Competitive and biological ability of the beet and cowpea-vegetable intercropping deriving from green manuring and spatial arrangements

ABSTRACT The objective of this work was to evaluate the competitive and biological ability of the beet and cowpea-vegetable intercropping as a function of biomass amounts of roostertree incorporated into the soil and of spatial arrangements. The experimental design was a randomized complete block d in a 4 x 3 factorial scheme, comprising the combination of four amounts of roostertree biomass (20, 35, 50 and 65 t ha-1 on dry matter) and three spatial arrangements between plant rows of the component crops of the intercropping (2:2, 3:3 and 4:4). The competition indexes were evaluated: actual yield loss, aggressivity, relative crowding coefficient and competitive ratio. The biological efficiency indexes evaluated were: land equivalent ratios for the system, and also for beet and cowpea as sole crop. It was verified that the cowpea-vegetable crop obtained higher production gain and a better competition capacity than the beet crop in the established intercropped, and that spatial arrangements did not interfere with the productive performance of the crops. The cowpea-vegetable crop was more competitive than the beet in the intercropping system. The highest biological viability of the beet and cowpea-vegetable intercropping was obtained in the amount of 65 t ha-1 of roostertree biomass incorporated into the soil. There was no influence of spatial arrangements on the competitive ability and agroeconomic viability of the beet intercropping and cowpea-vegetable