Minnesota Crop News

Sulfur-deficient corn. Photo: UMN Extension As commercial corn yields continue to climb, optimizing input efficiency is no longer just about deciding how much nitrogen (N) to apply. Today, there is a lot of information out there that focuses on nutrient interactions – specifically the biological partnership between N and sulfur (S). But a common question persists among agronomists and progressive growers alike: If you crank up your nitrogen application rates, do you need to scale up your sulfur rates in tandem? Extension nutrient management specialist Dan Kaiser addressed exactly this question over ten study locations in Minnesota. From 2011 to 2013, Kaiser led a rigorous research project conducted across central and southern Minnesota. By examining leaf chemistry at silking (R1) and nutrient concentration in the harvested grain, the study provides definitive insights into managing this complex nutritional duo. The nitrogen-sulfur partnership: What happens in the plant? Biochemically, ...

University of Minnesota Extension nutrient management specialist Dan Kaiser recently finished a four year study on potassium (K) fertilizer application for corn and soybeans. The study aimed to determine the optimal K rate for both crops, assess if spring application of potash (potassium chloride, KCl) negatively impacts soybean yield (potentially due to too much chloride), and evaluate the accuracy of current plant tissue and soil testing guidelines. About the study The study was conducted from 2022 through 2025 at locations around Minnesota with various soil types. There were six trial locations each year totaling 24 site-years of data. Five K fertilizer rates were tested: 0, 40, 80, 120, and 160 lbs K 2 O per acre. Fall versus spring application timing was compared at each rate. Potassium was applied as potassium chloride (KCl), commonly known as potash. Researchers targeted locations with low soil test K levels, specifically those testing at 150 ppm or less (ideally 100–120 ppm or...

Photo: University of Minnesota Extension By: Daniel Kaiser, Extension nutrient management specialist One thing I hear a lot from people is that sulfate, the form of sulfur available to plants, does not hang around in the soil from one year to the next. In most soils, the rate at which sulfur leaches is much slower compared to nitrogen in the nitrate form (the exception being sandy soils which can quickly leach most nutrients). While it is true that sulfate has a negative charge and can be leached, the rate of leaching really depends on the soil. What does current research say about how sulfate carries over in Minnesota soils? Currently, I have multiple research projects funded by both the Agricultural Fertilizer Research and Education Council (AFREC) and the Minnesota Soybean Research and Promotion Council studying how sulfur carries over in our soils. In my AFREC-funded long-term sulfur trial, we applied sulfur over a period of four years in continuous corn. In year five, we divided t...

Photo: University of Minnesota Extension Today on the Nutrient Management Podcast we're turning our attention to micronutrients. What does current research tell us about micronutrients - for corn specifically - that growers need to consider? Boron is another important micronutrient in Minnesota. What should farmers be aware of regarding boron? Is tissue sampling the answer to help predict where some of these micronutrients are needed? What are other important micronutrient takeaways? All this and much more on today's episode. Read the full transcript Guests & Contact Info: Daniel Kaiser, Extension nutrient management specialist (St. Paul) - email: dekaiser@umn.edu Carl Rosen, Extension nutrient management specialist (St. Paul) - email: rosen006@umn.edu Jeff Vetsch, U of M researcher (Waseca) - email: jvetsch@umn.edu Additional Resources: Micro- and secondary macronutrients Understanding plant analysis for crops Zinc for crop production Are you overspending on fertilizer? I...

On this episode of the  Nutrient Management Podcast , we talk all about fall manure application. What should be on a farmer’s to-do list to prepare for fall application? What names need to be on an operation's emergency response plan, and what kind of PPE should farmers keep nearby? How much lead time does a lab need to return sample results? If a farmer plans to work with a commercial applicator, what can they do ahead of time to ensure a successful season? All of this, plus a farmer Q&A, on-farm research advice, an update on ManureDB and more on today's show. Read the full transcript Guests: Melissa Wilson, Extension manure nutrient management specialist (St. Paul) Chryseis Modderman, Extension manure nutrient management specialist (Morris, MN) Nancy Bohl Bormann, researcher, manure and nutrient management (St. Paul) Eduardo Garay, on-farm research manager, manure management (St. Paul) Additional Resources: How to put together a manure management plan UMN Manure (YouTube)...

In this episode of the Advancing Nitrogen Smart series, our two experts discuss nitrogen pools. What are nitrogen pools, and where do we find them? How is N actually consumed by the plant, and what forms of N will plants take up more readily? What are some potential signs of N deficiency in the plant? How do nitrogen pools relate back to the 4R's, like timing? TRANSCRIPT Guests: Brad Carlson, Extension educator (Mankato) Daniel Kaiser, Extension nutrient management specialist (St. Paul) Additional resources: Will soil microbes deliver nitrogen to my crop? Yes, but not in a predictable way Nitrogen Understanding nitrogen in soils --- Click here to listen to all Advancing Nitrogen Smart podcast episodes. For the latest nutrient management information, subscribe to the Nutrient Management Podcast . And don't forget to subscribe to the Minnesota Crop News daily or weekly email newsletter, subscribe to our YouTube channel, like UMN Extension Nutrient Management on Facebook , foll...

By: Dan Kaiser, Extension specialist Interpreting plant tissue reports can be challenging due to variation in tissue concentrations from one field to the next. Plant tissue sampling has been used for years to help diagnose potential nutrient deficiencies in fields. Variations in nutrient concentrations in plant tissues can be impacted by many factors; some which can be controlled and some cannot. When planning tissue sampling, there are a few factors you should consider to get the most out of the information you receive. 1. Don’t sample too early or too late in the growing season:  Proper sample timing is critical to ensure that you get accurate data which can be utilized to help diagnose issues in the field. Tissue concentrations vary over time and knowing when to sample is important if the samples are being compared to a known sufficiency value. The optimal time to start taking plant tissue samples is near the point where rapid growth occurs through early reproductive growth stag...