Soil formation is a result of an interaction of five factors: climate, biota, relief, parent material and time (Dokuchaev 1949). Accumulation of organic matter and its downward migration in the soil profile play major roles in soil formation (Abakumov 2008, Cerli et al. 2008). Accumulation of organic matter leads to formation of an organic layer and affects many soil properties such as water holding capacity, C or N content, soil biota, etc. The humification process involves the main agents of soil weathering, chelatization and complexation of soil mineral compounds, and migration and translocation of organo-mineral compounds. The quality of organic matter (Kononova 1966, Ponomareva and Plotnikova 1980, Andreux 1996) and the soil biota (Ponomareva and Plotnikova 1980, Emmer and Sevink 1994, Androkhanov et al. 2000, Abakumov 2008) determine soil formation.