Irrigation Scheduling of Pawale Project using FAO-CROPWAT 8.0

Abstract

Application of irrigation water to various crops in the command area on the basis of daily crop water requirement considering water holding capacity of various irrigated soils is vital aspect of irrigation management. Considering importance of irrigation scheduling present version of FAO CROPWAT 8.0 is very much useful tool, as it gives crop water requirement and irrigation schedule on the basis of climatological and physiographic factors of the command area. In this study CROPWAT 8.0 model is used for calculation of crop water requirement and thus irrigation requirement which can be used for scheduling the irrigation for command area of Pawale irrigation project. Pawale irrigation project is located in Thane district of Maharashtra India. Nineteen years of climatic data is used for the analysis, considering seven crops to calculate the crop water and net irrigation requirement for kharif and rabi season. The result indicates that crop wise and season wise variation of crop water requirement is from 2.5 to 1055.1 mm and net irrigation requirement for the year is 618.6mm. It’s also observed that rice requires more water from initial stage upto development stage as compared to other crops considered in this study. The results indicates that evapotranspiration has greater impact on crop water requirement and net irrigation requirement because in both the cases, the increase or decrease of ETo will affect the crops and their water requirement. The sensitivity analysis for different type of soils is also carried out for groundnut. The result indicates that, apart from crop, the water holding capacity of soil is very important characteristic for irrigation scheduling. It is seen that. 9 rotations are required for red sandy soil as compared to 6 rotations and 4 rotations to red sandy loamy soil and black clay soil respectively.