Coal ash in crop production system: effect on heavy metal distribution, plant accumulation, microbial activity and crop response

摘要

Coal ash has potential in supplying nutrient elements for plant growth besides act as an ameliorant for balancing soil pH. Suitability of using coal ash individually or as mixture with organic wastes, paper factory sludge, sewage sludge, animal manure and also chemical fertilizer in growing field crop was assessed with major thrusts on nutrient supply, crop response, changes in microbial properties, heavy metal accumulation and distribution in soil and in plant and changes in physico-chemical properties of soil. Application of ash individually or its mixture at different doses and forms in rice-peanut cropping system has increased growth and yield with significant improvement in availability of essential elements and also the status of physical, chemical and biological properties of soil. Incorporation of coal ash at all levels did not show any appreciable accumulation of environmentally sensitive metal either in soil or in the plant and also there is no evidence of increase in the mobile form of heavy metals: hence, the coal ash may be used as an ameliorant or as a source of plant nutrients.