Impact of fly ash incorporation in soil systems

Fly ash (FA)-a coal combustion residue of thermal power plants has been regarded as a problematic solid waste all over the world. The conventional disposal methods for FA lead to degradation and contamination of the arable land. However, several studies proposed that FA can be used as a soil-additive that may improve physical, chemical and biological properties of the degraded soils and is a source of readily available plant micro- and macro-nutrients. Numerous studies revealed that the lower FA incorporation in soil modifies the physico-chemical, biological and nutritional quality of the soil. However, the higher dosage of FA incorporation results in heavy metal pollution and hinders the microbial activity. Practical value of FA in agriculture as an "eco-friendly and economic" fertilizer or soil amendments can be established after repeated field experiments for each type of soil to confirm its quality and safety. Integrated Organic/Biotechnological approaches should be applied for the reducing toxicity of FA contaminated site near thermal power plants. Overall, study reveals that FA could be effectively used in the barren or sterile soil for improving quality and enhancing fertility. The purpose of this paper is to explore the possibility of FA addition into degraded soils for improving nutritional and physico-chemical properties. (C) 2009 Elsevier B.V. All rights reserved.