Changes on microbial C and enzyme activities in soil with amendment of composted tannery sludge after 9?years

摘要

Abstract PurposeThe consecutive amendment of composted tannery sludge (CTS) could promote changes in the status of soil microorganisms. Thus, this study evaluated the changes on microbial C and enzyme activities in soil after 9?years of CTS amendment.MethodsCTS was amended from 2009 to 2018 at five rates: 0, 2.5, 5, 10, and 20?ton?hasup?1/sup. In 2018, the soil chemical properties (pH, electric conductivity, P, K, Cr, and total organic C), microbial C and enzyme activities were evaluated after 30?days from the amendment.ResultsThe values of chemical properties increased after nine years of CTS application. The content of microbial C and the enzyme activities increased with the amendment of 2.5 and 5?ton?hasup?1/sup, and decreased with the amendment of 10 and 20?ton?hasup?1/sup.ConclusionThis study showed that the amendment of 10 and 20?ton?hasup?1/sup of CTS increased soil pH and Cr concentration and promoted a decreasing on soil microbial C and enzyme activities.