Irrigation Management with Brackish Water Impacting Biomass and Protein Productivity in Intercropped Opuntia stricta and Clitória ternatea

The use of brackish water associated with intercropping is an approach that can enhance the resilience of agriculture in semi-arid regions. Therefore, this study aimed to evaluate irrigation with brackish water as a strategy to ensure the sustainability of forage production in isolated and intercropped systems. The study was conducted under a hot semi-arid climate in the years 2022, 2023, and 2024. Two water scenarios (rainfed and irrigated) and four production systems with forage cactus-FC (<i>Opuntia stricta</i>) and butterfly pea-BP (<i>Clitória ternatea</i>) were evaluated: FC-forage cactus, BP-butterfly pea, FC+1BP-forage cactus intercropped with one row of BP, and FC+2BP-forage cactus intercropped with two rows of BP. Butterfly pea received supplemental irrigation from February to August, while the forage cactus was irrigated during the dry season (July to December). Our results showed that the strategic management of irrigation with brackish water optimizes biomass and protein production in crops adapted to the tropical semi-arid region. The FC+1BP intercropping system (forage palm with a row of butterfly pea) proved to be the most advantageous, mainly in terms of crude protein production and water use efficiency, proving to be an alternative for forage production and food security for livestock in the tropical semi-arid region.