of air temperatures as low as 24 F but are killed at 20 F, because they have not developed crown and root systems. Normally air temperatures of 24F or less are unlikely after early May, but there is still some risk given the extreme air temperature fluctuation we have seen. <br /><br />For more information, see <a href="https://blog-crop-news.extension.umn.edu/2022/04/alfalfa-seedling-tolerance-to-freezing.html">Alfalfa seedling tolerance to freezing temperatures</a>.<br /><h2 style="text-align: left;">Some key points: </h2><ul style="text-align: left;"><li>There is potential for no alfalfa winter injury this year. Even with lack of snow cover, because of above normal air temperatures, 2-4 inch soil temperatures have consistently been in the 20-30 F range, above the 5-15 F temperatures associated with winterkill. </li><li>Residue left in the fall plays a significant role in reducing early soil warmup and premature breaks in dormancy which is stimulated by soil temperatures above 41 F.</li><li>The greatest risks to alfalfa survival are due to fluctuating air temperatures. If alfalfa breaks dormancy, there is a risk of significant frost damage to herbage, should we have periods of minimum air temperatures of 24 F or less.</li></ul> <br /><br /> </div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-12751717943917535972024-03-04T10:57:00.003-06:002024-03-04T10:57:34.782-06:00Video recordings of 2024 Nitrogen and Nutrient Management Conference presentations now available<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqpqOPGDeNfELaku1QYvNTBEsSg-D4bZrvxNSnn7AwJWufzulFUJhdzEemTZqNhyd5Wucm9jtAulycSZs-7bh_M6hKKaLxfCbVKHKyU9liqO5t4UHMMxLzY9OYo6neNzOtIhyJ_Kr5mpxe-pOkNcFVTeu20ezw4-apDQAggfxdYVGEqS4rh5Bul78tVG19/s5883/IMG_6730.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Farmer panel at Nutrient Management Conference" border="0" data-original-height="2854" data-original-width="5883" height="310" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqpqOPGDeNfELaku1QYvNTBEsSg-D4bZrvxNSnn7AwJWufzulFUJhdzEemTZqNhyd5Wucm9jtAulycSZs-7bh_M6hKKaLxfCbVKHKyU9liqO5t4UHMMxLzY9OYo6neNzOtIhyJ_Kr5mpxe-pOkNcFVTeu20ezw4-apDQAggfxdYVGEqS4rh5Bul78tVG19/w640-h310/IMG_6730.JPG" title="Farmer panel at Nutrient Management Conference" width="640" /></a></div>You can now watch video recordings of all of the full presentations from the 2024 Nitrogen Conference and the 2024 Nutrient Management Conference. Learn about the latest fertilizer, manure and water quality research from Minnesota and around the Midwest.<p></p><p></p><div><h2>Nitrogen Conference</h2></div><a href="https://www.youtube.com/watch?v=jZmP50gsJic&list=PLTu3QqN1w5ZsB6sC5mFVFBieOeSEerCzQ&index=1&pp=iAQB" target="_blank">Introduction to the 10th Annual Nitrogen Conference</a><div>Fabian Fernandez, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=NlWqGc-MtDg&list=PLTu3QqN1w5ZsB6sC5mFVFBieOeSEerCzQ&index=2&pp=iAQB" target="_blank">Enhanced efficiency fertilizers and new horizons in nitrogen sources</a></div><div>Alan Blaylock, Nutrien<br /><br /><a href="https://www.youtube.com/watch?v=PAkTiXtixnQ&list=PLTu3QqN1w5ZsB6sC5mFVFBieOeSEerCzQ&index=3&pp=iAQB" target="_blank">Conducting your own on-farm studies</a></div><div>Tyler Nigon, Sentra<br /><br /><a href="https://www.youtube.com/watch?v=KKumGTbPqMI&list=PLTu3QqN1w5ZsB6sC5mFVFBieOeSEerCzQ&index=4&pp=iAQB" target="_blank">Funding for innovative nitrogen management</a><br />Will Bomier, Minnesota Department of Agriculture<br /><br /><a href="https://www.youtube.com/watch?v=eKkMqo9mU8U&list=PLTu3QqN1w5ZsB6sC5mFVFBieOeSEerCzQ&index=5&pp=iAQB" target="_blank">Performance of asymbiotic N-fixing products in the North Central Region</a></div><div>David Franzen, NDSU<br /><br /><a href="https://www.youtube.com/watch?v=u_CS3TkXOVo&list=PLTu3QqN1w5ZsB6sC5mFVFBieOeSEerCzQ&index=6&pp=iAQB" target="_blank">Nitrogen management with manure</a></div><div>Chryseis Modderman, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=kVpH7UN2wpU&list=PLTu3QqN1w5ZsB6sC5mFVFBieOeSEerCzQ&index=7&pp=iAQB" target="_blank">Variable rate irrigation and nitrogen management for corn</a></div><div>Vasudha Sharma, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=rBN6MgLWdB8&list=PLTu3QqN1w5ZsB6sC5mFVFBieOeSEerCzQ&index=8&pp=iAQB" target="_blank">Nitrogen for sugar beet production</a></div><div>Daniel Kaiser, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=M3WLTlQ2KJs&list=PLTu3QqN1w5ZsB6sC5mFVFBieOeSEerCzQ&index=10&pp=iAQB" target="_blank">Nitrogen loss: Lessons from an exhaustive review</a></div><div>Laura Christianson, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=1WVmZP5x8jQ&list=PLTu3QqN1w5ZsB6sC5mFVFBieOeSEerCzQ&index=11&pp=iAQB" target="_blank">Optimizing irrigated corn along with cover crops</a><br />Fabian Fernandez, University of Minnesota<br /><br /></div><div><h2 style="text-align: left;">Nutrient Management Conference</h2><a href="https://www.youtube.com/watch?v=E_Pi5Sl23ds&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=1&pp=iAQB" target="_blank">Introduction to the 16th Annual Nutrient Management Conference</a><br />Fabian Fernandez, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=-u3Hq3iBmUI&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=2&pp=iAQB" target="_blank">Nutrient bioavailability: nutrients, water, & roots</a></div><div>Fabian Fernandez, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=bA6zF6D5TZ8&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=3&pp=iAQB" target="_blank">Understanding mechanisms of sulfur cycling in MN soils</a><br />Daniel Kaiser, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=eq1xWQp9DCs&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=4&pp=iAQB" target="_blank">Chloride in Agriculture</a><br />Carl Rosen, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=Cy5Z4S54dWM&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=5&pp=iAQB" target="_blank">Nitrogen rate and timing for corn production in SE MN</a><br />Jeff Vetsch, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=X_q_00GtGVY&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=6&pp=iAQB" target="_blank">In-season nitrogen and sulfur application for continuous corn</a><br />Jeff Coulter, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=YtkNkgpttds&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=7&pp=iAQB" target="_blank">Cover crops and effective nutrient management</a><br />Matt Ruark, University of Wisconsin<br /><br /><a href="https://www.youtube.com/watch?v=dHxmJ_uT48A&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=8&pp=iAQB" target="_blank">Nutrient and cover crop management for sugar beet production</a><br />Lindsay Pease, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=nBJvwXWqv9A&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=9&pp=iAQB" target="_blank">Farmer Panel: Lessons from our own experience managing nutrients on the farm</a><br />Farmer Panel<br /><br /><a href="https://www.youtube.com/watch?v=1nyE3tcEosA&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=10&pp=iAQB" target="_blank">Agricultural biologicals?</a><br />Paulo Pagliari, University of Minnesota<br /><br /><a href="https://www.youtube.com/watch?v=5EAas7602d8&list=PLTu3QqN1w5ZvXqs2MA5tc5F7RwaXcapgF&index=11&pp=iAQB" target="_blank">Best practices for manure sampling & ManureDB update</a></div><div>Nancy Bohl Bormann, University of Minnesota<br /><div><h2>Past conference resources</h2><div>You can also find video recordings of presentations and presentation slides from past conferences on <a href="https://mawrc.org/events/" target="_blank">this page</a>.</div><div><h2>Thank you to our supporters!</h2></div><div>The conferences are organized by U of M Extension and the <a href="https://mawrc.org/" target="_blank">Minnesota Agricultural Water Resource Center (MAWRC)</a> and are supported by: Corteva, Koch Agronomic Services, Southern Minnesota Beet Sugar Cooperative (SMBSC), Minnesota Corn Growers Association, Minnesota Valley Testing Laboratories (MVTL), Nutrien Ag Solutions, Minnesota AgriGrowth Council, Syngenta, Mosaic, Natural Resources Conservation Service (NRCS), Minnesota Department of Agriculture, Agricultural Fertilizer Research and Education Council (AFREC), University of Minnesota Extension, and Minnesota Agricultural Water Resource Center (MAWRC).<br /><br />---<br /><br />For the latest nutrient management information, subscribe to the <a href="https://nutrientmanagement.transistor.fm/subscribe" target="_blank">Nutrient Management Podcast</a> wherever you listen and never miss an episode! And don't forget to subscribe to the <a href="https://pub.s6.exacttarget.com/k0nz2zsg2m4" target="_blank">Minnesota Crop News</a> daily or weekly email newsletter, subscribe to our <a href="https://youtube.com/playlist?list=PLOPc3IDYKqybHLzKb5j1tOIl_Yeii_ofn" target="_blank">YouTube</a> channel, like UMN Extension Nutrient Management on <a href="https://www.facebook.com/UMNNutrientMgmt/" target="_blank">Facebook</a>, follow us on <a href="https://twitter.com/UMNNutrientMgmt" target="_blank">Twitter</a>, and visit our <a href="https://extension.umn.edu/crop-production#nutrient-management" target="_blank">website</a>.<br /><br />Support for Minnesota Crop News nutrient management blog posts is provided in part by the Agricultural Fertilizer Research & Education Council (AFREC).</div></div></div>Jack Wilcoxhttp://www.blogger.com/profile/14996004057706995837noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-7571540577638802652024-03-04T09:37:00.004-06:002024-03-04T11:44:40.339-06:00Strategic Farming: Let's talk crops! discussed thirsty cover cropsPhyllis Bongard, Extension content development and communications specialist, Dan Smith, Nutrient and pest management specialist, University of Wisconsin, and Anna Cates, State soil health specialist<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6VERp-Aw0sWxr_zVdt_SqyBpgKi3KDcJVkKduIOqWElq_J3OyA8Oq5YNvxQ2deBZYxJnQxsl8O0ZBFt-IWlMaPropb60eqo5Sihus0qMF2Om6hoRSVVVfraeGGRyXPwh6zXsHyFzJdxGaArzjOUIwWBtVE3BsYXRNxWgej0tb76oMuw449ApTLI6g2iNL/s5472/cover-crop-seedlings-soybean-canopy-Rosholt-43.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="3648" data-original-width="5472" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6VERp-Aw0sWxr_zVdt_SqyBpgKi3KDcJVkKduIOqWElq_J3OyA8Oq5YNvxQ2deBZYxJnQxsl8O0ZBFt-IWlMaPropb60eqo5Sihus0qMF2Om6hoRSVVVfraeGGRyXPwh6zXsHyFzJdxGaArzjOUIwWBtVE3BsYXRNxWgej0tb76oMuw449ApTLI6g2iNL/s320/cover-crop-seedlings-soybean-canopy-Rosholt-43.JPG" width="320" /></a></div>Cover crops are thirsty, but they also protect the soil surface and provide other benefits. Dan Smith, Nutrient and pest management outreach specialist at the University of Wisconsin, and Dr. Anna Cates, State soil health specialist, discussed the push-pull relationship of cover crops and soil moisture in the February 28 Strategic Farming: Let’s talk crops session. <br /><h2 style="text-align: left;">Cover crops in dry years </h2>Smith saw zero rain for two months between May 6 and July 4 in southern Wisconsin last year. By July 1, the precipitation deficit was already 6 inches below normal at the UW Arlington Research Station. Similar scenarios played out in much of the Upper Midwest during 2023, including significant portions of Minnesota. Under this kind of stress, how do cover crops impact the following row crops? <br /><br />After a tough June, Smith dug into their cropping systems study for some answers. The study included full tillage, no-till, and “planting green” treatments – a system where corn was planted into 12-inch-tall cereal rye. In the full tillage treatment, the corn was 2 growth stages ahead of the other two treatments, but the roots and soil were powder dry. In the no-till treatment, roots were concentrated closer to the soil surface suggesting there was some moisture in the soil. Even so, it was still very dry. What surprised Smith the most was that there was soil moisture and good soil structure in the top 2-inches of the planting green treatment. The cereal rye hadn’t stolen all of the moisture and in fact helped retain more soil water than the other treatments. <br /><br />An early adopter of regenerative ag practices in Dodge County, Wisconsin, has also seen these benefits. During the peak of the 2023 drought, his fields were able to retain soil moisture resulting in excellent crops. The various mixes of cover crops he employs year-round have helped increase soil organic matter, water retention, and other soil health factors, but maintaining soil moisture is a major component of his success. <br /><h3 style="text-align: left;">Nutrient management study observations </h3>Smith also conducted nitrogen (N) rate studies with corn planted into cereal rye residue. One might expect the corn to be limited where no fertilizer N had been applied; however, it was a healthy green, had good shoot and root growth, and yielded well. It’s likely that the level of precipitation wasn’t enough to flush the previous year’s nitrates through the soil profile and the cereal rye helped retain what soil moisture there was. <br /><h3 style="text-align: left;">Termination challenges </h3>Deciding when to terminate a cover crop can be challenging. If your goal is maximizing biomass, the competition from the cover crop could compromise both the cash crop and soil moisture in a dry year. Just how long is too long when it comes to leaving a cover crop in the spring? Studies conducted in both Wisconsin and Minnesota shed some light on this. <br /><h4 style="text-align: left;">Wisconsin studies </h4>Wisconsin studies were located at the Arlington and Lancaster farms on silt loam soils in both corn and soybeans. Conventional tillage, no-till, three rye termination timings and forage treatments were included. Rye was terminated 2 weeks before planting (early), at planting, and 2 weeks after planting or planting green (late). <br /><br />One of their goals is to reach 4,000 pounds of biomass per acre to suppress weeds, so rye is seeded at a bushel per acre. Most of the time, they’ve been able to achieve that level of biomass when rye is terminated two weeks after planting. However, with the dry conditions in 2023, the rye smothered out the crop when it was left in the field and corn grain and silage yields were significantly reduced. There was even a yield drag when the rye was terminated at planting. However, when the rye was terminated two weeks before planting, corn performed as well as the conventional and no-till treatments. While Smith would like to see biomass maximized, in a dry year he recommends terminating the rye before planting to avoid competition. <br /><br />Soybeans showed a slight yield drag at high levels of biomass in 2023. Even in this dry year, however, the termination timing didn’t matter. As a crop, soybeans seem to be impacted less by cover crops and soil moisture concerns than corn is. <br /><h4 style="text-align: left;">Minnesota studies </h4>Minnesota planting green studies are concentrated in western Minnesota and currently focus on soybean. Termination timings were similar to Wisconsin’s: 1-2 weeks before planting, at planting and 1-2 weeks after planting. Biomass yields ranged widely, from a max of 72 lb/acre in Polk county, and over 2400 lb/ac in Yellow Medicine County. <br /><br />Soybean yields were significantly lower with late termination, but not in the field with the highest biomass. Cates suspects that it was due more to planting issues and other limiting factors than to the quantity of rye biomass. In five of six study sites, preplant termination protected soybean yield. <br /><h3 style="text-align: left;">Planter issues </h3>In heavy residue systems, planter issues can follow, particularly in a dry year. Getting the planting depth right in powder dry soils is critically important. Not only does uneven emergence make nitrogen management and herbicide decisions challenging, but the field doesn’t look very good either. <br /><h4 style="text-align: left;">Do I need a new planter for cover crops? </h4>Unless your planter is severely worn out, Smith’s answer is a resounding ‘No, you don’t need a new planter!’ Instead, he suggests making planter adjustments. For example, he upgraded the double disc openers and closing wheels for their silt loam soils, keeping one stock closing wheel and adding a spike closing wheel. Some are better suited for clay soils, so decisions should be made on an individual farm basis. Other tools, like hydraulic down pressure, air down pressure, variable air ride and row cleaning wheels also help. Check with your neighbors who are doing this and see what they’re using for attachments. <br /><br />While you may not need a new planter, you will need to frequently check that the seeding depth is correct and that the rows are getting closed. Because the gauge wheels are riding on top of the residue, you’ll need to adjust the seeding depth to account for that. To make sure it is operating correctly, tie up the closing wheels with a heavy bungee cord or ratchet strap, run the planter for 10 to 15 feet, then examine the row for proper seed spacing and seeding depth. <br /><h3 style="text-align: left;">Seeding date </h3>Research out of the Southwest Research and Outreach Center (SWROC) in Lamberton has found that for optimal seeding success and biomass production, rye should be planted by mid-September. When seeding gets delayed into mid-October, biomass production declines in both the fall and subsequent spring. <br /><h3 style="text-align: left;">Seeding rate </h3>Seeding rate thresholds are currently being researched and results will depend on the system and crop. In Wisconsin, Smith seeds a bushel per acre to maximize biomass, but if the goal is to hold soil in place, seeding rye at 20 pounds/acre after crop harvest might be adequate. <br /><br />Other work at the SWROC studied higher seeding rates of 60, 90, and 120 pounds/acre to try and maximize biomass and weed control. Seeding rates above 60 pounds/acre are not recommended in a conventional system and rates below 60 pounds are an active area of research interest. <br /><br />Drilling the cover crop between crop rows is another option. This strategy minimizes competition with the crop while providing soil coverage benefits. <br /><h2 style="text-align: left;">Cover crops and soil water </h2>Cereal rye removes a significant amount of moisture, particularly as it gets closer to reproductive stages. However, it also protects the soil surface from evaporation where residue is in place. How does this push-pull play out through the soil profile? <br /><br />Cates compared volumetric water content (VWC) between a cover crop and no cover crop in different tillage systems in 2021 and 2022 at three soil depths at Waseca: 10, 30, and 60 cm. There were no differences due to cover crops at the 10 cm depth in either year. At 30 cm, there was a slight increase in VWC with a cover crop treatment in strip till, but that effect reversed at 60 cm in 2021. In 2022, there were few differences at 30 cm, but like 2021, the conventional system may have had a slight edge over cover crops at 60 cm. At shallower depths, the competing effects of evaporation and cover crop uptake may be offsetting each other over the course of the season. <br /><h3 style="text-align: left;">Soil’s response to rain </h3>Can soil with good structure in reduced tillage and cover crop systems take in more water? To get at this question, Cates’ graduate student studied soil moisture, aggregation, and pore size before and after rain at on-farm sites with long-term conventional and soil health systems. <br /><br />The soil health systems generally captured more water, although results were somewhat inconsistent. Again, competing factors of cover crop uptake and evaporation from the soil surface could be at play. <br /><br />Water stable aggregates – those greater than 2mm – are the larger elements of soil structure. Intensive tillage can destroy these elements by physically breaking them apart. Large aggregates are a good indicator of reduced soil disturbance and a healthy soil system. In this study, rain promoted biological activity in the soil health system resulting in an increase of aggregation. In contrast, rain tended to dissolve the aggregates in the conventional system over time. <br /><br />Finally, pore size is also an indicator of good soil structure. In the soil health systems, pore sizes skewed larger than in the soil health system. <br /><h2 style="text-align: left;">Building drought resilience </h2>A strong plan for managing soil structure, soil fertility, crop pests, and variety selection are all pieces of a puzzle that have large implications. Be strategic about the number of passes across the field and remember that they affect both soil moisture and structure. Several practices promote long-term resiliency under dry conditions. Consider incorporating cover crops, reducing soil disturbance, and adding other crops into the rotation to build soil health and resiliency. <br /><h2 style="text-align: left;">Why cereal rye? </h2>What makes cereal rye a popular choice as a cover crop? In Cates’ experience, it’s reliable in terms of both establishment and getting decent growth in the short corn-soybean rotation window. It’s also relatively inexpensive and usually readily available. <br /><br />More diverse mixes would be more appropriate with a longer window, such as after corn silage or small grains, when the goal is to graze the cover crop, or when interseeding into corn at V4 toV5. A mix with a brassica, oats, or a legume planted in the fall has the added advantage of not needing to terminate a grass in the spring. <br /><h2 style="text-align: left;">Management in 2024 </h2>If you have been working with cover crops for a while, Smith recommends staying the course with your management plan. If 2024 remains dry, terminate cover crops 10 days to two weeks before planting to reduce competition with the crop. However, the rye must be actively growing for adequate control. Temperatures should be in the 50s at night and 60 to 70 degrees during the day to ensure that the herbicide will be translocated. <br /><br />Cates agrees. Terminating rye before planting is less risky when it’s dry and if you’re going to err, it might be wise to err on the early side. <br /><h2 style="text-align: left;">Cover Crop Academy registration is open! </h2>If you are a crop advisor, consultant or an ag advisor in a Soil and Water Conservation District (SWCD) or the Natural Resources Conservation Service (NRCS), the Minnesota Cover Crop Academy is for you. The Academy is a year-long, hybrid course to give you the tools to work with farmers who want to incorporate cover crops into their crop production systems. We’ll explore how to utilize soil health practices that are agronomically and economically successful, how to work with Minnesota's short growing season, and how to help address crop production challenges with cover crops. For more information, visit the <a href="https://extension.umn.edu/courses-and-events/cover-crop-academy">Cover Crop Academy</a> webpage. <br /><h2 style="text-align: left;">Join the webinar series </h2>Join us this week when we welcome Dr. Dan Kaiser and Jeff Vetsch to discuss how to get the best return on your fertilizer investment. <div><br />University of Minnesota’s Strategic Farming: Let’s talk crops! webinar series, offered Wednesdays through March, features discussions with specialists to provide up-to-date, research-based information to help farmers and ag professionals optimize crop management strategies for 2023. For more information and to register, visit <a href="https://z.umn.edu/strategic-farming">z.umn.edu/strategic-farming</a>. <br /><br /><b><i>Thanks to the Soybean Research and Promotion Council and the Corn Research and Promotion Council for their generous support of this program.</i></b></div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-38730551839913175622024-02-29T14:51:00.005-06:002024-03-07T09:01:38.386-06:00Cover crops in Minnesota: Recent challenges and future solutions<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFZmUf0keh2LfHG10YXgQbkVpyPNA0qV7TEuEchv2SW9x9DGN_U2WRfBK9Cg5MYjYB8C434bw7JpqcTB6AByc-nWZLsgSDrfnebMyIvc4hR0p6ZJYPT_rRWkH7V7e0OnU0QzD8jGsb7YfXR8jeGT-fJqsHODCA5G41vzhUvBTe-LyPySFMYSTFeSdjBXMf/s4624/PXL_20240220_230939129.jpg" style="margin-left: 1em; margin-right: 1em; text-align: center;"><img border="0" data-original-height="3472" data-original-width="4624" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFZmUf0keh2LfHG10YXgQbkVpyPNA0qV7TEuEchv2SW9x9DGN_U2WRfBK9Cg5MYjYB8C434bw7JpqcTB6AByc-nWZLsgSDrfnebMyIvc4hR0p6ZJYPT_rRWkH7V7e0OnU0QzD8jGsb7YfXR8jeGT-fJqsHODCA5G41vzhUvBTe-LyPySFMYSTFeSdjBXMf/w640-h480/PXL_20240220_230939129.jpg" width="640" /></a><br /><br /><div> In this episode of the Nutrient Management Podcast, we’re talking about recent cover crop challenges and potential solutions. What were the cover crop issues for 2022 and 2023? Based on the conditions right now and from last spring, what might some good management practices be going forward? What was the decision-making process for adjusting rye seeding rate requirements in the fall of 2024 when drilled? What advice would the panel have for someone brand new to cover crops, and who has concerns that were exacerbated by this last cycle?</div><div><br />
<iframe frameborder="no" height="180" scrolling="no" seamless="" src="https://share.transistor.fm/e/722f858a" width="100%"></iframe><br /><h3 style="text-align: left;"><a href="https://docs.google.com/document/d/e/2PACX-1vSfYfGQOh1wo40oObcpudlUqmga8tkBekX0ArBFbhARtwkJfSH5Ns5ei-5cBFIg1-Mtgg1NbDAvfj4v/pub" target="_blank">TRANSCRIPT</a> </h3><h3 style="text-align: left;">Guests:</h3><ul style="text-align: left;"><li>Anna Cates, Extension soil health specialist (St. Paul)</li><li>Jeff Vetsch, U of M researcher (Waseca)</li><li>Jared House, Grant County Soil & Water Conservation District (Elbow Lake)</li><li>Ryan Buetow, Minnesota NRCS State Agronomist (St. Paul)</li></ul><h3 style="text-align: left;">Additional resources:</h3><ul style="text-align: left;"><li><a href="https://blog-crop-news.extension.umn.edu/2023/09/why-did-cover-crops-cause-issues-in.html" target="_blank">Why did cover crops cause issues in Minnesota the last two years and what should growers do going forward?</a></li><li><a href="https://youtu.be/LLt1ayXvy1o?si=90YWp1sI0esR7wie" target="_blank">Recording of Feb. 2024 Strategic Farming webinar on "Thirsty cover crops: Do they impact our cash crops?"</a></li><li><a href="https://blog-crop-news.extension.umn.edu/2024/02/announcing-university-of-minnesota.html" target="_blank">Register for Cover Crop Academy: New hybrid, year-long, statewide course starts June 2024</a></li><li><a href="https://blog-crop-news.extension.umn.edu/2021/03/growing-cover-crops-in-minnesota-4.html" target="_blank">Growing cover crops in Minnesota: 4 great resources to get you started</a></li><li><a href="https://www.midwestcovercrops.org/getting-started-correct/#recipes" target="_blank">Cover crop recipes (Midwest Cover Crops Council)</a></li><li><a href="https://grantswcd.org/" target="_blank">Grant County SWCD</a></li><li><a href="https://www.nrcs.usda.gov/conservation-basics/conservation-by-state/minnesota" target="_blank">Minnesota NRCS</a></li></ul>---<br /><br />For the latest nutrient management information, <a href="https://nutrientmanagement.transistor.fm/subscribe" target="_blank">subscribe to the Nutrient Management Podcast</a> wherever you listen and never miss an episode! And don't forget to <a href="https://pub.s6.exacttarget.com/k0nz2zsg2m4" target="_blank">subscribe</a> to the Minnesota Crop News daily or weekly email newsletter, subscribe to our <a href="https://youtube.com/playlist?list=PLOPc3IDYKqybHLzKb5j1tOIl_Yeii_ofn" target="_blank">YouTube</a> channel, like UMN Extension Nutrient Management on <a href="https://www.facebook.com/UMNNutrientMgmt/" target="_blank">Facebook</a>, follow us on <a href="https://twitter.com/UMNNutrientMgmt" target="_blank">Twitter</a>, and visit our <a href="https://extension.umn.edu/crop-production#nutrient-management" target="_blank">website</a>.<br /><br />If you have questions or comments, please email us at <a href="mailto:nutmgmt@umn.edu?subject=Response to your podcast episode">nutmgmt@umn.edu.</a>
<div><div><div><br />Support for the Nutrient Management Podcast is provided by Minnesota's fertilizer tonnage fee through the Agricultural Fertilizer Research & Education Council (AFREC). Learn more at <a href="http://mnsoilfertility.com/" target="_blank">MNsoilfertility.com</a>.</div></div></div></div>Jack Wilcoxhttp://www.blogger.com/profile/14996004057706995837noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-65415997277293091992024-02-29T09:18:00.000-06:002024-02-29T09:18:06.098-06:00MN CropCast: U of M Agronomy Alum Update with Matt Pfarr<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjj4JDquJW3xRyAqy7Zq5k5Ev4T1RufEgrl5vDx70SzJx08OAGJO0WcJQizUqqRWPUuTgZtP5DnhyLxKeNTAh4M2NcMp57ZvGQAXz5_uGk8XMKbDHRV1i8h0MJybIHCVecWDZC1W6PX3Zmg2qb7YCQOsVM9dIg4qCY-YOMS1UoOrZrRIiZrur3s-MdHNig/s320/podcast-minnesota-cropcast-cover-art.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="320" data-original-width="320" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjj4JDquJW3xRyAqy7Zq5k5Ev4T1RufEgrl5vDx70SzJx08OAGJO0WcJQizUqqRWPUuTgZtP5DnhyLxKeNTAh4M2NcMp57ZvGQAXz5_uGk8XMKbDHRV1i8h0MJybIHCVecWDZC1W6PX3Zmg2qb7YCQOsVM9dIg4qCY-YOMS1UoOrZrRIiZrur3s-MdHNig/s1600/podcast-minnesota-cropcast-cover-art.png" width="320" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div>In episode #30 David Nicolai and Seth Naeve chat with Matt Pfarr. Matt is a Field Solutions Manager for Lallemand Plant Care and a graduate of the Applied Plant Sciences graduate degree at the University of Minnesota. We invited Matt into the studio to talk about his own history, his time at the University of Minnesota and Lallemand, and the biologicals business. We had a great time.<br /><br />
Matt talked about his family’s strong ties to the University of Minnesota. Not only did his father attend the U, but so did he and his three siblings (and their spouses). All four have CFANS based degrees and his sister continues to work as a postdoctoral research geneticist with the Cereal Disease Laboratory. Matt worked on a soybean physiology project with Seth from 2014-2016. His experiments were focused on environmental effects on secondary constituents of soybean seed. Today, his work forms the cornerstone of our understanding of the tradeoffs between protein quantity and quality in soybean that is important for Northern produced soybeans. <br /><br />
Matt grew up on a farm in Sibley County Minnesota, in a family where hogs, crops, and wrestling ran deep. Matt wrestled at St John’s University (MN) during his undergraduate years while his brothers were both well known Gopher wrestlers. Although Matt is fully employed by Lallemand, he continues to farm alongside his family making him a seventh-generation farmer on both his mother’s and father’s side. His mother’s investment on the farm is extraordinary including hauling grain, tillage and animal care.<br /><br />
The Lallemand company is one of the largest producers of yeast and bacterial cultures for the baking, brewing, enology, dairy and industrial ethanol industries. The company entered the plant care business only about twenty years ago through acquisitions of French, Finnish, Brazilian, Uruguayan, and Canadian companies. Today Lallemand is a key player in the plant biologicals space. Dave and Seth chatted with Matt about the industry’s explosive expansion and the future of biologicals for crop farmers. Join us for another fascinating and far-ranging conversation on Minnesota CropCast.</div><div><div><h3><a href="https://mncropcast.transistor.fm/episodes/u-of-m-agronomy-alum-update-matt-pfarr" target="_blank">Listen to the podcast</a></h3></div><h2 style="text-align: left;">What is Minnesota CropCast?</h2><div>Hosts David Nicolai and Seth Naeve discuss the progress and challenges of Minnesota's agronomic crops in this new podcast. They are joined by a diversity of specialists representing all crops and agronomic disciplines to discuss their research and its impact on future Minnesota crops. Dave Nicolai is a crops Extension educator and Seth Naeve is the Extension soybean agronomist.</div><h3>How do I sign up?</h3><div>You can subscribe and listen to <b>Minnesota CropCast</b> using one of many popular podcasting apps or directories. <a href="https://mncropcast.transistor.fm/subscribe" target="_blank">Learn more</a>.</div></div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-42357604721459176732024-02-29T08:57:00.002-06:002024-02-29T09:02:03.104-06:00Farmers needed for research on soil pests in corn and soybean<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJd5ivKiV7S5xBsy3oTR9e38DyIcZallPdy3xDK7-n0kCvoBZeJr4CDr-EiQIL-YW8ctZeHoAVamMEzbZDa8R3HdtsWVpDH1maxug3AjkS8tJBr87sliCBmrFgxZZnmJc3ob3L17l8vgGgDdtyMHRiQbYrSL05CEMF-78v8djJrK7RFi3OG4zT0_4hfaVK/s800/seedcorn-maggot-cotyledon.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="450" data-original-width="800" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJd5ivKiV7S5xBsy3oTR9e38DyIcZallPdy3xDK7-n0kCvoBZeJr4CDr-EiQIL-YW8ctZeHoAVamMEzbZDa8R3HdtsWVpDH1maxug3AjkS8tJBr87sliCBmrFgxZZnmJc3ob3L17l8vgGgDdtyMHRiQbYrSL05CEMF-78v8djJrK7RFi3OG4zT0_4hfaVK/s320/seedcorn-maggot-cotyledon.jpg" width="320" /></a></div>Drs. Fei Yang, Extension corn entomologist, and Bob Koch, Extension soybean entomologist, are initiating a new project to evaluate pests that feed on seeds and seedlings in corn and soybean fields. In areas with severe infestations, these pests can cause significant stand losses or even require replanting of fields. Despite these potential impacts, much remains unknown about these pests in Minnesota corn and soybean.<br /><br /><b>They are seeking cooperating farmers to allow their research team to sample corn and soybean fields from April to June 2024</b>. <br /><br />They are especially interested in sampling corn and soybean fields with the following characteristics: <br /><ul style="text-align: left;"><li>have recently come out of pasture, CRP, etc., </li><li>are no-till,</li><li>are following cover crops,</li><li>have high organic matter, and/or</li><li>have not had insecticide seed treatments used in recent years.</li></ul>However, the sampling will not be limited to fields with those characteristics.<br /><br />Farmers with fields selected for sampling will receive a free report on the pests encountered in their fields.<br /><br />Please fill out this short form by <b>March 31, 2024</b> if you are interested in allowing their research team to sample your field.<br /><br />
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<button class="button"><a href="https://app.smartsheet.com/b/form/652940cfbb10427d895a53b12c7bb7d0"><span style="color: white;">Fill out the form</span></a></button><br /><br />If you have questions, contact:<br />Dr. Fei Yang, <a href="mailto:yang8905@umn.edu">yang8905@umn.edu</a> or 612-624-7436<br />Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-12028491029510196752024-02-27T10:24:00.007-06:002024-02-27T15:23:52.089-06:00Manure and minimum tillage: How to balance soil health and nutrient loss goals<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6v9zBdQHRXKWZUB1tj2hNUhDA4mzbdNguF8ACBKtbgPGZywZTymy2AkKweJThIGdCSzV3oshf5Vs7JUH5lTQStnGg1SbVzYHmxeiZUFzKqSSd-76-_i4GqkKjZy2GmewhYKIlRlRjbVzuJXo6WFjpBkLKAB3NwBpv1C4Yu1GEpcCRMYgHhbHb7udLtNXp/s4032/Manure%20into%20CC.jpg" style="margin-left: 1em; margin-right: 1em;"><img alt="manure being applied to field" border="0" data-original-height="3024" data-original-width="4032" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6v9zBdQHRXKWZUB1tj2hNUhDA4mzbdNguF8ACBKtbgPGZywZTymy2AkKweJThIGdCSzV3oshf5Vs7JUH5lTQStnGg1SbVzYHmxeiZUFzKqSSd-76-_i4GqkKjZy2GmewhYKIlRlRjbVzuJXo6WFjpBkLKAB3NwBpv1C4Yu1GEpcCRMYgHhbHb7udLtNXp/w640-h480/Manure%20into%20CC.jpg" title="manure being applied to field" width="640" /></a></div>By: Chryseis Modderman, Extension educator<br /><br />In the manure management world, we’re constantly telling you to incorporate your manure into the soil; get it under the soil surface as soon as possible after application or you could lose up to half of your total nitrogen. This advice directly contradicts soil health advice which advocates for minimum soil disturbance. Both recommendations are correct, and manure use and soil health are complements, not contradictions; so, what is a producer to do?<br /><h3 style="text-align: left;">Why do we recommend manure incorporation?</h3>We’re trying to minimize volatilization and nutrient stratification. Volatilization occurs when the ammonium form of nitrogen in manure converts to ammonia gas and is lost to the atmosphere. Volatilization is minimized when the manure is incorporated into the soil and not left on the surface. Most of this loss happens within the first 24 hours of application, and after four days we consider nearly all the ammonium form nitrogen to be gone. Remember, manure contains two forms of nitrogen: organic N (not immediately plant-available) and ammonium (is immediately plant-available). That means not all the manure’s nitrogen will be lost – the organic N will stick around – but the form that plants can immediately use will mostly be lost to the atmosphere. That organic N can eventually be used by plants after it is broken down by microbes, in a process called mineralization.<br /><br />Nutrient stratification is the layering of nutrients in the soil. Without the soil mixing that tillage provides, nutrients tend to accumulate heavily in the first couple inches of the soil which stimulates root growth near the soil surface. In general, plant roots seek out and grow toward the components they need to live such as water and nutrients. And so, if soil water is not a limiting factor where the root would mine deeper to find moisture, root growth will tend to remain shallow. And a shallow root system may lead to root lodging from lack of a good, deep anchor. Another concern is nutrient pollution from runoff and erosion of the soil surface. Nutrient stratification is not just a manure challenge, it affects commercial fertilizer applications as well.<br /><h3 style="text-align: left;">What should producers do?</h3>There’s no easy answer here, and those with success in both manure management and soil health will understand that it’s a balancing act and it all boils down to what works for your operation. Fortunately, minimum tillage systems often already have factors working in their favor to minimize the consequences of volatilization and nutrient stratification. Many no-till fields have ample crop residue and remaining roots which helps hold surface-applied manure better than the bare soil of conventional tillage. Just as healthy soil improves rainfall infiltration, liquid manure applied to the surface will find its way into the soil easier than in fields with degraded soil structure due to excessive tillage. Also, even if nutrients are concentrated at the surface, runoff and erosion of those nutrients are less likely in systems with good soil structure and cover.<br /><br />If an operation isn’t strictly no-till, minimum disturbance injection and tillage are options to get the best of both worlds as any small amount of incorporation will help retain ammonium, and even a small reduction in soil disturbance can improve soil health. Though keep in mind that soil type and moisture will impact how much soil is turned up and disturbed, even with minimum disturbance tools.<br /><br />Remember that going no-till is not a black-and-white decision. Some operations choose to do both no-till and conventional till, sometimes within the same field, depending on the ammonium content of the manure, soil type and moisture, and proximity to sensitive features like tile intakes or streams. Every producer and operation must consider all factors and make the best decision for their manure management and soil health goals while balancing finance and environmental protection considerations.<br /><br /><i>This article was originally published by <a href="https://www.manuremanager.com/manure-minute-manure-and-minimum-tillage-its-a-balancing-act/" target="_blank">Manure Manager</a> on February 20, 2024 and has been republished here with permission. </i><br /><div><br /></div>---<div><br />For the latest nutrient management information, subscribe to the <a href="https://nutrientmanagement.transistor.fm/subscribe" target="_blank">Nutrient Management Podcast</a> wherever you listen and never miss an episode! And don't forget to subscribe to the <a href="https://pub.s6.exacttarget.com/k0nz2zsg2m4" target="_blank">Minnesota Crop News</a> daily or weekly email newsletter, subscribe to our <a href="https://youtube.com/playlist?list=PLOPc3IDYKqybHLzKb5j1tOIl_Yeii_ofn" target="_blank">YouTube</a> channel, like UMN Extension Nutrient Management on <a href="https://www.facebook.com/UMNNutrientMgmt/" target="_blank">Facebook</a>, follow us on <a href="https://twitter.com/UMNNutrientMgmt" target="_blank">X (formerly Twitter)</a>, and visit our <a href="https://extension.umn.edu/crop-production#nutrient-management" target="_blank">website</a>.</div><br />If you have questions or comments, please email us at: <a href="mailto:nutmgmt@umn.edu?subject=Response to your blog post">nutmgmt@umn.edu</a>.<div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div>Jack Wilcoxhttp://www.blogger.com/profile/14996004057706995837noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-33294479887795076342024-02-26T11:24:00.001-06:002024-02-26T11:24:56.540-06:00Announcing the University of Minnesota Extension Cover Crop AcademyBy Liz Stahl, Extension Educator - Crops, Phyllis Bongard, Educational Content Development & Communications Specialist, and Anna Cates, Extension Specialist in Soil Health <br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-bQ4RczMW9LzCOSB7edAHyq4ONgybOl15QXhecC8gsUy8bkZK7Qkuq33RsaTJJU5KLjgxKxSoB98Ni3MLqIHyCTAFUNu5jaAre8kq8UA7aZSc0rXL2YZ49DsWFS5_BLVqwa645G1qRaYIwFGU5mmISjNu2EpTxKN5JZhG-72QQDgtR-WJwDXFqUiujugb/s5472/cover-crop-seedlings-soybean-canopy-Rosholt-43.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="3648" data-original-width="5472" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-bQ4RczMW9LzCOSB7edAHyq4ONgybOl15QXhecC8gsUy8bkZK7Qkuq33RsaTJJU5KLjgxKxSoB98Ni3MLqIHyCTAFUNu5jaAre8kq8UA7aZSc0rXL2YZ49DsWFS5_BLVqwa645G1qRaYIwFGU5mmISjNu2EpTxKN5JZhG-72QQDgtR-WJwDXFqUiujugb/s320/cover-crop-seedlings-soybean-canopy-Rosholt-43.JPG" width="320" /></a></div>Do you work with farmers who want to use cover crops but are struggling to incorporate them into Minnesota’s short growing season? Are you striving to help producers build soil health systems that are agronomically and economically successful? If you want to learn more about using cover crops to help address crop production challenges, join us for the University of Minnesota Extension Cover Crop Academy. <br /><br />The UMN Extension Cover Crop Academy is a hybrid, year-long, statewide course for crop advisors, consultants, educators, agency personnel, and ag advisors who work with cover crops in coops, ag retailers, lending institutions, non-profits, soil and water conservation districts (SWCD) and Natural Resources Conservation Service (NRCS) offices. This unique opportunity will take a deep dive into cover crops and will be tailored to Minnesota cropping systems and conditions.<div><h2 style="text-align: left;">Cover Crop Academy overview </h2>The academy will kick off with in-person meetings at the Research and Outreach Centers (ROC) in Lamberton, Waseca and Crookston in June 2024 (select the nearest site to you). You will visit cover crop research plots and learn about what is and is not working in your region. </div><div><br /></div><div>Bi-monthly webinar meetings that dive deep into cover crop topics will follow. The Academy will wrap up in May 2025 with a final in-person session where you will be able to see results from trials you helped develop as an attendee.</div><div><h3 style="text-align: left;">UMN Cover Crop Academy Schedule </h3><div>Note: Online sessions will run from 10 a.m. to noon.</div><ul style="text-align: left;"><li><b>June 2024: In-person meetings at the ROC nearest you in (attend only one) </b></li><ul><li>June 18, Southern Research and Outreach Center, Waseca (in conjunction with the SROC Agronomy Field Tour)</li><li>June 20, Northwest Research and Outreach Center, Crookston</li><li>June 27, Southwest Research and Outreach Center, Lamberton (in conjunction with the SWROC Cover Crop Field Day)</li></ul><li><b>July 9, 2024: ONLINE-Developing a cover crop plan.</b> Discuss cover crop species selection, seeding methods, and seeding rates. Determine regional cover crop research treatments.</li><li><b>September 10, 2024: ONLINE-Managing weeds and cover crops</b>. Learn about herbicide residuals and carryover concerns with cover crops and best management practices for cover crop termination.</li><li><b>November 19, 2024: ONLINE-Managing soil fertility in cover crop systems.</b> Learn about nitrogen management, manure applications and reduced tillage in cover crop systems.</li><li><b>January 14, 2025: ONLINE-Avoiding cash crop issues after cover crops. </b> Discuss planter specifications and modifications and insect pest issues. Learn from a famer panel about what to expect in the spring.</li><li><b>March 11, 2025: ONLINE-Where’s the easy button to get started? </b>Discuss easy entry points in the crop rotation, and special topics based on participant interest.</li><li><b>May 2025: In-person meetings at the ROC nearest you.</b> Course wrap-up, including a visit to your small plot trials to assess results.</li></ul>All Academy attendees should leave with an expanded knowledge base and toolkit to help in cover crop implementation and a peer network of cover crop advisors. Certified Crop Advisor CEUs will be applied for, primarily in the soil and water, nutrient management, and pest management categories.<div><h2 style="text-align: left;">Register for the Cover Crop Academy </h2>The cost to participate in the UMN Extension Cover Crop Academy is only $75, thanks to our program sponsors. For more details and to register, go to <a href="https://extension.umn.edu/courses-and-events/cover-crop-academy#:~:text=If%20you%20want%20to%20learn,offices%20who%20work%20with%20cover">Cover Crop Academy</a></div><div> (<a href="https://z.umn.edu/CCAcademy">https://z.umn.edu/CCAcademy</a>). </div><div><br /></div><div><b>Register by June 10, 2024 </b>to reserve your spot for one of three locations: Waseca, Crookston, or Lamberton. Registration will be limited and filled on a first come, first served basis. Note, all attendees are expected to attend all events and complete short assignments to earn a certificate of completion at the final session. <br /><br /><b><i>This program is brought to you by University of Minnesota Extension, with support from the Minnesota Natural Resources Conservation Service, General Mills, and the Minnesota Office of Soil Health.</i></b></div></div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-16227304261229096752024-02-26T09:36:00.001-06:002024-02-26T09:36:08.528-06:00Strategic Farming: Let's talk crops focused on what pays for soybean pest managementPhyllis Bongard, Extension content development and communications specialist, Bob Koch, Extension soybean entomologist <br /><br />Which soybean pest management practices will pay off in 2024? Dr. Bob Koch, Extension soybean entomologist, described the latest developments in soybean pests and their management in the February 21 <b>Strategic Farming: Let’s talk crops</b> session. <br /><h2 style="text-align: left;">Soybean aphid </h2><h3 style="text-align: left;">Insecticide management </h3><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3qTUyeclVjCswNst9sqTf2AHjfAypxmJFftP6rlgVme78oR9al_TX_dPlD8mJlRqHPe_mdlavAMzziAIuaUcHn9JWSxarTZbygLasXVmuZht9FOxfpwrF6J9379UMNKXwuva53tOT6WvhqTXjjHDwfU7UKMzmsVDTl80ak1LQlwnua1rRFq5GzN6otmX5/s320/soybean-aphid-early-infestation-koch.jpg" style="clear: right; margin-bottom: 1em; margin-left: 1em; margin-right: auto;"><img border="0" data-original-height="320" data-original-width="240" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3qTUyeclVjCswNst9sqTf2AHjfAypxmJFftP6rlgVme78oR9al_TX_dPlD8mJlRqHPe_mdlavAMzziAIuaUcHn9JWSxarTZbygLasXVmuZht9FOxfpwrF6J9379UMNKXwuva53tOT6WvhqTXjjHDwfU7UKMzmsVDTl80ak1LQlwnua1rRFq5GzN6otmX5/s1600/soybean-aphid-early-infestation-koch.jpg" width="240" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Early soybean aphid infestation. <br />Photo: Bob Koch</td></tr></tbody></table>For over 20 years, insecticides have been used to control soybean aphids (SBA). Keeping track of the available products has been something of a roller coaster ride recently, particularly as it pertains to chlorpyrifos, one of the organophosphate insecticides (Group 1B). In 2022, the EPA revoked the tolerances and chlorpyrifos could no longer be applied to Minnesota crops. Then in November, the 8th Circuit Court vacated that order, which allowed the Minnesota Department of Agriculture to begin conditionally registering products containing chlorpyrifos for crop use in the 2024 growing season. <br /><br />Where does chlorpyrifos fit in this season? While it is an effective tool, it’s also a toxic chemical with associated health concerns. Koch warns against immediate, widespread use, but instead suggests using it in rotation with other effective insecticides. <br /><br />Pyrethroid (Group 3) insecticides have also been used heavily to control soybean aphid. That reliance or over-reliance has resulted in an increasing number of performance failures. Lab assays and molecular work have documented resistant soybean aphid populations, but that data couldn’t readily predict how products are performing in the field. <br />Practical pyrethroid resistance <br /><br />To get at that, Koch dug into efficacy studies conducted in Rosemount and Lamberton from 2005 to 2020 and compiled the data for the pyrethroid, lambda-cyhalothrin. What he found was that the efficacy of field applications for this pyrethroid worked very well against soybean aphid from 2005 to 2014. After 2014, however, control in the field deteriorated rapidly and this coincided with a significant increase in SBA pyrethroid resistance in lab studies, as well. <br /><br />As a result, Koch shies away from recommending a pyrethroid as the initial treatment to control soybean aphid. While it may be tempting to apply a pyrethroid because it’s inexpensive, it may do more harm than good if aphids are resistant to it. The application wouldn’t provide much for aphid control, but it would be very effective in killing the predators and natural enemies that suppress SBA populations. The result may be even more aphids and the potential for developing even stronger resistance. <br /><h4 style="text-align: left;">Can pyrethroid resistance be reversed? </h4>If insecticide resistance management practices were implemented, could pyrethroid resistance be reversed? To study this, Koch asked whether aphid populations display a fitness cost when developing resistance. If they did, it might be possible for susceptible populations to outnumber resistant ones in the absence of pyrethroids. <br /><br />What he found was that the resistant populations did better than the susceptible ones when not exposed to insecticides, so the result was the opposite of a fitness cost. The evidence suggested that even if pyrethroid inputs into the system were reduced, it’s unlikely that the resistant populations would revert to being susceptible again. <br /><h4 style="text-align: left;">Protect insecticide effectiveness </h4>The resistance issues with pyrethroids reinforce how important it is to manage the other available insecticides to maintain their efficacy. Koch’s research is showing that the newer insecticides – sulfloxaflor (e.g. Transform), flupyradifurone (Sivanto) and afidopyropen (Sefina) – and mixtures with neonicotinoids are still effective against soybean aphids, including pyrethroid-resistant aphids. Some of these insecticides, like afidopyropen, sulfoxaflor, flupyradifurone, are also less toxic to SBA’s natural enemies. <br /><h4 style="text-align: left;">Scouting pays! </h4>By the time soybean aphids colonize many soybean fields, seed treatment concentrations in the plant have generally decreased to ineffective levels. In a regional economic study comparing prophylactic seed treatments to scouting and threshold-based applications, scouting and using the 250 aphids per plant economic threshold (ET) provided a much larger return on investment. Preventative or insurance applications are not only costly, they kill beneficial insects and put the field at risk for aphid recolonization and increased insecticide resistance. <br /><br />For more information, see <a href="https://extension.umn.edu/soybean-pest-management/soybean-gall-midge-minnesota-soybean">Soybean aphid in Minnesota soybean</a>, <a href="https://extension.umn.edu/soybean-pest-management/scouting-soybean-aphid">Scouting for soybean aphid</a>, and <a href="https://extension.umn.edu/soybean-pest-management/fact-based-soybean-aphid-insecticide-recommendations">Fact-based insecticide recommendations</a>. <br /><h2 style="text-align: left;">Soybean gall midge </h2><h3 style="text-align: left;">Distribution</h3><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg13CI2rLdFF5tbUGvLAM1YzsxewELGkjqCFAyZ_TjAJKpldE9LbwNMM21Uio92ITaQI_rSCWEh9SVYR6dYpqa1yRmlxNo6w1rCytnquDFsk0UVNXvLVfZ6KS0dezRroaYYANZtF1L3ikblWXrHrna8l6e4Cj-skC88f6f3R8DZxjRNgthjZoVGd_rx6PtV/s407/soybean-gall-midge_lisak.jpg" style="clear: right; margin-bottom: 1em; margin-left: 1em; margin-right: auto;"><img border="0" data-original-height="316" data-original-width="407" height="248" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg13CI2rLdFF5tbUGvLAM1YzsxewELGkjqCFAyZ_TjAJKpldE9LbwNMM21Uio92ITaQI_rSCWEh9SVYR6dYpqa1yRmlxNo6w1rCytnquDFsk0UVNXvLVfZ6KS0dezRroaYYANZtF1L3ikblWXrHrna8l6e4Cj-skC88f6f3R8DZxjRNgthjZoVGd_rx6PtV/s320/soybean-gall-midge_lisak.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Soybean gall midge larvae. Photo: Sarah Lisak</td></tr></tbody></table>Soybean gall midge (SGM) is a newer pest in Minnesota. It’s been found throughout much of the southwestern part of the state up to Stevens and Swift Counties and as far east as Rice County. Females lay eggs in the fissures in soybean stems. Once hatched, the bright orange larvae feed under the outer layers of the stem tissue, causing dark lesions at the base of the plant. Feeding damage can lead to plants breaking off, wilting, and dying. <br /><br />Entomologists in Nebraska have documented yield losses of 100% on field edges and 17 to 31% losses in the field interior in infested fields. Most Minnesota fields are nowhere near this heavily infested, but it is a pest we need to watch for and be aware of. <br /><h3 style="text-align: left;">Potential management strategies </h3>Because the larvae feed under the stem tissue and adult emergence occurs over an extended period of time, spraying insecticides is largely ineffective. Seed treatments haven’t shown much efficacy, but research from the University of Nebraska-Lincoln has shown that the soil-applied insecticide Thimet (phorate) has some efficacy; however, specialized equipment is often needed for application of such treatments. With chemical control not standing out as effective as it is for other pests, true integrated pest management incorporating non-chemical tactics will have to be used for SGM. <br /><h4 style="text-align: left;">Cultural control </h4>The University of Nebraska-Lincoln has been conducting research on SGM for several years with some promising results. Through a lot of screening work, they’ve identified soybean lines or varieties that appear to have resistance to SGM. Those could be fed into different breeding programs to increase the availability of SGM-resistant varieties. <br /><br />They have also done interesting research into hilling soybeans, which protects the stem from SGM adult egg-laying. While the results are positive, the logistics of hilling soybeans would be a challenge and require special equipment. <br /><h4 style="text-align: left;">Biological control </h4>Koch and colleagues have been studying biological control with SGM predators and parasitic wasps. They wondered if ground beetles, those abundant little beetles that scurry around on the soil surface, might include SGM in their diets. In a lab setting, they found that ground beetles did indeed eat soybean gall midge larvae. Then through gut analysis, they documented that ground beetles will also eat SGM larvae in the field. <br /><br />Parasitism is the other aspect of biological control that they are studying. They discovered an entirely new species of parasitic wasp that’s associated with SGM. Through molecular and other methods, this new wasp has also been confirmed in multiple locations across Minnesota, South Dakota, Iowa, and Nebraska. The female wasp lays eggs directly in the SGM larva, which eventually kills it. Koch estimates that 5 to 10% of the SGM population is being killed by these wasps. <br /><br />For more information, see <a href="https://extension.umn.edu/soybean-pest-management/soybean-gall-midge-minnesota-soybean">Soybean gall midge in Minnesota soybean</a>. <br /><h2 style="text-align: left;">Soybean tentiform leafminer – a new pest </h2><h3 style="text-align: left;">Distribution </h3><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh3kSarsXpvflj-OwxyFEBkcK5lty_GR81wtB9ao24lNhPPTqHAWflIPNGQKUMzumocOlzbxH972yJfdlpSIpykMFx7WQow77tZXvOeeV2Acw79mjZxbzCk57_XnHVaSTYpzyj4vUt9tUvuZ8lPFhUle2FXSNwKfXdZ_FZXda6YN3sWJMAkGP_7F4GWYJuO/s2048/soybean-tentiform-leafnminer-mines.JPEG" style="clear: right; margin-bottom: 1em; margin-left: 1em; margin-right: auto;"><img border="0" data-original-height="2048" data-original-width="1536" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh3kSarsXpvflj-OwxyFEBkcK5lty_GR81wtB9ao24lNhPPTqHAWflIPNGQKUMzumocOlzbxH972yJfdlpSIpykMFx7WQow77tZXvOeeV2Acw79mjZxbzCk57_XnHVaSTYpzyj4vUt9tUvuZ8lPFhUle2FXSNwKfXdZ_FZXda6YN3sWJMAkGP_7F4GWYJuO/s320/soybean-tentiform-leafnminer-mines.JPEG" width="240" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Bottom of soybean leaf with soybean<br /> tentiform leafminer mines.</td></tr></tbody></table>The soybean tentiform leafminer was first detected in Minnesota soybean in 2021. The heaviest infestations to date have occurred in pockets in the Minnesota River Valley and seem to be most severe on field edges near trees. This developing pest situation is being examined closely. <br /><h3 style="text-align: left;">Damage </h3>Larvae hatch from eggs that are laid on the leaf surface. These tiny caterpillars move into the leaf where they live and feed. To begin with, the feeding pattern seen on the leaf is linear or serpentine. As they grow, the larvae hollow out the leaf leaving a leaf blotch and eventually they create a tentiform mine – where the upper leaf surface buckles up. These blotches reduce photosynthetic area, so larvae can be considered defoliators. Standard defoliation thresholds will likely apply to this pest: 30% prior to flowering and 20% after flowering. However, research to examine yield loss specifically from this pest will begin this summer. <br /><h3 style="text-align: left;">Control studies </h3><h4 style="text-align: left;">Insecticide </h4>Koch’s lab started evaluating insecticides in case this pest becomes an economic issue. In a lab study, insecticides with translaminar properties were applied at different larval development stages: serpentine mine stage, blotch stage, or tentiform stage. What they discovered was that the if insecticides were applied at the serpentine or blotch stages, control was good. However, there was almost no control at the tentiform stage. <br /><h4 style="text-align: left;">Choice studies – what do adults prefer for laying eggs? </h4>Several soybean genotypes – both susceptible and resistant to defoliators or aphids - were included in a choice study to evaluate which were preferred by females for laying their eggs. They found that susceptible plants had the most eggs while varieties known to be resistant some other pests had fewer eggs. These promising results suggest that there is some soybean germplasm that could potentially provide resistance to this pest. <br /><br />They also conducted a choice study with several legume species. Soybean was the most preferred host species followed by vegetable soybean (edamame). None to few eggs were found on lima bean, mung bean, cowpea, red kidney bean, chickpea, fava bean or pea. Alfalfa was not included. <br /><br />For more information, see <a href="https://extension.umn.edu/soybean-pest-management/soybean-tentiform-leafminer-minnesota-soybean">Soybean tentiform leafminer in Minnesota soybean</a>. <br /><h2 style="text-align: left;">Green cloverworm </h2><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6jOhfik0OdJJbmM0Fa-DT7Nqw5mJz28ngVkYu5RghqxvY9Auz7iMPyMqr5BEFg6-a7qqMkp43WLMJb9L8SIXm0gJUDJgc4e7Hy5C3NUa_ZP6nySqiZ2Evnb174JEbNSDcKYgHG4182hSu4doc1DuDIPMprdARzLydk0C_ra80kgGaMl3vmHMcXcmnlYLO/s624/green-cloverworm_potter.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="468" data-original-width="624" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6jOhfik0OdJJbmM0Fa-DT7Nqw5mJz28ngVkYu5RghqxvY9Auz7iMPyMqr5BEFg6-a7qqMkp43WLMJb9L8SIXm0gJUDJgc4e7Hy5C3NUa_ZP6nySqiZ2Evnb174JEbNSDcKYgHG4182hSu4doc1DuDIPMprdARzLydk0C_ra80kgGaMl3vmHMcXcmnlYLO/s320/green-cloverworm_potter.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Green cloverworm. Photo: Bruce Potter</td></tr></tbody></table>The green cloverworm is a sporadic pest in soybean. Typically, infestations are usually not large enough to reach treatable levels alone, but when combined with other defoliators may reach threshold. To date, no insecticide performance issues have been noted. <br /><br />For more information, see <a href="https://blog-crop-news.extension.umn.edu/2023/07/foliage-feeding-caterpillars-nearing.html">Foliage feeding caterpillars nearing threshold in some Minnesota soybeans</a> <br /><h2 style="text-align: left;">Other pests </h2>There are increasing reports of the defoliating insects, Japanese beetles and bean leaf beetles, in Minnesota. While typically not major pests, there may be pockets that approach thresholds. To get a good defoliation estimate, examine the whole canopy – not just the top where most of the Japanese beetle feeding occurs - at several field locations. Use the same threshold mentioned above: 30% defoliation prior to flowering and 20% after flowering. <br /><h2 style="text-align: left;">Weather and soybean insect pests </h2><h3 style="text-align: left;">Winter survival outlook </h3>If we were experiencing normal winter temperatures, we’d expect higher insect mortality since there is no insulating blanket of snow to protect them. However, the above normal temperatures – even without protection from snow – may lead to good survival for overwintering insects. <br /><h3 style="text-align: left;">Drought and the soybean insect pests </h3><a href="https://extension.umn.edu/soybean-pest-management/twospotted-spider-mites-soybean">Two-spotted spider mites</a>, an arthropod, is one species that benefits from drought. Scouting for this pest and assessing damage will be important if the dry pattern continues. For any infestations that reach the economic threshold this season, chlorpyrifos’ conditional registration reinstates an effective management tool. Otherwise, the only pyrethroid effective against spider mites is bifenthrin. Dimethoate, one of the organophosphates, does an okay job and traditional miticides are also an option. <br /><br />Dry weather is also conducive to grasshoppers. Populations can increase over consecutive droughty years because the dry conditions suppress pathogens that help control populations. For more information, see <a href="https://extension.umn.edu/soybean-pest-management/grasshoppers-minnesota-soybean">Grasshoppers in Minnesota soybean</a>. <br /><h2 style="text-align: left;">Join the webinar series </h2>University of Minnesota’s Strategic Farming: Let’s talk crops! webinar series, offered Wednesdays through March, features discussions with specialists to provide up-to-date, research-based information to help farmers and ag professionals optimize crop management strategies for 2023. For more information and to register, visit <a href="https://z.umn.edu/strategic-farming">z.umn.edu/strategic-farming</a>. <br /><br /><b><i>Thanks to the Soybean Research and Promotion Council and the Corn Research and Promotion Council for their generous support of this program.</i></b>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-26375477893454102882024-02-24T15:49:00.001-06:002024-02-24T15:49:43.368-06:00When is Early too Early (to Plant Wheat, Barley or Oats)?<p>In all likelihood, this winter will go in the books as the warmest on record for Minnesota and even surpass the winter of 1877-1878 that was dubbed the <a href="https://www.dnr.state.mn.us/climate/journal/1877_1878_winter.html#:~:text=For%20over%20145%20years%2C%20the,its%20records%20had%20seemed%20untouchable." target="_blank">Year Without a Winter</a>. Much of the state has enjoyed an extended "January Thaw" with daytime highs well above freezing. In the metro area, for example, daytime temperatures never dropped below 32 between January 22 and February 14th. Needless the say, fields are bare and drying off rapidly. That immediately begs the question of whether to start thinking about seeding wheat, barley, and oats. After all, early seeding is very advantageous for the yield potential of these cool-season grasses.</p><p>This scenario of a possible very early start to the growing season played out in the first and second week of March 2012 too. Below is an updated/expanded version of what I wrote then.</p><p>Spring wheat (and spring barley and oats) will start germinating in earnest when soil temperatures reach 40⁰F. Once the imbibition phase starts there is no return to dormancy and the germination and emergence should be as quick as possible to establish a healthy, vigorous seedling. The imbition phase is a passive process and if the seed freezes during the imbition phase it will eventually rot. Germination means that the germ starts growing. Once the germ is actively growing, it has some tolerance to freezing temperatures. It can tolerate temperatures down to 28⁰F and probably even handle short periods of temperatures as low as 22⁰F. </p><p>The first things you will see emerge from the seed are the shoot and radicle. Eventually, the coleoptile will bring the first leaf to the soil surface. Bauer and Black developed a <a href="https://ndawn.ndsu.nodak.edu/help-wheat-growing-degree-days.html" target="_blank">Growing Degree Day model</a> that predicts emergence using air temperatures. In this model, it takes approximately 180 GGD for spring wheat to reach the one-leaf stage (it takes oats and barley a few less). When you have nights just around freezing and daytime highs around 60⁰F, you accumulate about 15 GGD each day (follow the link above to see the math). </p><p>During germination, seedling emergence, and up to the 5-leaf stage, the growing point will be at ~1 inch depth. At this depth, it is already protected from the ambient air temperatures. Even if above-ground leaves freeze, the plant will survive and continue its development as long as the crown does not suffer any freezing injury. </p><p>Ideally, we like to emergence to be as quick as possible and yield a healthy, vigorous seedling. Daytime highs in the high sixties to low seventies and night temperatures around forty are great and will allow the crop to emerge in 8 to 10 days and make for a robust stand. Protracted emergence will predispose the seeding to attacks of soilborne fungi like Pythium damping off or common root rot, ultimately reducing stands. </p><p>However, if in the coming weeks, the current weather continues its current streak and your fields are ready to be seeded, I would seriously look at the immediate weather forecast at that time. If it looks like you can accumulate some 120 to 180 GGD between getting the seed in the ground and a return to freezing temperatures, I would not be afraid to go as the risk/reward equation is not a fool's errand. </p><p>To assess the risk of winter returning you can do what I did in 2012 to quantify that risk. I took the weather records from the Northwest Research & Outreach Center that date back all the way to 1890. If I took the 30-year climate normal at that time (1981 through 2010), winter could still return in April and if it did, the number of days the minimum temperatures went below 22⁰F between April 1 and May 15 was relatively small at 9% (Table 1). The number of days the nighttime temperatures dipped below 28⁰F was much greater at 25%. If however, the warmer weather continues and I looked at the 30 warmest April months on record, these percentages were cut in half. Taking the warmest 5 April months on record, it cuts those percentages again in half. </p><p>Obviously, that was somewhat of a roughshod approach as each individual day has its own probability function, meaning that it has its own mean and distribution around that mean. To do these calculations statistically correct you would have to calculate the probability that temperatures dropped below 22, 28, and 32 degrees for each individual day and then average them out over the same period. Intuitively you would understand that the risk is greatest in late March/early April and diminishes with each day the season progresses. </p><p><span style="white-space: normal;">The bottom line is that frost is likely to return after you seed the crop this early but the odds of really cold temperatures that could damage the crown are relatively small when looking at historical weather data with similar weather records. Of course, if any snow accompanies the cold weather, the snow will act as insulation and reduce the risk of the crowns freezing further.</span></p><p><span style="white-space: normal; white-space: pre;"> </span></p><p>Table 1. <span style="white-space: pre;"> </span>The percentage of days that temperatures dropped below 22, 28, or 32⁰F between April 1 and May 15 in the last 30 years, the warmest 30 April months on record and the 5 warmest April months on record at the NWROC.</p><p><span> Temperature </span><span> </span><span> </span><span> </span><span> </span>30-year Average <span> </span><span style="white-space: pre;"> </span>30 Warmest April Months<span style="white-space: pre;"> </span>5 Warmest April Months</p><p><span style="white-space: normal; white-space: pre;"> </span></p><p><22⁰F<span style="white-space: pre;"> <span> <span> </span><span> </span><span> </span><span> <span> </span></span></span></span>9%<span style="white-space: pre;"> <span> </span><span> </span><span> </span><span> </span></span>4%<span style="white-space: pre;"> <span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span></span>4%</p><p><28⁰F<span style="white-space: pre;"> <span> </span><span> </span><span> </span><span> </span><span> </span></span>25%<span style="white-space: pre;"> <span> </span><span> </span><span> </span><span> </span></span>15%<span style="white-space: pre;"> <span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span></span>6%</p><p><32⁰F<span style="white-space: pre;"> <span> </span><span> </span><span> </span><span> </span><span> </span></span>45%<span style="white-space: pre;"> <span> </span><span> </span><span> </span><span> </span></span>36%<span style="white-space: pre;"> <span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span></span>20%</p><p><span style="white-space: normal; white-space: pre;"> </span></p><p><br /></p><p><br /></p><p><br /></p><p><br /></p><p> </p>Jochum Wiersmahttp://www.blogger.com/profile/12077401423747385722noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-28716013698567111062024-02-21T11:52:00.000-06:002024-02-21T11:52:21.405-06:00Strategic Farming: Let's talk crops session talks adjuvants for maximizing herbicide efficacy<p>By Angie Peltier, UMN Extension crops educator, Joseph Ikley, North Dakota State University (NDSU) Extension weed management specialist, and Greg Dahl, retired Winfield product development manager</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjuoZiuvs6HPEOS6LuvoP3vXU9bvvQ3n_3QRHQVmwQrZHxQsJRGsaI3V2KWSJTDnLGMisOe-aPtCBjaAAWdEddvgZAgalUdTxR4cEEMqL490rVfBlODzxZ8lBjT1HVWzmEUBq2RfSp_fZAVFOwmlhsRP_mqgrW1dtWYjZTVS7Mzz5dI-3r6H_QqDhjU9_GY/s320/spraying-pesticides.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="240" data-original-width="320" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjuoZiuvs6HPEOS6LuvoP3vXU9bvvQ3n_3QRHQVmwQrZHxQsJRGsaI3V2KWSJTDnLGMisOe-aPtCBjaAAWdEddvgZAgalUdTxR4cEEMqL490rVfBlODzxZ8lBjT1HVWzmEUBq2RfSp_fZAVFOwmlhsRP_mqgrW1dtWYjZTVS7Mzz5dI-3r6H_QqDhjU9_GY/s1600/spraying-pesticides.jpg" width="320" /></a></div>On February 14, 2024, Joseph Ikley, NDSU Extension weed management specialist and Greg Dahl, retired Winfield adjuvant development advisor joined UMN Extension crops educator Dave Nicolai for a wide-ranging discussion of herbicide adjuvants and how best to use them effectively. This was the fifth weekly episode of the 2024 Strategic Farming: Let’s talk crops! webinars. The series runs through March.<p></p><p>To watch this and other episodes, visit <a href="http://z.umn.edu/SFrecordings">z.umn.edu/SFrecordings</a> <br /></p><h2 style="text-align: left;">A long history and current abundance of adjuvants </h2>Tank-mix adjuvants are products that can be added to the tank that make a pesticide active ingredient work better. Formulators may add adjuvants directly into the herbicide formulation if there is enough room and the adjuvant does not cause storage or compatibility issues. Often there is not room for the adjuvant to be added to the herbicide so tank-mix adjuvants are used instead. <p></p><p>Adjuvants have been in regular use since the 1700’s when molasses, sugar and resins were used to help sulfur and copper fungicides stick to grapes and kerosene emulsions and whale-oil-derived soaps were used to improve efficacy of insecticides made from arsenic. It wasn’t until the 1940’s however, that adjuvants began to be studied and routinely used with herbicides. It was then that non-ionic surfactants (NIS) were identified and ammonium sulfate (AMS) was found to increase herbicide uptake. Methylated seed oils (MSO) began to be used in the 1980’s. <br /><br />Currently, there are hundreds of different adjuvant active ingredients that can be placed into several functional classes, including activators, spray modifiers and utility modifiers. Spray modifiers modify the spray solution in the tank on its way to the target or on the target itself. Utility modifiers widen the range of conditions under which a herbicide can be used. Activator adjuvants such as non-ionic surfactants and crop oils increase the biological activity of the pesticide. The discussion during the webinar focused on activator adjuvants. <br /></p><h2 style="text-align: left;">Surface active adjuvants</h2><div>Surfactants - or surface active adjuvants - work at surfaces to help solve various issues. </div><h3 style="text-align: left;">Non-ionic surfactants (NIS)</h3>The outside of plant leaves are often coated in a waxy, hydrophobic (water-repelling) coating that makes water droplets bead up and away from the surface. NISs reduce the surface tension of water droplets which allows the same volume of water in the droplet to spread out over more of the leaf surface, providing more opportunity for the herbicide to absorb into the plant tissue. Some NISs have additional functions above and beyond reducing water’s surface tension including emulsifiers, wetters, stickers and dispersants. <br /><br />Surfactants can also ensure that the spray droplet makes its way to the leaf surface and doesn’t just get hung up on leaf hairs, slowly shrinking in size as it evaporates, never having made its way to the leaf blade surface. <br /><h3 style="text-align: left;">Crop oil concentrates (COC)</h3>Because oil loving herbicides and oil adjuvants are hydrophobic like the waxes on a leaf surface, the primary function of petroleum-based COCs is to increase the movement of a herbicide active ingredient through a leaf’s waxy cuticle and reduce water evaporation from within the spray droplet. Similar to NISs, COCs can enhance spreading of spray droplets on the leaf surface. When herbicide carrier volume is relatively low (~15 gal/acre) as it often is in northwest Minnesota, it is important to use enough COC to facilitate the deposition onto and movement into the plant. To ensure that oil and water (which don’t naturally mix) do indeed mix, an emulsifier that will provide a consistent mixture needs to be used in the tank. <br /><br />Crop oil concentrates are most commonly used with oil soluble herbicides such as ALS inhibitors (Group 2), triazines (Group 5), ACCase inhibitors (Group 1), HPPD Inhibitors (Group 27) and PPO inhibitors (Group 14). <br /><br />Methylated seed oil (MSO), derived from soybean, sunflower and canola oil, is made using crop-based fatty acids mixed with methanol or ethanol. An emulsifier type surfactant is also added to blend the MSO with water. MSO can be more effective as an adjuvant but can sometimes make a mix that is ‘too hot’ and harms the crop. However, from a weed management strategy, an injured crop, particularly one like soybean that has an innate capacity to compensate for some injury, also means that weed management is likely better in that field. MSOs provide better control than petroleum oils in the drier west (including the first couple of counties into MN from the west). In lusher, wetter environments, MSOs can cause crop phytotoxicity. <br /><h4 style="text-align: left;">COC weather considerations and antagonism </h4>Rather than use an NIS in a drought year, more weed scientists recommend that folks consider using a COC. During drought conditions, the waxy cuticle on the outer layer of plant leaves tends to get thicker as the plant desperately tries to stop water loss. Oil-based droplets will have a slower evaporation rate than droplets made up primarily of water, which can provide a bit more time for the herbicide active ingredient to be absorbed by the plant. <br /><br />Some emulsifiers that are used in the oil adjuvant can cause glyphosate antagonism. AMS and NIS are good adjuvants to use with glyphosate. COC or MSO adjuvants may cause glyphosate antagonism unless you use one that is ‘glyphosate friendly.’ If using one of these glyphosate friendly adjuvants, be sure to use a high rate of glyphosate to help overcome any antagonism.<br /><br />A newer class of adjuvants are the HSOC or high surfactant oil adjuvants. These are a combination of petroleum or MSO type adjuvants with at least 25% emulsifier by weight. These combine the performance of oils and surfactants and can be used at lower rates than COC’s or MSO’s as long as they do not become oil limited. If these products are used at GPAs at or above 15 gallons per acre they should be fine.<div><br />If the GPA is below 12 gallons per acre, these products should be used at an oil per acre rate. Otten 1 pint/a would be fine. Be sure to check the label instructions. <br /><div><h2 style="text-align: left;">Adjuvants that modify water quality </h2>Carrier pH is an important factor for solubility of some herbicide active ingredients. For example, the sulfonylurea herbicides (Group 2), the post-emergence HPPD inhibitors (Group 27) and the Group 14 herbicide Sharpen tend to be more soluble and work better in water with a pH above 7. <br /><br />In some areas of the state, many of our sources of water have high concentrations of both positively charged ions such as calcium, magnesium, sodium, potassium and iron and negatively charged ions such as sulfate, chloride, bicarbonate and nitrate. Ammonium sulfate (AMS) can be added to the tank in sufficient quantity to be able to tie up the positively charged ions. By adding up the concentration of positively charged ions in your water obtained in a water quality report, one can determine how much AMS would need to be added to overcome a specific water source’s hardness. Both granular and liquid AMS formulations work well. While granular formulations tend to be much less expensive, they also take some time to move into solution and so which formulation one chooses to use will depend upon one’s budget and patience during a busy time of year.</div><div> <br />Some weed species such as lambsquarters, volunteer sunflower and velvetleaf can have positively charged ions on their surface, requiring additional AMS in the tank in order to overcome this antagonism. AMS or water conditioning adjuvants should be used at rates above those needed to condition the water when soil and dust is present on plants, when weeds are hard to control, when the environment is dry and hot and when weeds populations are high.<br /><br />Research has shown that AMS can often improve weed control with herbicides even when distilled water is used. The positively charged ammonium in AMS can bind to negatively charged weak acid herbicides and facilitate movement within a plant demonstrating its benefit in distilled water which does not need to be conditioned. <br /><h2 style="text-align: left;">Research results tell the story </h2>After reviewing thousands of adjuvant research studies, the Council of Producers & Distributors of Agrotechnology (CPDA) found that when a herbicide is applied without its required adjuvant, herbicide efficacy can be reduced by 30 to 90%. For example, when Sharpen is used without an adjuvant, no injury symptoms will be observed on weeds, whereas Sharpen with the required adjuvant provides excellent control. Efficacy was reduced and there was between a 5 and 50% increased risk of crop injury when the wrong type of adjuvant was selected. Lastly, when a ‘good enough’ adjuvant was selected over a ‘premium’ adjuvant in the same class of adjuvants, there was between 5 to 25% less weed control with the good enough adjuvant than when using a premium adjuvant.</div><div><h2 style="text-align: left;">Tank mixing best practices </h2>As herbicide mixtures have become more complex over time, there is a great need to determine the proper mixing order to avoid a sludgy mess setting up in your spray tank. Know that when the water is cold, as it is when it is first drawn from the well, it will take longer for dry materials to solubilize. The best and least costly way to ensure that you have the proper mixing order is to do a jar test. Because cleaning out a jar is much preferred over cleaning out an entire sprayer. <br /><h2 style="text-align: left;">Fielding audience questions </h2>Ikley and Dahl answered many audience questions including: 1) with Minnesota’s 2023 drought still top of mind, does a non-ionic surfactant become an even more important consideration under drought conditions?, 2) which is better, granular or liquid ammonium sulfate formulations?, 3) what adjuvants would you recommend to use with diquat used for burndown in dry conditions?, 4) is AMS helpful for all chemistry or just glyphosate?, 5) can there be such a thing as too much AMS?, 6) what about adjuvant to use with insecticides and fungicides?, 7) is there a need for adjuvants when one uses Enlist and Liberty?, 8) how do the adjuvants affect the breakdown of herbicides?, 9) when using Liberty and clethodim together, would you use an adjuvant?, 10) is there any benefit to adding an adjuvant to a residual to improve control?, 11) is tank mixing Enlist, Liberty and glyphosate a good idea?</div><div><h2 style="text-align: left;">Join us next week! </h2>Join us again next week on February 28 when we welcome Dan Smith, Nutrient and pest management outreach specialist at the University of Wisconsin, and Anna Cates, State soil health specialist to discuss cover crops.</div><br />University of Minnesota’s Strategic Farming: Let’s talk crops! webinar series, offered Wednesdays through March, features discussions with specialists to provide up-to-date, research-based information to help farmers and ag professionals optimize crop management strategies for 2024. For more information and to register, visit <a href="https://z.umn.edu/strategic-farming">z.umn.edu/strategic-farming</a>.</div><div><br /><div><b><i>Thanks to the Minnesota Soybean Research & Promotion Council and the Minnesota Corn Research & Promotion Council for their generous support of this program!</i></b><br /><p></p><div style="mso-element: comment-list;"><div style="mso-element: comment;"><div class="msocomtxt" id="_com_14" language="JavaScript"><p class="MsoCommentText"><o:p></o:p></p>
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</div></div></div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-18090423785597556792024-02-21T10:19:00.005-06:002024-02-21T10:19:39.393-06:00Advanced Nitrogen Smart training March 1 in Farmington: A deep dive into the 4Rs<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikIK1-k_IMknulEXX4miarLWyDN_FCt5BimI7Vnl7m7-Y05vz6eFA5JmpsqUNr5p_H-gxWNHrXIjh7an0EsYJUHRspoFDhVSOVFjnLDXK06jPJIR6caQS3yRVAt4l_H2RNMP_e1ZrmVx4boQN2lo7fMrWxiyFJRqIUqI9NoRNOMT-uhrtayiniatTXXXoD/s5472/Sidedress%20liquid%20fertilizer%20UAN%202%20(1).JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="sidedress liquid fertilizer" border="0" data-original-height="3648" data-original-width="5472" height="426" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikIK1-k_IMknulEXX4miarLWyDN_FCt5BimI7Vnl7m7-Y05vz6eFA5JmpsqUNr5p_H-gxWNHrXIjh7an0EsYJUHRspoFDhVSOVFjnLDXK06jPJIR6caQS3yRVAt4l_H2RNMP_e1ZrmVx4boQN2lo7fMrWxiyFJRqIUqI9NoRNOMT-uhrtayiniatTXXXoD/w640-h426/Sidedress%20liquid%20fertilizer%20UAN%202%20(1).JPG" title="sidedress liquid fertilizer" width="640" /></a></div>University of Minnesota Extension is hosting an Advanced Nitrogen Smart training in Farmington on Friday, March 1. The session, “A Deep Dive Into the 4Rs,” runs from 9 a.m. to noon at the Dakota County Extension and Conservation Center, 4100 220th St., Farmington. This training is free and registration is not required.<br /><br />Most involved in agriculture in southeast Minnesota are aware of the issues surrounding nitrates in groundwater, and the recent EPA directive to the state to take additional action to address the problem. It is imperative that farmers understand the issues and how they can help address the situation.<br /><br />“A deep dive into the 4Rs” picks up where the <a href="https://extension.umn.edu/event/nitrogen-smart-fundamentals" target="_blank">Nitrogen Smart Fundamentals course</a> left off, with a detailed discussion on N rate, the contributions from soil and the stress from climate factors.<br /><br />The 4Rs were developed in collaboration between university researchers and the fertilizer industry during the late 1980s. They promote a nutrient management approach that balances crop productivity with environmental preservation:<br /><ul style="text-align: left;"><li><b>Right rate:</b> Nitrogen rates have the potential to make the largest impact on both crop production and the environment. The key to optimizing rates is to follow university N guidelines, use soil nitrate-N tests when appropriate, and scout for deficiencies.</li><li><b>Right source: </b>Once in a plant-available form, the plant doesn't distinguish one N source from another. However, there are differences in how N fertilizers interact with the environment, which can affect both availability and loss.</li><li><b>Right time:</b> The nutrient supply should be synchronized with crop demand and uptake. Several factors influence N availability, including fertilizer source, the use of stabilizers or inhibitors, and field conditions. Together they help determine when it's most appropriate for that particular N source to be applied. </li><li><b>Right place:</b> Nutrients should be placed where the crop can use them. Consequently, the application method is important for optimum fertilizer efficiency.</li></ul>Thanks to the generous support of the Minnesota Corn Growers and their checkoff, there is no preregistration required and no cost to attend. For more information you can visit our website at <a href="http://z.umn.edu/NitrogenSmart" target="_blank">z.umn.edu/NitrogenSmart</a>.<div><br /></div>---<br /><br />For the latest nutrient management information, subscribe to the <a href="https://nutrientmanagement.transistor.fm/subscribe" target="_blank">Nutrient Management Podcast</a> wherever you listen and never miss an episode! And don't forget to subscribe to the <a href="https://pub.s6.exacttarget.com/k0nz2zsg2m4" target="_blank">Minnesota Crop News</a> daily or weekly email newsletter, subscribe to our <a href="https://youtube.com/playlist?list=PLOPc3IDYKqybHLzKb5j1tOIl_Yeii_ofn" target="_blank">YouTube</a> channel, like UMN Extension Nutrient Management on <a href="https://www.facebook.com/UMNNutrientMgmt/" target="_blank">Facebook</a>, follow us on <a href="https://twitter.com/UMNNutrientMgmt" target="_blank">Twitter</a>, and visit our <a href="https://extension.umn.edu/crop-production#nutrient-management" target="_blank">website</a>.Jack Wilcoxhttp://www.blogger.com/profile/14996004057706995837noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-40260059598231111652024-02-20T09:39:00.005-06:002024-02-22T08:18:21.769-06:00European corn borer: Old pest, new problemsWilfrid Calvin, University of Minnesota Dept. of Entomology, Postdoc Researcher<br />Tatum Dwyer, University of Minnesota Dept. of Entomology, MSc Student<br />Fei Yang, University of Minnesota Extension corn entomologist<br /><h2 style="text-align: left;">What is European corn borer? </h2>The European corn borer (ECB), <i>Ostrinia nubilalis </i>(H<span style="font-family: "Times New Roman",serif; font-size: 12.0pt; line-height: 107%; mso-ansi-language: EN-US; mso-bidi-language: AR-SA; mso-fareast-font-family: Calibri; mso-fareast-language: EN-US; mso-fareast-theme-font: minor-latin;">ü</span>bner), is a significant pest of corn and once caused substantial yield losses and economic damage throughout the U.S. Corn Belt and most corn growing states east of the Rocky Mountain range. Damage and management costs were historically estimated to exceed one billion dollars annually. In 2021, ECB alone was responsible for the losses of approximately 338.6 thousand bushels of corn in the U.S. <br /><br />The presence of ECB in the U.S. dates back to its initial discovery near Boston, Massachusetts, during the summer of 1917. It is widely believed that ECB was introduced into the country from Europe through shipments of broomcorn. Since its introduction, the pest has rapidly spread to all major corn-growing regions in the U.S. and Canada. Evidence suggests that ECB made its way into Minnesota during the 1940s.<br /><h3 style="text-align: left;">How to identify European corn borer</h3>The female moth has an approximate wingspan of 1-inch and is slightly longer than of males. Both female and male ECB moths have triangular wings. Females typically exhibit a color range from yellow to brown marked with wavy patterns on their wings, while males tend to have darker coloration (Figure 1).<div><br /><div>Female moths lay eggs in clusters of 20-30 eggs that resemble fish scales in appearance. Initially, the eggs appear whitish but darken to black prior to hatching (Figure 2). <br /><div><br /></div><div>The larvae of ECB exhibit a range of coloration, spanning from light cream/tan to brown, with each segment of their bodies with several dark brown spots (Figure 3). The head capsule of larvae is dark brown. Upon hatching, neonates typically measure between 1/32 to 1/16 inch in length, while mature larvae can reach lengths of approximately 3/4 to 1 inch. </div><div><br /></div><div>Examples of corn stalk tunnel damage and lodging caused by larval feeding are shown in Figures 4-6.<br /><div><br /></div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7Tuo2Raim7u32XrbJEZjqsYpEkALJyfxmi_kxQEq8guKmihK3VpDQhNyXsq5esBAsXqqzwoaK6alBr9KNhmC-Ou5JZsTWi0iXGbeS7IjYIifFoJB8fbEw06eCfEo6tB20rMQd_hkgABpMLHOpNrUq2p60syIvNktUBBOmf53zgE9aqk0-eRqG6QNjWdsV/s197/ecb-moth-A.png" style="display: block; margin-left: auto; margin-right: auto; padding: 1em 0px; text-align: center;"><img alt="" border="0" data-original-height="121" data-original-width="197" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7Tuo2Raim7u32XrbJEZjqsYpEkALJyfxmi_kxQEq8guKmihK3VpDQhNyXsq5esBAsXqqzwoaK6alBr9KNhmC-Ou5JZsTWi0iXGbeS7IjYIifFoJB8fbEw06eCfEo6tB20rMQd_hkgABpMLHOpNrUq2p60syIvNktUBBOmf53zgE9aqk0-eRqG6QNjWdsV/s320/ecb-moth-A.png" width="320" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Fig 1. European corn borer moths. Photo: M.E. Rice</td></tr></tbody></table></div>
<div style="float: right; width: 48%;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVtteQbZk5NtyurmD0MQJTtiE0yjFm-5Dz4MgNKWcQibryRXIa_ZLbp5sbMYbdGUfHL48jsGeqvMUQPlRXGNuO2_ePazyp4fHSpRQNxESdNPlTQVUV7GLy_lcuzTbxPkzVKTOTp4rGW50fg2j4p2A5_lrJpo7bNUD2N-ANxthYnJ2b1H-gUbvyEUiC0-lo/s201/ecb-eggs-B.png" style="display: block; margin-left: auto; margin-right: auto; padding: 1em 0px; text-align: center;"><img alt="" border="0" data-original-height="116" data-original-width="201" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVtteQbZk5NtyurmD0MQJTtiE0yjFm-5Dz4MgNKWcQibryRXIa_ZLbp5sbMYbdGUfHL48jsGeqvMUQPlRXGNuO2_ePazyp4fHSpRQNxESdNPlTQVUV7GLy_lcuzTbxPkzVKTOTp4rGW50fg2j4p2A5_lrJpo7bNUD2N-ANxthYnJ2b1H-gUbvyEUiC0-lo/s320/ecb-eggs-B.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Fig 2. Egg mass. Photo: B. Potter</td></tr></tbody></table></div>
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<div style="float: left; width: 60%;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhG9JYF9BMPT8FLL2uWDgq8dx9Jd8qm5usMlUH9IT4mewaFTze4DvwBFbvtUAXxTu602Iam2jgwq7bB9Ydf1SoIlDmzCxG5UNQYBQiiHFWjGzyQ0SiiLk4bq1bamwGu56ryMGGoKbMDl09kFIhYc9X2cE7kIcA9HiAVTZmfTBkgwsDZ6qXvqHeXK7CmT6ak/s220/ecb-larva-C.png" style="display: block; margin-left: auto; margin-right: auto; padding: 1em 0px; text-align: center;"><img alt="" border="0" data-original-height="112" data-original-width="600" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhG9JYF9BMPT8FLL2uWDgq8dx9Jd8qm5usMlUH9IT4mewaFTze4DvwBFbvtUAXxTu602Iam2jgwq7bB9Ydf1SoIlDmzCxG5UNQYBQiiHFWjGzyQ0SiiLk4bq1bamwGu56ryMGGoKbMDl09kFIhYc9X2cE7kIcA9HiAVTZmfTBkgwsDZ6qXvqHeXK7CmT6ak/s320/ecb-larva-C.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Fig 3. Larva. Photo: W. Calvin</td></tr></tbody></table></div>
<div style="float: right; width: 40%;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqdXRyJH4um6BvslnamXQVCZAddDv-gBW5vPqtK9DRCGEJXsrYRbI4_xuaOgOikdnqF8pCFKx-zqIMCRbgXJnBSL0f95cLDvGGvtwBR6OIKYRwQ13kP3tTaKUjsu0OjsIC5rlHsdnbB4put5k8D1VAZJldkt7dRA1XAUkN__SlZ11oOAzp9zSibS8X0nk2/s131/ecb-stalk-damage-D.png" style="display: block; margin-left: auto; margin-right: auto; padding: 1em 0px; text-align: center;"><img alt="" border="0" data-original-height="131" data-original-width="128" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqdXRyJH4um6BvslnamXQVCZAddDv-gBW5vPqtK9DRCGEJXsrYRbI4_xuaOgOikdnqF8pCFKx-zqIMCRbgXJnBSL0f95cLDvGGvtwBR6OIKYRwQ13kP3tTaKUjsu0OjsIC5rlHsdnbB4put5k8D1VAZJldkt7dRA1XAUkN__SlZ11oOAzp9zSibS8X0nk2/s320/ecb-stalk-damage-D.png" width="220" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Fig 4. Corn stalk tunneling damage. Photo: W. Calvin</td></tr></tbody></table></div>
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<div style="float: left; width: 48%;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXkPAeZr32MQTbp1JqgotzUAW9IoqOfqJ0jate7Vz6fFkEw9fYo2HPA5tn1QkeLGJkM0aoqwqMDeQCV_9w6qyloULcRfvbXB1Ra3kFeXc548LNfMnD6p5oOGBFfbMSnXpJUtyQ2FEnYVbjxZkdNx-XKl5Wo-O2A7TFLX2Hb4q1Pl_Pn3z2IwUXsgKK_vCg/s179/ecb-lodged-stalk-E.png" style="display: block; margin-left: auto; margin-right: auto; padding: 1em 0px; text-align: center;"><img alt="" border="0" data-original-height="179" data-original-width="172" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXkPAeZr32MQTbp1JqgotzUAW9IoqOfqJ0jate7Vz6fFkEw9fYo2HPA5tn1QkeLGJkM0aoqwqMDeQCV_9w6qyloULcRfvbXB1Ra3kFeXc548LNfMnD6p5oOGBFfbMSnXpJUtyQ2FEnYVbjxZkdNx-XKl5Wo-O2A7TFLX2Hb4q1Pl_Pn3z2IwUXsgKK_vCg/s320/ecb-lodged-stalk-E.png" width="300" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Fig 5. Stalk damage with larva.</td></tr></tbody></table></div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiODHaJ2i4nYlbt6a9dbNVWbmZvNcGiL-IUB8av7cLIqYciEIYJuaxNY-lHX8Plxl9lUO77BpnKe9tc7wmqVp0KFSauT4ggt9bzgE6wjhadnBZ1LXjf4aXByF6JTxTJoEzKO5_xxN3QxTaPGL-den3JV-39dqdXtFFZRPbp61XHwA6tOf2aydBMhJvIIwy6/s154/ecb-lodged-stalk-F.png" style="display: block; margin-left: auto; margin-right: auto; padding: 1em 0px; text-align: center;"><img alt="" border="0" data-original-height="151" data-original-width="154" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiODHaJ2i4nYlbt6a9dbNVWbmZvNcGiL-IUB8av7cLIqYciEIYJuaxNY-lHX8Plxl9lUO77BpnKe9tc7wmqVp0KFSauT4ggt9bzgE6wjhadnBZ1LXjf4aXByF6JTxTJoEzKO5_xxN3QxTaPGL-den3JV-39dqdXtFFZRPbp61XHwA6tOf2aydBMhJvIIwy6/s320/ecb-lodged-stalk-F.png" width="320" /></a></td></tr><tr><td class="tr-caption" style="font-size: small; text-align: center;">Fig 6. Lodged corn stalk due to larval feeding damage. </td></tr></tbody></table></div>
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<h3>Management of European corn borer with Bt technologies in the U.S.</h3>The use of <i>Bacillus thuringiensis (Bt)</i> proteins has proven to be a highly effective strategy in managing ECB infestations. <i>Bt</i> corn hybrids are the result of genetic modification, where genes from the soil-dwelling bacterium, <i>B. thuringiensis</i>, are incorporated, enabling the plant to produce proteins with insecticidal properties specifically targeting the desired insect pests. <div><br /></div><div>The adoption of <i>Bt </i>corn technology has resulted in areawide suppression of ECB in the U.S. This adoption has brought about several notable benefits, including a marked reduction in the need for insecticide applications aimed at combating pests, a decrease in the utilization of fossil fuels associated with pesticide application, and an overall increase in corn yields. Moreover, the adoption of <i>Bt</i> corn has not only been financially advantageous for farmers cultivating <i>Bt</i> corn but has also provided economic benefits to non-<i>Bt</i> corn growers due to the areawide suppression of ECB populations facilitated by the adoption of Bt corn hybrids. Currently, only Cry1Ab, Cry1F, Cry1 A.105, and Cry2Ab2 Bt proteins in the market are effective for ECB control. These different Cry <i>Bt </i>proteins are often utilized in combinations as "pyramids" in various corn hybrids to enhance ECB control.<br /><h3 style="text-align: left;">Field-evolved resistance found in European corn borers in Canada: why we should care? </h3>The high reliance on <i>Bt </i>crops has placed strong selection pressure on target pest populations for the evolution of resistance, the main threat to continued public benefits from this technology. In recent years, the effectiveness of <i>Bt</i> proteins targeting ECB has been challenged. In 2018, field-evolved resistance was identified for multiple field populations of ECB in Nova Scotia, Canada, more than two decades after the introduction of <i>Bt</i> technology targeting this pest. </div><div><br /></div><div>More recently, it was reported that resistance to Cry <i>Bt</i> proteins has expanded to several other regions in Canada, including Quebec and Manitoba. This situation has raised concerns regarding potential resistance to Cry <i>Bt</i> proteins in ECB in the U.S. Corn Belt. The proximity of Canada to the U.S. Corn Belt heightens the risk of migration of ECB strains resistant to <i>Bt </i>proteins from Canada to the U.S., where they could proliferate throughout the Corn Belt regions. Indeed, instances of field-evolved resistance to <i>Bt</i> proteins have already been detected within the U.S. In 2023, a field of Bt sweet corn producing Cry1A.105 and Cry2Ab2 proteins in Connecticut experienced significant damage from ECB infestation. </div><div><br /></div><div>In addition, a field of conventional corn in Crookston, Minnesota was found to be heavily infested with ECB larvae in 2023, with 30-35% of 1000 surveyed plants exhibiting damage, a clear indication of an ECB "hot spot" in the field. Larvae from this site were transported to the lab to establish colonies to check for Bt susceptibility or resistance. Considering these observations, we are concerned that the emergence of <i>Bt </i>resistance in Canada and Connecticut could pose a severe risk for further spread across U.S., potentially reaching Minnesota, and could accelerate the evolution of resistance to other <i>Bt </i>traits.<br /><h3 style="text-align: left;">What can we do? </h3>The high dose/refuge strategy has proven to be highly effective in delaying the development of resistance to <i>Bt</i> proteins in ECB populations in the U.S. Continued adherence to this strategy is crucial in maintaining susceptibility among ECB populations. Additionally, the adoption of multi-<i>Bt</i> proteins (also called <i>Bt</i> pyramids) corn hybrids is crucial for effective resistance management in this pest.</div><div><br /></div><div>Proactive resistance monitoring is paramount in slowing the evolution of insect resistance, as early detection provides valuable insights for devising appropriate management strategies. Currently, our corn lab at the Department of Entomology, University of Minnesota is conducting surveys to assess susceptibility levels and Bt resistance allele frequencies in ECB populations collected from Minnesota and neighboring states. </div><div><br /></div><div>If you encounter ECB infestations in your fields, please reach out to us, and we can assist in determining the Bt resistance levels of these insects. Moreover, implementing integrated pest management (IPM) approaches targeting ECB is crucial. Cultural practices that foster the conservation of beneficial arthropods and enhance their population and diversity should help control ECB infestation. Additionally, practices such as plowing corn plant residue to a depth of at least 8 inches and shredding corn stalks can significantly reduce larval densities within fields, thereby aiding in the prevention of resistant ECB establishment.<br /><h2 style="text-align: left;">Funding support </h2>We appreciate the Minnesota Corn Growers Association, and Minnesota Corn Research and Promotion Council for their generous funding support for this project.<br /><h2 style="text-align: left;">References </h2>Caffrey, D. J., and L. H. Worthley. 1927. A progress report on the investigation of the European corn borer. United States Department of Agriculture Bulletin no. 1476. <br /><br />Cook, K. A., S. T. Ratcliffe, M. E. Gray, and K. L. Steffey. 2003. European Corn Borer (<i>Ostrinia nubilalis </i>Hubner). University of Illinois Extension Publication. <br /><br />Cullen, E. M., and J. Wedberg. 2005. The European corn borer. University of Wisconsin Extension publication. A1220. <br /><br />Hutchinson, W. D., E. C. Burkness, P. D. Mitchell, R. D. Moon, T. W. Leslie, S. J. Fleischer, M. Abrahamson, K. L. Hamilton, K. L. Steffey, M. E. Gray, R. L. Hellmich, L. V. Kaster, T. E. Hunt, R. J. Wright, K. Pecinovsky, T. L. Rabaey, B. R. Flood, and E. S. Raun. 2010. Areawide Suppression of European corn borer with Bt Maize Reaps Savings to Non-Bt Maize Growers. Science. 330: 222-225. <br /><br />Potter, B. 2020. European corn borer in Minnesota. University of Minesota Extension publication. <a href="https://extension.umn.edu/corn-pest-management/european-corn-borer-minnesota-field-corn">https://extension.umn.edu/corn-pest-management/european-corn-borer-minnesota-field-corn</a> <br /><br />Smith, J. L., Y. Farhan, and A. W. Schaafsma. 2019. Practical Resistance of <i>Ostrinia nubilalis</i> (Lepidoptera: Crambidae) to Cry1F Bacillus thuringiensis maize discovered in Nova Scotia, Canada. Scientific Reports. 9:18247. <br /><br />Smith, J. L., and Y. Farhan. 2023. Monitoring resistance of <i>Ostrinia nubilalis</i> (Lepidoptera: Crambidae) in Canada to Cry toxins produced by <i>Bt</i> corn. J. Econom. Entomol. 116: 916-926.
</div></div></div></div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0tag:blogger.com,1999:blog-5575265938373902114.post-52525213485800988822024-02-13T10:42:00.002-06:002024-02-13T17:19:30.239-06:00MN CropCast: "Where is winter in Minnesota?" with Dennis Todey<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjj4JDquJW3xRyAqy7Zq5k5Ev4T1RufEgrl5vDx70SzJx08OAGJO0WcJQizUqqRWPUuTgZtP5DnhyLxKeNTAh4M2NcMp57ZvGQAXz5_uGk8XMKbDHRV1i8h0MJybIHCVecWDZC1W6PX3Zmg2qb7YCQOsVM9dIg4qCY-YOMS1UoOrZrRIiZrur3s-MdHNig/s320/podcast-minnesota-cropcast-cover-art.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="320" data-original-width="320" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjj4JDquJW3xRyAqy7Zq5k5Ev4T1RufEgrl5vDx70SzJx08OAGJO0WcJQizUqqRWPUuTgZtP5DnhyLxKeNTAh4M2NcMp57ZvGQAXz5_uGk8XMKbDHRV1i8h0MJybIHCVecWDZC1W6PX3Zmg2qb7YCQOsVM9dIg4qCY-YOMS1UoOrZrRIiZrur3s-MdHNig/s1600/podcast-minnesota-cropcast-cover-art.png" width="320" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div>In episode #29 Dave Nicolai and Seth Naeve chat with Dennis Todey, Director of the USDA Midwest Climate Hub in Ames, Iowa. In this podcast Dennis discussed and reviewed the major factors involved in this winter’s above-average temperatures and lower than average snowfall/precipitation. Dennis also reviewed the effects of warmer than average El Niño and anticipated La Niña and its possible effects on upper Midwest agricultural weather events for the 2024 cropping season. </div><div><br /></div><div>Dennis is a native Iowan with his BS and PhD from Iowa State in Meteorology and Agricultural Meteorology. He has spent two stints in South Dakota, first completing his MS at the South Dakota School of Mines and Technology and most recently as Associate Professor and State Climatologist for South Dakota at South Dakota State University before moving to the Midwest Climate Hub, based in Ames, Iowa. </div><div><br /></div><div>The mission of the USDA Midwest Climate Hub is to develop science-based, region-specific information and technologies alongside USDA agencies and partners, and deliver these products to agricultural and
natural resource managers that enable climate-informed decision-making. The Midwest Climate Hub produces several climate related publications and on-line tools. One such publication is the Midwest Climate Hub monthly which utilizes NOAA and USDA outlooks, placing them in context for agriculture in the Midwest based on current impacts. For the most current edition, visit the<a href="https://www.climatehubs.usda.gov/sites/default/files/2024_01_04_MidwestFocusAgOutlook.pdf"> Midwest Ag-Focus Outlook</a>. </div><div><br /></div><div>Join Dave and Seth for a lively discussion on this week’s edition of Minnesota Crop Cast.<div><h3><a href="https://mncropcast.transistor.fm/episodes/where-is-winter-in-minnesota-with-dennis-todey-director-of-the-udsa-midwest-climate-hub" target="_blank">Listen to the podcast</a></h3></div><h2 style="text-align: left;">What is Minnesota CropCast?</h2><div>Hosts David Nicolai and Seth Naeve discuss the progress and challenges of Minnesota's agronomic crops in this new podcast. They are joined by a diversity of specialists representing all crops and agronomic disciplines to discuss their research and its impact on future Minnesota crops. Dave Nicolai is a crops Extension educator and Seth Naeve is the Extension soybean agronomist.</div><h3>How do I sign up?</h3><div>You can subscribe and listen to <b>Minnesota CropCast</b> using one of many popular podcasting apps or directories. <a href="https://mncropcast.transistor.fm/subscribe" target="_blank">Learn more</a>.</div></div>Phyllis Bongardhttp://www.blogger.com/profile/03400102213039160712noreply@blogger.com0