Problems in characterizing the ecological quality of soil in relation to human activities

The soil ecosystem is composed of various groups of organisms which have complex relations. The physical structure and chemical characteristics of the soil provide the boundary conditions. In view of various deteriorating human activities, it is important to find soil quality characteristics with respect to its most important function: the ecological function. An enumeration has been given of chemical, physical and biological soil parameters which are more or less important for soil quality. Several of these parameters are discussed. For use as indicators of deterioration, for a given site, the optimum values of the soil parameters have to be established, as well as acceptable deviations from the optimum, taking into account natural fluctuation. It is concluded that, due to lack of data, such an approach is not possible at this moment. However, it might be possible to identify those soil parameters which should be taken into consideration when evaluating human activities.