Influence of Soil Acidification on Soil Microorganisms in Pear Orchards

Abstract

To evaluate the influences of soil acidification on soil microorganisms and soil fertility, soil physicochemical and microbial properties were studied in pear orchards of Wendeng city where soil acidification is severe with soil pH value ranging from 4.06 to 6.59. Soil pH value was found to be significantly positively correlated with the amount of culturable bacteria (r = 0.935) and total extractable microbial fatty acids (r = 0.931) by correlation analysis and stepwise regression analysis, as well as amount of culturable actinomycetes (r = 0.865) and fluorescein diacetate hydrolysis activity (r = 0.780) by correlation analysis. Soil pH was determined to have a large influence on microbial community structure by principal component analysis of fatty acid methyl ester, which showed that microbial community structures were similar in soils with similar pH values. Being sensitive to environmental changes, soil microorganisms proved to be good indicators for the evaluation of soil health conditions and to monitor changes of soil quality.