[Originally posted August 27, 2013]
Farmers are being encouraged to consider growing cover crops on their fields through the winter. Studies show that a living, growing plant in the ground year round improves the soil, productivity, and nutrient runoff.
The science behind this makes sense. On a big picture level, Illinois is prairie and having grasses growing on our soil year round is a return to what built the rich organic soils in the first place. But looking closer, planting rye grass or cereal rye after you harvest your corn crop makes sense.
In central Illinois, many farmers plant corn on corn (this is the way we describe a crop rotation of corn every single year without planting another crop in between). Because corn uses nitrogen from the soil to grow, farmers apply nitrogen every year to replenish what the corn used the previous year. If that nitrogen isn’t applied at exactly the right time, the plant doesn’t get to use all of it, meaning that valuable nitrogen is lost to the soil and water, causing problems in the environment and costing farmers money.
Additionally, corn doesn’t grow well in the leftover stalks and leaves from the previous year. This causes farmers using a corn on corn rotation to have to till the soil which isn’t good for soil erosion. The current industry standard is to no till the soil, meaning, literally, no tillage.
Growing crop like cereal rye or rye grass from the time you harvest the corn until you replant in April, helps with both concerns.
As the cover crop grows in the fall, it uses the nitrogen left in the soil to grow and stores it within the plant. In the spring when the farmer kills the cover crop, the nitrogen is released back into the soil for the corn crop to use. This management technique significantly minimizes the nitrogen remaining to run off into the water supply.
A cover crop also reduces compaction, increases organic matter in the soil, and otherwise helps the health of the soil and increases productivity for the farmer. In fact, some farmers doing trials in Illinois this past year have noticed up to 20 bushels per acre increase in yield!
The Council on Best Management Practices is now working one-on-one with farmers in the Springfield, IL area (they had a bigger problem than most, remember?). Several will be growing cover crops this winter as a trial and demonstration for other local farmers. And we hope to show farmers the environmental and economic benefit of growing cover crops on their fields as a part of the normal corn on corn rotation.
Using science as our base, farmers will definitely be on board for improving the resources in their care.