共查询到20条相似文献，搜索用时 15 毫秒
1.
M. E. Kotenko T. A. Zubkova M. V. Gorlenko 《Moscow University Soil Science Bulletin》2009,64(2):89-92
The health status of microbial communities in soils of the Sulak Lowland (Dagestan) was estimated on the basis of data on their functional diversity. The health status of the microbial communities decreased in the following soil sequence: typical meadow soil > meadow-chestnut soil > dark chestnut soil > saline soil (solonchak). The low concentration of soluble salts (<1 meq/100 g of soil) had a positive effect on the functioning of the microbial communities. The health status of the microbial communities also depended on the soil humus content and pH conditions. 相似文献
2.
V. I. Ubugunova I. N. Lavrent’eva L. L. Ubugunov T. P. Nikheleeva 《Eurasian Soil Science》2007,40(8):866-874
Mesofauna of chestnut, meadow-chestnut, meadow alluvial, clayey mucky-gley swampy alluvial soils, and hydromorphic solonchaks has been studied within the Ivolga depression. Variations in the population density of soil invertebrates (from 29.9 to 284.3 specimens per m2) are controlled by the particular soil ecological conditions. Dominant mesofauna species are morphologically and physiologically adapted for living near the soil surface. About 85–90% of them are allocated to the uppermost 10-cm-thick soil layer. The hydrothermic regime (r = 0.94) and the low bioproductivity of phytocenoses (r = 0.74) are the major factors limiting the mesofauna functioning in soils of the Ivolga depression. The biocenotic similarity of the invertebrate complexes in the chestnut, meadow-chestnut, and solonchak soils and in the alluvial swampy and meadow soils is revealed. The highest diversity of the ecological groups of soil mesofauna is seen in the clayey mucky-gley swampy alluvial soils. 相似文献
3.
T. I. Chernov A. K. Tkhakakhova M. P. Lebedeva A. D. Zhelezova N. A. Bgazhba O. V. Kutovaya 《Eurasian Soil Science》2018,51(9):1057-1066
The analysis of ribosomal genes has been applied to study microbiomes of two soils of the solonetzic soil complex in the northern Caspian region. These soils—solonetz and quasigleyic chestnut soil—drastically differ in their salinity characteristics. The specificity of the vertical distribution of prokaryotes by the genetic soil horizons from the surface to the depth of 120 cm in these soils is discussed. The differences in the structure of microbiomes in the upper soil horizons can be related to the differences in the vegetation cover of the two soils, whereas the differentiation of microbiomes along the soil profiles is affected by the soil salinization. The solonetz is characterized by a much sharper decrease in the abundance and diversity of microorganisms down the soil profile in comparison with the leached quasigleyic chestnut soil. The total number of prokaryotes is mainly limited by the organic carbon content. In the upper soil horizons, Archaea from the phylum Thaumarchaeota are relatively abundant; their percentage decreases down the soil profiles. In the lower horizons of the solonetz, the genes of Marinobacter bacteria, which are considered marine inhabitants, have been found. It is probable that they persist in the soil since the previous transgression of the Caspian Sea. 相似文献
4.
O. E. Marfenina D. S. Sakharov A. E. Ivanova A. V. Rusakov 《Eurasian Soil Science》2009,42(4):432-439
Fragments of buried Late Pleistocene (30000-year-old) and Early Holocene (10000-year-old) paleosols contained viable complexes of microscopic fungi. The mycobiota of these paleosols represents a pool of fungal spores that is lower in number and species diversity as compared to that in the recent humus horizons and higher than that in the inclosing layers. The central part of the paleosol profiles is greatly enriched in microscopic fungi. In the intact humus horizons of the Late Holocene (1000–1200 years) paleosols, actively functioning fungal complexes are present. These horizons are characterized by their higher level of CO2 emission. The buried horizons, as compared to the recent mineral ones, contain a greater fungal biomass (by several times) and have a higher species diversity of microscopic fungi (including fungi that are not isolated from the recent horizons). Nonsporulating forms are also present there as sterile mycelium. The seasonal dynamics of the species composition and biomass of the fungal complexes were more prominent and differed from those inherent to the surface soil horizons. In the buried humus horizons, the dynamics of the fungal biomass were mainly due to the changes in the content of spores. The data on the composition of the fungal complexes in the buried soils confirm (due to the presence of stenotopic species) the results of paleobotanic analyses of the past phytocenoses or do not contradict them. 相似文献
5.
Data on the morphology and radiocarbon ages of humus of dark vertic quasigley nonsaline clayey soils with alternating bowl-shaped (Pellic Vertisols (Humic, Stagnic)) and diapiric (Haplic Vertisols (Stagnic, Protocalcic)) structures are discussed, and the genetic concept for these soils is suggested. The studied soils develop on loesslike medium clay in the bottom of a large closed depression on the Eisk Peninsula in the lowest western part of the Kuban–Azov Lowland. The lateral and vertical distribution of humus in the studied gilgai catena displays a lateral transition of a relatively short humus profile of the accumulative type with a maximum near the surface and with a sharp increase in 14C dates of humus in the deeper layers within the diapiric structure to the extremely deep humus profile with a maximum at the depth of 40–80 cm, with similar mean residence time of carbon within this maximum, and with a three times slower increase in 14C dates of humus down the profile within the bowl-shaped structure. The development of the gilgai soil combination is specified by the joint action of the lateral–upward squeezing of the material of the lower horizons from the nodes with an increased horizontal stress toward the zones a decreased horizontal stress, local erosional loss of soil material from the microhighs and its accumulation in the adjacent microlows, leaching of carbonates from the humus horizons in the microlows, and the vertical and lateral ascending capillary migration of the soil solutions with precipitation of calcium carbonates in the soils of microhighs. 相似文献
6.
7.
《Communications in Soil Science and Plant Analysis》2012,43(15-16):2077-2090
Abstract Soil salinization and sodication affect large areas of agricultural land in the world. Amelioration of these soils to make them suitable for agricultural production depends on understanding sodium dynamics and chemical interactions governing nutrient availability. Three locations in eastern Croatia were characterized to the 5‐m depth. The two solonetz‐solonchak soils were alkaline, whereas the solonetz soil had near‐neutral A/E horizon and alkaline deeper horizons. Electrical conductivity of the saturated extract (ECe) was greater than 4 dS m?1 in the top horizons in the solonetz‐solonchak soils. The solonetz soil had 2.8–4.7 dS m?1 in shallow A/E, CG, and G horizons and up to 6.3 dS m?1 below 1.5 m. Highly alkalinized sodic horizons (exchangeable sodium percentage, ESP >20) had 24–47% Ca2+ and 27–33% Mg2+ on the cation exchange complex. Sodium adsorption ratio (SAR) was high (18–26) in the P horizon and even more so in Bt,na horizon (35–36) of solonetz‐solonchak soils. A strong negative exponential relationship existed between soluble Ca2+ and SAR (SAR increased greatly when Ca2+ dropped to around 3 mg dm?3). An increase in pH to greater than 8.4 resulted in an exponential increase in SAR. Leaching of Na+ with successive volumes of water was similarly effective for the P and Bt,na horizons in the solonetz‐solonchak soils, but SAR remained greater than 15 even after six successive cycles of leaching. In conclusion, extensive amelioration of tested soils with gypsum and leaching will be required to overcome poor physical and chemical characteristics caused by various degrees of alkalization and sodication to bring these soils into production. 相似文献
8.
The stocks of organic carbon and mean rates of the CO2 emission during the growing season (May–September) and the entire year were estimated in a sequence of grass ecosystems along the transect encompassing chestnut and meadow-chestnut steppe soils, marsh and meadow alluvial soils, and a haloxerophytic community on a typical solonchak. The total stocks of organic carbon comprised 6.17–9.70 kg С/m2 in steppe, 7.41–10.04 kg С/m2 in floodplain, and 4.74 kg С/m2 in haloxerophytic ecosystems. The portion of humus carbon in the upper 50-cm-thick soil layer comprised 79–92% of the total carbon stock. The mean daily CO2 emission (С–CO2/(m2 day)) from alluvial soils was moderate (3.3–4.9) or low (1.5–2.5). The dependence of the CO2 emission on the moistening of steppe soils, temperature of alluvial soils, and temperature and moistening of solonchak was revealed. In comparison with the CO2 emission from the zonal chestnut soil, its mean values during the growing season and the entire year were 1.2 times higher for the meadowchestnut soil, 3.3 times higher for the marsh alluvial soil, 2.3 times higher for the meadow alluvial soil, and 1.7 times higher for the solonchak. The portion of the CO2 emission beyond the growing season in the mean annual emission averaged 19.8–24.2% and depended on the type of grass ecosystem and on weather conditions of particular years. The sink of carbon in the grass ecosystems exceeded carbon emission, especially in the steppe ecosystems. 相似文献
9.
The interaction between pipelines and soils manifests itself in the soil disturbance in the course of the pipe installation,
in the transformation of the water and temperature regimes in the trenches, and in the appearance of corrosion and cracks
on the pipe walls. The more contrasting the soil water regime in the pipe-adjacent sections of the trench, the greater the
amount of the pipe damage. The damage of the pipe insulation activates the pipe corrosion. The emission of gases (H2S, CH4, CO2, CO, and H2) and the activity of sulfate-reducing bacteria are the main causes of the pipes’ destruction. The humus content and the redox
potential decrease, and the soil density and concentrations of ferrous compounds increase in the soils of the trench zone.
Accidents along pipelines occur most often in the area of serozems and chestnut soils, and this is related to the salinization
in the lower soil horizons and to the contrasting soil water regime near the pipe. The number of accidents along the pipelines
installed into soddy-podzolic soils is lower. 相似文献
10.
T. I. Chernov M. P. Lebedeva A. K. Tkhakakhova O. V. Kutovaya 《Eurasian Soil Science》2017,50(1):64-69
The taxonomic structure of the microbiota in two associated soils—solonetz on a microhigh and meadow-chestnut soil in a microlow—was studied in the semidesert of the Caspian Lowland. A highthroughput sequencing of the 16S rRNA gene was used for the soil samples from genetic horizons. A considerable reduction in the bacterial diversity was found in the lower horizons of the solonetz and compact solonetzic horizon with a high content of exchangeable sodium. In the meadow-chestnut soil, the microbial diversity little decreased with the depth. In both soils, a portion of archaea from the Thaumarchaeota group also decreased in the deeper horizons. In the soil horizons with the lower total bacterial diversity, a share of proteobacteria of the Enterobacteriaceae, Pseudomonadaceae, and Sphingomonadaceae families became higher. The difference between the structure of the microbial population in the solonetz and meadow- chestnut soil can be first explained by the different water regimes and soil consistence. 相似文献
11.
The study of soils of different ages in different physiographic regions of the Crimean Peninsula made it possible to reveal
the main regularities of pedogenesis in the Late Holocene (in the past 2800 years). With respect to the average rate of the
development of soil humus horizons, the main types of soils in the studied region were arranged into the following sequence:
southern chernozems and dark chestnut soils > mountainous forest brown soils > gravelly cinnamonic soils. In the newly formed
soils, the accumulation of humus developed at a higher rate than the increase in the thickness of humus horizons. A sharp
decrease in the rates of development of soil humus profiles and humus accumulation took place in the soils with the age of
1100-1200 years. The possibility for assessing the impact of climate changes on the pedogenetic process on the basis of instrumental
meteorological data was shown. The potential centennial fluctuations of the climate in the Holocene determined the possibility
of pulsating shifts of soil-geographic subzones within the steppe part of the Crimea with considerable changes in the rates
of the development of soil humus horizons in comparison with those in the Late Holocene. 相似文献
12.
The study of post-irrigated and virgin soils at the Kislovsk irrigation system has shown that the salt regime of the post-irrigated soils is determined by the (1) depth and salinity of the groundwater, (2) the litho-logical structure of the soil and subsoil, (3) the local microtopography, (4) the presence or absence of a solonetzic horizon in the post-irrigated solonetzes, and (5) the portion of solonetzes in the soil cover. The post-irrigated soil complexes on the Privolzhsk sand ridge with a groundwater depth of more than 4 m do not undergo secondary salinization. At the groundwater depth of 2.0–2.6 m, post-irrigated meadow-chestnut soils remain nonsaline, chestnut soils and solonetzes with an artificially destroyed (due to deep tillage) solonetzic horizon undergo desalinization, and solonetzes with a preserved solonetzic horizon undergo salinization in the subsolonetzic layers. The post-irrigated soils of the Khvalyn undrained sea plain used for rainfed farming have become saline in the deep part of the profile, and their plow layers remain nonsaline. 相似文献
13.
Soil salinization features in semidesert, dry steppe, and chernozemic steppe zones within intermontane depressions in the central part of the Tuva Republic are discussed. Chernozems, chestnut soils, and brown desert-steppe soils of these zones are usually nonsaline. However, salinization of these zonal soils is possible in the case of the presence of salt-bearing parent materials (usually, the derivatives of Devonian deposits). In different natural zones of the intermontane depressions, salt-affected soils are mainly allocated to endorheic lake basins, where they are formed in places of discharge of mineral groundwater, and to river valleys. The composition and content of salts in the natural waters are dictated by the local hydrogeological conditions. The total content of dissolved solids in lake water varies from 1 to 370 g/L; the water is usually of the sulfate–chloride or chloride–sulfate salinity type; in some cases, soda–sulfate water is present. Soil salinity around the lakes is usually of the chloride–sulfate–sodium type; gypsum is often present in the profiles. Chloride salinization rarely predominates in this part of Tuva, because chlorides are easily leached off from the mainly coarse-textured soils. In some cases, the predominance of magnesium over sodium is observed in the composition of dissolved salts, which may be indicative of the cryogenic transformation of soil salts. Soda-saline soils are present in all the considered natural zones on minor areas. It is hardly possible to make unambiguous statements about the dominance of the particular type of salinity in the given natural zones. Zonal salinity patterns are weakly expressed in salinization of hydromorphic soils. However, a tendency for more frequent occurrence of soda-saline soils in steppe landscapes and chloride–sulfate salinization (often, with participation of gypsum) in the dry steppe and semidesert landscapes is observed. 相似文献
14.
The distribution of the fungal biomass and diversity of cultivated microscopic fungi in the profiles of some soils from East (Progress Station, valleys of the Larsemann Hills oasis) and West (Russkaya Station, the Marie Byrd Land) Antarctica regions were studied. The structure of the biomass (spore/mycelium and live cells/dead cells) was analyzed by fluorescence microscopy with staining using a set of coloring agents: calcofluor white, ethidium bromide, and fluorescein diacetate. The species composition of the cultivated microscopic fungi was determined on Czapek’s medium. The fungal biomass in the soils studied is not high (on the average, 0.3 mg/g of soil); the greatest biomass (0.6 mg/g) was found in the soil samples with plant residues. The fungal biomass is mainly (to 70%) represented by small (to 2.5 μm) spores. About half of the fungal biomass is composed of living cells. There are differences in the distribution of the fungal biomass within the profiles of different primitive soils. In the soil samples taken under mosses and lichens, the maximal biomass was registered in the top soil horizons. In the soils with the peat horizon under stone pavements, the greatest fungal biomass was registered in the subsurface horizons. Thirty-eight species of cultivated microscopic fungi were isolated from the soils studied. Species of the genus Penicillium and Phoma herbarum predominated. 相似文献
15.
The role of aluminium on humus accumulation in acid forest soils The impact of soil-borne aluminum on humus accumulation was investigated in a forest soil of the chestnut zone (Castanea sativa) in southern Switzerland (Ticino). Soil samples of two soils formed on bedrocks which differ mainly in their aluminum content were extracted with HNO3, NH4Ac.-EDTA, NH4Cl, KCl, and NH4F-HCl and analyzed for the most abundant elements. On gneiss which contains up to about 10% of total aluminum the common soil type in this area is a Cryptopodzol. This soil is similar to the nonallophanic Udands. It is rich in wellhumified organic matter and shows dark-colored Ah-, A(E)- and Bh-horizons. The soil samples of these horizons are extremely rich in nonexchangeable aluminum which is, however, extractable with NH4Ac.-EDTA. It is assumed that this Al is intimately bound to the organic matter. The soil samples of these horizons contain large amounts of HNO3-extractable phosphorus. Up to 90% of this P appears in the organic fraction. The content of NH4F-HCl-extractable P is only 0.7 to 3.4 mg/kg. It is concluded that due to excessive Al in the organic matter the humus mineralization is inhibited compared to the Haplumbrepts of the region. 相似文献
16.
作者认为分布在起伏台地区中更新统沉积物上的黑土(无石灰反应,有机质丰富,几乎全部耕垦)和平原中部晚更新统和近代冲积物上的淡黑钙土(强石灰反应,有机质少,常混有盐斑),其发生学上的差异主要是成土母质和年龄的不同。后者远较前者为年幼。淡黑钙土是按沼泽→草甸→草甸淡黑钙土→淡黑钙土的过程形成的。现代气候条件下,植被制约着草甸土类的发生方向。不论是由于天然的或人为的任何原因,一旦植被破坏,随着蒸发的加强,即便地下水的矿化度不高,也能形成强碱性、结构极坏的苏打盐(碱)土。按照土壤发生的观点,合理利用碱性草原和改良苏打盐(碱)土的原则,应是保护和恢复植被。 相似文献
17.
The microrelief affects the distribution of soluble salts in the upper horizons of salt-affected soils. This has been shown for semidesert soils—meadow solonchak, solonchakous meadow, and meadow soils—within the Sulak Lowland in the Republic of Dagestan. The total content of salts and the concentrations of sodium, magnesium, chlorine, and sulfate ions are higher in the soils of microelevations. However, no significant effect of the microrelief on the distribution of calcium in the soil water extracts has been found. The properties of the solid soil phase (the humus content and the content of adsorbed bases, including calcium, magnesium, and sodium) and the soil pH are not reliably differentiated by the elements of the local microtopography. 相似文献
18.
Soils with intricate patterns of their humus profiles developing in the neutral-calcium landscapes of the southern taiga of
Western Siberia under highly dynamic paleogeographic, climatic, and weather conditions are characterized. The specific features
of these soils comprise the diverse modern humus horizons along with the relic ones of different preservation rates, shallow
leaching of carbonates, and a weak development of the middle-profile soil horizons. Specifying these organo-accumulative soils is substantiated by their high humus content against the geochemical
background of the clayey calcareous parent rocks. The conjugated series of soils reflect different stages of the soil evolution
(the humus profile degradation, the development of eluvial process, and the increase of contrasts in the acid-base conditions)
and the hydromorphic transformation accompanied by the formation of organic horizons making the humus profile more complicated.
In accordance with the diagnostic horizons, the position of the soils studied was determined in the Classification and Diagnostics of Soils of Russia. The relic enrichment of the humus horizon is proposed to be used as a specific feature of these soils. 相似文献
19.
Towada Ando soils consisted of five soils—Towada-a (1,000 years old), Towada-b (2,000 years old), Chuseri (4,000 years old), Nanbu (8,600 years old), and Ninokura soils (10,000 years Amorphous clay materials of these soils taken at different localities were studied by the combined use of selective dissolution and differential infrared spectroscopy, X-ray analysis, electron microscopy, etc. The main clay minerals of Towada-a soils, present-day soils, were montmorillonite-vermic-ulite chloritic intergrades and opaline silica, or these minerals and allophane in the humus horizons, and allophane in the non-humus ones. Towada-b soils overlain by the Towada-a soils showed the clay mineralogical constituents similar to those of Towada-a soils. However, allophane was one of the main clay minerals in all the humus horizons as well as non-humus ones. The main clay minerals of Chuseri soils were allophane and layer silicates consisting chiefly of chloritic intergrades and chlorite in the humus horizons, and allophane in the non-humus ones. Opaline silica was present in minor amounts in the humus horizons of Chuseri soils, but nearly absent in Nanbu and Ninokura soils. There were remarkable differences in the clay mineralogical composition of Nanbu and Ninokura soils with differences of their environmental conditions. Allophane and imogolite Were dominant in the clay fractions of both humus and non-humus horizons of very shallowly buried Nanbu soil which was subjected to the strong leaching process. Allophane was the main clay mineral of deeply buried Nanbu and Ninokura soils which showed the absence of notable accumulation of bases and silica. On the contrary, halloysite with a small amount of siliceous amorphous material appeared in very deeply buried Nanbu and Ninokura soils where bases and silica were distinctly accumulated. The amounts of halloysite in the clay fractions were larger in the humus horizons than non-humus ones, and in Ninokura soil than Nanbu soil. Soil age, soil organic matter, and depositional overburden of tephras were observed to be conspicuous among various factors relating to the weathering of amorphous clay materials in Towada Ando soils. 相似文献
20.
Salinization dynamics in irrigated soils of the Svetloyarsk irrigation system,Volgograd oblast 总被引：1，自引：0，他引：1
On the basis of soil surveys performed by the Volgograd hydrogeological reclamation expedition in 1998 and 2006, published
data, and original materials obtained by the authors, the dynamics of soil salinization within the Svetloyarsk irrigation
system in Volgograd oblast during the irrigation and post-irrigation periods have been traced. It is found that high irrigation
rates under conditions of poor drainage and closed drainage basins upon both shallow (within the Caspian Lowland) and relatively
deep (on the Ergeni Upland) occurrence of saline groundwater and the presence of natural salts in the soils and subsoils lead
to the rise in the groundwater level above the critical level and the development of secondary salinization in the previously
surfacesaline, deeply saline, and even nonsaline soils. During the post-irrigation period (15–18 years) under modern climatic
conditions, the groundwater level has been descending to a depth of more than 3 m, and the degree of salinity in the upper
meter of light chestnut and meadow-chestnut soils has decreased owing to the leaching of salts with atmospheric precipitation. 相似文献