Irrigation Scheduling of Pawale Project using FAO-CROPWAT 8.0

Introduction: The application of irrigation water to various crops in the command area based on daily crop water requirements considering the water holding capacity of different irrigated soils is a vital aspect of irrigation management. Considering the importance of irrigation scheduling, the FAO CROPWAT 8.0 is a patent tool, as it gives crop water requirements and irrigation schedules based on climatological and physiographic factors. Method: In this patent study, the CROPWAT 8.0 model is used to integrate the Cropwat model, long-term climate data is used, soil sensitivity analysis is performed and crop-specific water need is identified for the command area of the Pawale irrigation project which is a novelty as cropwat is not used previously for the study area. Pawale irrigation project is located in the Thane district of Maharashtra, India. Nineteen years of climatic data are used for the analysis, considering seven crops to calculate the crop water and net irrigation requirement for the kharif and rabi seasons. Result: The result indicates that crop-wise and season-wise variation of crop water requirement is from 2.5 to 1055.1 mm, and the net irrigation requirement for the year is 618.6 mm. It is also observed that rice requires more water from the initial stage up to the development stage than other crops considered in this study. Conclusion: In conclusion, we can say that the cropwat model with long-term climate data can develop effective data for crop's specific water needs. The results indicate that evapotranspiration has a greater impact on crop water and net irrigation requirements because, in both cases, the increase or decrease of ETo will affect the crops and their water requirement. The sensitivity analysis for different types of soils is also carried out for groundnut. The result indicates that, apart from crops, soil water-holding capacity is essential for irrigation scheduling. It is seen that nine rotations are required for red sandy soil as compared to six rotations and four rotations for red sandy, loamy soil and black clay soil, respectively.