Leaching model (soil) 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. <br> The model may describe the process (1) in time and (2) as a function of amount of water applied. <br> 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. The leaching process in a salty soil to be reclaimed is illustrated in the leaching curves
The Formation of Vegetable Mould through the Action of Worms causes, such as dust deposition and washing down of soil, have buried such ruins. Denudation (removal of matter to a lower level) is caused mainly by air and water movement. Humic acids generated by worms disintegrate rock; their burrowing behaviour speeds this up. But as the soil layer thickens, this process is slowed down. Worms swallow hard objects (e.g. stones) to aid digestion, which causes attrition to such objects. This has geological significance, especially for the smaller particles which otherwise are eroded very slowly. Rain causes castings to move down an incline; Darwin worked out the weight moving a certain