Effect of fly ash application on soil microbial response and heavy metal accumulation in soil and rice plant

A K Nayak; R Raja; K S Rao; A K Shukla; Sangita Mohanty; Mohammad Shahid; R Tripathi; B B Panda; P Bhattacharyya; Anjani Kumar; B Lal; S K Sethi; C Puri; D Nayak; C K Swain

doi:10.1016/j.ecoenv.2014.03.033

Effect of fly ash application on soil microbial response and heavy metal accumulation in soil and rice plant

Ecotoxicol Environ Saf. 2015 Apr:114:257-62. doi: 10.1016/j.ecoenv.2014.03.033. Epub 2014 May 14.

Authors

A K Nayak¹, R Raja², K S Rao², A K Shukla³, Sangita Mohanty², Mohammad Shahid², R Tripathi², B B Panda², P Bhattacharyya², Anjani Kumar², B Lal², S K Sethi², C Puri², D Nayak², C K Swain²

Affiliations

¹ Central Rice Research Institute, Cuttack 753006, Odisha, India. Electronic address: aknayak20@yahoo.com.
² Central Rice Research Institute, Cuttack 753006, Odisha, India.
³ Central Rice Research Institute, Cuttack 753006, Odisha, India; AICRP (Micronutrients), IISS, Bhopal, India.

PMID: 24836933
DOI: 10.1016/j.ecoenv.2014.03.033

Abstract

Fly ash (FA), a byproduct of coal combustion in thermal power plants, has been considered as a problematic solid waste and its safe disposal is a cause of concern. Several studies proposed that FA can be used as a soil additive; however its effect on microbial response, soil enzymatic activities and heavy metal accumulation in soil and grain of rice (cv. Naveen) to fly ash (FA) application was studied in a pot experiment during dry season 2011 in an Inceptisol. Fly ash was applied at a rate of zero per cent (FS), five per cent (FA5), ten per cent (FA10), twenty per cent (FA20), 40 per cent (FA40) and 100 per cent (FA100) on soil volume basis with nitrogen (N), phosphorus (P) and potassium (K) (40:20:20mg N:P:Kkg(-1) soil) with six replications. Heavy metals contents in soil and plant parts were analysed after harvest of crop. On the other hand, microbial population and soil enzymatic activities were analysed at panicle initiation stage (PI, 65 days after transplanting) of rice. There was no significant change in the concentration of zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), cadmium (Cd) and chromium (Cr) with application of fly ash up to FA10. However, at FA100 there was significant increase of all metals concentration in soil than other treatments. Microorganisms differed in their response to the rate of FA application. Population of both fungi and actinomycetes decreased with the application of fly ash, while aerobic heterotrophic bacterial population did not change significantly up to FA40. On the other hand, total microbial activity measured in terms of Fluorescein diacetate (FDA) assay, and denitrifiers showed an increased trend up to FA40. However, activities of both alkaline and acid phosphatase were decreased with the application of FA. Application of FA at lower levels (ten to twenty per cent on soil volume basis) in soil enhanced micronutrients content, microbial activities and crop yield.

Keywords: Fly ash; Heavy metals; Heterotrophs; Nitrifiers; Oxidizers; Soil enzymes.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Actinobacteria / isolation & purification
Bacteria / isolation & purification
Coal Ash / pharmacology*
Fungi / isolation & purification
Metals, Heavy / analysis*
Nitrogen / metabolism
Oryza / chemistry*
Soil / chemistry*
Soil Microbiology*
Solid Waste

Substances

Coal Ash
Metals, Heavy
Soil
Solid Waste
Nitrogen