Fertile soil has lots of humus. Why?

Fertile soils are rich in organisms that decomposes dead organic matter forming humus. Humus gives minerals, absorbs water and makes soil porous.

Fertile soils are rich in organisms that decompose dead organic matter forming humus. Humus gives minerals, absorbs water and makes soil porous.

Fertile soil contains sufficient amount of humus because (i) Humus is required for binding soil particles into crumbs. Crumb formation helps in both hydration and aeration of soil. (ii) Humus makes the soil porous for easy passage of plant roots (iii) Humus is a source of mineral. (iv) Humus contains chemical that promote growth of plants.