Why Rainfall is imprtant factor in active soil formation

Of the various climatic elements that take part in active soil formation, rainfall or precipitation is the most important factor.  It supplies water whose movement through the parent material controls the nature of the soil body to a very large extent. As it percolates and moves from one part of the parent material to another, it carries with it substances in solution as well as in suspension.  The substances so carried are either redeposited in another part of the parent material when the movement of water stops or leached out and completely removed from the soil
body. The movement may take place downward, upward or even lateral. As a result of this, one part of soil body is deprived of some constituents and other enriched.