A MODEL OF CROP YIELD RESPONSE TO IRRIGATION WATER SALINITY - THEORY,TESTING AND APPLICATION

A relationship between crop yield and irrigation water salinity is dev eloped. The relationship can be used as a production function to quant ify the economic ramifications of practices which increase irrigation water salinity, such as disposal of surface and sub-surface saline dra inage waters into the irrigation water supply system. Guidelines for t he acceptable level of irrigation water salinity in a region can then be established. The model can also be used to determine crop suitabili ty for an irrigation region, if irrigation water salinity is high. Whe re experimental work is required to determine crop yield response to i rrigation water salinity, the model can be used as a first estimate of the response function. The most appropriate experimental treatments c an then be allocated. The model adequately predicted crop response to water salinity, when compared with experimental data.