What’s Up With Cover Crops
Cover crops have been around for a long time. Until recent years, they prompted little interest. That’s changed.
“There is a lot of momentum for cover crops in the Midwest,” says Jeremy Singer, research agronomist for the National Laboratory for Agriculture and the Environment (NLAE) in Ames, Iowa.
Perks are plenty. Cover crops curb soil erosion while adding soil organic matter. Cover crops also can protect nutrients and capture 20 to 40 pounds per acre of nitrogen (N), 2 to 5 pounds per acre of phosphorus (P), and 30 pounds per acre of potassium (K). Wildlife also thrives.
Singer spoke earlier this month at the Iowa State University Southeast Iowa Research Farm near Crawfordsville.
Cover crops work well in areas like wheat growing regions of Michigan. There, radishes can follow wheat during a fallow period in late July or August.
Cover crop choices are more limited in states like Iowa, where corn and soybeans are in fields the bulk of the growing season.
“We are looking at winter wheat or rye,” says Singer. “They germinate in cool weather in the fall, and are winter hardy,” says Singer. They are relatively inexpensive.” Seeding costs for overwintering cover crops tally around $30 per acre.
It’s cheaper to establish a non-wintering cover crop like oats. Costs tally around $20 per acre. These costs can be deferred by cost sharing through the federal program EQIP. Seeing cut-off dates exist, though. For non-wintering crops, the cutoff date in Iowa is September 15. For winter-hardy cover crops like rye or winter wheat, the seeding cutoff date in Iowa is October 15.
Planting a winter cereal in September and October is challenging in row corps. Aerial seeding that deposits these grains in between corn or soybean rows is one solution. Seeding choice will impact seeding rates. Small grain seeding rates normally tally 1 bushel per acre by ground, 1.5 bushels per acre by air. Oat seeding rates are higher. Its ground seeding rate is 2 bushels on the ground, 3 bushels per acre by air.