No-till, cover crops, irrigation management impacts on water and N efficiency and quality in corn-soy

What is this project about?

Minnesota farmers are facing increasingly unpredictable weather, and current farming guidelines don’t fully explain how conservation practices work under these specific conditions. This study by University of Minnesota researchers examines how combining no-till farming and cereal rye cover crops impacts water and fertilizer efficiency in irrigated corn-soybean rotations.

The Main Problems Being Addressed

• Erratic Weather and Water Extremes: Minnesota weather is shifting between heavy rainfall/flooding in some years and severe droughts in others. Extreme rain washes nitrogen down past the root zone, while drought strains irrigation supplies.
• Nutrient Loss and Leaching: On coarse-textured, sandy soils (like those in central Minnesota), nitrogen fertilizer leaches easily into groundwater during wet periods or over-irrigation.
• Lack of Local Data: While no-till and cover crops are known to improve overall soil health, their actual impact on water storage, crop water use (evapotranspiration), and nitrogen leaching on irrigated sandy soils is not well understood. Existing studies from other regions show mixed results.
• High Input Costs & Risk: Farmers need clear, locally tested proof before changing their tillage or cover crop routines—especially when trying to balance irrigation schedules and protect yields without wasting expensive fertilizer.

By running these trials locally, the researchers aim to deliver practical, proven irrigation and fertilizer strategies that protect groundwater, save input costs, and keep crops resilient against wild weather swings.

What the Study is Testing

• Locations: Field trials at the Rosholt Farm in Westport, Minnesota, focusing on sandy, coarse-textured soils, and at Becker, Minnesota being conducted through a separate State agency.
• Practices: Comparing no-till versus deep tillage, and a cereal rye cover crop versus no cover crop.
• Water Scenarios: Testing four irrigation levels—rainfed, optimum water, over-watered (simulating heavy rainfall years), and water-stressed (simulating drought).

Key Goals & What Farmers Will Learn

• Nitrogen Leaching: Measuring how much nitrate washes past the root zone under different weather and management conditions to help keep fertilizer in the root zone.
• Water Savings: Tracking continuous soil moisture to determine how much water cover crops and no-till actually save or use.
• Yield & Crop Health: Evaluating nitrogen uptake and final harvest yields for short-season corn and soybean hybrids.
• Practical Recommendations: Developing updated, site-specific irrigation and fertilizer guidelines for sandy soils.

How You Can Get Involved

• Annual Field Days: The project team will host an annual demonstration field day at the Westport research farm so growers can see the field plots and soil moisture setups firsthand.
• Extension Updates: Results and practical guidance will be shared regularly through local extension events, bulletins, and blog posts.