What is the exact meaning of soil erosine?

Answer 1

I take it you mean "soil erosion": there is no such word as erosine.

The dictionary definition of erosion is "the mechanical process of wearing or grinding something down." In soil erosion this is expanded to mean any process that removes soil, such as rainfall washing soil into water courses or wind blowing soil away.

Soil erosion is usually prevented by vegetation such as grass holding the soil in place and allowing it to accumulate. Soil erosion often occurs when the native vegetation is stripped away e.g for farming. This exposes the soil to the effects of the weather such as wind and rain and allows erosion to carry away the soil in which crops could be grown. Eventually so much soil can be lost that the land is no longer useful for farming.