The concept of irrigating in excess of plant water requirement to restrict soil profile salinity to acceptable limits is well established. The tolerable upper salinity limit is used to calculate the leaching requirement. This upper limit is determined mainly by crop salt sensitivity and acceptable yield decrease. It is proposed that when salinity limits are such that reduced yields result, then plant water use is also reduced. Should the crop be irrigated according to water requirements for non-saline conditions, the leaching fraction will be higher than planned. A degree of self-adjustment in the leaching fraction can thus be expected. Calculations were carried out to confirm and demonstrate the importance and applications of this concept.S. Afr. J. Plant Soil1986, 3: 181–184