Grain Corn Response to Crop Sequences in Sod-based Rotation.

An experiment was conducted at the University of Florida’s North Florida Research and Education Center, Quincy, FL to determine corn (Zea mays L. cv. Dekalb 69-72 RR2) growth and grain yield responses to different crop sequences in sod-based rotational systems on irrigated land. Treatments included: (1) bahiagrass-bahiagrass-cotton-corn (B-B-C-M); (2) bahiagrass-bahiagrass-peanut-corn (B-B-P-M); and (3) bahiagrass-bahiagrass-corn-corn (B-B-M-M). The experimental plots were established in 2001 as a randomized complete block design and four replications. Corn plant height, the number of nodes, leaf chlorophyll content, and leaf area index (LAI) were measured in the 2007 growing season. Grain yield and yield components were determined, as well as soil plant nutrients, water content and soil organic matter (OM). Although 2007 was an extremely drought year at the experimental location, corn plants following bahiagrass in the B-B-M-M had greater LAI and leaf chlorophyll content than corn following either cotton in the B-B-C-M or peanuts in the B-B-P-M, resulting in a 430 to 488 kg ha^-1 greater grain yield. Soil N, P, and K concentrations at planting did not differ among the three rotations, but soil OM and soil water content of the first-year corn plots in the B-B-M-M were consistently higher than water content from corn plots in the B-B-C-P and B-B-P-M. These results suggest that a primary contribution of bahiagrass to subsequent corn growth is its ability to improve soil water holding capacity, in part, by increasing soil OM in a dry year with limited irrigation.