Alternative cropping systems for eastern Nebraska

Environmental and health concerns, and increased crop production costs has increased interest in alternative cropping systems research. The object of these studies was to compare alternative cropping systems with conventional systems. Experiments were conducted at the Agricultural Research and Development Center to evaluate strip intercropping studies of corn (Zea mays L.) and soybean (Glycine Max (L.) Merrill), and grain sorghum (Sorghum bicolor (L.) Moench) and soybean, grown in 6.1 m alternating strips under dryland and irrigation from 1986-1990. In conjunction with these experiments, individual row yields and yield components of crops were evaluated in both intercropping systems from 1988-1990. Corn yields increased on the outside two border rows and average of 1.08 and 0.34 Mg/ha under irrigated and dryland conditions, respectively. Soybean yields were decreased on the outside border rows compared to the middle four rows under both environments. Grain sorghum border row yield increases averaged 0.59 Mg/ha under irrigation. Soybean yield reduction in border rows was significant, but variable from year to year. Corn and grain sorghum border row yields were significantly increased compared to the middle six rows. Both seed number and seed weight made significant contributions to corn border row yield increases; seed number influenced grain sorghum border row yields. Soybean border row yields were significantly decreased in the corn/soybean strip intercropping system, with seed numbers significantly reduced in soybean border rows. Soybean was less affected in the grain sorghum/soybean system. A corn-soybean-corn-oat (Avena sativa (L.)/sweet clover (66%) Melilotus officinalis (L.) Lam, red clover (34%) Trifolium pratense) rotation with feedlot manure only, fertilizer only, or herbicide and fertilizer were compared with continuous corn. The past 12 years corn, soybean and oat yields were similar among the rotation management systems. The average corn yield of the rotation management systems (5.11 Mg/ha) produced 18% more grain than the continuous corn system (4.32 Mg/ha). Corn following oat/cover and corn following soybean yielded 4.77 and 5.47 Mg/ha, respectively. From 1976-1990, soil organic matter, P, K, and pH in manured plots increased significantly