Arranjos espaciais de mistura de adubos verdes antecedendo o cultivo orgânico do feijoeiro

Abstract

This study aimed to evaluate the performance of a succession of corn and bean, submitted to organic management associated with green manure from a mixture of species with different spatial arrangements. The experiment was conducted in the Sistema Integrado de Produção Agroecológica - SIPA, located in Seropédica - RJ, Brazil. The statistical design was a completely randomized blocks with six treatments and four replicates, totaling twenty four plots. In this sense, the experiment was planned in two parts, the first part was the study of spatial arrangements of planting, consisting in a mixture (Canavalia ensiformis, Crotalaria juncea and Helianthus annuus) of cover crops species (ECS) for green manure contemplating: intercropping with corn (cv. Caatingueiro) in double rows. The treatments consisted : ECS haul sowing; ECS furrow sowing; ECS haul sowing in a intercropping with corn; ECS furrow sowing in a intercropping with corn; corn monoculture; fallow (control). The evaluated parameters were: cover soil provided by ECS; fresh and dry biomass productivity; chemical composition of ECS aerial part; and corn grains productivity. The second part of the experiment took place in the same area, and bean (cv. Constanza) was planted in the same plots of the first part of the experiment. It was evaluated the influence of cover crops species on weed reinfestation and on the productivity of beans. As a general conclusion it was observed that the ECS covered the soil faster than the current spontaneous vegetation on fallow did. The fresh and dry biomass productivity and the cumulative quantity of nutrients in the biomass of the treatments that took in the ECS were higher than in corn monoculture. It was noted that the presence of the ECS influenced positively on weed reinfestation control. The corn grains productivity was lower when intercropping with ECS, however, the yield of beans was not influenced. The sowing way, haul or furrow, showed no differences, one interesting finding because the smallholder have freedom to choice the sowing way, without concern with related losses.