Assessment of Available Water and Crop Water Requirements of Major Crops in Nagarjuna Sagar Right Canal Command Area, Andhra Pradesh, India

The mean water releases at head section of 11 years of Nagarjuna Sagar Jawahar right main Canal, Andhra Pradesh, India is found to be 128.13 TMC (3,627.71 MCM). The mean surface water availability was estimated as 2,229 MCM. For the efficient utilization of groundwater, the quality plays a major role in terms of selection of crop variety for sustainable agriculture. The ground water quantity of the command area available was estimated 1385 MCM and the mean annual conjunctive use of command area was 3,614 MCM (128 TMC).

The crop water requirement for paddy, cotton, chilies, millet and pulses were estimated in the command area by using CROPWAT model. The crop water requirement for paddy in NSRC command area of Guntur district for black soils was 848.2 mm. The irrigation water requirement was 638.9 mm and for red soils, crop water requirement for paddy and irrigation water requirements were 848.2 mm and 624.5 mm respectively. Similarly, computed for all the crops and overall crop water demand for both (Guntur and Prakasam) districts of NSRC command area for different soils and different crops per annum was 4,456 MCM without considering cattle and domestic water use. Based on the research, it was concluded that the available water is not sufficient and it is suggested to choose alternative crops for bringing entire area into cultivation.