Leaching model (soil)

A leaching model is a hydrological model by which the leaching with irrigation water of dissolved substances, notably salt, in the soil is described depending on the hydrological regime and the soil's properties.
The model may describe the process (1) in time and (2) as a function of amount of water applied.
Leaching is often done to reclaim saline soil or to conserve a favorable salt content of the soil of irrigated land as all irrigation water contains salts.

Leaching curves

The leaching process in a salty soil to be reclaimed is illustrated in the leaching curves of figure 1, derived from data of the Chacupe pilot area, Peru. It shows the soil salinity in terms of electrical conductivity (EC) of the soil solution with respect its initial value (ECi) as a function of amount of water percolating through the soil. The top-soil leaches quickly. The salinity of the deeper soil first increases due to the salts leached from the top-soil, but later it also decreases.

Leaching efficiency