sentences:  By varying the fraction of used drain or well water (to be given in the input data), the long-term effect of different fractions can be simulated.The dissolution of solid soil minerals or the chemical precipitation of poorly soluble salts is not included in the computation method, but to some extent it can be accounted for through the input data, e.g.by increasing or decreasing the salt concentration of the irrigation water or of the incoming water in the aquifer.