Assessment of irrigation water management using FAO-CROPWAT 8 in the Paliganj distributary of the Sone irrigation scheme in Bihar: a case study

ABSTRACT Around 15% of India's gross domestic product comes from agriculture, which is the foundation of the country's economy. India's economic development and efforts to combat poverty have already benefited greatly from its agricultural sector. Sustainable management of water resources can increase agricultural productivity. The study was performed in the Paliganj distributary, a part of the Sone canal system in south Bihar, India. The Paliganj distributary command area lies wholly in the Gangetic plain. The estimation of crop evapotranspiration was carried out using the Modified Penman–Monteith equation for the period 1980 to 2015. The crop coefficient of the crops has been estimated by using a single crop coefficient and a dual crop coefficient. The crop water requirement, irrigation water requirement, and irrigation scheduling of crops grown in the study area were determined using CROPWAT 8.0 software. The results conclude that the maximum, minimum, and average values of ET0 were found to be 7.65 mm/day, 1.31 mm/day, and 3.86 mm/day respectively. The crop water requirement and irrigation requirement of crops grown in Kharif, Rabi, hot weather, and annual seasons in the study area were lower by using dual crop coefficient.