Soil to new conditions. Whether these are slow or rapid changes depends on climate, topography and biological activity. The physical properties of soils, in order of decreasing importance for ecosystem services such as crop production, are texture, structure, bulk density, porosity, consistency, temperature, colour and resistivity. Soil texture is determined by the relative proportion of the three kinds of soil mineral particles, called soil separates: sand, silt, and clay. At the next larger scale, soil structures called peds or more commonly "soil aggregates" are created from the soil separates when iron oxides, carbonates, clay, silica and humus, coat particles and cause
Polish Soil Classification effect of specific groups of soil forming processes. Soil types are divided into subtypes. Geological origin of bedrock described by "rodzaj gleby" describes geological origin and properties of material from which the soil was formed. It is not the same as soil family from USDA Soil Taxonomy. Examples can be: granitoid, basalt, amphibolite, sandstone, limestone (with specified period of formation), gypsum, glacial till, sandur sand, loess and others. Sizes of soil particles and texture of soil material are very similar to USDA classification. It makes possible correlating results of particle size analysis of soils described using USDA and Polish Soil