Swampy Soils Research Articles

METHOD OF ACCOUNTING SOIL-AGROCHEMICAL POTENTIAL FOR OPTIMIZING THE STRUCTURE OF LAND USE OF THE VOLOZHINSK DISTRICT OF THE REPUBLIC OF BELARUS

The article discusses one of the ways to assess the condition of soil cover to improve the efficiency of land management using the example of the Volozhin region of the Republic of Belarus. A comprehensive assessment of the agrochemical and natural potential of the soil is proposed by means of typing the soil cover depending on agrochemical indicators (pHKCl, humus content, mobile compounds of phosphorus and potassium) and a quality score reflecting the natural state of the soil. Using geostatistical methods, the values of agrochemical indicators were interpolated from elementary areas into areas of soil varieties of agricultural lands and classified according to the degree of content of agrochemical elements that made up the agrochemical potential (AP). After crossing the AP with the bonitet score, 9 groups of soils were identified according to soil-agrochemical potential (SAP), of which the largest share (58,2 %) is occupied by soils with average potential (61,950 ha). Based on the results of a spatial assessment of the PAP, it was determined that sod-podzolic and sod-podzolic swampy soils developing on light loams and cohesive sandy loams have the greatest potential. It was also revealed that areas with low PAP gravitate towards the most dissected areas of the terrain with sandy and cohesive sandy soils. Based on the typification carried out, the main types of preferred land use in the Volozhin region were determined: more than half of the agricultural land can be used for intensive agricultural use for arable land (52,1 %) and meadows (12,5 %), traditional land use is possible for 29,3 % territories and only 6,2 % of lands require the use of soil protection farming systems, primarily focused on erosion-hazardous areas of the area.

SALINE AND SWAMPY (WATERLOGGED) SOILS OF KAZAKHSTAN AND WAYS TO IMPROVE THEM

The article describes the patterns of distribution of saline and swampy soils across the soil and climatic zones of Kazakhstan, describes the features of salt accumulation processes depending on geological development and identifies soil-halogeochemical provinces. Reclamation measures for their development are recommended. The most effective method of reclamation of hydromorphic meadow solonchaks of the chloride-sulfate type of salinization is leaching against the background of open deep horizontal drainage. Leaching of meadow solonchaks of the foothill plain of the Ili Alatau with a water norm of 5000 m3/ha provides desalination of the soil and soil thickness with a capacity of 0-80 cm. During soda salinization of solonetzic meadow-chestnut soils, the application of 2.1 and 4.2 t/ha of 1% sulfuric acid solution ensures the transformation of the ionic composition of the pore solution from soda to sulfate, which is subsequently removed by leaching. On swampy (waterlogged) soils, the most rational is the creation of highly productive meadow agrocenoses and the preservation of meadow biocenoses.

Agrochemical Features of Soils Under Vegetable Crops in the Lankaran Zone (Azerbaijan)

The article presents the materials of agrochemical studies of the soils of the Lankaran Zone. Silt-mursh soils are divided into 2 groups: fully developed silt-mursh soils and poorly developed silt-mursh soils. The studied soils are sufficiently provided with humus and nitrogen; there are few nitrogen-containing compounds that can be absorbed by plants. Unlike nitrogen, the source of phosphorus nutrition for plants is only phosphates in the soil and fertilizers applied to the soil. Due to the large amount of humus in waterlogged soils, organic phosphorus compounds are also high. As a result of studies conducted by various scientists on swampy soils, it was found that 40% of total phosphorus is in organic and 58% in mineral forms.

A new semiaquatic worm (Annelida, Oligochaeta) from southeastern Mexican tropical rain forests

A new Oligochaete worm genus with a single species is described from tropical rain forests of Southern Mexico. Lacandodrilus paludosus Fragoso & Rojas gen. et sp. nov., found in sandy and acid poor swampy soils, presented a characteristic morphology of semiaquatic oligochaetes. The new taxon is holandric, with male pores and ovaries in segment 13, with genital prostatic- like lobular glands in segments 13 and 14 and with long seminal vesicles contained within ovisacs. It is also characterized by exonephric holonephridia covered by a peritoneal granular layer, septal glands and long vascular commissures in former segments. It presents a pair of spermathecae without diverticula in segment 10 and it lacks gizzards, typhlosole or esophagus glands. The new taxon is tentatively placed in family Alluroididae, waiting for additional histological studies that will clarify some characters.

Results and prospects of optimization of agrochemical indicies of arable soils fertility in Belarus

A critical overview of dynamics of agrochemical indices of arable soils fertility over 50-year period is presented. The low-yield sod-podzol and swampy soils of Belarus were relatively poor in available plant nutrients. As a result of the largescale water engineering, liming and the intensive use of fertilizers over the period of 1965–2020 the productivity of arable land increased from 1.5 to 4.6 tons per hectare in grain equivalent. The significant improvement of soil fertility status was also achieved. Data of soil fertility status are based on the large-scale soil test monitoring conducted by State Agrochemical Service every 4–5 years. The share of strongly and moderately acid soils with pH < 5.0, that are harmful for the main crops, decreased from 66.8 % in 1970 to 4.5% of total area of arable land in 2004. However, the share of acid arable soils increased up to 9.8% in 2020, due to insufficient volume of liming that will be increased in the forthcoming years. The average organic matter (O.M.) content had been strongly increased from 1.77 to 2.28 % during the period of 1970–2000, due to high share of perennial grasses in cropping structure and manure application up to 14–15 t/ha per year. About 1 million ha of drained soils with the high O.M. content was also involved to arable land. The average O.M. content in the last two decades had been in mobile equilibrium of 2.23–2.27 % with a tendency to decline in some districts. The average contents of mobile Phosphorous and Potassium in arable soils increased up to 2.4–3.2 times during the experimental period and they are in the optimal range for cultivated crops. Currently balanced fertilization is the most important, with differentiation of fertilizer rates that would be most suitable to crop requirements and soil tests on each field. Formation and maintenance of optimal soil fertility indices, especially pH and mobile Р2О5 and К2О contents, are strictly controlled as protective measures on the land contaminated with radionuclides 137Cs and 90Sr after Chernobyl accident. Measures to improve the efficiency of capital investment at fertility reproduction and use of arable soils are discussed currently.

Results of the analytical study of the growth, development, grain yield and quality of Mung Bean (Rhaseo1is Aireis Piper) varieties under the conditions of grassy swampy soils

In this article was described the effect of the studied factors on the height and productivity of mung bean stalks and grain quality. According to the results of the experiment, it was found that the growth of the varieties according to the planting period was 2.3-5.2 cm higher than the height of the stem when planted on June 20 and July 1 compared to the spring period. It was found that on June 20, the yield of the “Durdona” variety increased by 2.2-2.8 s/h compared to the spring planting period. In addition, planting dates and rates affect the protein content of mung bean grain, as the planting rate increases, the amount of protein decreases, and when repeated planting, the amount of protein in the variety “Navruz” is 1.7-1.0%, “ It was found that it increased by 0.3-0.5% in Durdona variety. Key words: mung bean, Asian bean, meadow-swampy soil, Navruz, Durdona, variety, podding, tuganak, stem, protein, productivity.

Fish farming facilities for cultivation in agricultural reservoirs with intense hydrochemical regime

Agricultural reservoirs built on acidic, swampy soils, peat processing, as a rule, have a tense hydrochemical regime. Overseas phenomena are also a natural consequence of the intensification of pond fish farming. In the hottest time of the year (most often in July, the first half of August), the massive development of phyto-, zooplankton, benthos and, above all, microorganisms (bacteria), compaction of fish planting for cultivation, intensive feeding with artificial feeds, lead to the accumulation of organic matter and a sharp decrease in oxygen content in water. One of the ways to develop such lands is to expand the number of breeding facilities with increased resilience. Widespread, the most hardy, having high nutritional qualities of fish — golden and silver crucian carp, as well as their hybrids have considerable commercial value in reservoirs of various origins and conditions, especially unfavorable hydrochemical regime. A promising object is the snakehead. This is a predatory freshwater Far Eastern fish, which is characterized by rapid growth and has high-quality meat. It breathes both at the expense of oxygen dissolved in water, and at the expense of atmospheric air, for breathing which it has a gill organ. The snakehead cannot exist only due to water respiration by gills. It feeds at a young age mainly on crustaceans and insects. As they grow, more and more switch to fish food, and large specimens feed almost exclusively on fish and frogs. In reservoirs with a tense hydrochemical regime, due to its unpretentiousness and undemanding to oxygen, tench can be grown. Tench is a promising object for breeding and stocking reservoirs. It is unpretentious, undemanding to water quality, can live in reservoirs with a very low oxygen content (up to 0.3 ml/l), a heavily silted bottom and acidic water, tolerating a decrease in pH to 5.

Influence of agro-landscape on the ecological sustainability of cover oats and perennial herbs phytocenoes

Biodiversity is the cornerstone of modern agro-phytocinology. Based on its records, the ecological sustainability of agricultural landscapes is predicted. The aim of the research was to study the influence of soils and the topography of the terminal moraine hill, as well as the age of phytocenoses, on the value of the coefficient of floristic similarity of oat communities with over-sowing of grasses (2019) and clover-and-timothy herbage of 1 year of use (2020). Monitoring of the botanical composition of phytocenoses was carried out on a transect – a field crossing slopes of different exposures and soils of varying degrees of swampiness, located at the agroecological station All-Russian Research Institute of Reclaimed Lands (VNIIMZ; Tver region, Russia). The standing density of oats, red clover, timothy grass, weed species, as well as other environmental parameters were taken into account on 30 systematically located land plots. It is shown that only a few plant species affect the Jaccard coefficient. The topography and soil features of the agricultural landscape, as well as the age of the plant community, have a significant impact on the stability and productivity of the agrocenosis. The main factor affecting the variability of the floristic similarity indicator is soil hydromorphism. An increase in the index of the floristic similarity coefficient is observed on all soils and slopes as the herbage matures. Productivity of grasses depends to the greatest extent on the nature of the interaction of the relief and soils – on the southern slope of the hill, a low hay yield was noted (on average, 5.34 t/ha), the minimum of which was observed on highly swampy soils (4.92 t/ha), on the northern slope, the yield of hay was higher (on average 6.57 t/ha), the minimum of which was noted on moderately swampy soils (6.26 t/ha). Based on the revealed patterns, it is possible to develop measures to adapt technologies for growing perennial grasses to the natural conditions of farms in the mode of adaptive landscape fodder production.

RESISTÊNCIA DO SOLO E ANÁLISES MULTIVARIADAS COMO UM MÉTODO A UXILIAR PARA A SELEÇÃO DE PROGÊNIES DE Calophyllum brasiliense

ABSTRACT Precision silviculture is being developed to manage and improve Calophyllum brasiliense, a tree species associated with wet and swampy soils. This study estimated genetic parameters for growth traits in response to soil resistance as an auxiliary tool for identifying and selecting progenies adapted to water-saturated soils. This was undertaken in a progeny test of C. brasiliense in which 1,200 seedlings grown from seeds collected from a natural population were planted in a randomized complete block design for single-tree plots. Genetic statistical analysis was conducted using the REML/BLUP method. Significant differences (p<0.01) in diameter at breast height were observed among the progenies. The coefficients of genetic variation and heritability at the individual and progeny levels were low for diameter at breast height and height, indicating low genetic control for these traits, while high positive and significant genetic and phenotypic correlations were detected between diameter at breast height and height. Theoretical genetic gains and multivariate statistical analysis indicated three groups of progenies with different degrees of tolerance and adaptability to flooded soils, which could be useful in future breeding programs for this species, although further analysis at advanced ages is still required. The mean heights of tolerant and sensitive progenies were 12 and 58%, respectively, lower than the theoretical values, indicating that constant soil flooding is harmful to this species.

Palaeoenvironment of the middle Miocene wetlands at Drzewce, Konin region, central Poland

Palynological analysis of the 1st mid-Polish lignite seam (MPLS-1) of the Drzewce deposit (Konin region, central Poland) was used as the data source for palaeoenvironmental and palaeoclimatic interpretations. Lignites of the 1st group developed in the middle Miocene, during and shortly after the last peak of the Mid-Miocene Climatic Optimum, over a large area of Poland, and they are the youngest of the main Neogene lignite seams in Poland. In the Konin region, these lignites have a relatively significant thickness (up to 20 m) and therefore they are (or were in the past) exploited in several open-pit mines. A total of 36 palynological samples from the 6.3-m-thick seam of the Drzewce opencast mine was studied in detail. Palynological analysis of the lignite seam indicates that the area was overgrown by palustrine wetland communities, similar in composition to modern pocosins. The most characteristic elements of them were shrubs in the Ericaceae family. The climate at that time was warm temperate and humid. The estimated mean annual temperature (MAT) for the lignite seam at Drzewce is 15.7–17.8 °C. Comparison with other palynofloras from the MPLS-1 shows that the climate during the formation of the group of seams was more or less homogenous across the entire Polish Lowlands. Sedimentological data and results of palynological studies (including NPPs) at Drzewce indicate that the palaeomires were relatively distant from the channels of the river system in the Konin Basin. The fossil fungal assemblage indicates dense vegetation on damp, swampy soils and the presence of small, shallow-water bodies, with a variable water level or even periodic reservoirs, existing only during the wet season or after floods. In small, flooded depressions, such as the pools in bogs, filamentous green algae occurred. The presence of zygospores of the desmids Desmidiaceaesporites cosmarioformis most probably indicates relatively nutrient-poor (ombrotrophic) conditions. Fluctuations in the frequency of individual plant taxa (including Sequoia and Sciadopitys ) are likely to reflect changes in water level and trophic conditions.

Changes in vegetation and environment in the Betula microphylla wetland of Ebinur Lake in Xinjiang, China since 3900 cal. aBP.

Based on the high resolution record of fossil pollen data from a 190 cm sediment profile collected in a Betula microphylla-dominated wetland of Ebinur Lake in Xinjiang, we aimed to reveal the changes of vegetation and environment in this wetland over the past 3900 years. Results showed that, in the period between 3420 cal. aBP and 3940 cal. aBP, this area was a desert landscape dominated by plants from Chenopodiaceae and Artemisia. During the period of 2830-3420 cal. aBP, this area became a desert steppe dominated by Thelypteris palustris, surrounded by desert plants mainly composed of Chenopodiaceae and Artemisia. In the period between 2640 and 2830 cal. aBP, Typha pollen increased and occupied a dominant position. The area thus became a typical desert intrazonal wetland mainly composed of Typha. In the period between 1200 and 2640 cal. aBP, Phragmites australis began to grow vigorously and became the dominant species. In the period between 660 and 1200 cal. aBP, the population of Betula expanded rapidly, and P. australis plants continued to grow. During the period of 340-660 cal. aBP, the population of B. microphylla became the dominant species, and the abundance of P. australis decreased. However, there was still some P. australis wetlands in the area. Over the past 340 years, as the area of wetlands decreased and the surface water gradually declined, B. microphylla had grown on swampy meadow soils with suitable moisture conditions. In the past 200 years especially, the sharp increases of Chenopodiaceae pollen in palynological assemblage was closely related to the enhancement of human activities and climate change, resulting in the degradation of wetlands and endangerment of B. microphylla. Therefore, it is necessary to strengthen the protection of wetlands and endangered species in this area.

Biological features of common persimmon (Diospyros virginiana L.)

The article presents the results of long-term observations on the biology of common persimmon. Both positive and negative properties of this specie are given. Phenological indicators are provided: bud swelling, appearance of the first leaves, budding, flowering, fruit ripening. Diospyros virginiana L. is a hexaploid (2n = 90), however, it should be noted that along with the hexaploid race there is also a tetraploid one (2n = 60). Plants of this species are mainly dioecious, the flowers are bisexual. The flowering phase takes place in the first decade of June, which is one to two weeks later than that of the Eastern and Caucasian persimmons. The percentage of useful ovary is quite high and makes 27-29%. The fruit is smaller in size than the eastern persimmon, but three to four times larger than the Caucasian one. They have a spherical or conical shape, ranging in size from two to five cm in diameter. In a solid state, the fruits are very tart, but ripe fruits are very sweet, the sugar content reaches 20%. The ripening period is one and a half months. The number of seeds in the fruits is three to five pieces, they are larger in comparison with the seeds of the Caucasian persimmon. Diospyros virginiana L. is mainly found in the wild in the USA, where it is used as a rootstock on heavy, swampy soils for cultivated varieties of eastern persimmon, as it easily tolerates the proximity of groundwater, temporary flooding and river floods. In the Russian Federation, it is practically not used, since it is inferior in yield to plants grafted on Caucasian persimmon and forms a lot of growth. A great advantage of the common persimmon is its winter hardiness, it is much higher than that of cultivated varieties. It tolerates a drop in temperature to minus 25–280 С without any damage. In breeding, it is used to obtain varieties with high frost resistance to expand the cultivation area and move to more northern regions.

Willow communities, optimal absorption of carbon dioxide from the atmosphere

High biological productivity of willow communities contributes to the effective performance of carbon dioxide absorption in photosynthesis. In natural communities, shrub willows hectareve a better effect on carbon dioxide balance: the amount of absorbed gas significantly exceeds its emission. Deciduous willows are able to fulfill the same condition, but only when grown in plantations. For the effective absorption of carbon dioxide, willow communities should meet the following parameters depending on the soil conditions. A one-year phytomass growth of axial shoots (in terms of absolutely dry matter) should be more thectaren 3.11 tons⋅hectare−1⋅year−1 on rich soils. This condition is fully met by the Salix dasyclados and S. viminalis communities. When growing on poor soils, annual phytomass growth of axial shoots of more thectaren 0.93 tons⋅hectare−1⋅year−1 is sufficient, which is noted in the communities of S. purpurea. The annual increase in phytomass of axial shoots should be more 2.48 tons⋅hectare−1⋅year−1 when growing on swampy soils. S. dasyclados and S. viminalis are the most suitable for plantation cultivation. These willow species perform the raw material function in the most effective way and, along with this, absorb carbon dioxide from the atmosphere in the greatest amount.

Soils in Devonian and Carboniferous. Current State of Knowledge in Russia: A Review

Information on Devonian and Carboniferous paleosols is limited. In this paper, published data (about 50 sources) on findings of these paleosols mostly on the territory of paleocontinents Laurussia and Pangea are summarized. For visualization of this information, sketch maps of paleosol distribution for Devonian, Mississippian, and Pennsylvanian times have been developed. Their analysis shows that most of Devonian paleosols belonged to the groups of azonal and intrazonal soils; soils of wetlands predominated. The discoveries of Middle and Late Devonian zonal soils—Oxisols and texturally differentiated Alfisols—in the area of Voronezh High (south Russia) are unique. Most of Mississippian paleosols also belonged to azonal and intrazonal soils. The wide distribution of wetland paleosols in the Mississipian subperiod was also reflected in the increased area of coal basins (8% of land in comparison with 1% in Devonian). In the area of the Moscow sedimentary basin, along with Histosols, zonal paleosols—Spodosols and others—have been described. Pennsylvanian soil cover consisted of azonal, intrazonal, and zonal soils. In North America and Western Europe, swampy soils were still widely distributed (22% of land was occupied by coal basins). Oppositely, in the area of the Moscow sedimentary basin, Pennsylvanian paleosols of semiarid and arid ranges with palygorskite as the major clay mineral were widely present. The differentiation of Pennsylvanian soil cover of Laurussia and Pangea reflects the changes in climatic zonality of the planet with an increase in the degree of climatic contrast.

To the characteristics of water-coastal flora steppe rivers of the central Caucasus

When studying the vegetation of water bodies, it is necessary to pay attention not only to the vegetation of the water body itself, but also to the vegetation of the low part of its shores. Thus, we study plants with a different attitude to water: hydrophytes that are real aquatic plants, fully or mostly immersed in water. Hygrophytes, hygrophilous plants that live on excessively moist soil under neutral acidity conditions, are usually found in swamps, along the banks of water bodies, on the swampy soils of meadows and forests. The transition group between hydrophytes and hygrophytes is hygrophytes – amphibians or wetland plants (helophytes). They occupy both aquatic and humid habitats on the shores. Aquatic vegetation is divided into real aquatic and amphibian vegetation.

Economic feasibility of restoration of degraded and neglected lands

Neglect of soils leads to their degradation, worsens useful properties, and reduces fertility and productivity. (Research purpose) The research purpose is in conducting a comparative analysis of technologies for treating degraded soils, taking into account the economic feasibility of their restoration in non-black-soil regions of Russia. (Materials and methods) The article shows the main technological scheme of restoration of degraded soils. Authors have identified the main groups of land that are located in non-black-soil regions of Russia. (Results and discussion) The article presents the need for equipment, economic and labor costs for the restoration of each type of land in the non-black-soil regions of Russia. Authors took into account that the salary of machine operators depends on the time of direct execution of the task. It was found that the restoration of virgin and fallow lands was the most preferable from the economic, energy-saving and environmental points of view. The article shows that the restoration of pasture areas exceeds the cost of processing virgin lands, but the number of necessary machine and tractor units is comparable to work on virgin lands. Authors recommend to develop the soils with woody and shrubby vegetation in the first place, starting with land occupied by young plants. It is necessary to take into account the criteria for the fertility of the soil layer. It was found that soils with a small excess of moisture have small cost of its development, while on heavily swampy soils the cost of work on their development is many times higher than the cost of restoring other types of land. (Conclusion) The article shows that the restoration of neglected land is a necessary condition for improving the provision of human needs for food and a number of industrial goods. First of all, it is necessary to develop land that requires minimal investment of economic and labor costs.

Diversity and Chemical Composition of Weeds in Sand-Filled Mangrove Forest at Eagle Island, Niger Delta, Nigeria

Mangroves are habitat specific and grow mainly in swampy soil, but due to anthropogenic activities (e.g. sand mining) other species had encroached into their habitat. It is thus hypothesized that change in species diversity will lead to change in soil chemistry. In a 40 m × 90 m plot, diversity index (H) and importance value (Iv) of weed were estimated. Soil and weed samples were collected and analyzed for total hydrocarbon content (THC), Zinc (Zn), Lead (Pb) and Cadmium (Cd). All samples were analyzed with atomic absorption spectrophotometric method using the HACH DR 890 calorimeter (wavelength 420 nm). The result shows that swampy soils were more acidic (3.1 - 3.5) than sandy soils (4.2 - 4.7). Swampy soil was also more saline and thus has higher conductivity (8320 - 9880 μS/cm) than sandy soil (4320 - 5650 μS/cm). Mangrove swamp had higher total organic carbon (TOC) (2.25% - 3.41%) than sandy soil (0.12% - 0.21%). There was a significant difference in THC and heavy metals in soil (F8,63 = 2.04, P 8,63 = 247.0, P > 0.05). Concentration of THC and heavy metal was higher in plant than in soil. Reissantia indica, an aquatic weed, had the highest concentration of THC in root soil. A total of fifteen (15) weed species were identified, out of which Mariscus longibracteatus had the highest diversity (-0.366) followed by Mariscus ligularis (-0.339) and Paspalum vaginatum (-0.270). Similarly, M. longibracteatus had the highest importance value in the study site (Iv = 58.24). This result implies that the presence of weed species in mangrove forest is an indicator of human disturbance of the ecosystem. It also means that the weeds were bioaccumulating THC and heavy metals present in the soil.

Cytological aspects of recalcitrance in dormant seeds of Mauritia flexuosa (Arecaceae)

We evaluated the physiological and cytological aspects of the embryos of the palm tree Mauritia flexuosa, whose seeds show a rare association of recalcitrance and dormancy. Seeds were subjected to dehydration, or stored with stabilized water contents for 420 days. Seed viability and germination, as well as the anatomy, cytochemistry and ultrastructure of the embryos were evaluated using standardized methodologies. Under initial conditions (seeds with water contents of 44.6 %), viability was as high as 94 %, although without germination. Seeds dehydrated to water contents of 20 % lost all viability, whereas 87 % of the seeds stored while hydrated remained viable and 25 % germinated. Embryonic cells showed characteristics associated with recalcitrance in other palms species, such as the presence of large vacuoles and the absence of lipidic reserves, but also had abundant protein bodies and terpenoids in their cytoplasm as well as carbohydrate and protein reserves in their vacuoles—conditions found in the embryo cells of palms having orthodox seeds. Dehydration caused invagination of the cell walls, retraction of the plasma membrane, proliferation of the endoplasmic reticulum and autophagic vacuoles, and increased the densities of vacuolar contents—culminating in the collapse of the protoplast. Stored seeds showed preserved cell structures. M. flexuosa seeds are sensitive to dehydration, but will retain viability if kept hydrated, allowing dormancy to be overcome in seed banks in the swampy soils where this species occurs. The accumulations of secondary metabolites, vacuolation and the storage of carbohydrates and proteins in the vacuole all have important roles in the modulation of recalcitrance.

Nanoparticles of noble metals in peat of the Upper and Middle Amur Region

Swampy soils of the Upper and Middle Amur Region territory occupy an area of 5663.5 km 2 accounting for 13.6% of the whole territory of the Amur Region. Swampy soils are formed under sphagnum mosses and, partly, sedges. In the zone of deciduous forests, these soils are formed from different grasses. The upper peat-bearing horizon of soils consists of vegetation in the stage of semidecay. This horizon is underlain by a mineral glue layer consequently transforming into rock. About 600 deposits of peat with summary potential resources of 1.3 billion tons are located on the investigated territory [1]. The aim of this work was to study the concentration levels of the following noble metal elements (NMs) in peats of the Amur Region: Ru, Rh, Pd, Ag, Os, Ir, Pt, and Au. Mass shares of NMs were detected in the laboratory of chemical analysis of the Institute of Geology and Nature Management, Far East Division, Russian Academy of Sciences, from 10 g samples after stepwise ashing at temperatures below 600 ° C with a heating speed of 100 ° C per hour. The mass shares of Au, Ag, Rh, Pd, and Pt have been detected by the atomic adsorption method [2, 3]. The kinetic method was used for detecting Os and Ir [4, 5], and the catalytimetric method for Ru detection [6] (the average values are shown in Table 1). Analysis was performed according to the III accuracy category with the maximal error of NM determination amounting to ± 30%. Oxidized forms of NMs are well dissolved in mineral acids that are not oxidants. In contrast, metal forms of NMs are practically insoluble in it. This feature was used for extracting the oxidized forms of NMs by an acid extract. Peat samples of 10 g in weight were processed by a definite amount of strong hydrochloric acid (with a density of 1.19 g/cm 3 ) during 1 hour of mixing. The concentration of the solution was further brought to 2‐3 M of HCl, and then it was heated under a cover up to boiling. The hot solution was passed through the double filter “blue band” with a pore diameter of 1‐2 µ m, and then it was twice washed by a hot solution of 3 M HCl. The acid extract consists of nanoparticles of NMs with dimensions less than 1 µ m and ions of oxidized forms of NMs. The filtrate was analyzed due to the methods of [2‐6]. The concentration of oxidized forms of NMs was determined from the acid extracts by their extraction of the following mixture: 0.025 M paraalkilaniline and 0.05 M diethylhexylditiophosphoric acid in toluene. The oxidized forms of Pt, Pd, Ir, and Os were additionally instrumentally determined with the help of the inversion voltamperometric analyzer TA-4. Thus, the proposed method allows separating ions of the oxidized forms of NMs and their nanoparticles from silicate and organic matrixes and performing their separate determination by instrumental and extracting methods of quantitative chemical analysis. Within the Amur Region, the investigated area con

Genesis and evolution of soils in the Selenga River delta

Five types of soils representing an evolutionary sequence have been distinguished within the Selenga River delta. At the first stage. alluvial meadow-swampy, swampy, and stratified soddy alluvial soils are formed. At the second stage, meadow calcareous alluvial soils are developed. At the third stage of evolution, leached meadow soils are widespread. This soil sequence is related to changes in the hydrological regime of delta areas upon gradual aggradation of the surface with corresponding changes in the character of vegetation.