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Register to Attend These Nutrient Management Conferences in February

Farmers, agronomists and other ag professionals with an interest in nutrient management and water issues are encouraged to attend upcoming conferences showcasing the latest research on fertilizer and manure management, water quality and tile drainage, and more.

2018 Research Updates for Ag Professionals - January 2-4 & 9-11

by Dave Nicolai, Coordinator for the Institute for Ag Professionals

Soybean plot harvest at Lamberton, MN. Photo: Emily Evans The 2018 Research Update sessions are scheduled for these locations: Waseca, Rochester and Lamberton (Jan 2, 3 and 4 respectively) and Morris, Willmar, and Crookston (Jan 9, 10 and 11 respectively) from 12:30 pm–4:40 pm for each location. Registration fee is $55 through 12/31/2017, $60 beginning 1/1/2018. Online registration and session abstracts can be found on our website at z.umn.edu/iapru or onsite registration begins at 11:30 a.m. at each location.

The program will feature research-based strategies to deal with today's changing pests, diseases, varieties, and nutrient and environmental recommendations. Continuing education units for Certified Crop Advisors have been applied for including: 1 in Nutrient Management and 3 in Pest Management, (additional 1 in Crop Management at Crookston).

Nutrient Management Podcast: Managing Nutrients in Winter

On this episode of the podcast, Dan Kaiser, Jeff Vetsch, Fabian Fernandez and Brad Carlson talk about managing nutrients as we head into winter. We're talking fall urea, tile flow, cover crops and hard freeze, and how all those factors affect nutrient loss.

Managing Nutrients in the Winter Season

Guests Dan Kaiser, Jeff Vetsch, Fabian Fernandez and Brad Carlson cover everything you need to know about nutrient management heading into the winter season. We talk about fall urea, tile flow and N loss, cover crops and how to manage after a hard freeze.

For more the latest on nutrient management, follow us on facebook at facebook.com/UMNNutrientMgmt or Twitter at twitter.com/UMNNutrientMgmt.

5 Best Practices for Late Fall Fertilizer Management

Daniel Kaiser, Paulo Pagliari and Fabian Fernandez

Late fall can present challenges when it comes to fertilizer application. If you don’t apply fertilizer at the right time in the fall, you risk loss of nutrients via runoff. As soil temperatures move toward freezing, the chance of nutrients getting held in the soil decreases and the risk for nutrient loss goes up. Here are some best practices for late fall fertilizer management to keep in mind.

2018 January Research Updates for Ag Professionals

By Dave Nicolai, Coordinator for the Institute for Ag Professionals
Each year brings new crop production challenges. Keeping up with these new issues is a top priority for agricultural professionals. At the 2018 University of Minnesota Research Update for Ag Professionals, you will find research-based strategies to deal with today's changing pests, diseases, varieties, and nutrient and environmental recommendations. Presentations and discussions at the update will allow you to visit with experienced university researchers and offer you the opportunity to visit with colleagues to discuss topics of interest to you in your region. The 2018 Research Update Sessions are scheduled for these locations: Waseca, Rochester and Lamberton (Jan 2, 3 and 4 respectively) and Morris, Willmar, and Crookston (Jan 9, 10 and 11 respectively). Registration by site is listed below.

Minnesota Field Crop Trials available

The 2017 Minnesota Field Crop Trials is now available on the Minnesota Agricultural Experiment Station website at https://www.maes.umn.edu/publications/field-crop-trials/2017-crop-trials.

Each year, crop scientists conduct performance tests of both public and private varieties of grain, forage, and oilseed crops at several locations throughout the state. This objective information helps producers select varieties and crop brands best suited to their individual situations and locations.

Nutrient Management Podcast: High Yields and Nutrient Removal

On this episode of the podcast, we're talking nutrient removal in high yield cropping systems. Hear from Dan Kaiser, Jeff Vetsch, Melissa Wilson and Carl Rosen on covering removal rates with fertilizer and manure, maintaining soil tests and how to manage in the face of fluctuating crop and fertilizer prices.

High Yields and Nutrient Removal

Dan Kaiser, Jeff Vetsch, Melissa Wilson and Carl Rosen talk nutrient removal in high yield cropping systems on this episode of the Nutrient Management Podcast.

For more the latest on nutrient management, follow us on facebook at facebook.com/UMNNutrientMgmt or Twitter at twitter.com/UMNNutrientMgmt

Advance corn hybrid selection with trial results and criteria

By Jeff Coulter, Extension Corn Agronomist
Hybrid selection is one of the most important agronomic decisions for corn production. Results from the 2017 University of Minnesota corn grain and silage performance trials are available at http://z.umn.edu/corntrials

Hybrids that consistently perform well over multiple locations or years in a region are desirable because next year’s growing conditions are uncertain.

Fall N Loss: Do These Scenarios Apply to You?

Greg Klinger and Anne Struffert, Extension Educators 
Not all fall-applied nitrogen sources are equal. Fall-applied anhydrous ammonia behaves very differently than fall-applied urea. Anhydrous ammonia is as harmful to microorganisms as it is to people, so the microbes that convert ammonium to nitrate in the soil are typically killed in the area right around the injection band. These microorganisms will eventually recolonize the injection zone and ammonium will begin converting to nitrate. Urea does not inhibit the activity of these microorganisms. As a result, anhydrous ammonia delays the conversion to nitrate by at least 2 weeks longer than urea and other fertilizer forms.

Here's How to Assess Fall N Loss

Greg Klinger and Anne Struffert, Extension Educators 

Substantial nitrogen loss from fall applied fertilizer can happen under a few key conditions:


Warm temperatures (especially above 50°) that increase the activity of nitrifying microorganismsA large portion of nitrogen in the soil in the form of nitrate nitrogen (NO3-N), usually due to nitrifying microorganisms,Significant precipitation.

Field Studies: Blowing the Whistle on Marketing Claims

By Sara Berg, South Dakota State University; John Thomas, University of Nebraska Lincoln; Lizabeth Stahl, University of Minnesota; Josh Coltrain, Kansas State University

Photo: Sara Berg, SDSU Extension
With technology being so prevalent in today’s culture, data and marketing information has become a key part of life. Farmers especially have been targeted with large quantities of new technology to generate more efficient farming systems and easy real-time data access. With large amounts of data and fast access to information and product marketing being the new norm, producing a commodity requires many decisions.

While the number of US farms has dropped, average farm size has risen 23 percent from 2009 to 2016 (USDA, 2017). At the same time, producers have seen a shift in the types of ag services available. With such a wide scope of products and options available, it can be difficult to determine what products or technologies to invest in and what to leave on the shelf.

Fall vs. Spring: When to Apply Phosphorus

Paulo Pagliari, Nutrient Management Specialist

Among the major nutrients (nitrogen, phosphorus and potassium), phosphorus (P) has the least mobility. As the fertilizer granule dissolves, most of the P in the fertilizer will likely only move a couple eights of an inch away from the granule, primarily by diffusion. The dissolved P will then start to react with cations in solution such as calcium, aluminum, and iron, and will start to adsorb onto soil particles. In general, tie up of P as calcium phosphates is a concern when the soil pH exceeds 7.3. Soils will become more acidic over time if they are not limed. With the decrease in pH, the availability of P will change. When the pH of soils range between 4.8 and 5.5, P is more reactive with aluminum in the soil and is tied up as aluminum phosphates that are not available to the plants. Liming of the soil can help to increase P availability from Fe and Al bound forms. The reaction of sorption and precipitation will limit P availability to…

Manure and Nutrients: A Complicated Relationship

Melissa Wilson, Manure Management Specialist

Animal manure - or “brown gold” as some like to call it - is a valuable source of nutrients for growing crops when applied at agronomic rates. In Extension, we often get questions about how to manage manure nutrients. Unfortunately, there is not a simple answer. The nutrient content and availability depend on many factors.

U of M Extension and NDSU Extension to host 2017 Conservation Tillage Conference

Photo: Jodi DeJong-Hughes The University of Minnesota Extension along with North Dakota State University Extension Service is hosting the 2017 Conservation Tillage Conference on Dec. 5-6 in Willmar, Minn.

Roll up your sleeves for some practical, hands-on information that will save you soil, time, fuel, and money. This conference emphasizes proven farmer experience and applied science. Straight from the fields, learn how heavier, colder soils aren’t necessarily the challenge they’re made out to be. Hear from long-time no-till and reduced tillage farmers as they share their experiences, so you can be spared the same hard-learned lessons.

Managing wet corn with a late harvest

By Liz Stahl, Dave Nicolai and Jeff Coulter

Photo: Liz Stahl There is a significant amount of corn to be harvested throughout the Upper Midwest. Grain moisture for most of this corn is not at a level safe for long-term storage, ranging from 17 to 20 percent. Dr. Kenneth Hellevang, Extension Engineer with North Dakota State University, is a regional expert on corn storage issues. Suggestions from Dr. Hellevang and publications for dealing with wet corn and a late harvest include the following:

VIDEO: Interpreting the Basal Stalk Nitrate Test

Daniel Kaiser, Soil Fertility Specialist

Once you’ve taken the basal stalk nitrate test, it’s time to interpret your results. Remember that this test is diagnostic, not predictive. The results will come in measurements of PPM, or parts per million. This is an indication of nitrogen availability throughout the season. Watch the video below for more on how to interpret these results.

VIDEO: Taking the Basal Stalk Nitrate Test

Fabian Fernandez, Nutrient Management Specialist

The basal stalk nitrate test is a diagnostic test taken at the end of the growing season in corn. Results will show how well you did with your nitrogen management during the season. While this test won’t tell you how much N you need to apply next year, over time it can reveal a picture of your fertilizer management practices.

2017 U of M SE Minnesota regional soybean yield results now available

by Lisa Behnken, Fritz Breitenbach, Liz Stahl, and Ryan Miller
Performance comparisons of early (1.2-1.8) and late (1.9-2.3) maturity glyphosate tolerant/RoundUp Ready soybean in southeastern Minnesota are now available. The studies with 30 early-maturity and 30 late-maturity entries were conducted near Rochester, MN (Lawler site) on a Port Byron silt loam. Trials were planted on May 12, 2017 with a 4-row John Deere 7000 planter equipped with cone units. The seeding rate was 150,000 seeds per acre with seed planted at a depth of 1.5 inches in 30 inch rows. Plots were four rows wide by 22 feet in length and the center two rows of each plot were machine harvested on October 20, 2017.

Nutrient Management Podcast: Manure & Nutrient Availability

Nora Nolden, Communications Specialist
We're back with another Nutrient Management Podcast episode. This month, it's all about manure and nutrient availability. Fabian Fernandez, Dan Kaiser and Paulo Pagliari are joined by Extension's new manure management specialist, Melissa Wilson.

Manure and Nutrient Availability

Fabian Fernandez, Dan Kaiser, Paulo Pagliari and new manure specialist Melissa Wilson talk all things manure on this episode. Hear about sampling, application recs, best practices and more.

Resources from this episode:

MPC rate application guide: https://www.pca.state.mn.us/sites/default/files/wq-f6-26.pdf

UMN Extension manure land application website: https://extension.umn.edu/manure-management/manure-land-application

For more the latest on nutrient management, follow us on facebook at facebook.com/UMNNutrientMgmt or Twitter at twitter.com/UMNNutrientMgmt

Oct. 5 Sauk Centre Hay Auction

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties, Crop Systems Focus, 320-968-5077, marte011@umn.edu

Click on Links to my summaries from the Oct. 5, 2017 Sauk Centre Hay Auction.

1. Oct 7, 2017 Summary - All tested loads sold, groups based on hay and bale type and quality.

2. History of Selected Lots. Averages from recent years, and summer and fall sales so far.

3. Graph of Selected Alfalfa hay groups.
The 2016-17 season is the RED line.
I’m marking Summer, Sept, Oct 7 sales with a VERTICAL LINE indicating high, low, average.
I’ll start a 2017-18 new red line after the Oct 21 auction.

Harvest Note: It takes about 0.02 gallons of LPG per point of moisture removal per bushel to dry corn.

Five Tips for Getting the Most out of Fall Soil Sampling

Dan Kaiser, Soil Fertility Specialist

1. Sample at the correct depth
We calibrate soil test results to a specific sampling depth, so it's important to get this right. Immobile plant nutrients tend to accumulate near the soil surface, so shallow sample depths can inflate results. For immobile nutrients and soil pH, sample at zero to six inches. For fall nitrate, sample at zero to 24 inches.

Corn harvest, drying, storage challenging this year

Ken Hellevang, North Dakota State University Extension Service, and Dave Nicolai, UM Extension
Each year brings challenges for crop production, North Dakota State University Extension Service grain drying expert Ken Hellevang warns.

The U.S. Department of Agriculture estimates that 82 percent of the Minnesota corn crop is mature compared with a five-year average of 93 percent. As of Oct. 15, only 7 percent of the Minnesota corn crop had been harvested, compared with a 38 percent average.

Inhibitors for Fall Nitrogen Application

Jeff Vetsch, Soil Scientist

Soil temperatures are dropping and moving toward the 50 degree threshold for fall nitrogen applications. If you’re thinking about fall applications, should you use an inhibitor? Our research shows that nitrification inhibitors can protect fall nitrogen against loss and increase the amount of nitrogen present in the ammonium form the following spring, as long as best practices are followed.

UMN Extension Debuts Nutrient Management Podcast

Nora Nolden, Communications Specialist

University of Minnesota Extension's nutrient management team has a new way for you to hear the latest nutrient management research, timely news and seasonal information. Once a month, the team will share the most up-to-date trends and information on what we're seeing in fields across Minnesota.

Sept 21 Sauk Centre Hay Auction Summary

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties, Crops Focus, 320-968-5077, marte011@umn.edu

Links are listed for summaries of Sauk Centre hay auction information for September 21.

1. Sept 21, 2017 Summary - All tested loads sold, groups based on hay and bale type and quality.

2. History of Selected Lots NOW INCLUDES AVERAGES FOR SEPT 2016 through MAY 2017, along with previous years.

3. Graph of Selected Alfalfa hay groups.

The 2016-17 season is the RED line. I'll start a new Line in October.

I’m marking Summer and September with a VERTICAL LINE indicating high, low, average.

SMALLER LOAD NUMBERS MAY NOT REPRESENT THE MARKET AS WELL. Compare to other market information. Remember your livestock and crop budgets are the key to what you pay or accept for hay.

MFA Winter Forage Workshops are being planned again for:
SE MN January 30
Central MN January 31
If you have suggestions for topics or speakers, please let me know.
NE MN February 1

MORE HAY MARK…

Here's What the Latest Research Says about Micronutrients

Daniel Kaiser, Extension Soil Fertility Specialist

Micronutrients are elements essential to plant growth and development, but in smaller amounts than the big nutrient players like N, P and K. Where the big guys get taken up in pounds per acre by the plant, we measure micronutrient uptake in ounces per acre. Though they may seem inconsequential in the grand scheme of things, micronutrients can significantly affect yield if they’re deficient in the plant. Researchers have identified boron, chlorine, cobalt, copper, iron, manganese, molybdenum, nickel and zinc as micronutrients required for plant growth.

The 50 Degree Rule, Inhibitors and MAP and DAP

On this episode of the Nutrient Management Podcast, Dan Kaiser, Fabian Fernandez and Jeff Vetsch talk all about fall fertilizer. Find out when to apply, what source to use and if you should use an inhibitor. Also, how should you be thinking about nitrogen credits with MAP or DAP fertilizers? Plus, thoughts on Minnesota's proposed nitrogen rule.

For more the latest on nutrient management, follow us on facebook at facebook.com/UMNNutrientMgmt or Twitter at twitter.com/UMNNutrientMgmt

How to Estimate Nitrogen Loss from Leaching

Brad Carlson, Extension Educator

The nitrogen cycle dictates the form and movement of nitrogen in the soil and in plants. Given adequate time and temperature, nitrogen in the soil will convert to the nitrate form, which is susceptible to loss in two pathways: denitrification, which happens in saturated soils that lack oxygen, and leaching, which happens when water moves through the soil, taking nitrate with it.

Think of the soil and the different forms of nitrogen as the charged ends of a magnet. The nitrate form of nitrogen is negatively charged, so it is not attracted to the negatively charged clay particles in the soil. This means it does not adsorb to clay particles, leaving it “loose” in the soil and subject to move with water. Though we can’t determine the exact extent of nitrate movement through leaching, we can estimate it.

Herbicides alone cannot adequately manage herbicide-resistant weeds -- Thoughts regarding planning for next year's soybean crop

Jeff Gunsolus, Lisa Behnken and Fritz Breitenbach
As we enter the fall harvest, many will be evaluating what soybean variety to select for next year. No longer is the focus solely on yield and tolerances to disease, iron chlorosis, and nematodes. This fall, farmers, consultants and advisors will be asking questions regarding how label modifications, if any, to the newly introduced dicamba formulations of Xtendimax, FeXapan, and Engenia might affect their variety selection decisions. The conundrum is that discussions at EPA and State Departments of Agriculture assessing the impact of this year’s off-target events on next year’s label will likely extend well into the fall. As you strategize future weed management plans, we would like for all of us to rethink the dicamba issue. Think about what brought on this issue in the first place: weed resistance to multiple groups of herbicides.

Sept. 7 Sauk Centre Hay Auction Summary

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties, Crops Focus, 320-968-5077, marte011@umn.edu

Click on Links to my summaries from the Sept 7, 2017 Sauk Centre Hay Auction

1. Sept 7, 2017 Summary - All tested loads sold, groups based on hay and bale type and quality.

2. History of Selected Lots NOW INCLUDES AVERAGES FOR SEPT 2016 through MAY 2017, along with previous years.

3. Graph of Selected Alfalfa hay groups.

The 2016-17 season is the RED line.

I’m marking Summer and September with a VERTICAL LINE indicating high, low, average.

SMALLER LOAD NUMBERS MAY NOT REPRESENT THE MARKET AS WELL. Compare to other market information. Remember your livestock and crop budgets are the key to what you pay or accept for hay.

MORE HAY MARKET INFO:


Everything You Need to Know Before Applying N This Fall

Fabián G. Fernández, Extension nutrient management specialist

It’s that time of year again. Fall is upon us and harvest is just around the corner. There are big decisions to make when it comes to fall nitrogen. Should you apply? If so, when? What form of N should I apply? Should I use an inhibitor? We’ve rounded up our most frequently asked questions about fall applications and the answers are all right here.

Your Guide to Foliar Nutrient Applications -- With Video!

Dan Kaiser, Extension Soil Scientist

When crops are actively growing in the mid- to late part of the season, they demand greater quantities of nutrients on a daily basis. Immobile nutrients applied to the soil surface can face difficulty getting down to the roots where they’ll be taken up. When looking at in-season corrective measures, foliar fertilization has been growing as the go-to option for growers to supply those nutrients.

While foliar applications are a helpful management tool for in-season applications, there is a risk for crop damage if applied incorrectly. Here’s a look at the how-tos and limitations of foliar fertilization.


Rotation and nitrogen management are keys to optimizing corn production following alfalfa

Jeff Coulter, Extension corn specialist
Corn grown after alfalfa usually has increased yield, reduced nitrogen requirement from fertilizer or manure, and reduced pest pressure compared to when following other crops. The extent and consistency of these benefits in first- and second-year corn are influenced by the effectiveness of alfalfa termination and nitrogen management.

June July Aug Hay Auction Summaries, Sauk Centre

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties, 320-968-5077, marte011@umn.edu

Links are noted for Information Listed:

1. June 1 Hay Auction Summary - All tested loads sold, groups based on hay and bale type and quality.

2. July 6 Hay Auction Summary - Some lots in a group have the same test results. It might be that 2 or 3 loads came from the same field and one test was taken for them.

3. Aug 3 Hay Auction Summary

4. History of Selected Lots - INCLUDES AVERAGES FOR SEPT 2016 through MAY 2017, along with some previous years.

5. Graph of Selected Alfalfa hay groups.

The 2016-17 season is the RED line now.
I marked the June, July, August markets with a VERTICAL LINE indicating high, low, average.
SMALLER LOAD NUMBERS MAY NOT REPRESENT THE MARKET AS WELL. Read more for other market sources, a Corn Silage Note, Note on an Extension Beef Tour in Morrison County Sept 6, and a Strip Till Expo Sept 6 near Fergus Falls.

Post-Tassel Nitrogen, Tissue Sampling and Luxury Uptake

Welcome to University of Minnesota Extension’s first ever nutrient management podcast. Every month we’ll bring you the latest nutrient management information for farmers in Minnesota and across the Midwest.

On this podcast, Extension soil scientists Dan Kaiser and Fabian Fernandez talk about post-tassel nitrogen applications, more effective tissue sampling and luxury nutrient uptake.

Trends from the 2017 Growing Season

Daniel Kaiser, Extension Soil Scientist

Throughout the 2017 growing season, we’ve seen a few trends in nutrient management that stand out. By taking a look back at our observations, we’re better able to plan for the future, observing what worked and what didn’t. Here’s a look at the stand out trends of 2017.




Iron Deficiency Chlorosis 

2017 has been a banner year for iron deficiency chlorosis (IDC) issues. IDC is greatly impacted by the weather. Cool and wet soils can increase issues, but not all soils prone to IDC will produce it in soybean plants.

Field studies: What do you mean 5 bushels per acre is not significant?

By Lizabeth Stahl, University of Minnesota; Sara Berg, South Dakota State University; Josh Coltrain, Kansas State University; John Thomas, University of Nebraska Lincoln

Tillage plots at the Southwest Research and Outreach Center, Lamberton, MN. Photo: Liz Stahl Utilizing sound research results to help make decisions on the farm is a wise business practice. It can be confusing, however, when you see two numbers that are clearly not the same labeled as "not significantly different." One can quickly calculate the value of a few bushels per acre over hundreds of corn or soybean acres. It is key to look at just what this terminology means and its practical importance when using this information to make decisions.

Study finds intensified nutrient management can improve corn yield

Jeff Coulter, Extension Specialist, Corn-Based Cropping Systems
Jeff Vetsch, Soil Scientist

Across the world, corn producers and their advisors have been working toward shrinking the exploitable yield gap – the difference between attainable yields and yields under current farmer practices – by increasing their management intensity. In a new study, research evaluated increased management intensity with the goal of ecological intensification and how those practices compared with standard practices.

Use small grain stubble fields to boost forage supply

By: Jared Goplen and Eric Mousel

Photo 1: Forage cover crops have the potential to reduce feed costs. Photo: Eric Mousel. Now is the prime time to be seeding small grain stubble fields with a cover crop to be grazed this fall, winter or next spring. One of the many benefits of incorporating small grains into the crop rotation is the ability to get a forage cover crop established by the end of August, which is a great way for beef and dairy producers to add value to their crop fields by extending the grazing window or adding to the forage supply.

Mow fenceline weeds now to prevent seed production

By: Jared Goplen and Dave Nicolai

Photo 1: Mow fencelines now to minimize deposits to the weed seed bank. Photo: Jared Goplen. As summer field activities wind down, harvest will soon be in full swing. Take the time now to mow fenceline weeds to prevent or minimize seed production. Fencelines are often where weed infestations start. By eliminating fenceline weeds, we prevent combine harvesters from picking up weed seeds from the field edges and pulling them into the field, where they can be further spread by harvesting and tillage equipment.

Update: Wheat Stem Sawfly infestation levels found in Polk County

prepared by Phillip Glogoza, Jochum Wiersma and Ian McRae

Wheat stem sawfly (WSS) are being found at significant levels in Polk County. Field surveys were conducted from August 14 to 18, 2017 to learn more about the levels of infestation and the possible size of the area impacted. 

The inspected fields had infestations on the field margins ranging from a low of 0 to a high of 15 WSS/row foot. Every field inspected had fewer infested stems as sampling moved further into the field. Edge effects are pretty strong with this insect as they overwinter in stubble and migrate to nearby wheat the next year.

Your Guide to Profitable Sulfur Fertilization in Spring Wheat

Dan Kaiser, Extension Soil Fertility Specialist

The major cause of sulfur deficiencies in crops is a lack of mineralized S in the soil. Research and recommendations in Minnesota have shown well-documented yield increases for corn with the application of sulfur, but what about wheat? Recent research funded by the Agricultural Fertilizer Research and Education Council and the Minnesota Wheat Research and Promotion Council shows us that sulfur applications can benefit wheat yield and protein concentration. Here are some tips and recommendations for sulfur applications in spring wheat based on that research.




Factors influencing dicamba volatility

Jeff Gunsolus, Extension weed scientist
Earlier Crop News articles focused on dicamba’s potential routes of injury, injury symptomology, soybean sensitivity and yield loss potential. In this article, I would like to explore in greater detail the factors that could contribute to dicamba volatility's role as a potential route of injury. I will be working off the assumption that the primary cause of dicamba volatility is due to degradation of the new dicamba formulations to dicamba acid, dicamba’s most volatile form. A 1979 Weed Science publication by Behrens, R. and W. E. Lueschen titled "Dicamba Volatility" will serve as my reference (Weed Sci. 27:486-493).

Target weeds after small grain harvest

By Jared Goplen, Tom Peters, and Dave Nicolai

Waterhemp in a wheat stubble field in Ottertail Co., Minnesota. Photo: Dave Nicolai One of the many benefits of including small grains in crop rotations is improved broadleaf weed control and breaking up weed lifecycles. Although freshly harvested small grain fields have a clean look, they often have weeds hiding in the stubble. The most prominent weeds in stubble fields are often late-emerging weeds like waterhemp and other pigweed species that emerged after early season herbicide applications were made. Control escaped weeds now to prevent seed production and weed seed bank replenishment.

When good butterflies go bad

Bruce Potter, IPM specialist and Bob Koch, Extension entomologist

Photo 1. Thistle caterpillar leaf feeding and webbing. Photo: Bruce Potter The second 2017 MN generation of thistle caterpillars continue to cause concern in some soybean fields. Most of the reports of Minnesota high populations are from SW, SC, C, and the WC part of the state.

Adults and egg-laying are now tapering off but more than two weeks of painted lady butterfly egg-laying activity means that there is a wide range of larval sizes out there.

Wheat Stem Sawfly Causing Problems in Polk County Wheat Fields

Prepared by Phillip Glogoza, Jochum Wiersma and Ian McRae

Figure 3. Wheat stem sawfly cut stems were so extensive, the cut stems could be picked up as a bundle on the edge of this wheat field west of Crookston, MN. As wheat harvest moves northward, we are detecting infestations of Wheat Stem Sawfly in fields in Polk County. Recent storms and strong winds have helped bring these problems to front and center.

Farmers have noticed lodged stems, particularly on field margins, where in some cases plants are 100% lodged for 50+ feet from the edge inward. In those cases, the cut stems could be grabbed and picked up in a bundle (Figure 3) and the stubble below was all cut (Figure 4). As we inspected the interior of these fields, the percent lodging, declined, but there was still evidence of Wheat Stem Sawfly damage.

What the Research Says About Post-tassel Nitrogen Applications

Fabian Fernandez, Nutrient Management Specialist
Paulo Pagliari, Soil Scientist

Optimal nutrient application timing can be hard to nail down. Should you apply everything at the beginning of the season? Sidedress? If so, when? Many people wonder about nitrogen applications late in the season, even after post-tassel, as a way to increase yield. The basic thinking is that the crop still needs to take up half of its total N at this point in the growing season. The truth is, in locations with a shorter growing season, like Minnesota, we have no evidence that post-tassel N applications have any advantage.

Response of soybean yield to dicamba exposure: A Research-based report

by Jeff Gunsolus, Extension weed scientist

Xtendimax drift onto non dicamba-tolerant soybean. Photo: Liz Stahl As you continue to assess and document the impact of dicamba injury on soybean yield, I thought it would be timely to make you aware of an excellent summary of Dr. Andy Robinson’s research conducted when he was a graduate student at Purdue University. This summary came from Purdue Extension and was authored by Joe Ikley and Bill Johnson: https://z.umn.edu/2vhs

The published manuscript can be accessed at: https://z.umn.edu/dicamba-purdue

Late season weed escapes in soybeans? What Now?

By Jared Goplen, Dave Nicolai, Lisa Behnken, Jeff Gunsolus

Giant ragweed escapes in soybean. Photo: Dave Nicolai Despite your best weed-control efforts this year, you still ended up with patches or fields with weeds coming through the crop canopy. Now that August has rolled around, what options are available to control weeds and prevent them from going to seed? What can we do differently to prevent this problem next year? August is a good time to evaluate your current weed management plan and develop strategies for next year.

Assessing and documenting yield loss due to dicamba injury in soybean

by Jeff Gunsolus, Extension weed scientist

Photo 1. Leaf cupping symptoms of dicamba injury in soybean. Photo: Bruce Potter As we enter August, the big unknown in fields presenting dicamba injury symptoms will be dicamba’s impact on soybean yield. Unfortunately, due to the sensitivity of non-Xtend soybeans to dicamba, injury symptoms are not reliable indicators of yield loss. The level of yield loss depends on exposure at vegetative or reproductive stage of growth, persistence of injury symptoms, and growing conditions post-exposure.

Research Shows N Rate in Sweet Corn Higher than Current Recommendations

By Carl Rosen, Professor and Head Department of Soil, Water and Climate
Vince Fritz, Professor, Horticultural Science

New research conducted at the Southern Research and Outreach Center in Waseca shows that the optimal N application rate for new sweet corn hybrids following soybeans in non-irrigated, on medium- to high-organic matter soils is higher than the current recommended rate of 110 lbs N/ac.

Pyrethroid resistant soybean aphids: What are your control options?

Bruce Potter (Extension IPM Specialist, U of MN), Robert Koch (Extension Entomologist, U of MN), Phil Glogoza (Extension Educator – Crops, U of MN), Ian MacRae (Extension Entomologist, U of MN), and Janet Knodel (Extension Entomologist, NDSU)

We are receiving an increasing number of reports of pyrethroid insecticide failures for soybean aphid management from northwest and central Minnesota, and northeastern North Dakota this year. However, many areas of Minnesota and North Dakota still have low, non-yield threatening aphid numbers and scouting should continue to determine when to apply insecticides.

In this article, we review the insecticide groups used for soybean aphid control (Table 1) and discuss the potential role of and challenges associated with insecticide mixtures.

Uncovering dicamba herbicide's wayward ways

by Jeff Gunsolus, Extension weed scientist

Leaf cupping symptoms of dicamba injury in soybean. Photo: Fritz Breitenbach Dicamba injury to non-target soybeans has been widely reported in south central and southwest Minnesota. Symptoms range from cupping and strapping of newly emerged leaves to height reduction and injury to growing points. At low dicamba concentrations, symptoms were slow to emerge, showing up 14 to 21 days after exposure. The big unknown, of course, will be impact on soybean yield, which will require negotiations now to determine the most accurate in-field yield comparisons later.

Estimating Grain Small Grains Grain Yields

The USDA-NASS' July 1 yield forecasts for barley, oat, and spring wheat were 67, 71, and 61 bushels per acre, respectively.  This would mean a new state record for spring wheat, while the forecast for barley and oats are 10 and 7 bushels off the records set in 2015.

To estimate yield the USDA-NASS collects farmer's assessment of yield prospects throughout the growing season, i.e. the USDA-NASS asks producers to predict their final yield. At first glance, this may seem a bit unscientific and not very accurate. The statistical methods that are used to crunch the collected data and have it confess a forecast, however, are robust and because enough producers are surveyed, the forecasts have been proven predictive at the aggregate level.  This is, in a way, a testament that you each know you crop and operation pretty well. The completely methodology can be found here.

Luxury Uptake of Boron: How Much is Too Much?

By Dan Kaiser, Extension Soil Fertility Specialist
The ultimate goal of nutrient management is to ensure that the plant has enough nutrients to produce maximum potential yield. This involves monitoring soil nutrients and crop uptake, and often supplementing nutrients that the crop is lacking. But what happens when the plant takes up more than enough of a certain nutrient? That’s called luxury uptake. Though it isn’t usually a problem for crops, it can become an issue if a nutrient reaches toxic levels in a plant. In Minnesota, the main concern is with Boron in soybeans and other broadleaf plants.

Soybean aphid infestations and reports of failures of pyrethroid insecticides to control soybean aphid

Robert Koch (Extension Entomologist), Ian MacRae (Extension Entomologist), Bruce Potter (Extension IPM Specialist), and Phil Glogoza (Extension Educator – Crops)
By now you should be scouting your soybean fields for soybean aphid on a regular basis.Soybean aphid can be found in most fields throughout the state and populations have reached economic threshold (250 aphids per plant) in some fields in northwest Minnesota and have require insecticide application to protect soybean yield.In northwest Minnesota (especially around Norman County), applications of pyrethroid insecticides are failing to adequately control aphid populations in some, but not all, fields.

The Dicamba Dilemma: Facts and speculations

Used with permission by Aaron Hager, University of Illinois

Dicamba injury to soybeans in a southwestern Minnesota field. Photo: Stephan Melson Dicamba injury to non-target crops has dominated Extension discussions this week. Non-tolerant soybeans are extremely sensitive to this chemical and damage has been reported in a number of fields throughout the state. The following article by Dr. Aaron Hager at the University of Illinois echoes observations we have been making in Minnesota and summarizes injury symptoms on soybean, possible routes of exposure, and potential yield effects. His article is reprinted in its entirety:

Hay Rake Impacts Ash Content in Alfalfa Hay

Abby Neu, Craig Sheaffer, Scotty Wells and Krishona Martinson, University of Minnesota; Marvin Hall and Dan Kniffen, Pennsylvania State University; and Dan Undersander, University of Wisconsin.
Summary: Using a hay merger or sidebar rake to combine swaths resulted in less ash content compared to a wheel rake; however, rake-type rarely resulted in differences in forage nutritive value. In addition to wide swaths, cutting heights ≥2 inches, and flat mower knives, the use of a hay merger or sidebar rake can be added to the list of best management practices to reduce ash content in alfalfa hay.

Pre-harvest Management of Small Grains

To save time and money most of you prefer to straight cut your wheat, barley, rye or oats.  The allow for straight cutting the crop has be evenly ripe across the field and the straw and grain has to be dry enough that it will feed through the combine.

Waiting for a whole field to dry down poses a risk for the portion of the field that is already harvest ripe, including sprout damage, straw breakage and lodging. To even out dry-down and/or speed up dry-down you have two basic options. Swathing or windrowing, at one time, was the default operation that signaled the beginning of harvest.  A second preharvest option is an application of glyphosate at the hard dough stage.

Glyphosate is labeled as a harvest aid to control late emerged weeds that may interfere with harvest. The RoundUp PowerMax II  label doesn't define it as a desiccant. Research has shown that glyphosate applied with or without ammonium sulfate may hasten drydown of the wheat crop if conditions for drydown are adverse.…

White Heads

Jochum Wiersma, Ian MacRae, and Madeleine Smith Is not the reincarnation of the Detroit rock due the White Stripes but a phenomenon that often can be seen this time of year in wheat fields are they are starting to ripen.  The causes of these premature ripened heads are varied and a diagnostic key can be found here.

People of commented that especially the wheat stem maggot is more prevalent this year and my travels to the different field trials across the state confirm this. The seemingly high numbers of wheat stem maggot may be related to the mild winter conditions.  Several insect pests that overwinter in Minnesota have had comparatively high and early populations this year.

Incidence will generally be worse along field edges and taper off as you walk further into the field.

4 Steps to More Effective Tissue Sampling

Daniel Kaiser, Extension Soil Fertility Specialist

For over 50 years, the practice of plant tissue sampling has been used to determine the status of nutrients in crops. More recently, there has been a movement to use tissue sampling to determine “hidden deficiencies” in the crop. While tissue analysis represents just one tool in the toolbox for managing nutrients and should be viewed like a report card, it can provide useful information in diagnosing problems when done properly. Here are the 4 things you need to make the most out of tissue analysis.

Field Studies: Setting up a Trial

Josh Coltrain, Kansas State University; Sara Berg, South Dakota State University; Lizabeth Stahl, University of Minnesota; John Thomas, University of Nebraska Lincoln

Photo 1. Example of an on-farm trial. Higher yields, greater efficiency, reduced environmental impact!  This may sound like a used-car dealership sales pitch, but it could represent the objectives that make an operation sustainable. Increasingly, farmers are generating on-farm research data that encompass a wide-range of practical topics.  However, setting up those experiments so that the data is statistically valid is not necessarily common knowledge.

Short(er) Spring Wheat Crop = Lower Grain Yield?

Some of you have noticed and commented that the spring wheat crop is shorter when compared to the last few years and subsequently questioned its yield potential. A few weeks ago, Dr. Joel Ransom wrote a nice article in the Crop & Pest Report explaining why the spring wheat crop was shorter and whether its yield potential had already been reduced.  
The physiology of grain fill has been well researched and we have a good understanding how temperature and droughts tress affect grain fill and grain quality. Table 1 summarizes the results of one of the published studies that illustrates how daytime and nighttime temperatures affect the length of the grain fill period and ultimately yield. The bottom-line is that higher nighttime temperatures are more detrimental than the maximum daytime temperatures.
Just in the last two days has the grain fill suffered some heat-stress, as maximum temperatures had not yet reached above 85F in the two weeks prior while minimum temperatures were mostl…