Horizons are usually explained by either selective removal or accumulation of certain minerals, colloids and chemical compounds. Calcification Mild temperature and mild precipitation Gleization Low temperature high precipitation Salinization High temperature and low precipitation Sketch of Temp vs. Precipitation Soil - water balance and soil temperature are important factors in soil formation including biological processes and Man. Soil texture is largely an inherited feature of a given soil and depends on the composition of the parent matter. These particles give soil brown or black coloration. The colloids make the ions available to pits which have normally been lost through leaching.
Cations replaces in soil making the soil less fertile.
The degree of acidity or alkalinity of is designated by pH number. High soil acidity is typical of cold humid climates High soil alkalinity is typical of dry climates. Based on overall properties and history of development the 10 orders can be grouped into 3 classes. With subsurface horizon of clay acc. Alfisols - Some leaching clay accumulation in B zone.