Articles

Sewage sludge introduced 28 years ago in sod-podzolic sandy loam soils determines the increased content and mobility of Zn, Cd, Cu, and Ni compounds, and it is the most characteristic for Cd and Zn. The most polluted are the arable horizons of soils. The contaminated layer is within the arable horizon, which indicates on the low rate of heavy metals (HM) migration, which were introduced into the studied soils as part of SS. Heavy metals are washed out of soils with intrasoil runoff insignificantly. This is determined by their chemical properties: low solubility of their compounds, adsorption by mineral and organic components of soils, as well as neutral pH values of the soils themselves. Plants grown on contaminated soils are characterized by an increased content of HM, which varies in 5-7 times depending on the type of plants and their ability to accumulate HM.

The current study presented a genesis characterisation of iron-illuvial podzols formed on esker mainly coarse-grained deposits consisting of coarse and moderately coarse-grained sands including the gravel-pebble fractions with rubblestones. Under similar bio-climatic conditions, the iron-illuvial podzols on esker showed quantitative differences in composition and their properties from the iron-illuvial podzols formed on sandy moraines. The source of these differences were the relief and lithology of deposit genesis of uncommon structure of esker. The still commonly used description of fluvioglacial deposits, without their differentiation in esker as an inner-glacial deposit and periglacial deposits formed out of glacier range were insufficient in terms of a pedogenesis with special features in relief and sediments.

The features of the dynamics of the morphology and chemical properties of forest litter during post-agrogenic reforestation of arable land in the southern taiga subzone are studied. The relationship between the dynamics of the structure of litter with the floristic composition and the ecological-coenotic structure of the soil cover is shown. The increase in stocks, as well as the diversity of the structure and the degree of spatial variation of the main morphological indicators of litter as the regeneration of the stand has been established. Acidification and a decrease in the ash content of litter, as well as a decrease in the fraction of easily decomposed fractions, are adequately reflected in the composition of the soil cover, in which the role of species adapted for increased acidity and low content of nutrients in the substrate increases. After spruce enters the first tier, the spatial distribution of the structure, reserves, power, and fractional composition of litter is determined by the position in the tesser. In general, the course of succession, as well as the dynamics of the morphology and chemical properties of litter, indicates a decrease in the rate of circulation in biogeocenosis. The ecological scales of Ellenberg, Landolt, Tsyganov and Ramensky as applied to ground cover can serve as an important tool in analyzing the dynamics of forest litter in forest ecosystems.

For the first time, the ratio of large taxa and the genera spectrum in the prokaryotic complex of the rhizosphere soil under typical plants of bogs were revealed by high-performance sequencing. The dominance of acidobatheria and alpha-proteobacteria was established with a low proportion of other taxa (less than 10%). Among the 24 bacterial genera found, representatives of the phylums Acidobacteria and Actinobacteria, as well as the Alphaproteobacteria class, predominate. Common bacterial genera were identified in rhizosphere soil under plants and surface layers of peat. Representatives of most of these bacteria are adapted to grow in an acidic environment and at low temperatures. Their functioning is determined by the use of various sugars, polysaccharides, aromatic compounds, organic and amino acids. Bacteria of the genera Cytophaga and Acidothermus are capable of cellulose destruction, Occallatibacter - chitin, Nocardia - humic substances and lignin.

Some aspects of application of simulation modeling of radionuclide behavior in food chains of terrestrial ecosystems are discussed. The model of behavior of ¹³⁷Cs in the system of type soil-vegetation-herbivores-predators is described. The results of modeling, including the calculation of the dynamics of dose load on animals, are presented. It is shown that in the simplified “Chernobyl” scenario of the radiological situation, dose loads on herbivores are significantly lower than on predators. In general, in animals in the first 10 years, the main contribution to the dose load is made by external irradiation. Then the external and internal dose loads become approximately equal.

In closed soil conditions on tomato, cucumber and pepper cultures, the effectiveness of the integrated use of chicken compost, silicon fertilizer based on diatomite and the microbial preparation of the Bacillus amyloliquefasciens culture was evaluated. New technology allows you to get a crop increase of all high-quality vegetable crops. The studied agrochemical properties of gray forest medium loamy soil after harvesting did not deteriorate. In contrast to experiment options using traditional mineral fertilizers, the collected products fall under the definition of “organic” or with improved quality indicators, the so-called “green”. The resources of raw materials for the creation of nature-like innovative technologies of “green agrochemistry” are calculated. Now Russia produces about 310 million tons of organic animal waste, less than 70 million tons or 23% is used. The total content of only three plant nutrient elements (NPK) in the organic matter is 2,9 million tons of active substance. Their cost at current prices for mineral fertilizers exceeds 70 billion rubles. Perhaps the full useful use of organic resources in the system of measures for the “revitalization” of rural territories in terms of maintaining soil fertility and preventing “decarbonization”. This will reduce the negative impact of uncontrolled turnover of nitrogen and carboncontaining products on the components of the environment.

The composition of water-soluble organic matter (WSOM) of coniferous-deciduous, coniferous and moss litter was studied. Type of decay affects the composition of WSOM. Sphagnum litter contains less N and dissolved organic carbon (DOC), but more carbohydrates, the WSOM is characterized the lowest extinction coefficients Е₂₅₄. WSOM from mixed litter with a predominance of birch litter has a maximum content of N and a small amount of soluble phenolic (SP) substances. WSOM from litter of pine needles differ from the rest with a lower content of carbohydrates, the maximum amount of SP and hydrophobic fraction. All investigated WSOM are characterized by high rates of decomposition: half-decomposition time of their stable fractions is 2-4 months. WSOM from pine litter at pH ~ 6 are absorbed by the BF horizon of Podzol, since the concentration of DOC of 100 mg/l. Substances from birch-spruce litter in similar conditions adsorbed slightly.

Based on publications on the soils of the Northwest Pacific, particularly wide effect of climatic factor on soil formation associated with the influence of the ocean has been established. Together with the amount of liquid atmospheric precipitation, the regime and the intensity of their precipitation play an important role. Heat supply is determined not only by insolation, but also by the wind regime, as well as the presence of warm and cold currents. The scale of the pulsed contribution of sea water salts with sediments is related to the distance to the coastline. In additions, the ornithogenic factor acts on small islands. All this creates variants of soil formation specificity on the characterized islands.

Research of soil cover heterogeneity of Khibiny mountains within the Polar-Alpine Botanical Garden was carried out. Podzols and podburs occupy larger area in the garden (90%). Human-transformed soils are widely spread in the areas disturbed during the construction and introduction of plants. The soils of the garden are in the zone of influence of apatite-nepheline factories and metallurgical plants. As a result, in upper horizons there is a high content of some heavy metals and metalloids such as Ni, Cu, Pb, As, Zn, V, Sr.