Cover crops on a field in Black Hawk County, Iowa.
Cover crops on a field in Black Hawk County, Iowa.

Farmers are the ultimate survivors.  By definition, their work requires incredible planning, but it also requires creativity. This year, farmers have faced the test of limited summer rains, which have lowered the productivity of many farmers’ yields.  With fall approaching, farmers have an opportunity to invest today for better outcomes next year by planting what are called “cover crops.” Not harvested like a main crop, cover crops are mowed to stay on top of the soil or disked in for soil improvements.

Cover crops offer a wide range of benefits: they “trap” nitrogen left behind by fertilizer in the field, which otherwise may be washed away over the winter. They conserve water, improve the quality of soil, suppress weeds, and control insect pests and erosion.  Cover crops can also provide an excellent source of animal feed during periods when drought has reduced forage.

USDA science counts conservation research as an important area, so our scientists continually study cover crops, including timely focus on the impacts of drought stress to reduce potential losses in U.S. production capacity.  Using a grant provided by USDA’s National Institute of Food and Agriculture, researchers at Purdue University show that cover crops left on the soil surface after germination in spring will conserve soil moisture acting as a soil cover. This can increase crop yields in dry years and reduce year-to-year variability in yields.

Agricultural Research Services scientists estimate that when farmers use cover crops and no-till farming practices, they can save an estimated 4 to 14 percent on water than when they use conventional tilling practices.  During drought years, farmers in some areas can reduce their need for water an additional 1 to 6 percent by not plowing 40 percent more of the farmed acreage.

Using cover crops is good for anyone who works with the land – from back-yard gardeners to large scale farmers.  In a backyard, cover crops improve soil and act as mulch to regulate soil moisture and temperature. So if you’ve got a late summer garden getting ready to be rested for the winter, consider planting some cover crops such as clover, rye, oats, or winter wheat in the next month. spring, you’ll be happy you did. And so will your plants.

Source: Diana Jerkins, National Institute of Food and Agriculture