Rehabilitation of Limestone Minespoils with Reference to Agroforestry

Abstract

The sensitive eco-system of outer north-west Himalaya has been greatly disturbed by mining and other developmental activities. Efforts were made since 1983 to rehabilitate these minespoils. For their rehabilitation, measures adopted were a combination of mechanical and biological techniques to arrest soil, water and nutrient losses on one hand and increase productivity on the other hand. Measures undertaken comprised construction of drop structures upto 40% slope, silt detention basins upto 20% slope, construction of log wood, brushwood and loose rock filled check dams, crib structures especially on slide faces on steeply sloping areas, toe and retaining walls, terracing, contour trenching, contour wattling, mulching, normal soil placement and mixing in trenches and pits, fertility management through leaf manures, farm yard manure and fertilisers, direct seeding, pitting and planting of suitable MPTs, shrubs and grass species. Apart from this, measures like use of geo-jute, netlon, geogrids, excelsior matting, mulching with native plant material, etc. also proved very effective for steep slopes (30- 70%) stabilisation. The MPTs and other plant species were identified based on experimental findings.

 With continuous biotic protection together with rehabilitation measures retrogression and erosion has come to stand still. The vegetal cover has increased from 10% to > 80% over a period of 15 years. Techniques adopted over time have helped in improvement of spoil characteristics. Runoff and soil loss has considerably decreased and water quality improved rendering it potable. Treated mine sites have now started generating additional resources of water, firewood, fodder, timber, fibre, etc. on sustainable basis and have improved the economy of the area.