Quality

Soil quality may be defined as a measure of how well a soil fulfills either its intrinsic role in the biosphere, or its role as defined by the needs of human society.

With regard to its intrinsic role, soil provides habitat on the land surface, accumulates biomass, and ensures a level of biodiversity. Photosynthesizing species in the biomass collect solar energy and become the principal source of energy for other species, either by direct consumption, or indirectly as dead organic matter in the soil, metabolized by micro-organisms, mycorrhizae and fungi. In addition the soil acts as a conduit for nutrients and is an integral part of all material cycles on the land surface. (See Soil , Biogeochemical Cycles ).

For societal purposes soil quality may be defined in terms of the ability of soil to perform a number of services such as: protection of the environment, maintenance of biodiversity, disposal of the wastes we generate, production of food, provision of foundations for roads and...