Grain size distribution

In addition to determining the type of soil, knowledge of the composition of the grain size fractions makes it possible to estimate the storage and leaching capacity for water, nutrients or pollutants as well as the aeration, shrinkage behavior or stability of the soil. These parameters determine, for example, the water balance of a soil, suitable forms of use, agricultural suitability, workability or trafficability.

If no further details are given, the soil type refers to the fine soil (equivalent grain diameter <2 mm). The proportion of coarse soil is only given as additional information. If the proportion of coarse soil is <75% of the total soil, the coarse soil fraction is specified instead of the soil type. The fine soil is subdivided into the soil types sand, silt and clay, which can be represented in the grain size triangle. Loams contain all three fractions in similar proportions.