In this book laboratory experiments and theoretical modelling are reported that investigate water use efficient methods of leaching saline clay soils that would be applicable to the soils in Pakistan. Analytical and numerical solutions of the diffusion equation were developed to determine the amount of solute leaving a single aggregate under conditions envisaged for the various leaching methods.Since solute transfer was more rapid when aggregates were initially unsaturated, methods are needed to de-saturate the soil before the desalinisation process. In the field, unsaturated soil conditions are obtained not only by surface evaporation but also by growing some plants.