Water and Irrigation Requirement for Summer Rice Crop of North Eastern Coastal Plain Zone of Odisha

Abstract

Due to continuous increase in population, the water demand and utilization have increased significantly. Rainfall is a limited source for productive agriculture in the province. But the sustainable management and use of water resources for food production is an important issue. So water requirement of crops was also an important part. Water used by crops is predominantly lost by transpiration (T) but there are also evaporative (E) losses from the soil and from plant surfaces. Crop water requirement is defined as the depth of water needed to meet the water losses through evapotranspiration (ET) of a disease free crop, growing in large fields under non restricting soil conditions including soil water and fertility while achieving full production potential under the given growing environment. Evapotranspiration is important to evaluate the irrigation potentialities of various agricultural zones and helps improve the practices of water management and crop production. The crop water requirement (CWR) and irrigation requirement (IR) of various crops were calculated using CROPWAT 8.0. Relevant crop coefficients (Kc), duration of crops and cropping pattern were used to calculate CWR from ETo. These coefficients present the relationship between references (ETo) and crop evapotranspiration (ET crop) or ET crop = Kc * ETo. Value of Kc varies with the crop, its stage of growth, growing season and the prevailing weather conditions. ET crop or CWR can be determined in mm per day. Water (ETc) and irrigation requirement of summer rice is 853mm and 661mm respectively