Tillage × Rotation × Management Interactions in Corn

Abstract

Although corn (Zea mays L.) yields following soybean [Glycine max (L.) Merr.] or wheat (Triticum aestivum L.) exceed yields of continuous corn, continuous corn is common in the northeastern USA because of demand for corn by the dairy industry. We evaluated corn under different tillage (moldboard plow, chisel, and ridge), rotation (continuous corn, soybean–corn, soybean–corn–corn, and soybean–wheat/red clover (Trifolium pratense L.)–corn), and management systems (high and low chemical input) for 6 yr to determine optimum cropping systems for corn. In moldboard plow, corn in soybean–wheat/red clover–corn (9.2 Mg ha−1) and soybean–corn (8.5 Mg ha−1) rotations under low chemical yielded greater than continuous corn under high chemical management (7.9 Mg ha−1). In chisel tillage, corn in the soybean–corn rotation yielded greater under high chemical (8.9 Mg ha−1) and similarly under low chemical (7.9 Mg ha−1) compared with continuous corn under high chemical management (7.6 Mg ha−1). In ridge tillage, corn in soybean–corn or first‐year corn in soybean–corn–corn rotations yielded greater under high chemical (8.1 Mg ha−1) but less under low chemical (6.3 and 6.8 Mg ha−1, respectively) compared with continuous corn under high chemical management (7.5 Mg ha−1). Growers under similar environmental conditions to this study can increase corn yields while reducing inputs by adopting soybean–wheat/red clover–corn and soybean–corn rotations in moldboard plow or a soybean–corn rotation in chisel tillage. In ridge tillage, growers could adopt soybean–corn or soybean–corn–corn rotations, which would increase corn yields but not reduce inputs when compared with continuous corn.