Agriculture Reference
In-Depth Information
or gaseous phases depends on the spatial arrangement of the solid phase materials.
Because the properties and balance of these components largely determine how soils will
behave in undisturbed and in agricultural and engineering environments, considerable
effort has been expended in searching for useful ways to characterise soil components
in these terms.
Soil components may be classified in many ways, depending on the intended purpose
of the classification. Some common ways of classifying such materials are on their sizes,
shapes and origins, the phases they belong to, their chemical or physical characteristics,
their mineralogical compositions or on combinations of these. The classification of soil
components employed here is arbitrary and hierarchical and attempts to characterise the
individual components in ways that reflect their ecological interrelationships (Figure I.1).
The division of soil materials into separate components in no way implies that associa-
tions and interactions between the various components do not occur, or are unimportant.
Indeed, nearly all solid and liquid phase entities that occur within soils include both
organic and inorganic components, or are influenced by them. Further, as emphasised
in several sections of this topic, the formation and functioning of soil depends on
the myriad interactions that occur between the organic and inorganic, and the living and
non-living components of soils. An enormous variety of organic and inorganic compo-
nents are available within soils to interact in the synthesis and development of the unique
substance which is soil.
