DIN ISO/TS 22939:2011-06

This Technical Specification specifies a method for the simultaneous measurement of several enzyme activities in soil samples. Enzyme activities of soil vary seasonally and depend on the chemical, physical and biological characteristics of soil. The application of the method for the detection of harmful effects of toxic chemicals or other anthropogenic impacts depends on the simultaneous comparison of enzyme activities in a control soil similar to the test soil, or on exposure tests with chemicals or other treatments. Micro-organisms are responsible for many key processes in the cycle of elements. Enzymes are responsible for the degradation of organic molecules and their mineralization. The postulate is the microbial origin of soil enzymes, even if plant root exudates include enzymes. Extracellular enzymes in soil play key roles in the biodegradation of organic macromolecules. The simultaneous monitoring of several enzyme activities important in the biodegradation of organic compounds and mineralization of C, N, P and S in soil may reveal harmful effects caused by chemicals and other anthropogenic impacts. However, the measurements carried out under selected laboratory conditions using artificial substrates cannot be a substitute for the actual rate of enzymatic processes in soil in situ. This Technical Specification has been prepared by Technical Committee ISO/TC 190 "Soil quality". The responsible German Committee is NA 119-01-02-04 UA "Biologische Verfahren" ("Biological methods").