Utilization of fly ash as an amendment for sodic soil: An alternate source for gypsum

Abstract

Fly ash (FA) is the byproduct produced from combustion of coal in thermal power plant in large quantity become a solid waste all over the world. The disposal of fly ash by dumping in arable lands leads to degradation of cultivable lands. Though it contains lot of nutrients gaining its importance in agriculture. This study evaluated the potential of fly ash based vermicomposting in recovering the nutrients from fly ash for utilization of fly ash as a sodic soil amendment. Seven combination of partially decomposed cow dung (PCD) and fly ash (FA) at 1:1, 1:2, 1:2.5, 1:3, 2:1, 2.5:1, 3:1 ratios were imposed to find out the best combinations of fly ash based vermicompost (FAV). Earthworm (Eisenia fetida) was added to each treatment containing PCD and FA mixed in different ratios. The vermicomposting process was continued up to 42 days (6 weeks) and nutrients such as Total carbon, Total Nitrogen, Total Phosphorus, Total Potassium and Total Calcium content were analyzed. The results showed that among the different combinations, cow dung: fly ash in the ratio of 3:1 reached maturity in rapid matter with low pH, EC and C:N ratio whereas rich in other nutrients like Total Nitrogen (TN), Total Phosphorus (TP), Total Potassium (TK) and Total Calcium (TCa) during the process of vermicomposting. Since the fly ash based vermicompost contains 14.4% calcium content, it can be used as an amendment for sodic soil reclamation.