FAO Irrigation and Drainage Paper Crop by
This publication presents an updated procedure for calculating reference and crop evapotranspiration from meteorological data and crop coefficients. The procedure, first presented in the FAO Irrigation and Drainage Paper No. 24 'Crop Water Requirements', ETo' approach, whereby the effect of the climate on crop water requirements is given by the reference evapotranspiration ETo and the effect of the crop by the crop coefficient Kc. Other procedures developed in FAO Irrigation and Drainage Paper No. 24 such as the estimation of is termed the 'Kc dependable and effective rainfall, the calculation of irrigation requirements and the design of irrigation schedules are not presented in this publication but will be the subject of later papers in the series.