Rehabilitation of lands mined for limestone in the Indian desert

In the Indian desert. the economics of mining is second only to agriculture in importance. However, research on the rehabilitation of land disturbed b y mining has only recently received serious attention. An attempt has been made to determine both the qualitative and quantitative success of rehabili tation plans used to revegetate limestone mine spoils in an area near Barna . northwest arid India. Rehabilitation success was achieved using a combina tion of rainwater harvesting techniques, soil amendment application approac hes, plant establishment methods and the selection of appropriate germplasm material (trees, shrubs and grasses). It is expected that the resulting ve getative cover will be capable of self-perpetuation under natural condition s while at the same time meeting the land-use needs of the local people. Th e minespoils have adequate levels of the major nutrients (except P, Mo and Se) for proper plant and grazing animal health. Levels of organic matter ar e low whereas total B concentrations are exceptionally high. Also, the popu lation of soil fungi, Azotobactor, and nitrifying bacteria is negligible. E nhanced plant growth was achieved in treated plots, compared to control plo ts, where spoil moisture storage was improved by 5-45 per cent. Due to the decomposition of farmyard manure and nitrogen fixation by planted leguminou s plant species, the electrical conductance of treated mine spoils increase d threefold, CaCO3 content decreased from 20.0 to 5.2 per cent, and organic carbon, P, K, and biological activity increased significantly. The rehabil itation protocol used at the site appears to have been successful because p lant self-regeneration is occurring. The increased diversity of woody peren nials resulted in 'dominance' being better shared among species and 'evenne ss' being increased within the plant community elements. The early to mid-s uccessional trends are continuing for six years following initial rehabilit ation. This study developed methods for the rehabilitation of lands mined f or limestone and has also resulted in an understanding of rehabilitation pr ocesses in arid regions with an emphasis on the long-term monitoring of reh abilitation success. Copyright (C) 2000 John Wiley & Sons, Ltd.