Legumes as green manure for common bean cultivated in two growing seasons at southeast Brazil

Abstract

The use of legumes in pre-cultivation on the common bean has the possibility of providing atmospheric N to the soil, making it available to this crop, and may cover part of its N demand and increase grain yield. The objective of present study was to evaluate the effect of hyacinth bean and jack bean as green manures on the production of common bean grown in two seasons. Cover crops were evaluated for fixed N 2 , dry matter yield, nitrogen (N) and carbon (C) concentrations, C:N ratio and N accumulation in the shoot. The jack bean accumulated higher biomass and more total N than hyacinth bean and spontaneous vegetation (control). However, both legume species, when used as green manure, resulted in an increase in the N concentration of common bean. Compared to the spontaneous vegetation, hyacinth bean residue increased yield of common bean by 32% and jack bean residue increased the bean yield by 46%. These yields were recorded when common bean was cultivated a few weeks after residues incorporation into the soil and about seven months later, thus showing a flexibility to family farmers for making their decisions on the best cropping season.

Sustainable productive intensification for family farming in developing tropical countries

“…Legume species such as jack bean (Canavalia ensiformis), black bean (Phaseolus vulgaris), lab-lab bean (Dolichos lablab) and crotalaria-juncea (Crotalaria juncea) are preferred for consortium and green manuring for symbiosis with nitrogen-fixing bacteria, adding this nutrient to the system (Souza et al, 2018). This practice has made production more sustainable by increasing productivity and reducing environmental impacts (Filipe et al, 2016;Xie et al, 2016;Meena et al, 2018).…”