This universal process of transforming precursors of humification and polymerization of oligomer and monomer molecules into dark colored, high-molecular-weight supermolecules has been described in terms of organic chemistry [3, 4], environmental dynamics [5, 6], and various zonal soil
In order to determine the dependence for all zonal soil
types of the East European Plain of empirically determined humus horizon limit values from climatic potential, we summarized the data of numerous soil surveys.
Initially, interest was concentrated on the extensive zonal soil
types, whose diverse characteristics were formed by the prevailing climatic peculiarities and the resulting vegetation (e.g.
to "zonal soil
," a soil found in a large area having similar climate and vegetation, the text appears to have been carefully controlled for reading level difficulty.
According to the majority of researchers, the variety adapted to zonal soil
and climatic conditions can provide an increase in grain yield up to 20% at no extra cost.
The zonal soils
are Calci-Orthic Aridisols, which are derived from proluvium and alluvium, according to Chinese Soil Taxonomy (Cooperative Research Group on Chinese Soil Taxonomy 2001).
The crop yields on these affected soils are considerably reduced compared to those on non-saline zonal soils
The zonal soils
correspond to the phytoclimatic forest zone on the top of the hills--brown and brown illuvial soils--, and to the silvosteppe zone in the valleys--cambic chernozem and clay-illuvial soils.