Soil quality, water quality, and possibly even farm profits will all benefit by using a perennial cover crop on corn fields that allows for similar yields to traditional farming methods, according to Iowa State University research.
Using standard agronomic practices and managing a perennial cover crop between rows of corn can keep soil, nutrients and carbon in the fields, a three-year study says. Plus, farmers will still be able to yield 200 bushels per acre, the study showed.
For the study, researchers looked at 36 potential ground cover species, different corn hybrids and various tillage practices and found that strip till planting using Kentucky bluegrass as the perennial cover crop is the combination the researchers will recommend to offer environmental benefits while maintaining yield.
Ken Moore, professor in Iowa State University's Department of Agronomy, says that the system using Kentucky bluegrass with strip till yielded more than 200 bushels per acre, which was equal to the control plot, and might also be the easiest for farmers to accept.
"We evaluated all these ground covers and decided to work with Kentucky bluegrass, because it's as good as anything else," said Moore. "And Kentucky bluegrass is out in every lawn in Iowa. Every farmer grows it already. Every farmer knows how to kill it. We think farmers will be more likely to accept it as a ground cover."
Using ground cover to sustain and improve soil has become a focus of research because the need for biomass is increasing for use in producing biofuels.
Corn residue, or stover, usually remains on the ground after corn is harvested and helps reduce soil erosion and replenishes nutrients and organic matter.
The prospect of removing that stover to make biofuels causes many agronomists to fear that soil erosion will increase, while the remaining soil will suffer nutrient loss, says Moore.
Researchers received a Sun Grant for biobased research to identify ground covers that are compatible with corn, find corn that is competitive with the ground cover, and develop management systems that minimize competition between the corn and the ground cover. The Sun Grant Initiative is a national network of land-grant universities and federally funded laboratories working together to further establish a biobased economy.
Moore is pleased the results were so encouraging, but additional work is required before he and others recommend farmers try it.
"Yes, we can do it," Moore said of using perennial cover crops. "We don't know all the potential pitfalls of doing it. Under the circumstances that we tested, it does work."