Cotton Roots, Earthworms, and Infiltration Characteristics in Sod–Peanut–Cotton Cropping Systems

Diverse cropping systems offer many advantages to farmers. We evaluated root growth, soil water infiltration, and earthworm population densities in a conventional peanut (Arachis hypogaea L.)/cotton (Gossypium hirsutum L.) rotation using conservation tillage (CT), and a peanut/cotton/bahiagrass (Paspalum notatum Fluegge) farming system. The rotations were initiated in 2000 in Quincy, FL, and in 2001 in Headland, AL, in both cases on a Dothan sandy loam (fine, loamy siliceous, thermic Plinthic Kandiudults). In 2003, a year with more uniform rainfall, cotton in the sod-based rotation had larger average crown root diameter per plant (22.6 vs. 16.3 mm), root area (87.2 vs. 57.4 cm 2 ), root length (640 vs. 460 cm), and root biomass (18.59 vs. 10.45 g) as compared with cotton in the peanut/cotton rotation. Water infiltration rates were higher in both cotton and peanut after bahiagrass compared with the conventional peanut/cotton rotation in 2003. Earthworm population densities were greater in the sod rotation compared with the traditional peanut/cotton cropping system. Water infiltration was positively correlated to earthworm population densities. Despite the improvements in soil quality, cotton yield in the sod rotation was the same as the traditional cropping systems. Cotton developed excessive vegetative growth in the bahiagrass system at the expense of lint yield. Further research is needed to determine the N rate for the sod-based rotation in comparison with the conventional cotton/peanut rotation.