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1.
The composition of humus in leached chernozems differs from that in gleyed podzolized chernozem-like soils in the northern forest-steppe zone of European Russia. Leached chernozems have the fulvate-humate humus. Gleyed podzolized chernozem-like soils have the humate-fulvate humus. A more aggressive composition of humus in the latter soils is caused by their overwetting and the development of gley processes under conditions of a stagnant-percolative soil water regime. 相似文献
2.
The biological activity of soil samples taken from genetic horizons of plowed and virgin chernozems in the Kamennaya Steppe Reserve was determined as the amount evolved from the soil upon its incubation in laboratory conditions. In the top humus horizons, the biological activity of virgin chernozem was two to three times higher as compared with that in the plowed chernozem. The intensity of biological processes and the microbial biomass in the soil profile was mainly controlled by the quantity and quality of soil organic matter. Long-term agricultural use exerted a weaker effect on the biological properties of chernozems developed on microelevations (blocks) of the paleocryogenic microtopography in comparison with chernozems developed in the microdepressions between the blocks. The factor analysis showed that soil characteristics related to the biological processes comprise more than 50% of the total variance of factor loads and are distinctly differentiated in the soil profile. 相似文献
3.
Agrochronosequences of chernozems with different periods of their use in rainfed farming with application of traditional technologies have been studied in a typical forest-steppe area in Belgorod oblast. Certain stages in the development of these soils during more than two centuries of their agricultural use have been identified. These stages are related to changes in the intensity and direction of soil forming processes, such as soil compaction, soil aggregation, dehumification of the upper horizons, calcification of the soil profiles, argillization, etc. A significant impact on the soil changes during the agrogenic evolution of chernozems is exerted by the digging activity of burrowers, which is especially pronounced in the old-arable chernozems. 相似文献
4.
A generalized chronosequence of changes in the morphometric parameters of chernozems in the past 5100 years is analyzed. It
is shown that the development of chernozems in the center of the East European Plain is characterized by both long-term (interglacial,
encompassing the entire Holocene) and short-term (within separate climatic periods of the Holocene) trends. The long-term
trend of the evolution of ordinary chernozems developed from the loess-like calcareous loam consists of a continuous increase
in the thickness of the soil humus profile and an oscillating increase in the depth of the carbonate accumulations. The Late-Holocene
short-term trends of the natural evolution of chernozems are characterized by the high spatial heterogeneity related to the
patterns of climatic fluctuations and to the lithological composition of parent materials. In that period, the thickness of
genetic horizons in the forest-steppe chernozems was increasing faster than that in the steppe chernozems. 相似文献
5.
The physicochemical conditions and morphological features of solonetzic process in soils of chernozemic solonetzic complexes
were studied in the area of solonetzic experimental station no. 1 in the Kamennaya Steppe area in 55 years after a single
application of ameliorative measures (earthening, gypsuming, and manuring) and cessation of the annual plowing. It was found
that the modern soil-forming factors favor the development of soil processes inherent in native chernozems and solonetzes
prior to their plowing and amelioration. They cause the restoration of the humus horizon in chernozems and the morphological
differentiation of solonetzes after the cessation of plowing. Active postameliorative and postagrogenic restoration of solonetzic
features is related to the preservation of the physicochemical conditions (the low concentration of salts and the presence
of exchangeable sodium) in the soil profile. The humus horizon of chernozems applied over the surface of solonetzes is characterized
by the appearance of solonetzic features under hydromorphic conditions. 相似文献
6.
Yu. G. Chendev A. L. Aleksandrovskii O. S. Khokhlova M. I. Dergacheva A. N. Petin A. N. Golotvin V. A. Sarapulkin G. L. Zemtsov S. V. Uvarkin 《Eurasian Soil Science》2017,50(1):1-13
The Late Holocene stage of forest pedogenesis has been studied on the interfluves along river valleys in the forest-steppe zone of the Central Russian Upland. The development of gray forest soils from the former chernozems as a result of the Late Holocene advance of forest vegetation over steppes is discussed. It is argued that the climatic conditions of the Subatlantic period were unstable, so that multiple alternation of forest and steppe vegetation communities took place. This specified a complex character of soil evolution upon contrasting substitution of forest pedogenesis for steppe pedogenesis. On the interfluves near the natural drainage network (balkas, ravines, and steep slopes of river valleys), the climate-driven dynamics of forest and steppe vegetation with corresponding changes in the character of pedogenesis could take place during the entire Holocene, which is reflected in a lower thickness of humus profiles and deeper leaching of carbonates from chernozems of the Early Iron Age in comparison with their analogues formed under steppe cenoses in central parts of the interfluves. Two variants of the evolution of gray forest soils can be suggested: the pulsating evolution typical of balkas and interfluves near river valleys and the continuous progressive evolution typical of automorphic (plakor) positions in central parts of the interfluves. 相似文献
7.
L. S. Pesochina 《Eurasian Soil Science》2008,41(13):1406-1411
The regularities of the formation of the humus profiles in chernozems of the Azov province (“priazovskii chernozems”) were
revealed from studying the paleosols of burial mounds (archeological monuments) of the Bronze Age, Early Iron Age, and Middle
Ages. The principal differences in the geneses of different parts of the humus profiles were revealed. From 40 to 70% of the
current humus reserves in the 1-m-thick layer were shown to be accumulated by the late 3rd and early 2nd millennia BC. In
the following 4000 thousand years, the development of the upper soil layers was cyclic. In favorable climatic periods, the
humus content increased and accumulation processes predominated. Under aridization, the humus mineralization was intensified,
the humus content decreased to 3%, and its reserves did not exceed 18 kg/m2. The fluctuations in the humus reserves in the past were not higher than 30% as compared to the recent reference soils. They
were most actively replenished from the 1st to the 8th centuries A.D., and the rate of this process reached 0.5 kg/m2 for 100 years. In the same period, the thickness of the layer with the humus content above 1% drastically increased. The
illuviation of peptized organic matter and its further bioturbation upon the development of the solonetzic process had the
greatest importance in the formation of the lower part of the humus profiles. 相似文献
8.
Data on the fractional and group composition of humus in urban soils of Rostov-on-Don are discussed. We have compared the humus profiles of chernozems under tree plantations and those buried under anthropogenic deposits (including sealed chernozems under asphalt). It is shown that the type of humus in these soils remains stable despite a decrease in its total content after the long-term burial under asphalt. Under the impact of the trees, the organic matter of the chernozems acquired some features typical of gray forest soils, i.e., the humate-fulvate type of humus in the humus horizon and the sharp drop in the humus content down the soil profile. 相似文献
9.
The development of forest-steppe and steppe chernozems on the Dniester-Prut interfluve in the Holocene was studied on the basis of data on the paleosols buried under archaeological monuments of different ages. The parameters of the mathematic models of the development of the soil humus horizons in different subtypes of chernozems were calculated. They were used to determine the rate of this process and the age of the soils formed on the surface of Trajan’s lower rampart. The climate-controlled changes in the character of the soil’s development in the Late Holocene were differently pronounced in the different subtypes of chernozems. The suggested differentiation of the trends in the development of the humus horizon in the studied chernozems corresponds to the differences in the soil-forming potential of particular areas (as judged from the energy consumption for pedogenesis). 相似文献
10.
The results of long-term studies of chernozem development in anthropogenically disturbed landscapes of the forest-steppe zone
are discussed. Parameters characterizing the formation of the humus horizon of chernozems and the rate of this process are
presented. Critical points and characteristic times of the formation of humus horizons are determined. The regeneration of
soil properties as dependent on the degree of anthropogenic disturbance of chernozems is estimated. 相似文献
11.
The phenomenon of mineralization (biological mineralization) of organic matter in chernozems has been studied. A decrease
in the content of Corg with time can be considered an index of the organic matter mineralization. It is suggested that the humus horizons of modern
chernozems contain the pools of organic matter of different ages: easily decomposable organic matter, labile biologically
active humus, stable biologically active humus, and relatively inert humus. The composition and mean residence times of these
pools and their contribution to the total organic matter content have been estimated. The particular types of the biological
mineralization have been determined on the basis of the comparison between the velocities of mineralization (M) and humification
(H) processes: total unidirectional mineralization (M ≫ H), equilibrium mineralization (M ∼ H), nonequilibrium mineralization
(M> <H), and zero mineralization. The separation of subtypes is based on data on the relative rates (%) of the organic matter
mineralization. On the basis of available experimental data on chernozems buried under kurgans and in loess sediments (with
the age of up to 800 ka), the quantitative relationship of the humus content in the buried soils on their age has been found;
it has an exponential shape. During the first 100 ka after the soil burial, the soil humus content gradually (with a slowing
intensity) decreases from 100–75 to 6.5% of its content in the virgin chernozems. Then, 100–1000 ka after the soil burial,
the soil humus content remains approximately constant (6.5% of the initial level, or 0.3% of the soil mass). The rates of
mineralization have been estimated. It is shown that the elemental composition (C, H, N, O) of humic acids remains relatively
stable for a long time due to the regeneration of the chemical structure of humus (matric restoration of humus). It is suggested
that several different forms of humus related to pedogenesis should be distinguished in the biosphere. The renewable humus
in the equilibrium state with the environment is typical of the open biospheric (soil) systems. The fossil humus, whose content
decreases with time, and whose composition remains stable, is typical of the semiclosed and closed systems. With time, it
transforms into residual humus, whose content and composition remain stable. The fossilized organic matter in the fossil soils
and sediments of the past geological epochs (Mesozoic and Paleozoic) considerably differs from the renewable, fossil, and
residual humus. 相似文献
12.
It is shown that the water content in the upper part of chernozems in Western Siberia in the late fall period exceeds the
field capacity. An ice-rich barrier is formed in the humus horizon of these soils at temperatures below zero in the cold period.
This barrier has both negative and positive effects. Being impermeable for snowmelt water, it favors the development of erosion
processes. At the same time, it prevents infiltration of snowmelt water beyond the soil profile with the formation of a percolative
water regime (favoring soil leaching) in the chernozems. 相似文献
13.
A. N. Gennadiev A. P. Zhidkin K. R. Olson V. L. Kachinskii 《Eurasian Soil Science》2010,43(9):1047-1054
A new method of magnetic tracer was applied by the authors for a quantitative assessment of erosional processes. The rates
of erosion were determined for cultivated and virgin soils (predominantly, chernozems) on slopes in different parts of the
United States and Russia. Quantitative parameters of soil loss and soil deposition for the slopes of different shapes and
aspects were found. Specific features of erosional processes within different parts of slopes were revealed. The relationships
between the intensity of erosion and the humus state of the soils were characterized, and the effect of land use on the rates
of soil erosion was estimated. 相似文献
14.
S. I. Kolesnikov M. V. Yaroslavtsev N. A. Spivakova K. Sh. Kazeev 《Eurasian Soil Science》2013,46(2):176-181
The biological properties of chernozems in the south of Russia worsen under the impact of contamination with Cr, Cu, Ni, and Pb compounds. The tolerance of chernozems towards contamination decreases in the following sequence: ordinary chernozems > typical chernozems > southern chernozems > leached vertic chernozems. This sequence is specified by the soil reaction and the organic matter content. The high humus content determines the high buffer capacity of chernozems towards contamination with chromium, whereas the high pH values ensure the soil tolerance towards contamination with copper, nickel, and lead. With respect to their adverse effect on the biological properties of the chernozems, the studied heavy metals can be arranged into the following sequence: CrO3 > CuO > PbO ≥ NiO. 相似文献
15.
E. S. Bukhanistova T. A. Gorelova A. A. Tanasienko A. S. Chumbaev 《Eurasian Soil Science》2006,39(6):622-630
It is shown that humus loss may reach 1.7 t/ha per year as a result of plowing of leached chernozems and erosion development. Distribution of underground phytomass in uneroded and eroded chernozems and slightly aggraded meadow-chernozemic soils of dissected areas in the Cis-Salair region is analyzed. It is shown that an increase in the degree of soil erosion is accompanied by a decrease in the total phytomass reserves, whereas the average depth of the root zone increases. 相似文献
16.
Data on radiocarbon ages of different fractions of humus (humic acids, fulvic acids, and humin) in the profiles of chernozems
are analyzed. A chronoecological grouping of humus in modern and buried (fossil) soils is suggested. An increase in the radiocarbon
age of humic substances down the soil profile has a stepwise character. It is shown that the 14C content in chernozems decreases down the soil profile more somewhat slower than the 12C content. The dependence of a decrease in the humus content of buried soils on the age of burying is traced for a time span
of 800 ka. 相似文献
17.
Temporal changes of eroded soils depending on their agricultural use in the southern Cis-Ural region
I. M. Gabbasova R. R. Suleimanov I. K. Khabirov M. A. Komissarov M. Fruehauf P. Liebelt T. T. Garipov L. V. Sidorova F. Kh. Khaziev 《Eurasian Soil Science》2016,49(10):1204-1210
Temporal changes of eroded soils in the southern Cis-Ural region (Republic of Bashkortostan) depending on their agricultural use during the period from 1975 to 2011 were studied. In the northern foreststeppe zone, the development of erosion processes was retarded upon the use of soil-saving management practices and grain-fallow-grass crop rotations. In slightly eroded light gray forest soils (Eutric Retisols (Cutanic)), the thickness of humus-accumulative horizons and the content of humus increased; the conversion of cropland into permanent fallow was found to be the most efficient measure to control soil erosion. In podzolized chernozems (Luvic Greyzemic Chernic Phaeozems) and typical chernozems (Haplic Chernozems) of the Cis-Ural steppe, the content of humus in the plow layer under grain-row crop rotation and classical soil management decreased, especially in moderately eroded soils. The development of water and wind erosion on slopes depended on the slope shape: the texture of soils at different degrees of erosion on slopes with free runoff became coarser by one gradation after 35 years; in the presence of linear obstacles in the lower part of slopes, the content of fine fractions in moderately and strongly eroded soils increased. 相似文献
18.
P. S. Lozovitsii 《Eurasian Soil Science》2012,45(3):290-302
The results of long-term studies (1957–2007) of the changes in the morphology of soil profiles and in the reserves and fractional
composition of the humus in the soils of the Ingulets irrigation system are discussed. After 50 years of irrigation, the boundaries
of the genetic horizons shifted downward by 15–30 cm. The redistribution of the humus took place: its content decreased to
a low level in the plow layer of the irrigated and rainfed soils and significantly increased in the layer of 60–100 cm so
that the reserves of humus in the layer of 0–100 cm somewhat increased and corresponded to a moderate level. The distribution
of humus in the soil profiles was characterized by the gradual lowering down the soil profile. The concentration of nitrogen
in the humus of the irrigated southern chernozems was very low. The degree of humification of the soil organic matter was
high. The humus was of the humate type in the upper horizons and of the fulvate-humate type in the lower horizons. 相似文献
19.
I. V. Ivanov O. S. Khokhlova V. V. Galitskii O. A. Chichagova E. P. Zazovskaya 《Eurasian Soil Science》2012,45(8):802-810
The dynamics of the 14C content in the humus of chernozems in 1900?C2008 are considered. The elevated 14C content in the atmosphere because of nuclear weapons tests has led to the contamination of humus with bomb radiocarbon. In 1966?C1968, the 14C reserves in the profiles of chernozems exceeded the background ones by 15%; in 1978, by 12%; and, in 1998, by 2%. By the year of 2008, its reserves became equal to the background ones. The 14C distribution along the soil profiles changed. By 1978, the 0- to 30-cm-thick soil layer became free from radiocarbon due to its self-purification; however, at depths of 40?C70 and 100?C115 cm, its weak accumulation was registered. By 2008, the whole soil profile was free from 14C. The main mechanism of the soil self-purification from radiocarbon is suggested to be the constant substitution of fragments of humus compound structures for those of fresh organic matter entering the soils with the 14C content being in equilibrium with the atmospheric one, i.e., due to the renewal of the carbon in the humus. The rate of the carbon renewal and its migration in the soils are assed based on the 14C concentrations in the humus. 相似文献
20.
D. I. Eremin 《Eurasian Soil Science》2016,49(5):538-545
The results of long-term studies of changes in the content and fractional-group composition of humus in leached chernozems (Luvic Voronic Chernozems, WRB 2006) of the Trans-Ural forest-steppe since the beginning of their plowing are considered. These soils are characterized by the high humus pool (up to 500 t/ha in the virgin state and up to 430 t/ha in the plowed state) and the high degree of the organic matter humification. Humus is of the fulvate–humate type in the upper 30 cm and of the humate–fulvate type in the deeper layers. From 1968 to 2006, the total pool of humus in the 1-m-deep soil layer of the plowed chernozems decreased by 8.5% in comparison with the initial virgin soils. The rate of dehumification reached 1.0–1.4 t/ha per year. The long-term plowing of leached chernozems also led to a smaller content of nitrogen in the organic matter (the C/N ratio increased from 11.5 to 13.6). The relative content of free humic acids (HA-1) and humic acids bound to clay minerals (HA-3) increased, whereas the content of calcium humates (HA-2) decreased. The composition of fulvic acids in the plow horizon was characterized by the rise in the content of aggressive (FA-1a) and mobile (FA-1) fractions, while the amount of fulvates bound to calcium (FA-2) decreased. 相似文献