The parent material variability (or geodiversity) may be caused by soil texture variations (from sand to clay), mineralogical and chemical composition, calcareousness and acidity.
The base of the common site type of rendzinas (Acrostaphylos-alvar) is characterized by a modest fine earth stock in soil cover, high calcareousness and skeleton content, excessive natural drainage, low water holding capacity and an unstable water regime (Fig.
Quarry spoil, as fresh calcareous parent material for soil development, had the highest pH value, in the other soils pH decreased according to soil development and decreasing of parent material calcareousness
from North- to South-Estonia.
The data presented demonstrate the great importance of calcareousness
and moisture conditions in the SOC retention capacity of soil.
The distribution of total SOC stocks in mineral soil cover by land use, SOC quality, soil calcareousness, and vertical distribution is given in Fig.
Low soil calcareousness is connected with soil profile development (forming of illuvial and eluvial horizons).
During the last decade the mobilization and accumulation of both amorphous and total pedogenic nonsiliceous iron, characteristic of pedogenetic weathering of ferri- and alumosilicates and argillization, decreased in the variants where calcareousness
of fine earth had increased (Tables 5, 8, and 9).