Beet-arugula intercropping under green manuring and planting density lead to agro-economic advantages

Resumo

The objective of this work was to evaluate the performance of beet and arugula intercropping when influenced by green manuring with Merremia aegyptia and Calotropis procera and arugula population densities in two years of cultivation in semi-arid environment. The experimental design used was in randomized complete blocks, with the treatments arranged in a 4 x 4 factorial scheme, with 4 repetitions. The first factor this scheme consisted of equitable amounts of biomass mixtures of M. aegyptia and C. procera (20, 35, 50 and 65 t ha^-1 on a dry basis) and the second factor, by arugula population densities (40, 60, 80 and 100% of the recommended density for single cropping - RDSC). The production and their components were evaluated on beet and arugula. In addition to these characteristics, the following agro-economic indicators were also determined for each treatment: system productivity index (SPI), land equivalent coefficient (LEC) and monetary equivalent ratio (MER). The greatest agro-economic advantages of the beet with arugula intercropping were achieved with a system productivity index (SPI) of 53.47 t ha^-1, land equivalence coefficient (LEC) of 0.84 and a monetary equivalence ratio (MER) of 1.56, respectively, in the combination of 65 t ha^-1 of M. aegyptia and C. procera biomass with an arugula population density of 100% of the RDSC. The maximum optimized commercial productivity of beet roots in the system intercropped with arugula was 23.20 t ha^-1 in the amount of 65 t ha^-1 of M. aegyptia and C. procera with a density of 100% of the RDSC, while the maximum arugula productivity intercropped with beet was 9.65 t ha^-1, in the same combination of green manures amount and arugula population density. The optimized maxima productivities of large roots, extra AA and extra were 10.28; 6.33 and 4.12 t ha^-1 obtained in the amount of 65 t ha^-1 and in the arugula population densities of 85; 82 and 40% of RDSC, respectively.