Optimizing Cowpea Cultivation in Saline Hydromorphic Soils: A Sustainable Approach for Kaipad Agroecosystems

Abstract

Kaipad lands, a distinct coastal agro-ecosystem located in northern Malabar, Kerala, are characterized by saline-prone hydromorphic soils that pose significant challenges for traditional rice cultivation. The unique conditions of periodic waterlogging and salinity necessitate the exploration of alternative crops to enhance agricultural sustainability. This study investigates the suitability of cowpea (Vigna unguiculata L Walp) as a resilient leguminous crop for cultivation in traditionally organic rice growing problematic soils. Cowpea, known for its adaptability to diverse environmental conditions, nutritional value, and economic importance, presents a promising option for farmers facing the limitations of organic rice production. A pot culture experiment was conducted to assess the impact of potassium solubilizing bacteria (KSB) on cowpea growth and yield in saline hydromorphic soils. Treatments included combinations of KSB with various potassium sources, such as feldspar and mica, used as alternate sources for potassic fertilizers. Results demonstrated that KSB significantly improved growth parameters, including plant height, leaf area, total dry matter production, and pod and grain yields, compared to control. Soil analysis revealed enhanced availability of potassium and other essential nutrients in KSB-treated soils, indicating a synergistic effect on nutrient solubilization in aerobic conditions. The findings suggest that cowpea, supported by KSB application, can be effectively cultivated in problematic Kaipad lands, offering a viable alternative to traditional rice farming while promoting sustainable agricultural practices. This research highlights the potential for diversifying crop production in saline-prone areas, ultimately contributing to food security and economic resilience in coastal agro-ecosystems.