The increasingly intensified animal industry in recent decades has resulted in the discharge of a large
amount of wastewater with high concentrations of organic matter and nutrients into the ambient
environment, which influences soil properties. In this study, we applied a multi-parameter approach to
investigate changes in soil microbial properties and community compositions from three acid soil sites
that differed in land-use patterns and histories of receiving wastewater.Wastewater had been applied to
the sites for 2–20 years. Compared to controls, soil pH, EC and total nutrients were significantly higher in
soils receiving wastewater, as well as average increases of 149mg kg1 for microbial biomass carbon and
0.19mg CO2–Ckg1 h1 for basal respiration; whereas the metabolic quotient and the ratio of saturated to
monounsaturated phospholipid fatty acids decreased by 13% to 31%, and 32% to 61%, respectively. Soil
microbial communities of all sites changed with the impact of wastewater application and showed
significant increases in bacteria, especially Gram-negative bacteria. The differences in microbial
metabolic profiles from all sites were reduced by wastewater application. Soil pH and EC were the two
most important factors controlling microbial community composition under wastewater application.
These results suggested that wastewater application could reduce stress on acid soil microorganisms by
providing more organic carbon and nutrients, and through neutralization of soil acidity.