Impact of electrically operated tubewells on water use, water productivity and profitability of major crops in Gorai village, Samastipur district of Bihar

Abstract

A field study was conducted in Gorai village of Kalyanpur block, Samastipur district, to evaluate the economic and water-use efficiency of electric versus diesel-operated tubewell irrigation systems across major crops. The study encompassed 20 farmers and analysed multiple parameters including water productivity, irrigation costs, crop profitability and water balance. The irrigation water productivity values were highest for kharif maize at 7.77 kg/m³, followed by wheat (1.95 kg/m³), spring maize (1.45 kg/m3), rabi maize (1.01 kg/m³) and paddy (0.79 kg/m³). In terms of gross water productivity, wheat showed the highest efficiency at 1.69 kg/m³, followed by rabi maize (0.95 kg/m³), spring maize (0.89 kg/m³), kharif maize (0.74 kg/m³) and paddy (0.44 kg/m³). Economic analysis revealed that diesel pump irrigation costs were substantially higher than electric pump costs, ranging from 30 to 37 times more expensive across crops. This cost differential significantly impacted profitability, with electric pump users achieving higher profits of 22 % more for paddy, 13 % for rabi maize, 7.8 % for wheat, 4 % for spring maize and 2 % for kharif maize. The study demonstrates that crop selection and irrigation technology choice are critical factors for optimizing both water use efficiency and farm economics. While electric tubewells demonstrate clear economic advantages, the extremely low electricity tariffs (₹ 0.75/unit) raise sustainability concerns regarding potential groundwater overextraction, necessitating integrated groundwater governance frameworks.