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Long-term stationary field experiments were performed to study the efficiency of increased rates of nitrogen fertilizer in crop rotations with cereal crops, perennial grasses, clover, and plow fallow on gray forest soils. It was found that an excess of mineral nitrogen (mainly of nitrates) accumulated in the soil in the case of unbalanced nitrogen fertilization and long-term fallowing creates conditions for the development of unfavorable processes in the nitrogen cycle. Significantly increasing nitrogen losses from the agroecosystem because of leaching and denitrification constitute a depletion hazard for the soil nitrogen pool. 相似文献
3.
The carbon budget in agroecosystems with spring wheat was studied in long-term (1997–2004) field experiments on gray forest soils in the forest-steppe of the Lake Baikal region, including soils polluted with the fluorides emitted by an aluminum plant. Pollution was revealed to increase the deficit in the carbon budget due to the more intense mineralization of organic matter and CO2 emission from the soils. Raising of the crops’ productivity upon permanent application of fertilizers may provide maintenance of a positive carbon budget. 相似文献
4.
M. S. Kuznetsov 《Moscow University Soil Science Bulletin》2011,66(3):104-111
This article describes a “humus“ linear modification of the Skidmore method, allowing us to calculate the tolerable limits
of soil loss taking into account the current ecological requirements and economic opportunities. These limits were developed
depending not only on the genetic types of soil, but also on the degree of its erodability, types of use, the structure of
crop rotation, and crop capacity. 相似文献
5.
The amorphous iron content in the upper soil horizons, the profile distribution of iron oxides and hydroxides, and the Schwertmann (Feo/Fed) ratio can be used as diagnostic criteria for the degree of gleyization in the classification of hydromorphic soils. Drainage removes chemical elements, e.g., nonsilicate Fe, from soils. 相似文献
6.
B. E. Kondrashkin A. I. Pozdnyakov V. P. Samsonova M. I. Kondrashkina 《Moscow University Soil Science Bulletin》2011,66(2):75-78
The electrical resistivity of gray forest soils and gray forest soils with a second humus horizon was studied in the Bryansk
Opol’e region. The dependence of electrical resistivity on the soil’s organic content, moisture, and bulk density was found.
It was concluded that the supply of organic matter in the upper layer (50 cm) can be estimated in wet conditions using the
equation Csupply = 2.7ER + 34.3 (t/ha). 相似文献
7.
E. F. Vedrova 《Eurasian Soil Science》2008,41(8):860-868
The estimates of the carbon pool in the organic matter of gray soils of the southern taiga, the intensity of destruction of its components, and participation of the latter in the formation of the mineralized carbon flux to the atmosphere are presented for different stages of succession of deciduous (birch) and coniferous (fir) forests. The carbon pool varies from 139.7 to 292.7 t/ha. It is distributed between phytodetritus, mobile and stabile humus (32, 19, and 49%, respectively). The intensity of the mineralization carbon flux to the atmosphere amounts to 3.93–4.13 t C per year. Phytodetritus plays the main role in the formation of this flux. In the soils under the forests studied, 4–6% of the carbon flux are formed owing to mineralization of the newly formed soil humus. In birch forests, 2–6% (0.1–0.2% of the humus pool in the 0–20-cm layer) is the contribution to the flux due to mineralization of soil humus. In fir forests, the mineralized humus is compensated by humus substances synthesized in the process of humification during phytodetritus decomposition. 相似文献
8.
Summary Potential P and C mineralization rates were determined in a 12-week laboratory incubation study on subarctic forest and agricultural soil samples with and without N fertilizer added. There was no significant difference in net inorganic P produced between N fertilized and unfertilized soils. The forest soil surface horizons had the highest net inorganic P mineralized, 32 mg P kg-1 soil for the Oie and 17 mg P kg-1 soil for the Oa. In the cropped soils net inorganic P immobilization started after 4 weeks and lasted through 12 weeks of incubation. Cumulative CO2–C evolution rates differed significantly among soils, and between fertilizer treatments, with the N-fertilized soils evolving lower rates of CO2–C than the unfertilized soils. Soils from the surface horizons in the forest evolved the highest rates of CO2–C (127.6 and 89.4 mg g-1 soil for the Oie and Oa horizons, respectively) followed by the cleared uncropped soil (42.8 mg g-1 soil C), and the cropped soils (25.4 and 29.0 mg g-1 soil C). In vitro soil respiration rates, or potential soil organic matter decomposition rates, decreased with increasing time after clearing and in accord with the degree of disturbance. Only soils with high potential C mineralization rates and high organic P to total P ratios, mineralized P by the end of the study. Mineralizable P appeared to be associated with readily mineralizable organic C. 相似文献
9.
The technogenically induced salinization and alkalization (solonetzization) of gray forest soils results in their transformation into soils similar to natural solonchaks and solonetzes. Their density increases, the structure is disturbed, and the water stability of the aggregates becomes poorer. The humus content decreases, the nutrition regime is deteriorated, and the enzymatic activity is hindered. Under natural conditions, soil desalinization is seen within a ten-year-long period after its contamination with strongly saline oil-field waste water, while soil solonetzization remains very high. The soil properties are regenerated after application of an adequate rate of phosphogypsum and manure. Phosphogypsum applied alone causes a deterioration of the agrophysical properties as it produces an extremely high water stability of aggregates and strong soil compaction. 相似文献
10.
J. Ryan 《Geoderma》1983,29(4):341-354
This review deals with selected aspects of the forms, behavior and utilization of phosphorus in soils of dry regions. Such regions embrace most developing nations in the world. Amounts and major forms of phosphorus in the soils, indices of availability, fertilizer sources, initial and residual effects, modes of application and possibilities for improved utilization are considered. The supply and availability of phosphorus is a key factor in crop production. Consequently, for appreciable increases in production in dry regions, improvements in utilization of phosphorus are needed. Several possible improvements are therefore proposed as the final part of this paper. 相似文献
11.
Changes in the physical, physicochemical, and biological properties of cultivated gray forest soils after their abandoning
and overgrowing with meadow and forest vegetation for 8–10 years are clearly seen in the upper part of the former plow layer.
The organic matter content and the content of available forms of phosphorus and potassium increase; a significant increase
in the root biomass and in the soil biological activity is observed. Changes in the physical properties—an increase in the
degree of soil aggregation and a decrease in the bulk density values—are seen in the upper and middle parts of the former
plow layer. The biological factor is the major factor of transformation of formerly cultivated gray forest soils upon their
abandoning and overgrowing with meadow and forest vegetation. At the same time, a significant role in the improvement of the
structural state of the soils belongs to the physical shrink-swell and freezing-thawing processes. 相似文献
12.
O. V. Menyailo 《Eurasian Soil Science》2007,40(3):302-307
The biomass of two groups of microorganisms was studied in gray forest soils under six tree species (spruce, Scotch pine, Arolla pine, larch, birch, and aspen) and in the soil of a layland (a clearing in the forest) using kinetic methods. The biomass was the highest in the soil of the layland. The lowest (19.4 μg C/g of soil) biomass of heterotrophic microorganisms was found in the soil under the birch trees, and the highest one (41.7 and 32.0 μg C/g), under the pine and spruce ones. The biomass of denitrifying microorganisms was lower by thirty times than that of the heterotrophic ones. In the soils under the pine and spruce trees (8.4 and 9.2 μg C/g, respectively), the biomass of the denitrifying microorganisms was the lowest; under the birch and larch trees, it was the highest (16.7 and 13.7 μg C/g). 相似文献
13.
M. V. Bobrovskii 《Eurasian Soil Science》2010,43(13):1458-1466
The morphological structure of the soils in the forest areas of European Russia was analyzed. It was shown that most of the
soils were formed under the impact of both biotic and anthropogenic factors. Soils with poorly differentiated profiles without
podzolization features are typical for the least disturbed forest ecosystems. The presence of an eluvial (EL) horizon is associated
with the signs of old plowing and (or) fires. The character and rate of the soil cover transformation under various impacts
of the historical land use (felling, plowing, pasturing, burning, etc.) are discussed. The technologies of the main traditional
farming systems in the forest zone of European Russia (slash-and-burn, fallow, and shifting farming systems) are considered;
their effect on the long-term dynamics of the soil cover is estimated. Farming and the related impacts of historical land
use can be a major reason for the formation of degraded soils in the forest zone of European Russia. 相似文献
14.
On the basis of factual data obtained by the Soil Science Department of the Privolzhskii Federal University and available from literary, virtual reference “images” of gray forest soils as distinguished in classification systems of 1977 and 2004 have been obtained with the use of the methods of multivariate statistics for the Volga-Kama forest-steppe region. Discriminant functions and have been obtained, and classification functions have been developed with the help of numerical methods to diagnose new representatives of gray forest soils. The virtual “images” of the soils can be used for the improvement of soil systematization and for solving various applied problems of land use. 相似文献
15.
Mechanisms of the agropedogenic transformation of cultivated gray forest soils are discussed. It is shown that the loss of
organic carbon from these soils upon their cultivation is mainly due to the intense mineralization of an easily decomposable
fraction having a density of less than 2 g/cm3 and a characteristic size above 50 μm. Simultaneously, a certain portion of soil microaggregates is destroyed. Several additional
indices of the processes of soil erosion and sediment accumulation on the soil surface (soil aggradation) are suggested. These
indices take into account the character of soil clay minerals and soil organic matter. Indicative characteristics of the second
humus horizon are suggested on the basis of published materials and new analytical data. 相似文献
16.
A. A. Larionova B. N. Zolotareva I. V. Yevdokimov D. V. Sapronov Ya. V. Kuzyakov F. Buegger 《Eurasian Soil Science》2008,41(13):1378-1386
The rates of soil carbon renewal were determined by the method of natural 13C abundance in a chernozem under a 40-year-long monoculture of corn and in a gray forest soil after application of corn residues.
The mean rate of soil carbon renewal in the chernozem reached 1271–1498 years, whereas in the gray forest soil it depended
on the amount of carbon introduced with corn residues and varied from 19 to 63 years. The rate of organic carbon renewal in
the chernozem decreased from 697 years in the upper horizon to 2742 years in the layer of 40–60 cm. The mean residence time
of organic carbon generally increased with a decrease in the size of particle-size fractions. 相似文献
17.
A. A. Larionova A. M. Ermolaev V. I. Nikitishen V. O. Lopes de Gerenyu I. V. Evdokimov 《Eurasian Soil Science》2009,42(12):1364-1373
The effect of different land-use practices on the carbon budget in old arable gray forest soils of Russia was studied in field
experiments. A short-term (for 6–7 years) cessation of mineral fertilization had no negative effects on the carbon budget
in the agrocenoses studied. Only the combination of zero fertilization with the return to monoculture and the introduction
of black fallows created a negative budget of humus in the soil. The regrassing of the eroded arable soil for 24 years increased
the humus reserve in the 0- to 60-cm layer by a factor of 1.6–1.7. The average annual accumulation of carbon and nitrogen
after the restoration of the perennial vegetation was 106–128 g C/m2 and 11–16 g N/m2, respectively. 相似文献
18.
A. M. Kuznetsova O. S. Khokhlova Yu. G. Chendev A. L. Aleksandrovskii 《Eurasian Soil Science》2010,43(13):1527-1534
The integrated study of the carbonate state of soils, which involves all the forms of soil carbonates at different levels
of the soil organization, allows exactly assessing the degree and the rate of the soil transformation due to agricultural
development. The evolution of the carbonate state in agrogenically transformed soils was assessed on a site with a known land-use
history and with remaining natural soils. The direction, rate, and stages of the carbonate state transformation upon the agrogenic
use of dark gray forest soils were determined on the basis of the morphogenetic analysis. Agricultural development entails
a significant reorganization of the carbonate profile: a dark gray forest soil evolves into a medium-thick slightly podzolic
chernozem with a greater pool of carbonates. The calcareous pedofeatures and horizons evolve stepwise: in the soil of a 100-year-old
plowland, the transition to another organization of the carbonate state is observed: carbonates migrate more actively, and
the dissolution-precipitation conditions are most dynamic. In the upper calcareous horizons, the structure of the calcitic
pedofeatures becomes more collomorphic, and this mass fills almost all the voids; in the lower calcareous horizons, calcite
is predominantly segregated into calcareous pedofeatures. 相似文献
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20.
Yu. G. Chendev A. L. Aleksandrovskii O. S. Khokhlova L. G. Smirnova L. L. Novykh A. V. Dolgikh 《Eurasian Soil Science》2011,44(1):1-12
A sequence of dark gray forest soils developing under a virgin broadleaved forest and under croplands used for 100 and 150
years was studied in the southern part of the forest-steppe zone on the Central Russian Upland. The application of multiple
study methods for these objects made it possible to trace the evolutionary changes in the soil properties during the 150-year-long
period of regular plowing. Several important trends in the soil development under the impact of the cultivation were revealed:
(a) an increase in the thickness of the humus layer (according to the measurements at 20 points for each of the objects),
(b) an increase in the amount of mole tunnels, (c) a decrease in the coefficient of the textural differentiation of the soil
profile (with respect to the clay content), (d) an increase in the contents and reserves of the major nutrients upon a stable
pool of humus in the upper meter, and (e) some alkalization and carbonization of the profile. Powdery accumulations of carbonates
and whitish calcareous coatings on the faces of prismatic peds appeared at a depth of more than 130 cm. The plowed soils contained
thin deep fissures, the surface of which was covered by dark-colored clayey-humus coatings at the depth of 50–110 cm. The
radiocarbon age of the humus in these coatings was 500–1000 years younger than the age of the humus in the soil mass between
the fissures. This set of features attests to the evolution of the plowed dark gray forest soils into chernozems under the
impact of plowing. 相似文献