APPLICATION OF BIO-DRAINAGE FOR RECLAMATION OF WATERLOGGED SITUATIONS IN DELTAIC ORISSA

Abstract

Management of excess water in agricultural field is a major challenge globally as well as in India, in particular, where about 8.5 million ha area is waterlogged. The extent of water logging and associated soil salinity has already thrown a serious challenge for sustainability of irrigated agriculture in irrigation commands. Flat and saucer shaped topography of land, high rainfall, and inadequate drainage often lead to water-logging in irrigation commands. To combat drainage problem of such an extent, the technology needed to be less expensive and environment friendly for its sustenance. Reliance on capability of vegetation to reduce water table has been reported promising both in India as well as in other countries. The main physiological feature of such vegetation is profuse transpiration whenever the root system comes in contact with groundwater. As physical drainage measures, several engineering approaches like tube well, surface, sub-surface drainage have been adopted to deal with the problem of water-logging. But they have limitations like high cost of construction and subsequent maintenance cost, etc. Moreover, large scale engineering intervention altering topography could be a source of environmental concern. In this context use of vegetation for drainage appears promising. It is reported that trees could be used to manage rising water table and salinity problem. The clear impact of lowering of water table is reported to be evident even within 10 years of establishment of vegetation. The approach is relatively cheaper, sustainable and ecologically compatible relying on natural capability of vegetation to transpire water. Introduction of suitable intercrops in bio-drained area is also an issue for strategic application of bio-drainage as a tool for reclamation of waterlogged area for agricultural production. It is perceived that combination of bio-drainage with conventional drainage might make drainage planning in irrigation commands socioeconomically more relevant and environmentally sustainable. This conjecture warranted present investigation for better understanding of the problems, issues and opportunities for fitting in bio-drainage into an integrated framework of agricultural drainage management on sustainable basis. An account of research accomplishments is reported in this bulletin.