Geoscience Reference
In-Depth Information
was displayed in the Russian Pavilion, at the foot of the Eiffel Tower.
There is, in Russia, an agricultural research station devoted to study
of the Tchernozem. Societies of soil science have added to the glory of
Tchernozem by naming it
Soil of the Year 2005
!
The Chernozem is deep, black, humus-rich (up to 16%) about 50 cm or, at
times, 1 m deep (Fig. 14.1). Its structure is granular, distinct and stable.
It constitutes an extraordinary 'garden soil' over millions of hectares.
The vertical profile is poorly differentiated, although accumulations of
CaCO
3
, gypsum and even salts are sometimes found at a depth of two
or three metres. The soil is base-saturated with pH near 7. Its cation
exchange capacity is high, around 50 cmol (+) kg
-1
. Biological activity
is high. Small burrowing animals (rats and specialized squirrels) are
active. Their burrows, filled with material from the upper horizons of
the soil, are
krotovinas
.
Description
Fig. 14.1
Left, typical Chernozem of Germany with krotovinas (Profi le DE 014 from
ISRIC-ISIS database, Wageningen, Netherlands); right, cultivated to potato in Poland
(
photo
G. Trouche, Dijon, France).
Generally, Chernozems overlie deep loess deposited south of the great
icecaps that covered the North of the planet in the cold periods of the
Quaternary. These soils occur under an annual rainfall of 350-500
mm. In their major Euro-Asiatic area, they form a kind of strip with
Ecology and distribution