Water requirements manual for irrigated crops and rainfed agriculture

Crop Evapotranspiration, ET (Crop), is figured from ETP and crop coefficients, KC. Desirable irrigation efficiencies are suggested, leaching requirements are defined, and soil conditions and other factors influencing the amount of water to be applied are described. A procedure is presented for scheduling irrigation using principally mean monthly climatic data. A concept of dependable precipitation is developed and used to relate to moisture adequacy and crop production or in the development of moisture adequacy production functions. Critical periods for moisture stress are given for a large number of crops. A classification of moisture deficits and climate is proposed to be used principally for evaluating precipitation potential for rainfall agricultural. Computer equations are shown for calculating potential evapotranspiration, dependable precipitation, evapotranspiration deficits, and a moisture availability index.