Adding nitrogen to fertilize their crop is a substantial expense corn farmers have to consider when calculating their bottom line. A University of Georgia scientist hopes to help lower that cost by planting clover and corn together.
With a $224,000 grant from the Southern Sustainable Agriculture Research and Education program, UGA researcher Nicholas Hill is beginning a three-year study of Durana white clover as living mulch in integrated corn systems.
Bacteria take nitrogen from the atmosphere and change it into a form that plants can use. Working with the bacteria in the soil, white clover fixes nitrogen in its leaves. This reduces the amount of fertilizer farmers have to apply to add nitrogen.
For the research project, a field is planted in white clover during the fall. Once nitrogen fixation begins, the clover absorbs the nutrients and stores it in its leaves. Corn is planted into strips of white clover that were treated with herbicides in the spring.
Once the corn is planted and established, it continues to grow and shade the clover. The clover drops its leaves, and the dead leaves decompose, releasing nitrogen into the soil. The clover is tolerant of corn herbicides and grows back after the corn is harvested.
“If we’re real lucky and have a good winter and a lot of clover growth, we can supply the nitrogen requirement for the corn by the clover,” said Hill, a professor with the UGA College of Agricultural Sciences.
Not having to apply nitrogen could potentially save corn growers a substantial amount of money. Hill remembers when nitrogen sold for 15 cents per pound. Today, that number has risen to between 65 and 75 cents. If a farmer applies 200 pounds of nitrogen per acre — which is not uncommon — farmers could spend between $130-150 per acre on fertilizer.
“What we hope will eventually happen is we’ll have a system where corn producers won’t require nitrogen fertilizer. Nitrogen prices seem to just continually go up, and grain prices don’t necessarily go up,” Hill said.
Hill also expects to see water quality increase in the clover/corn fields and water runoff and soil erosion decrease. The clover will suppress weeds, like Palmer amaranth, between the rows, so herbicide usage will decrease, too.
“We want to make sure we can get by with fewer inputs without compromising the yield of the crop,” he said.
For more on UGA CAES corn research, see the website http://www.caes.uga.edu/commodities/fieldcrops/gagrains/corn.html.
(Clint Thompson is a news editor with the University of Georgia College of Agricultural and Environmental Sciences based in Tifton.)