Assessment of Rainfed Crop Suitability in the Gomukhi Watershed of Tamil Nadu, India: A GIS-Based Analytic Hierarchy Process Approach

In the light of evolving climate patterns, water scarcity challenges, and economic constraints faced by farming communities in Tamil Nadu, India, the imperative to diversify crops beyond water-intensive varieties such as paddy and sugarcane, etc., has become increasingly evident. This study, aligned with the National Bureau of Soil Survey and Land Use Planning (ICAR) manual (Naidu et al., 2006), focuses on bolstering rainfed crop cultivation in the Gomukhi watershed area. Employing Analytic Hierarchy Process based GIS overlay methodologies, the research evaluates the suitability of key rainfed crops, including cereal crops (Sorghum and Ragi), oilseed crops (Groundnut and Sesamum), and fiber crops (Cotton). Assessment criteria encompass soil quality, climatic factors, and physical parameters, with relative weights determined through AHP. Suitability zones for each crop at the sub-watershed level are classified in accordance with Food and Agriculture Organization (FAO) guidelines (S1, S2, S3, and N categories). Specific sub-watersheds highly suitable for each crop are identified based on their distinctive requirements, offering crucial insights for farmers seeking alternative and sustainable cropping strategies. For Ragi, highly suitable sub-watersheds include 4C1A3f1, 4C1A3f11, and 4C1A3f12. Sorghum exhibits high suitability in sub-watersheds 4C1A3f30, 4C1A3f39, 4C1A3f22, and others. Groundnut flourishes in areas such as 4C1A3f17, 4C1A3f33, and 4C1A3f39. Sesamum is found to be suitable in sub-watersheds 4C1A3f11 and 4C1A3f12. Finally, cotton is identified as highly suitable in sub-watersheds like 4C1A3f17, 4C1A3f30, and 4C1A3f39. This comprehensive study provides valuable information for sustainable agricultural planning and resource optimization, offering a pathway for farmers in the Gomukhi watershed area to diversify their crops and adapt to the changing agricultural landscape.