Skip to main content


Showing posts from September, 2021

Sulfur fertilizer and corn production: What to know

Long-term sulfur trial at Waseca:  Continuous corn. 2021 is the third year at Waseca. Listen to the podcast to learn more. In  this episode  of the Nutrient Management Podcast, three U of M researchers discuss sulfur. How has atmospheric sulfur deposition changed over time and why does it matter for farmers? How did the dry conditions this year impact sulfur availability? Do dry soils mean sulfur responses will be greater?  Do dry soils affect which source of sulfur growers should use?  What do we know about interactions between sulfur and other nutrients?  What should farmers thinking about applying sulfur for the 2022 crop keep in mind? Listen to the podcast View the podcast transcript Guests: Dan Kaiser, Extension nutrient management specialist Paulo Pagliari, Extension nutrient management specialist - Lamberton Jeff Vetsch, researcher, Southern Research and Outreach Center - Waseca Additional resources: Fertilizer recommendations by crop Sulfur for Minnesota soils Video: What sourc

Fall cutting alfalfa in 2021

By: Craig Sheaffer, UMN Forage Professor and Jared Goplen, UMN Extension Educator, Crops Fall cutting can disrupt the fall dormancy reaction of adapted alfalfa varieties. Alfalfa is a perennial plant that depends on fall dormancy to prepare for winter survival. Shortening daylength and declining temperatures in the fall triggers alfalfa to undergo a dormancy reaction that decreases herbage production and develops crown buds—the source of the first spring regrowth (Figure 1). Alfalfa metabolism also changes to increase starch storage, increase sugar content, alter protein metabolism, and decrease free water in the plant cells all in preparation for winter (Figure 2). Disruption of the dormancy reaction by cutting or grazing in September to early October (depending on region), affects alfalfa winterhardiness and its survival. Plants cut during this sensitive time stop storing energy and instead expend energy on regrowth. Crown buds that would normally overwinter and regrow in the spring

Prevent stored grain pest issues before winter

Anthony Hanson, Extension Educator - Field Crops  Integrated Pest Management David Nicolai, Extension Educator -  Institute for Ag Professionals Program Coordinator Late summer and early fall is time ensure infested and spoiled grain in bins from previous harvests won’t cause more problems for this year’s harvest.  Over the summer, insect infestations may have grown in grain bins, especially in areas where spoiled grain accumulated even after being mostly emptied (Fig. 1). Keeping good sanitation practices prior to putting the next harvest into storage will help break pest cycles and reduce the likelihood of issues with spoilage or price docking at the elevator. Once grain is in the bin, options to manage existing insects are very limited, especially grain that is going to be stored through the following spring or summer. Figure 1. Insect feeding damage in spoiled corn. Photo: A. Hanson Integrated pest management for insects in stored grains is closely tied to sanitation to also preven

To seed or not to seed a cereal rye cover crop yet this fall

Cereal rye seeded with a drill 9/17 after corn silage harvest at Rosemount in 2020.  Picture was taken on 11/6, or 7 weeks after seeding.  Photo: Liz Stahl/U of M Extension By: Liz Stahl & Jared Goplen, Extension educators - crops Earlier this season, a lack of soil moisture across much of the state raised concerns about the potential for successful cover crop establishment this fall. Most areas still need more moisture to recharge the soil profile but recent rains have improved the moisture status overall. This has also improved the likelihood for successful establishment of a cereal rye cover crop this fall. One of the best fits for a cereal rye cover crop is following harvest of corn silage, a small grain, or a canning crop when going to soybean the next year. These rotations provide a wider window for establishment before frost, setting the rye up for increased growth in the spring. In a corn/soybean rotation, seeding cereal rye after corn, either after harvest or once c

Potassium needs for corn and soybean: Could soil clay type play a role?

By: Dan Kaiser, Extension nutrient management specialist & Leanna Leverich, graduate research assistant Potassium (K) is needed by all plants and potassium deficiencies can significantly reduce crop yield. While the chemistry of potassium in soils is relatively simple, K availability can be significantly impacted by environmental conditions. If soils are dry, K deficiencies can occur. Plant roots need water to efficiently draw K from the soil, which has been in short supply the last two years . But there are other things that can impact K availability as well. Cation exchange capacity Potassium is taken up by plants as the potassium anion (K+). Cation exchange capacity (CEC) , or the soil’s ability to hold cations, including the K+ ion, can also impact K availability. The soil’s CEC is influenced by the abundance and type of clay present. Most of Minnesota’s soils are classified as “mixed” clay mineralogy, but most farmers’ fields are dominated by one clay type. Soils high in illit

5 tips for continuous corn nutrient management

By: Dan Kaiser, Extension nutrient management specialist, & Jeff Coulter, Extension corn agronomist When it comes to nutrient management, continuous corn can present challenges. Research has identified a few things that you should consider when managing continuous corn to maximize yield and profitability. 1. Residue management is key Probably the biggest challenge when it comes to managing continuous corn is the amount of residue that can be left in the field. Corn residue can be slow to break down and tends to be high in carbon and low in nutrients, like nitrogen (N), which are needed for soil organisms to break the residue down.  More N is suggested when corn follows corn compared to corn following soybean to account for less available N from the soil due to N being used for microbial decomposition. The application of N as UAN or sulfur (S) as ATS in the fall has been studied as a means of speeding up residue decomposition, but it has not been found to be effective. 2. Do not st

Be on the lookout for Palmer amaranth

Jared Goplen, Extension educator-crops and Debalin Sarangi, Extension weed specialist Palmer amaranth in a Tennessee field. Note the long terminal seedhead. As we approach harvest this year, be on the lookout for Palmer amaranth, September's Weed of the Month . Palmer amaranth is on Minnesota’s prohibited noxious weed and seed list with the intention to eradicate it before it becomes widely established in the state. Now is a good time of the year to scout for it, when mature Palmer amaranth plants are easier to distinguish from other closely-related pigweeds like waterhemp. Identification is key Palmer amaranth is closely related to other amaranth (pigweed) species and it can be challenging to differentiate between them during the early vegetative stages. When scouting for Palmer amaranth at this time of year, be on the lookout for pigweeds with these distinguishing characteristics:  Look for long, terminal seedheads or pollen heads, up to 2-3 feet long, which are usually longer

Soil management and nutrient issues

In  this episode  of the Nutrient Management Podcast, three U of M researchers discuss soil management and nutrient issues. How do erosion and tillage practices impact nutrients in the soil and nutrient management?  After a dry spring and summer, what should growers know about soil and nutrient management heading into the fall?  How can farmers better manage soils to avoid nutrient issues? Are cover crops a good idea this year? Thank you to Minnesota's Agricultural Fertilizer Research and Education Council (AFREC) for supporting the podcast.

Fall 2021 soil testing considerations for the 2022 growing season

By: Dan Kaiser & Fabian Fernandez, Extension nutrient management specialists On top of limiting the yield potential of crops, dry soils also have other important impacts which need to be considered when making nutrient management decisions for future years. Here are few tips to keep in mind when taking soil samples and interpreting soil test results this fall to help make decisions for the 2022 growing season. 1. Pay attention to soil sampling depth With dry soils, soil sampling depth can be an issue. As this video covers, a standard series soil test is calibrated for the top six inches of soil, so it isn’t a good idea to scrape off the soil surface or go deeper than six inches. There are other measurements that call for a deeper sample, such as for nitrogen analysis, but for most purposes you want to stick to six inches. It also may be difficult to take the appropriate number of soil cores needed to get a good, representative soil sample. Sticking to the appropriate sampling dept

Nutrient Management Strategies Field Day - Friday, Sept. 10

Join us on Friday, September 10  near Le Sueur for the Nutrient Management Strategies Field Day. This event will highlight the various ways that livestock manure can be successfully and economically implemented into your cropping system. The events begins at 10am and goes until 12pm (noon), followed by a free lunch . Registration Registration is free. To register, email Emma Severns at  or call your Extension office (Nicollet County 507-934-7828 or Sibley County 507-237-4100). Location The event will take place on Dave Pfarr's farm at 40899 320th Street, Le Sueur, MN 56058 (Driveway east of location). Details Extension manure management specialist Melissa Wilson will present on her on-farm study on one of Pfarr's fields looking at sidedressing liquid swine manure into corn. The study is assessing what corn growth stage is optimal for sidedressing swine manure with a tanker system. SROC soil science researcher Jeff Vetsch will present on manure research includi

Got weeds in your beans? You're not alone

 Seth Naeve, Extension soybean agronomist, Jared Goplen and Dave Nicolai, Extension educators - crops Patch of volunteer corn in a soybean field. Volunteer corn, a weed in soybeans, competes for resources, adds foreign material to the harvested soybeans, and minimizes crop rotation benefits. Photo: Jared Goplen It’s been a memorable year for Minnesota soybean producers, but mostly for the wrong reasons. Dry conditions were problematic most of the year. Soybean emergence was affected by dry soil conditions in some fields. Preemergence herbicides laid dormant until rainfall and hot and dry conditions favored weed development over the crop. Dry soils this spring also delayed weed emergence of some weeds until later in the season. Poor canopy development has allowed waterhemp, volunteer corn, and other weeds to establish and poke out of the canopy in fields statewide. Do these weed escapes really matter? While farmers all strive for clean fields, it is likely that the sporadic escaped

Planning the rotation from alfalfa to corn

Jeff Coulter, Extension corn agronomist Photo: Matt Yost Alfalfa provides many benefits to the corn crops that follow it, with the most notable being higher yield and reduced need for nitrogen (N) application compared to when it is grown in other rotations.  Across 15 years at one location in southwestern Wisconsin and 21 and 30 years at two locations in northern Iowa , grain yield of first-year corn following alfalfa averaged 8 to 18% greater than that of continuous corn and 0 to 8% greater than that of corn following soybean (Mallarino and Ortiz-Torrez, 2006; Stanger and Lauer, 2008).  Additionally, grain yield of second-year corn following alfalfa averaged 0 to 8% greater than that of continuous corn, but 2 to 8% less than that of corn following soybean. Higher yields for first-year corn following alfalfa, and sometimes second-year corn following alfalfa in these experiments may have been due to improved soil aggregation and soil infiltration rate, and a reduction in soil compaction

When is the best time to stop irrigating for the season?

By: Vasudha Sharma, Extension Irrigation Specialist The last few irrigations of the season are as critical as the first ones to obtain optimum crop yield. Excess water in the crop root zone later in the season beyond maturity could result in yield loss and therefore reduced profits. Though it is important to provide adequate soil moisture in the root zone to carry the crop to maturity without reducing yields, the soil moisture can be depleted up to 60-70% of available water when nearing maturity, which will minimize the water supply needs, fuel and labor for the season, allow the off-season precipitation to recharge the soil profile and reduce the potential for leaching nutrients below the root zone. An additional benefit of maintaining low soil moisture at the end of the season is reducing harvest delays due to muddy soil conditions. For irrigation management late in the season, you will need to know the current crop growth stage and predicted crop maturity date, predicted rate of wat


In  this episode  of the Nutrient Management Podcast, three U of M researchers discuss sulfur. How has atmospheric sulfur deposition changed over time and why does it matter for farmers? How did the dry conditions this year impact sulfur availability? Do dry soils mean sulfur responses will be greater?  Do dry soils affect which source of sulfur growers should use?  What do we know about interactions between sulfur and other nutrients?  What should farmers thinking about applying sulfur for the 2022 crop keep in mind? Thank you to Minnesota's Agricultural Fertilizer Research and Education Council (AFREC) for supporting the podcast.

Pre-harvest considerations for corn

Jeff Coulter, Extension corn agronomist Corn maturity Photo: Jeff Coulter Corn in many fields in Minnesota is rapidly approaching maturity, while corn in other fields that has been under more severe drought stress has already reached maturity. Corn typically reaches maturity at about 60 days after the start of silking, but this can occur more quickly under drought stress. At maturity, the kernel milk line is no longer visible and there is a black layer at the tip of kernels where they connect to the cob. The black layer can be identified by scratching off tissue at the tip of kernels or cutting kernels lengthwise. Grain moisture and dry-down Corn grain contains around 32% moisture when the kernels first reach maturity. The optimal grain moisture at which to begin corn grain harvest is a balance among many factors, including the risk of ear loss due to stalk lodging or dropped ears, the likelihood of wet weather and its potential for slowing harvest and favoring the development of ear r

Soybean varieties with non-88788 SCN resistance adapted to Minnesota

Aaron Lorenz, Soybean breeder, Senyu Chen, Plant pathologist, Seth Naeve, Extension soybean agronomist, and Bruce Potter Extension IPM specialist Background SCN-resistant soybean variety on left and SCN-susceptible variety on right. The most common source of soybean cyst nematode (SCN) resistance in commercial soybean varieties adapted to Minnesota is PI 88788. Over 90% of the varieties entered into the 2021 UMN Variety trials carried this single source of SCN resistance. The PI 88788 resistance source provides good resistance to some races of SCN. Over time, however, the overuse of this resistance source has led to shifts in SCN populations to those that are able to overcome PI 88788 resistance. There has been increased interest in alternative sources of SCN resistance such as Peking and PI 89772. The commercial availability of these varieties adapted to Minnesota has gradually increased in recent years. However, little independent information is available on their actual resistance t