TN-37 : Drainage in heavy soils

Abstract

Drainage of heavy land is largly governed by the fact that the hydraulic conductivity of the subsoil is generally too low to allow percolation of excess rain water to lower depth. Vertisols and associated soils occupy about 72.9 m ha areas in India. In spite of high potential productivity of these soil and favourable climatic conditions, the soil remain under utilized due to number of problem. Most of the problem arise due to their generally low water intake rate and due to poor internal drainage.

There are several technique available for draining heavy clay soils. The solutions depends essentially on the ratio of rate of precipitation to the rate of downward flow through the soil system consisting of poorly previous layer and the presence or absence of a high pervious subsoil. The various technique of draining heavy soil currently practised in different parts of Maharashtra, Madhya Pradesh such as various surface methods, vertical drainage, pipe drainage have been reviewed. Also the use of various models for estimating field drainage from heavy land in the tropics have been presented. The various methods currently used in different parts of the world for draining heavy land such as artificial backfill, mole drainage, sub soiling, chemical methods and surface drainage have also been reported.