Soil Enzyme Activities as Indicators of Soil Quality

This chapter discusses soil enzyme activities as a potential biochemical/biological indicator of soil quality. With the advent of increased numbers of soil enzyme assays, there was considerable interest and effort in Europe and Russia to develop soil enzyme activities to be used as a soil fertility index. Studies from long-term sites have shown that soil enzyme activities are sensitive in discriminating among soil management treatment effects. Before soil enzyme activities can be used as soil quality indices, soil sample pretreatment, assay procedures, and units of measurement must be standardized. Systematic studies across ecosystems and long-term soil management sites are also needed to identify the most appropriate soil quality enzyme assays, and to provide data for calibration and interpretation of these assays as independent soil quality indexes or as a component of a larger universal index that includes other soil properties.