Cover Crop and Nitrogen Trials Expand Across Wisconsin Farms

By Blake Jackson

Conducting on-farm research trials is becoming an increasingly valuable way for Wisconsin farmers to answer real-world production questions while improving both profitability and environmental outcomes. In 2026, growers across the state are actively participating in farmer-led studies with support from extension and research programs.

One key initiative is the Nitrogen Optimization Pilot Program (NOPP), a grant-based effort designed to help farmers address nitrogen management challenges while also protecting water quality. The program focuses on generating practical, science-based answers to questions that directly affect crop yields and input costs.

Researchers at University of Wisconsin-Madison work closely with farmers, agronomists, and other partners to design effective on-farm trials. These studies begin with detailed planning and baseline data collection, including pre-plant nitrate testing, soil fertility sampling, and cover crop biomass measurements before planting begins.

Green Lake County farmer Jim Hebbe is one of the participants in the NOPP program. Hebbe is currently conducting a trial comparing fields with a rye cover crop to those without cover crops to evaluate impacts on soil nitrogen levels and crop yield within his long-term soil health system.

Hebbe has practiced no-till farming and cover cropping for more than a decade and is now examining whether rye may reduce yields in his system.

“I’ve always had lots of questions on my farm, and through NOPP, I can get some answers.” Hebbe said.

Hebbe trial includes randomized and replicated plots with six nitrogen rate treatments across both rye and no-cover scenarios. Other NOPP projects are also evaluating nitrogen credits from legume cover crops, with Extension educators collecting biomass and soil samples.

Data collection continues through the season, including pre-sidedress nitrate tests that help refine nitrogen decisions. Researchers emphasize that tracking soil fertility, cover crop nutrients, and field variability is essential for understanding results.

Farmers interested in nitrogen management research can connect with Megan Blauwet, Nitrogen Management Outreach Specialist, for further information and participation opportunities at megan.blauwet@wisc.edu.

Photo Credit: gettyimages-mvburling