Effect of Long-term Fertilization on Enzyme Activities and Soil Fertility for the Black Soil in the Farmland

Soil enzyme activities and soil fertility were studied to explore the long-term fertilization on soil enzyme activities and its relationship with soil fertility based on the 29-years long-term site-specific experiment with different fertilization methods.The results showed that combined application of chemical fertilizers and organic manure could significantly increase the soil organic matter,total nitrogen,total phosphorus,alkali-soluble nitrogen,available phosphorus content and enhance the soil urease,phosphatase,invertase,catalase,dehydrogenase activity.The correlation analysis showed that soil urease,phosphatase,invertase and catalase activity positively corrected with organic matter,total nitrogen,total phosphorus and alkali-soluble nitrogen significantly.Thus the integrated activities of soil urease,phosphatase,invertase,and catalase can reflect the changing of black soil quality in the farmland after long-term fertilization.