A Spatial Analysis of Crop-land Suitability for Sustainable Agricultural Development in Aiyar Basin, Tamil Nadu

Abstract

Land suitability analysis for agriculture plays a key role in sustainable agricultural production. The aim of this study is to develop suitability maps for major agricultural crops using multi-criteria spatial analysis for Aiyar basin - a sub-basin of Cauvery basin in Central Tamil Nadu as a case study. The main criteria such as soil, topography, irrigation and socio-economic factors and 18 sub-criteria (soil depth, drainage, texture, pH, salinity, sodicity, CEC, organic carbon, base saturation, slope, erosion, geomorphology, canal, groundwater, irrigation intensity, agricultural labour availability, cultivators and agricultural credit banks) were used for the suitability analysis. All the criteria used for the suitability classification were not equally important; each criterion would contribute towards the crop growth and yield at different levels. Hence, the relative importance of these criteria was formulated on the basis of the guidelines of the National Bureau of Soil Survey and Land Use Planning (NBSS & LUP) as adapted to local conditions. The Geographic Information System (GIS) based Analytical Hierarchy Process (AHP) method was used to determine the weight and rating for each criterion. Then the criterion layers were classified into four suitability classes which were high (S1), moderate (S2), marginal (S3), and not suitable (N). After the spatial overlaying of all criterion layers, crop-land suitability maps for paddy, pulses, maize and cashew were prepared. The results revealed that 18.93 %, 22.34 %, 20.37 % and 19.89 % of the study area were highly suitable for cultivating paddy, pulses, maize and cashew respectively. The results of suitability analysis could provide assistance for local farmers and decision makers to select suitable crops that are most adaptable to the land characteristics.