Estimation of crop water requirement of major crops under deficit rainfall conditions in the Chhattisgarh plains zone

Abstract

This study focuses on estimating crop water requirements (CWR) in the Chhattisgarh Plains Zone, a critical agricultural region covering half of the state’s area. With a significant dependence on monsoon rainfall, reliable irrigation is essential for sustaining crop productivity. The research utilizes the CROPWAT 8.0 model and long-term climatic data from IGKV, Raipur, to quantify water demands for major crops like rice, wheat, maize, and pulses. Climatic variables including rainfall, temperature, humidity, sunshine hours, and wind speed were considered for CROPWAT modeling. Over three decades (1991-2020), Raipur’s average annual rainfall was 1200.1 mm, with six years experiencing rainfall deficits, notably severe in 2002. The study analyzed crop-specific water needs based on crop durations, sowing times, and suitable soils obtained from FAO and Krishi Darshika. Soil data from IGKV, Raipur, provided insights into water retention and infiltration affecting irrigation requirements. Results showed notable seasonal variations in evapotranspiration (ETo), with peak demand in May (7.53 mm/day) and minimal in December (2.50 mm/day). During the severe deficit year (2002), ETo remained high, emphasizing sustained crop water demands despite reduced precipitation. Effective rainfall analysis revealed monthly variations in soil moisture availability for supporting crop growth. This research enhances understanding of water demand patterns and underscores the need for adaptive water management strategies to optimize agriculture in the Chhattisgarh Plains zone amidst changing climatic conditions