The model may describe the process (1) in time and (2) as a function of amount of water applied.
The salinity of the deeper soil first increases due to the salts leached from the top-soil, but later it also decreases.
In the Tagus delta, Portugal, the leaching efficiency of the dense clay soil was found as low as 0.10 to 0.15.
[4] The soil could not be developed for intensive agriculture and was used for rearing of bulls in coarse natural pasture.
[6] The figure illustrates the calibration process of leaching efficiency, which parameter is difficult to measure directly.