The objective of this work was to evaluate the biomass production and nutrient accumulation in potential cover crops sown in different cropping systems in the Brazilian Cerrado of Piauí State. The experiment was conducted in the crop season 2010/2011 in the Serra do Quilombo, county of Bom Jesus, Piauí, Brazil. This study was arranged in split plot scheme, with soil management systems (conventional tillage and no-tillage) evaluated in plots and crop systems in subplots: S1- Soybean monoculture in the crop-season; S2 - Soybean in crop-season and Pennisetum glaucum for off-season; S3 - P. glaucum before soybean crop-season and Urochloa ruziziensis oversown on soybean in the phenological stage R5.5; S4 - Soybean crop-season and P. glaucum oversown on soybean in R5.5; S5 - Maize + U. ruziziensis simultaneously in crop-season. The experimental design was in randomized blocks, with four replications. The crop systems with oversown of P. glaucum and U. ruziziensis on soybean and the consortium maize + U. ruziziensis improved the biomass production, soil coverage and nutrient accumulation during the off-season in the Cerrado from Piauí State, Brazil. The nutrients with greater accumulation rate by cover crops were nitrogen and potassium.
Brachiaria; millet; decomposition; crotalaria; no-tillage
