Grain yield response of corn, soybean, and oat grown in a strip intercropping system

Abstract

AbstractConventional Midwestern U.S. row crop agriculture has created significant environmental problems and made the farm economy reliant on government subsidies. Environmentally friendly and economically profitable alternatives are badly needed. This study addresses production characteristics of strip intercropping, a system that may meet both requirements. Two experiments were conducted in 1989 and 1990: one on a cooperating farmer's field with ridge tillage and the second at a university research farm with conventional tillage. The objective was to evaluate grain yields of different rows in adjoining strips (3.8 or 4.6 m wide) of three crops. Corn, soybean, and oat strips were either inter seeded with nondormant alfalfa or seeded with hairy vetch as a cover crop after oat grain harvest. Outside corn rows had significantly higher yields than center rows in 1990, when plant water stress was low, but under dry conditions in 1989, early season competition for water caused corn to yield less in the row bordering oat than in the row bordering soybean. Comparative soybean yields in border and center rows also depended on rainfall; with adequate water, soybean yield next to the oat strip was greater than or equal to yield in the center of the strip. Oat border rows yielded higher than those in the oat strip center. Timing differences in crop life cycles and water availability seem to influence how these crop species interact, particularly at the border positions. Overall, the strip intercropping system seems a suitable alternative to current practices.