Maximizing agro-bioeconomic benefits in intercropped systems of radish and lettuce in the semi-arid environment¹

Maximização de benefícios agro-bioeconômicos em sistemas consorciados de rabanete e alface em ambiente semiárido

HIGHLIGHTS:

Merremia aegyptia and Calotropis procera biomass amounts provide agro-bioeconomic returns in radish-lettuce intercropping.

Increasing population densities of lettuce provide agro-bioeconomic returns in radish-lettuce intercropping.

Using M. aegyptia and C. procera as green manures proves a viable technology for radish-lettuce producers in semi-arid.

ABSTRACT

Radish and lettuce are two crop vegetables that can be intercropped because they are companion cultures that complement each other. Thus, this study aimed to evaluate agro-bioeconomic returns arising from radish-lettuce intercropping in different equitable amounts of hairy woodrose (Merremia aegyptia) and roostertree (Calotropis procera) biomass at different population densities of lettuce, in the semi-arid environment. The experimental design was in randomized blocks, with treatments arranged in a 4 × 4 factorial scheme with four replicates. The first factor consisted of equitable amounts of M. aegyptia and C. procera biomass at doses of 20, 35, 50, and 65 Mg ha^-1 on a dry basis. The second factor comprised four lettuce population densities of 150, 200, 250, and 300 thousand plants ha^-1. The lettuce and radish cultivars planted were ‘Tainá’ and ‘Crimson Gigante’, respectively. Expressive agro-bioeconomic returns from this radish-lettuce intercropping were obtained in the land equivalent ratio (LER) of 2.25, a score of the canonical variable Z of 3.00, net income (NI) of 52,270.48 R$ ha^-1, respectively, in the biomass amount of 65 Mg ha^-1 of the green manures and lettuce population density of 300 thousand plants ha^-1. Also, there was a productive efficiency index (PEI) of 0.96 and a competitive ratio (CR) of 2.61 in the biomass amount of green manure of 65 Mg ha^-1 and lettuce density of 150 thousand plants ha^-1. Using M. aegyptia and C. procera biomass from the Caatinga biome proved to be a viable technology for producers who practice the cultivation of radish and lettuce in intercropping in the semi-arid environment.

Key words:
Raphanus sativus; Lactuca sativa; Merremia aegyptia; Calotropis procera; economic feasibility