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The work presents the results of studying the content of potentially toxic elements (Mn, Cu, Zn, Cr, Pb, Ni and Cd) in bottom sediments sampled at monitoring stations in the natural-anthropogenic systems of the Lower Don adjacent to the impact zone of the Novocherkassk Power Plant. The relationship between the content of metals in bottom sediments and their sorption properties is largely determined by the conditions of formation and the type of bottom sediments. Evaluation of the potentially toxic element content in sediments indicated that in particle size fractions (≤ 0.001 mm) could accumulate more than 15 times the levels of Cr and Zn and more than 6 times the levels of Cu, Cd and Ni in comparison to the particle size fractions that are 1.0 mm. Local zones of polyelemental pollution of bottom sediments with respect to Cu, Zn, Pb Cd and Cr were determined. These zones are confined to the geochemical sorption barriers of small watercourses of the power plant.

Data on the regional geochemical background and threshold values of heavy metals are required to establish anomalies and assess soil pollution. As a rule, the background values are the average contents of elements in natural undisturbed soils, or the threshold values for the study area, obtained by statistical methods. The aim of the study is to obtain geochemical threshold values of heavy metals in the soils of the Lower Don and the Taganrog Bay coast using different statistical approaches. A total of 86 topsoil samples were collected from the study area. The concentrations of Cr, Mn, Ni, Сu, Zn, As, Cd, and Pb were analyzed by X-ray fluorescence. The median element concentrations in the soils of the study area were consistent with world soil average and metal concentrations in background soils of protected area. Using a ‘geochemical’ approach is not suitable for this dataset because it does not take into account the natural variability of concentrations in different soil types. The Tukey inner fence method delivers estimates that do not detect outliers for Ni, As, Cd, and Pb. The ‘median + 2 median absolute deviations’ method was the most appropriate, as it consistently provided the most conservative background values.

Based on the cumulative pollution index, spatial distribution maps were obtained to establish categories of soil pollution taking into account the total content of heavy metals and the mobile forms of metals in the Don River estuarine region. The objects of the study included samples of zonal soils (Chernozem) and intrazonal soils (Fluvisols) from monitoring plots. The total concentrations of Mn, Cr, Ni, Cu, Zn, Pb, and Cd in the soils were determined by X-ray fluorescent scanning spectrometer. Mobile heavy metals compounds were transferred to a solution by extraction of 1 N NH4Ac, pH 4.8. When calculating the total metal content, it was shown the studied soils had generally an acceptable pollution category but taking into account mobile forms the categories of soils contamination variate up acceptable to extremely dangerous. The most polluted sites are associated with the estuary of small rivers and the branches flowing into the Taganrog Bay, the territory of the Taganrog port and its terminals, and road bridges. In line with hight categories of pollution, the use of the soils for cropping should be limited, and the cultivation of concentrator plants is excluded.

Sorption of heavy metals on solid matrices such as soils is one of the key processes which determine the fate of contaminants in the environment. Knowledge of adsorption behavior of heavy metals using biochar is essential for their application in soil remediation. Using the adsorption method, the possibility of using a wood biochar to detoxify Fluvisols contaminated with heavy metals (for example, copper) was studied. It is shown that the addition of biochar increases the metal adsorption capacity of soil. The results were analysed using the Langmuir and Freindlich isotherm equations. It was concluded that biocar can be applied to immobilize heavy metals in contaminated soils.

The environmental contamination by heavy metals (HM) and polycyclic aromatic hydrocarbons (PAH) is often due to exposure to complex sources of industrial and agricultural activities. The aim of the work is to evaluate the combined effect of CuO and benzo(a)pyrene (BaP) on the state of spring barley plants. It was established that the soil combined pollution by CuO and BaP has a negative effect on all morphobiometric parameters of barley. The most sensitive indicators of combined contamination are the length of the roots, the mass of 1000 grains and the yield of barley.

The effect of various doses of diatomite introduced into soil artificially contaminated by benzo[a]pyrene was analyzed. The negative effect of benzo[a]pyrene on the growth of barley (Hordeum sativum distichum) seedlings and reduction of toxic effect of polyarene on plants after implementation of diatomite as a sorbent into contaminated soil are shown. A significant increase (by 2–3 times) of the plant growth in contaminated soil with the addition of diatomite has been revealed. The introduction of 2.5% diatomite into contaminated soil had the significant positive effect on barley seedlings.

The aim of this article is to study the content of micronutrients in the soil of Terek sands region of the Chechen Republic and to identify the physiological response of the grape plants on micronutrients fertilization. The obtained data of the boron total content in the studied sandy soil showed that in 0–60 cm layer of the soil the boron total content ranges from 0.4 to 0.5 mg/kg, in 60–150 cm soil layer – from 0.75 to 0.78 mg/kg. The boron content in the sandy soils of studied area varies within wide limits and characterizes as insufficient. Fertilizing with boron is an effective agricultural technique for up-frost plants and productivity of grapes. This technique allows to increase the sugar content of the berries up to 0.8– 1.4 g/cm3, while substantially reducing the acidity of the juice. The yield of grape crystal grade in the variant with background + N90 P90 K90 + 2 kg of active boron addition was 76.8 t/ha, which is higher than in the control at 34.2 t/ha. The increasing of sugar berries in this variant was from 0.8 up to 1.4 g/cm3. The highest rates for plants productivity were observed by introducing a complex of boron micronutrients, cobalt, manganese, molybdenum, zinc in the form VIII, wherein the yield totally was 89.4 c/ha.