Function of soil cracks

Abstract

A characteristic feature of heavy soils such as the black cotton soil is their extensive cracking during summer fallow. Wide fissures are formed as a result of the shrinkage of the soil colloids under the baking action of the hot sun during summer months. These cracks vary from a fraction of an inch to 3-4 in. in width, and are often several feet in depth. It is generally recognized that cracking results in an improvement in the physical properties of the soil, but the factors which determine the character of cracking in field soils have remained rather obscure. Interesting information has been obtained in the course of a survey of the nature and extent of surface cracking in different fields under cotton in the Institute area. The technique adopted was as follows: