Subterranean Clover Cover Crop Used to Increase Rice Yield

Abstract

Abstract Management systems for flooded rice ( Oryza sativa L.) production that include a winter legume cover crop and no‐till planting are of interest to farmers seeking lower‐cost production methods. Field experiments were performed at Crowley and Baton Rouge, LA. The purpose was to determine the effects of N fertilization (0, 56, 112, and 168 kg urea‐N ha −1 ) and tillage (rototilling or no‐tillage) on the yield and yield components of rice planted in fallow plots or in plots containing subterranean clover ( Trifolium subterraneum L.) that had produced mature seed. Rice was dry‐seeded 1 wk after clover was desiccated with an herbicide or tilled into the soil. A permanent flood was established 30 d after planting. The presence of a clover cover crop increased rice yields about 10% in tilled and no‐till plots receiving various rates of N fertilizer. Flag‐leaf N concentrations and the amounts of total N assimilated into above‐ground biomass at harvest were greater in rice after clover than in rice after fallow, but the presence of a winter clover cover did not reduce the amount of N fertilizer required to produce maximum yield. The maximum yields of rice obtained by no‐till management were similar to or greater than those obtained by tillage. After rice harvest, stands of reseeded subterranean clover were better in no‐till plots than in plots where clover residues had been incorporated into the soil prior to rice planting.