An Encyclopaedia of Indian Archaeology v1.c14.s1.1

v1.c14.s1.1

Also called *regar*, this soil is formed as a result of weathering of the basaltic rocks, extensively spread over w. and c. India and the Deccan. The exact process of the weathering is little understood, but it may be partly due to the action of abundant humic acids in the soil formed under thick wild-grass and brushwood vegetation. The soil has a high degree of fertility in the plains but in the uplands and slopes of hills it is rather poor. It is largely used for growing cotton; hence its name. More often than not it is a highly-weathered pedocal. It is rich in iron oxide, alumina and lime. Much of the lime is found precipitated in the form of nodules in the illuvial zone of the soil. The depth of its weathered profile frequently goes down to 2 to 4 m or more. Its colour varies from 5 YR 3/2 dark reddish-brown to 2·5 YR 5/4 reddish-brown. Loamy and rich in clay and humus, it is retentive of moisture and sticky when wet. During winter and summer months it dries up, contracts, becomes hard and develops deep polygonal fissures, some of them measuring as much as 10 cm in breadth and 1 to 2 m in depth. Recent studies show that the soil was formed during the early part of the Holocene, under climatic conditions comparable to those of the present.