Abstract:This study is to investigate the responses of soil hydrolases to different fertilization and the influencing factors. Three fertilizer treatments were designed and compared, including an unfertilized control with only red soil (R), cow manure (R+C) and chemical fertilizer (R+NPK). Soil samples were taken at three times (5, 30 and 90 d) during 90 d incubation to evaluate the activities of soil hydrolases involved in the transformation of carbon, nitrogen and phosphorus using the microplate fluorescence method. Seven hydrolases were studied, including α-1,4-glucosidase, β-1,4-glucosidase, cellulase, xylanase, leucine aminopeptidase, β-1,4-N-glucosaminidase and phosphatase. At the 30 d, chemical fertilizer significantly decreased the total enzyme activity, and slightly reduced enzyme activities involved in the transformation of carbon, nitrogen and phosphorus compared with the control (R). Organic fertilizer had no effect on the total enzyme activity, but significantly increased the activity of α-1,4-glucosidase but decreased the activity of phosphatase during the incubation period. For the four hydrolases involved in carbon transformation, only α-1,4-glucosidase activity responded strongly to fertilization, which was promoted by the organic fertilizer but decreased by the chemical fertilizer. For the hydrolases involved in nitrogen transformation, the activity of leucine aminopeptidase was inhibited by chemical fertilizer, while β-1,4-N-glucosaminidase activity was promoted by organic fertilizer. Besides, phosphatase activity was reduced by organic fertilizer, but was not affected by chemical fertilizer. The responses of different hydrolases were different to fertilizers, NMDS analysis showed that the responses of α-1,4-glucosidase and leucine aminopeptidase were most obvious to fertilization, followed by phosphatase and xylanase. The correlation and redundancy analyses showed that soil pH and soluble organic carbon had the greatest influence on enzyme activities, indicating that fertilization-induced alteration of soil physicochemical properties is the main pathway that influencing soil enzyme activities.