They have intriguing names such as hairy vetch, pearl millet and birdsfoot trefoil. Collectively known as cover crops or green manure, they've been used for years to increase soil productivity by fixing atmospheric nitrogen into soil, making it available for cash crops such as corn and saving farmers money on input costs.
Cover crops have numerous benefits
But fixing nitrogen is just one benefit of cover crops. They improve soil health because they add diversity to the microbial community, foster natural biological processes, boost organic matter and increase soil porosity, which improves soil's water-holding capacity. What they capture is just as critical as what they add. Cover crops reduce soil erosion, sequester carbon and significantly mitigate nitrogen, phosphorus, and herbicide and pesticide losses to surface water.
Despite their myriad benefits, how to integrate them successfully into a production system still raises lots of questions for Missouri producers. Ranjith Udawatta, associate research professor in the College of Agriculture, Food and Natural Resources (CAFNR) at MU, and his collaborators aim to answer those questions and demonstrate cover crops' benefits to soil health, water quality, ecosystem services and farm profitability.
Udawatta's team was recently awarded a $500,000 Conservation Innovation Grant from the USDA Natural Resources Conservation Service to examine cover crop management practices in 12 watersheds in central and north-central Missouri. Several partners are contributing to the project, bringing the total budget to $1.1 million. Associated Electric Cooperative Inc. provided the principal research site in Chariton County.
According to EPA water quality studies, 44 percent of rivers, 30 percent of estuaries and 64 percent of lakes in the Mississippi River Basin are impacted by agricultural pollution and contribute to hypoxia in the Gulf of Mexico. Udawatta's previous watershed research at the MU Greenley Memorial Research Center in Novelty, Mo., has shown that the bulk of the loss of nitrogen and phosphorus occurs during the fallow period, when the ground is bare.
Plant Cover Crops In A Drought Year? You Bet
Cover crops can help conserve moisture, keep soil covered and provide residue going into the cropping season. Download our free report Cover Crops: Best Management Practices