Effect of landfill leachate spraying on soil respiration and microbial biomass in a northern hardwood forest ecosystem

The effect of municipal solid waste (MSW) landfill leachate application upon soil respiration and microbial biomass was investigated in a northern hardwood forest of sugar maple ( Acer saccharum Marsh.) and beech ( Fagus grandifolia Ehrh.). One-way analysis of variance and multiple range testing of soil respiration estimates indicated that the lightly sprayed area had significantly higher respiration rates than the unsprayed control. Soil respiration in the heavily sprayed area did not differ from the lightly sprayed area or the control. The application of landfill leachate had a negative effect on the total microbial biomass present in the soil. Microbial biomass decreased significantly in those areas which were spray-irrigated in comparison to those which were not, with the areas receiving the highest application yielding the lowest biomass-carbon estimates. Also notable was a decrease in microbial biomass with increasing soil depth and with time during the latter part of the season.