Green manuring and population density responses in radish and arugula strip-intercropping systems lead to agro-economic benefits

Resumo

The cultivation of radish with arugula in strip-intercropped systems is growing in semi-arid environments. The great challenge has been to assess whether there is agronomic and economic efficiency in the intercrops when fertilised with plant biomass of spontaneous species from the Caatinga biome. Thus, the objective of this study was to evaluate the productive and economic viability of radish and arugula strip-intercrops fertilised with Merremia aegyptia and Calotropis procera biomass equitable amounts from the Caatinga biome at different population densities of arugula at two cropping years. The experimental design used was randomised blocks, with the treatments arranged in a 4 x 4 factorial scheme, with four replications. The first factor was constituted by four biomass equitable amounts of M. aegyptia and C. procera (20, 35, 50 and 65 t ha^-1 on a dry basis), and the second factor by the population densities of arugula plants (40, 60, 80 and 100% of the recommended density for single crop - RDSC) intercropped with 100% of the radish RDSC. The highest agro-economic advantages of radish and arugula intercropping were obtained for a land equivalent coefficient (LEC) and monetary equivalent ratio (MER) of 0.55 and 1.35, respectively, for M. aegyptia and C. procera biomass amounts of 54.75 and 54.55 t ha^-1 added to the soil. The arugula population density of 100% of the RDSC provided the greatest agro-economic efficiency of the intercropped system of radish with arugula with LEC and MER of 0.58 and 1.33, respectively.