Plantas de cobertura, manejo da palhada e produtividade da mamoneira no sistema plantio direto

摘要

Cover crops that have high phytomass production and nutrient cycling are essential to maximize the crop yields in succession under no-tillage system. This study aimed to evaluate dry matter production and nutrients accumulation by pigeonpea (Cajanus cajan) and pearl millet (Pennisetum glaucum), in sole crop and intercropped, and the effect of straw mulch mechanical management on out-of-season castor bean performance, in no-tillage system establishment. The experiment was carried out on a Rhodic Nitisol, in Botucatu, SP, Brazil. A randomized blocks design, in a split-plot scheme, with four replications, was used. Plots were composed by cover crops (pigeonpea, pearl millet, and pigeonpea-pearl millet intercropping). Subplots were composed by absence or presence of straw mulch mechanical management, by horizontal crusher use, 20 days after chemical management. Pearl millet sole crop produced greater amounts of dry matter (14,040 kg ha-1) and showed higher K and Mg concentrations, accumulated greater amounts of nutrients in aboveground. Castor bean grain yield was higher in succession to pigeonpea-pearl millet intercropping. Castor bean grain yield was higher in the absence of straw mulch mechanical management.