Profitability of using irrigation in forage cactus-sorghum intercropping for farmers in semi-arid environment

ABSTRACT Irrigation plays a fundamental role in advancing agricultural frontiers and increasing crop productivity, especially in semi-arid environments, because they exhibit high spatiotemporal rainfall variation. This practice is suggested even for adapted crops, such as forage cactus (Opuntia sp.), sorghum (Sorghum bicolor), and single or intercropping systems. In this study, aimed to evaluate the profitability of using irrigation in a single and intercropping forage cactus-sorghum system in a semi-arid region. The experimental design was in randomized blocks in a 5 × 3 factorial arrangement: five drip irrigation depths (0, 25, 50, 75, and 100% of the reference evapotranspiration - ET0) and three cropping systems (single forage cactus, single sorghum, and intercropping forage cactus-sorghum), with four replicates. The 0% ET0 treatment corresponded to rainfed conditions at a depth of 355 mm. A cycle of forage cactus and two sorghum cultivars (plant and regrowth) was conducted between November 2014 and November 2015. It was verified that the highest costs for implantation of the crop systems in irrigated conditions are due to the acquisition of irrigation and input systems, representing 85.3% of the effective operational cost. The single sorghum and forage cactus-sorghum systems provided the highest fresh matter productivity (62,013.05 and 60,075.36 kg ha-1, respectively). Based on economic indicators, the adoption of irrigation depths (25, 50, 75, and 100% ET0) promoted profits for the systems (single and intercropping) from the second year of implementation.