Introduction To Classifying Soils
Soils can be classified according to their physical and chemical characteristics and, morphology(appearance) into groupings called taxonomic units.
Soil order is the highest level of taxonomic unit used.
There are 15 soil orders, each of which is defined by a broad range of characteristics.
Soil orders are subdivided into more related taxonomic units known as soil groups, which in turn are broken down into subgroups.
There is a fourth level of classification known as the soilform, in which parent material, particle-size and permeability are used to further identify the soil.
The diagram shows the relationships within the New Zealand Soil Classification System.
The Soil Orders and Soil Groups of the NZ Soil Classification