Optimizing onion crop water requirements using CROPWAT 8.0 and GIS-based spatial analysis

Abstract

Efficient water management is crucial for sustainable agriculture, especially in water-intensive crops like onion (Allium cepa L.). This study integrated CROPWAT 8.0 and Geographic Information System (GIS)-based spatial analysis to optimize the water requirements for onion cultivation in a semi-arid region of Northern India. Climate, soil, and topographic data were used to calculate reference evapotranspiration (ET0) and crop water requirements (CWR). The study identified three distinct water demand zones: high (40%), moderate (35%), and low (25%) demand areas. The optimized irrigation schedules reduced water consumption by 18%, improved water use efficiency from 4.8 to 6.1 kg/m³, and increased onion yield by 17% (from 18.5 tons/ha to 21.7 tons/ha). These results emphasize the potential of integrating CROPWAT 8.0 and GIS in precision agriculture for enhancing resource efficiency and sustainability. Future directions include expanding the methodology to diverse crops and incorporating real-time monitoring technologies.