Sustainable Intensification of Agricultural Productivity in Semi-Arid-Tropics (SAT) of India – Case studies

Sustainable intensification is a term now much used in discussions around the future of agriculture and food security. Semi-arid tropics have largely remained outside the process of excessive intensification, due to the paucity of water. Rather agricultural intensification was restricted to the smaller fractions of irrigated areas in the vast areas of semi-arid tropics. The present study analyses the sustainability using three different approaches. One, Geospatial analysis, second crop simulation modelling and third an econometric analysis. In Geospatial analysis both spatial and temporal changes in per unit cropped area are captured with more precision and accuracy. Crop simulation models are valuable tools in assessing sustainability of cropping systems. The major components of the model are vegetative and reproductive development, carbon balance, water balance and nitrogen balance. It simulates crop growth and development using a daily time step from sowing to maturity and ultimately predicts yield. In the present study we evaluated eight sustainability indicators, crop yield, water-use efficiency (WUE), the amounts of soil organic carbon (OC) across cycles of the rotation, nitrogen fixing, ‘N’ leaching, Nitrogen-use-efficiency, inorganic ‘N’ in soil at maturity, total ‘N’ uptake at maturity. Sustainability polygons were developed to illustrate the sustainability state of a crop rotations to traditional rotations. To measure sustainability, household survey data collected from designated studies was used to derive indicators of sustainability. A range of sustainability indicators were generated from the survey relating to ecological, economic and social dimensions. The main purpose of this study was to elicit changes across the farming systems and agro-ecological regions and derive conclusions for sustainability across study locations