Assessment of Crop Water Requirements of Nagarjuna Sagar Right Canal Command Area under Guntur District, Andhra Pradesh, India

The Nagarjuna Sagar Right (Jawahar) Canal Command area spans 37 mandals in Guntur. Surface water availability has been assessed using data from the Water Resources Department, specifically from the Lingamguntla and Ongole Circles within the command area of Andhra Pradesh. Groundwater levels are monitored through 300 observation wells across the command area, managed by the State Groundwater Department. The water requirements for various crops, including paddy, cotton, chilies, millet, and pulses, have been calculated. CROPWAT 8.0 was utilized to calculate the water requirements for crops, whereas EasyFit and SPSS software were employed to analyse the rainfall data that had been input for the crop water requirement calculations. For instance, the crop water requirement for paddy in the Guntur district's NSRC command area, particularly in black soil regions, is 488.2 mm, with an irrigation water requirement of 368.9 mm. The percentage of water requirement calculated for paddy in the Guntur district of NSPRC was 72%, for chillies 74%, for cotton 65%, for pulses 61%, and for millets 65%, when compared to the entire command area. Finally, the available water supply is insufficient, necessitating the selection of alternative crops to fully cultivate the area.