Minnesota Crop News

Photo: University of Minnesota Extension By: Dan Kaiser, Extension nutrient management specialist I have had a few questions this fall regarding lime application. Currently we have eight trials across the state of Minnesota evaluating rates and sources of lime. Sources include quarry lime from Goodhue County, pelletized lime (“pell lime”), and precipitated calcium carbonate (PCC) lime from the Southern Minnesota Beet Sugar Cooperative.  I will be providing an update on the lime research over the winter. One interesting thing we’ve seen so far is that a few trials have shown little to no pH change from the lime application. I would be curious to hear from retailers, consultants, and growers whether they have seen anything similar.  I still have enough lime for two field locations that I am looking to establish before the 2026 crop year. Fields and soils needed for 2026 We are looking for two additional field locations to establish trials in the fall of 2025 or spring of 2026 on...

Cation exchange capacity and cation balancing are the topics of the day in this episode of the Nutrient Management Podcast . What are the definitions of cation exchange capacity (CEC) and cation balancing (CB)? How is CEC measured and are those estimates reliable? What does the research say about CEC and CB and their role in a nutrient management strategy? What should farmers remember about cation exchange capacity and cation balancing for their own operations? TRANSCRIPT Guests: Fabian Fernandez, Extension nutrient management specialist (St. Paul) Daniel Kaiser, Extension nutrient management specialist (St. Paul) Carl Rosen, Extension nutrient management specialist (St. Paul) Additional Resources: Timing of K application for corn and soybean production Chloride and soybean: What to know about potash fertilizer management Impact of cation exchange on corn K guidelines Four soil test myths that farmers should know Corn planting and nitrogen management: 5 things to con...

It's the end of March, which means it's time for the annual Spring Fertilizer Outlook. What are field conditions like throughout Minnesota? What early fertilizer application options might MN growers want to consider? Which early fertilizer application practices might MN growers want to avoid, and why? What are growers excited - or hesitant - about? What about N carryover credits in this more typical season? Our four panelists weigh in. TRANSCRIPT Guests: Fabian Fernandez, Extension nutrient management specialist (St. Paul) Jeff Vetsch, U of M researcher (Waseca) Brad Carlson, Extension educator (Mankato) Daniel Kaiser, Extension nutrient management specialist (St. Paul) Additional Resources: Are you overspending on fertilizer? FINBIN Don't apply commercial fertilizers to snow-covered frozen soils Nutrient Management — Click here to listen to all Nutrient Management Podcast episodes. For the latest nutrient management information, subscribe to the Nutrient Management ...

By: Dan Kaiser, Extension nutrient management specialist Deciding whether to lime the soil can be a difficult choice, especially in rental situations, since the impact of liming can extend beyond short-term rental situations. The benefits of liming may not be achieved until two or more years post-application, so determining where lime is most economical can be difficult to assess. In addition, Minnesota maintains two separate lime recommendations depending on sub-soil acidity, which reflects differences in the parent material that formed the soils across the state. A current study is underway which will help assess the long-term benefits of lime applications in Minnesota. The study will also look into the rationale for parts of the current lime guidelines to determine whether changes should be made to better represent current cropping practices across the state. The history behind Minnesota’s lime guidelines The benefits of liming have been demonstrated through cooperative work between...

In this episode of the Nutrient Management Podcast, our panelists discuss liming in detail. What kind of variation is there in liming recommendations? Since pH changes aren’t instant, when is the best time to apply limestone? Is lime application economically justified, and in what circumstances? What should growers know about selecting liming materials? What other bits of advice do our panelists recommend? TRANSCRIPT Guests: Daniel Kaiser, Extension nutrient management specialist (St. Paul) Carl Rosen, Extension nutrient management specialist (St. Paul) Jeff Vetsch, U of M researcher (Waseca) John Jones, Soil Fertility, plant nutrition, and nutrient management research, University of Illinois Urbana-Champaign Additional resources: Soil test pH and liming: Common questions and answers Lime needs in Minnesota Liming materials for Minnesota soils Fertilizer Recommendation Support Tool (FRST) — Click here to listen to all Nutrient Management Podcast episodes. For the latest nutrien...

By: Dan Kaiser, Extension nutrient management specialist When it comes to soil tests, I commonly receive questions about pH and liming. Below are some common questions I get and my answers. What exactly is the buffer pH?  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 s...