NUTRIENT DISPERSION MODELING OF COAL OVERBURDEN DUMPS FOR RECLAMATION AND SUSTAINABLE MANAGEMENT

This study presents an innovative approach for the effective reclamation and management of coal overburden dumps. The study reveals that the existing and liberated nutrients due to natural phenomena are washed away by the run-off in the form of leachate during resting period of 5 years. The concentration of organic matters and organic carbon are also decreasing and as the result of these phenomena, the electric conductivity also decreases. The nutrients on the top layer starts increasing during 6th years while nutrient amendment was done just before plantation by means of biodegradable manures on the top-soil amended on the dump materials for reclamation purpose. After plantation, it has been observed that the nutrient loss on the top-layer is very less due to plantation as the roots control the soil erosion. However, there is no significant improvement in the nutrient refilling the dump as the leaves fall is not much. The nutrient status of the dump after plantation has been studied for different ages 6…10, 11…15, 16…30 years using the predictive model and the probable reasons have been well discussed. The study concludes that there are no soil amendments after 10 years but the plants are found to be capable to significantly refill the nutrients as there is a huge quantity of leaf-drops from the planted trees and become compost after going through the process of decaying to serve the plants. In this way, the plants survive without requirements of nutrient amendments meeting its nutrients themselves and such a capability of self-satisfying characteristics of plants through nutrient transaction between soil and plants go on as a cyclic phenomenon through the natural process due to recurrent seasonal changes. As a result of the combined effect of penetrated plant roots in all the directions across the soil and dump materials and the increased organic matter decreases the bulk density and increases the water holding capacity. Keywords: reclamation of coal overburden dumps; nutrient dispersion modeling; overburden dump management