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Discover the Cover

It's not your Grandfather's Cover Crop

By Jamie Johnson Ponder, Kentucky Division of Conservation

February 2015

Cover Crop on Wiley Brown's FarmIn the wake of renewed resurgence of dust storm activity in the west and unpredictable weather patterns occurring all across the country, it has become crucially important to educate landowners in the importance of healthy soils and how to achieve them. Many advances have been made in the field of soil health systems, and new methods of choosing the right cover crop blend at appropriate planting times allow soils to keep improving year after year.

Soil health is measured by biological, physical and chemical properties making it inherently important to farm in a way that addresses each of these properties. History proves that tilling destroys the structure of the soil; leaving the soil uncovered with no live growing roots destroys microbial habitat, reducing the amount of available nutrients and diminishing biological and chemical properties.  One of the best ways to reverse this process and restore healthy soil function is through the implementation of soil health systems, which include no-till cropping and cover crop seeding. Some of the benefits of soil health systems include better water infiltration, improved permeability, greater pore space, increased water holding capacity, better microbial habitat, greater nutrient cycling, increased soil organic matter, and reduction or possible elimination of the need for commercial fertilizer and chemical applications.  This method of production hinges on the single premise of keeping a living root in the ground at all times and is a departure from the standard monoculture cover cropping systems common in the past, rather relying on multiple species working synergistically to correct a multitude of soil health problems. At planting time, cover crops are not removed from the field, but rolled down and left as a green fertilize for the crop. What’s happening under the soil surface is just as important.

“The key to soil health improvement is implementing the five principles of soil health—no-till, maximize organic matter/residues on and in the soil surface, keep a live root growing throughout the year, maximize plant diversity through crop rotations and cover crop mixtures, and apply animal waste or high-quality compost if available,” said John Graham, state soil health specialist with the Natural Resources Conservation Service.

As part of a five-year trial, Wiley and Terrie Brown implemented cover crops on a five-acre soil health research plot on their Knox County farm in 2012. It included an eight-way mixture of pearl millet, proso millet, sorghum, black soybean, sunflower, radish, Austrian winter peas and corn. It was followed by a fall planting of cereal rye, crimson clover, Austrian winter peas and daikon radish.  In the spring of 2013, the cover crop was rolled down and sprayed with a single application of glyphosate followed by no-till seeding of corn. The plot flooded shortly after seeding, which affected germination rates. However, with no added fertilizer or chemical application the Browns realized an abundant crop that was harvested for silage and followed by a fall cover crop planting of daikon radish, Austrian winter peas, cereal rye and crimson clover. When implemented properly, this method of planting can eventually negate the need for commercial fertilizer and chemical weed control on crop ground.

The Browns, who spend more than $80,000 a year on commercial fertilizer, stated, “last year we didn’t add any commercial fertilizer to the soil health research plot and we had a tremendous yield.” The five-acre plot brought in 300 bushels of soybeans, significantly beating the national average of 40 bushels per acre.  To learn more about soil health systems, including alternative cover crops and no-till visit,, or visit your local USDA Service Center.