PPT Slide
Biological indicators include measures of the amounts, types, and activities of soil organisms. There is a great diversity in techniques to evaluate soil biology, which reflects the diversity in both the number of different organisms present and the numerous different processes in which they are involved. A diverse, healthy, and functioning population of soil organisms may be the most important indicator of a healthy, high quality soil, but an adequate level of soil biological activity may be the most difficult indicator to satisfactorily measure and interpret.