Soil enzyme activities as biological indicators of soil health.

Soil health can be defined as the continued capacity of a specific kind of soil to function as a vital living system, within natural or managed ecosystem boundaries, to sustain plant and animal productivity, to maintain or enhance the quality of air and water environments, and to support human health and habitation. Because of the conflicting pressures increasingly applied to the soil, it is clear that relevant indicators are urgently needed to assess and monitor soil health. Biological indicators of soil health offer certain advantages over physicochemical methods. Among the various biological indicators that have been proposed to monitor soil health, soil enzyme activities have great potential to provide a unique integrative biological assessment of soils and the possibility of assessing the health of the soil biota. Besides, soil enzyme activities provide an easy, relatively rapid, and low cost procedure to monitor soil health. Nevertheless, soil enzyme activities also present some limitations and must always be considered in conjunction with other biological and physicochemicals measurements if we are to diagnose soil health correctly.