A review on water management of crops and cropping system in India

The water requirement of crops is the quantity of water required by the crops within a given period for their maturity and it includes losses due to evapotranspiration plus the unavoidable losses during the application of water and water required for special operations such as land preparation, puddling and leaching. The quantity of water needed for irrigation on different soil types per meter depth of soil profile at 50% of soil moisture availability is as follows. Sandy soils (25-50 mm), Sandy-loam (45-80 mm), Loam (70-110 mm), Clay-loam (80-120 mm) and Heavy clay (100-140 mm). Light soils, long-duration varieties during Kharif, medium duration varieties during summer. For low land rice, the practice of keeping the soil saturated of submergence of about 5 cm throughout the growing period is beneficial. The water requirement of rice is higher than that of any other crop of a similar duration, an assured and timely supply of irrigation water has a great influence on the yield of the crop. The dwarf wheat needs more wetness and the optimum moisture range is from 100-60% of availability. For tall wheat, the optimum-moisture range is from the field capacity to 50% of availability. Four to six irrigations are enough for the wheat crop. However, crown root initiation and heading stages are the most critical to moisture stress.