ISSN 10674136, Russian Journal of Ecology, 2009, Vol. 40, No. 6, pp. 393–398. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © A.M. Rusanov, L.V. Anilova, 2009, published in Ekologiya, 2009, No. 6, pp. 417–422.
The exclusive significance of soil organic matter is
accounted for by its multiple functions in the bio
sphere (Vernadsky, 1987). Humification, or the forma
tion of humic substances from plant and animal
remains and products synthesized by microorganisms,
is a factor involved in the global process of organic
matter transformation, with humic acids being its
essential product (Aleksandrova and Nazarova, 1981).
The ecological situation in a certain territory closely
depends on humic substances, which largely account
for stability of terrestrial and aquatic landscapes, soils,
and biocenoses under the effect of natural and anthro
pogenic factors (Orlov, 1990). The role of soil organic
matter is especially important in regions of intensive
agriculture, since its trophic function is essential for
the trophic function of the soil itself (Popov, 2006).
Soils of the Orenburg Cisural region are highly fer
tile forest–steppe and steppe chernozem subtypes
(Erokhina, 1959). More than 75% of area with these
soils is plowed (Blokhin, 1997; Rusanov, 2003). The
soils of agrocenoses have retained genetic features of
chernozems, but their basic properties have changed
markedly, compared to those of their virgin counter
parts. Degradation processes have affected all compo
nents of these soils, especially their humus state and
living phase (Garifullin, 1987; Khaziev, 2000).
To prevent further development of these processes,
it is necessary to optimize parameters of biological
activity in soils as a prerequisite for their humification,
taking into account that soil organic matter itself is the
source and prerequisite of soil biological activity.
In the theoretical aspect, it is important to understand
the essence of interaction between an integrated sys
tem of biological factors (with regard to the processes
of matter and energy exchange between its compo
nents) and its abiotic environment, since selfregula
tion and, consequently, homeostasis of a complex,
multicomponent system, such as the soil, are possible
only if its qualitative and quantitative parameters fully
conform to environmental conditions.
The purpose of this study was to analyze the effect
the dynamics of vegetation and soil microbiological
and enzymatic activities on the ecology of humus for
mation and the humus state of natural and anthropo
genically disturbed zonal subtypes of chernozem soils
in the Orenburg Cisural region.
OBJECTS AND METHODS
Virgin and plowed soils of the typical–ordinary–
southern chernozem series were studied in 2005 to
2007. Test plots were selected with regard to similarity
in environmental conditions, including soilforming
rocks: all of them were in leveled watershed areas with
bioclimatic conditions typical of a given soil subzone,
including characteristic plant associations.
In each virgin plot and in adjoining agrocenoses, a
description of vegetation and estimation of above and
belowground phytomass were made by conventional
methods (Ramenskii, 1938), a fullprofile soil pit was
established, and four excavations were made to take
soil samples for laboratory analysis (Grishina, 1971;
Following the accepted procedure (Tepper et al.,
1991), soil samples for microbiologi
cal and biochemical analyses were taken from 5–7
points twice a year, in May–June and September, and
analyzed in 5–12 replications. The functional struc
ture of the soil microbial community was estimated
from the ratio of physiological groups growing on dif
ferent diagnostic media. In particular, we used meat
peptone agar (MPA) for ammonifiers and sporeform
Ecological Aspects of Humus Formation and Dynamics in Virgin
and Plowed Chernozem Soils of the Cisural Region
A. M. Rusanov and L. V. Anilova
Orenburg State University, pr. Pobedy 13, Orenburg, 460018 Russia;
Received September 22, 2008
—An attempt has been made to make a comprehensive assessment of biological factors in the ecol
ogy of humus formation in forest–steppe and steppe chernozem soils of the Cisural region. Certain regional
features in the effect of vegetation structure and composition and soil microbial and enzymatic activities on
the humus state of zonal chernozem subtypes in virgin and plowed landscapes have been revealed.
: ecology of humus formation, biological factor, humus state, agrocenosis.