Effects of liming and tillage systems on microbial biomass and glycosidases in soils

This study was undertaken to investigate the long-term influence of lime application and tillage systems (no-till, ridge-till and chisel plow) on soil microbial biomass C (C^sub mic^) and N (N^sub mic^) and the activities of glycosidases (α- and β-glucosidases, α- and β-galactosidases and β-glucosaminidase) at their optimal pH values in soils at four agroecosystem sites [Southeast Research Center (SERC), Southwest Research Center (SWRC), Northwest Research Center (NWRC), and Northeast Research Center (NERC)] in Iowa, USA. Results showed that, in general, the C^sub mic^ and N^sub mic^ values were significantly (P α-glucosidase. Lime application did not significantly affect the specific activities (g p -nitrophenol released kg^sup -1^ soil organic C h^sup -1^) of the enzymes. Among the glycosidases studied, β-glucosidase and β-glucosaminidase were the most sensitive to soil management practices. Therefore, the activities of these enzymes may provide reliable long-term monitoring tools as early indicators of changes in soil properties induced by liming and tillage systems.[PUBLICATION ABSTRACT]