Using Herbicide-Resistant Corn Hybrids to Establish an Alfalfa Cover Crop
Project Leaders: N. Gift, R.R. Hahn, and J. Mt. Pleasant, Department of Soil, Crop, and Atmospheric Sciences, Cornell University, Ithaca, NY
Recent introductions of herbicide-resistant corn hybrids in New York offer opportunities for corn growers to produce silage corn with little erosion, and to reduce herbicide and tillage inputs. These opportunities result from the possibility of growing an alfalfa cover crop in corn. A common rotational practice in N.Y. is to grow 3 to 4 years of corn, followed by 3 to 4 years of alfalfa. In the proposed system, alfalfa would be seeded at the start of the last year of corn in each cycle, would grow as a cover crop during the season, and would continue growth after corn silage harvest. Though this system has been tried in the past, one seemingly insurmountable difficulty was the lack of ability to control weeds, either chemically or culturally, without damage to either the corn or the alfalfa crop. The introduction of some herbicide-resistant corn hybrids means that weeds can now be controlled by herbicides which are naturally safe on legumes and safe on the resistant corn hybrids.