Tillage x rotation x management interactions in corn

Although corn (Zea mays L.) yields following soybean [Glycine max (L.) Merr .] or wheat (Triticum aestivum L,) exceed yields of continuous corn, contin uous corn is common in the northeastern USA because of demand for corn by t he dairy industry. We evaluated corn under different tillage (moldboard plo w, chisel, and ridge), rotation (continuous corn, soybean-corn, soybean-tor n-corn, and soybean-wheat/red clover (Trifolium pratense L.)-corn), and man agement systems (high and low chemical input) for 6 Sr to determine optimum cropping systems for corn. In moldboard plow, corn in soybean-wheat/red cl over-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 manag ement (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 lo w chemical (7.9 Mg ha(-1)) compared with continuous corn under high chemica l management (7.6 Mg ha(-1)). In ridge tillage, corn in soybean-corn or fir st-year corn in soybean-corn-corn rotations yielded greater under high chem ical (8.1 Mg ha(-1)) but less under low chemical (6.3 and 6.8 Mg ha(-1), re spectively) 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/r ed clover-corn and soybean-corn rotations in moldboard plow or a soybean-co rn rotation in chisel tillage. In ridge tillage, growers could adopt soybea n-corn or soybean-corn-corn rotations, which would increase corn yields but not reduce inputs when compared with continuous corn.