IRRIGATION SCHEDULING USING CROPWAT 8.0 FOR IRRIGATION COMMAND

Abstract

Increasing the efficiency of water use in agriculture sector is crucial for national development. Thus the improvement of irrigation water management has become a major priority to meet our present agricultural demand as our population is ever increasing. The purpose of irrigation is to enable the farmers to improve their agricultural production. The efficient management of irrigation water for maximising productivity requires both the on-farm development of the irrigated area and optimisation of the use of water and land through appropriate cropping, irrigation scheduling and water application method. Irrigation scheduling consists of applying the right amount of water at the right time-in other words, making sure water is available when the crops need it. It is the primary tool to improve water use efficiency and raise yield as it minimize the runoff and percolation losses. The irrigation schedule indicates when irrigation water has to be given to the crop. Since the cost of irrigation application has been increasing, elimination of unnecessary irrigation applications would improve economics of crop production. Scheduling is an accurate irrigation strategy to conserve water, minimize water wastage and to keep the associated costs down. In order to save both water and energy scheduling is required. This study is primarily aimed at to determine reference evapotranspiration, irrigation water requirement and to schedule the irrigation. The command area selected for the present study is Gadarjudda minor canal off taking from Deoband branch of Upper Ganga Canal System situated in Haridwar District, Uttrakhand. 'Different methods of determining ETo viz. Modified Penman; Penman Monteith; Radiation and Blaney Criddle are used to make a comparative study on ETo determination. For Penman Monteith method CROPWAT package is used. Irrigation requirements were worked out for wheat, sugarcane and rice crops. A Microsoft Excel based computer program was developed to work out the irrigation schedules using ETo inputs iv calculated by different methods. CROPWAT software was also used for preparing irrigation schedules.