Glyphosate can be degraded by soil microorganisms rapidly and is impacted by temperature and soil properties. Enhanced temperature and total organic carbon (TOC) as well as reduced pH increased the rate of ¹³C₃¹⁵N-glyphosate conversion to CO₂ and biogenic non-extractable residues (bioNERs) in a Haplic Chernozem (Muskus et al., 2019) and in a Humic Cambisol (Muskus et al., 2020). To date; however, the combined effect of temperature and TOC or pH on microbial community composition and glyphosate degraders in these two soils has not been investigated. Phospholipid fatty acid [PLFA] biomarker analysis combined with ¹³C labeling was employed to investigate the effect of two soil properties (pH, TOC) and of three temperatures (10 °C, 20 °C, 30 °C) on soil microorganisms. Before incubation, the properties of a Haplic Chernozem and a Humic Cambisol were adjusted to obtain five treatments: (a) Control (Haplic Chernozem: 2.1% TOC and pH 6.6; Humic Cambisol: 3% TOC and pH 7.0), (b) 3% TOC (Haplic Chernozem) or 4% TOC (Humic Cambisol), (c) 4% TOC (Haplic Chernozem) or 5% TOC (Humic Cambisol), (d) pH 6.0 (Haplic Chernozem) or pH 6.5 (Humic Cambisol), and (e) pH 5.5 for both soils. All treatments were amended with 50 mg kg⁻¹ glyphosate and incubated at 10 °C, 20 °C or 30 °C. We observed an increase in respiration, microbial biomass and glyphosate mineralization with incubation temperature. Although respiration and microbial biomass in the Humic Cambisol was higher, the microorganisms in the Haplic Chernozem were more active in glyphosate degradation. Increased TOC shifted the microbiome and the ¹³C-glyphosate degraders towards Gram-positive bacteria in both soils. However, the abundance of ¹³C-PLFAs indicative for the starvation of Gram-negative bacteria increased with increasing TOC or decreasing pH at higher temperatures. Gram-negative bacteria thus may have been involved in earlier stages of glyphosate degradation.

The content of various chemical elements such as metals, metalloids, and nonmetals in the environment is associated with natural and anthropogenic sources. It is necessary to normalize the content of metals, metalloids, and nonmetals as potentially toxic elements (PTE) in the Haplic Chernozem. The soils of the Southern Russia are of high quality and fertility. However, this type of soil, like Haplic Chernozem, is subject to contamination with a wide range of PTE. The aim of the work was to rank metals, metalloids, and nonmetals by ecotoxicity in Haplic Chernozem. To assess the ecotoxicity of chernozem, data for 15 years (2005–2020) were used. Biological indicators used to assess the ecotoxicity of Haplic Chernozem: catalase activity, cellulolytic activity, number of bacteria, Azotobacter spp. abundance, to change of length of radish’s roots. Based on these biological indicators, an integral indicator of the state of Haplic Chernozem was calculated. The ecotoxicity of 23 metals (Cd, Hg, Pb, Cr, Cu, Zn, Ni, Co, Mo, Mn, Ba, Sr, Sn, V, W, Ag, Bi, Ga, Nb, Sc, Tl, Y, Yb), 5 metalloids (B, As, Ge, Sb, Te) and 2 nonmetals (F, Se) as priority pollutants. It is proposed to distinguish three hazard classes of metals, metalloids, and nonmetals to Haplic Chernozem: I class — Te, Ag, Se, Cr, Bi, Ge, Sn, Tl, Hg, Yb, W, Cd; II class — As, Co, Sc, Sb, Cu, Ni, B, Nb, Pb, Ga; III class — Sr, Y, Mo, Zn, V, Ba, Mn, F. It is advisable to use the results of the study for predictive assessment of the impact of metals, metalloids, and nonmetals on the ecological state of the soil during pollution.

Reliable stable indicators are very important for assessing soil quality. This paper compares the dynamics of microbial parameters in two different soils (rich/poor in organic carbon), contaminated in laboratory experiments with an equal dose of heavy metals (HMs) after 30 and 90 days. For this purpose, the changes in the number, biomass, and taxonomic structure of bacterial and fungal communities were assessed in microcosm experiments using an organic carbon–rich ordinary chernozem (Ch-humus-rich soil) and a depleted carbon agrozem (Ag-humus-poor soil), spiked with high concentrations of a zinc, lead, and copper solution (1100 Zn + 660 Cu + 650 Pb mg per kg soil). At the 30th and 90th day from HM contamination, soil samples were collected for analyzing microbial community lipid markers by gas chromatography-mass spectrometry. The results show how both biomass and taxonomic structure of the bacterial and fungal communities analyzed were differently sensitive to HM contamination, depending on the type of soil. The Ag-humus-poor soil microbial community was significantly affected by the HM pollution with an increase in both fungi and bacteria and inside the latter several species changed their percentages. Differently, the Ch-humus-rich soil microbial community was not influenced by the HM addition. However, the negative impact of HM can manifest itself over time, so the microbial structure and its functioning cannot represent accurate indicators of the quality of all soil types. The results show that microbial characteristics should be taken into account only in a comprehensive assessment of soil quality in accordance with ISO 19,204:2017—soil quality TRIAD approach. This approach to environmental risk assessment combines biological data (from bioassay and ecological observations) with chemical analysis.

To protect forest cultures against browsing, chemical repellents can be used. With their applications, however, a problem arises with disruption of biological and chemical equilibria in the environment (e.g., soil-plant system). The aim of this study were to assess possible interactions of repellents, denatonium benzoate (DB), and capsaicin (Cps), with the soil matrix, especially the impact of their addition on the mobility of individual micronutrients and macronutrients, such as calcium, copper, iron, magnesium, manganese, phosphorus, sulfur, and zinc, and to verify the hypothesis that the presence of repellent compounds does not affect the plant-available nutrient concentrations in soil. Batch laboratory soil sorption experiment and the “diffusive gradient in thin films” (DGT) technique were applied to evaluate the elements’ mobility in the soils. Sorption experiment using Chernozem and Fluvisol showed decreased mobile forms of Cu and S with the additions of both repellents and conversely increased mobile forms of Ca and Mn for DB, in both soil types. With increasing Cps rates, the mobile forms of Fe in Chernozem decreased and Mn in Fluvisol increased. The DGT experiment confirmed increased mobile/available Mn in both soils for both repellents and Fe in Fluvisol in the case of capsaicin. Soil application of both, DB and Cps, suggested to be able to influence the elements’ mobility, particularly, Mn mobility in soil significantly increased after repellent application. Their possible behavior in rhizosphere soil/soil solution should be investigated in further research.

The objectives of this study are to test the penetration depth and determine the soil content in hydrocarbons’ components BTEX, PAHs, and TPH, after vertical movement of crude oil through undisturbed soils of different textures, and to assess their risk. The experiment simulates the fate of oil spills in the cold season. Three soil types were investigated: a sandy-textured eutric Arenosol, AR-eu; a loamy-textured haplic chernozem, CH-ha; and a clayey-textured, swell-shrink, Luvic Chernic Phaeozem, PH-ch-lv. Undisturbed small-scale lysimeters, 0.3 m in diameter and 1 m in length, were used. Crude oil was first applied and then water. TPH, BTEX, and PAH retention in the soils depends on soil texture. PH-ch-lv soil stored most of them in the upper horizons. TPH, BTEX, and PAH were found in different amounts as percentage from the applied ones, TPH as 48% (PH-ch-lv), and > 76% in the other two soils. BTEX was stored as 1.6% from the applied in PH-ch-lv, 5.1–5.1% in CH-ha and AR-eu soils, while PAH ranged from 15.1% in AR-eu soil to 24.8% in PH-ch-lv and 31% in CH-ha. Though subject to volatilization, chemical transformation, and bioremediation, TPH, BTEX, and PAH stored in soils present a health risk if they reach the groundwater. PH-ch-lv appears to be the most resilient soil to oil pollution. The results concern different soil textures and might be used in various countries. Future experimentation should focus on soil behavior in relation to crops, water, and certain crude oil types.

Biochar (BC) as a soil amendment has found considerable interest in global agriculture and food production. However, BC application to agricultural soils requires knowledge about side-effects on leachate composition potentially affecting deeper soil layers and groundwater. We investigated the effects of BC application on leachate water characteristics in a greenhouse pot experiment with two crops cultivated in series, mustard (Sinapis alba L., cv. Serval) and barley (Hordeum vulgare L., cv. Xanadu). The experiment was set up with three agricultural soils (Planosol, Cambisol, Chernozem), four different BC types, derived from three different feedstocks (wheat straw, woodchips, and vineyard pruning), added at two application rates of 1 % (w/w) and 3 % (w/w). Leachate sampling was performed five times from November 2010 to May 2011 by excess watering. The leachates were analyzed for their pH, electrical conductivity (EC), as well as their nitrate (NO₃ ⁻), dissolved phosphorus (PDISS), potassium (K⁺), and dissolved organic carbon (DOC) concentrations. The application of all BCs caused a significant pH increase in the leachates; EC increased most noticeably in the straw biochar treatment. All BC types significantly decreased leachate NO₃ ⁻ loads (by up to 80 % for woodchip-derived BC) compared to the control, while PDᵢₛₛ and K⁺ loads most significantly increased in the straw-derived BC treatment. The results show that BC may be suitable as soil amendment in soils prone to NO₃ ⁻ leaching; moreover, whereas straw-derived BC in particular may support soil nutrient status by introducing P and K.

Potential changes in the mobility and bioavailability of risk and essential macro- and micro-elements achieved by adding various ameliorative materials were evaluated in a model pot experiment. Spring wheat (Triticum aestivum L.) was cultivated under controlled condition for 60 days in two soils, uncontaminated Chernozem and multi-element contaminated Fluvisol containing 4900 ± 200 mg/kg Zn, 35.4 ± 3.6 mg/kg Cd, and 3035 ± 26 mg/kg Pb. The treatments were all contained the same amount of sulfur and were as follows: (i) digestate from the anaerobic fermentation of biowaste, (ii) fly ash from wood chip combustion, and (iii) ammonium sulfate. Macro- and micro-nutrients Ca, Mg, K, Fe, Mn, Cu, P, and S, and risk elements Cd, Cr, Pb, and Zn were assayed in soil extracts with 0.11 mol/l solution of CH₃COOH and in roots, shoots, and grain of wheat after 30 and 60 days of cultivation. Both digestate and fly ash increased levels of macro- and micro-nutrients as well as risk elements (especially Cd and Zn; the mobility of Pb decreased after 30 days of cultivation). The changes in element mobility in ammonium sulfate-treated soils appear to be due to both changes in soil pH level and inter-element interactions. Ammonium sulfate tended to be the most effective measure for increasing nutrient uptake by plants in Chernozem but with opposite pattern in Fluvisol. Changes in plant yield and element uptake in treated plants may have been associated with the higher proline content of wheat shoots cultivated in both soils compared to control. None of the treatments decreased uptake of risk elements by wheat plants in the extremely contaminated Fluvisol, and their accumulation in wheat grains significantly exceeded maximum permissible levels; these treatments cannot be used to enable cereal and other crop production in such soils. However, the combination of increased plant growth alongside unchanged element content in plant biomass in pots treated with digestate and fly ash suggests that these treatments have a beneficial impact on yield and may be effective treatments in crops grown for phytoremediation.

On the basis of a previous study performed in our laboratory, the use of organic and inorganic amendments can significantly modify the Hg mobility in soil. We have compared the effectiveness of organic and inorganic amendments such as digestate and fly ash, respectively, reducing the Hg mobility in Chernozem and Luvisol soils differing in their physicochemical properties. Hence, the aim of this work was to compare the impact of digestate and fly ash application on the chemical and biochemical parameters in these two mercury-contaminated soils in a model batch experiment. Chernozem and Luvisol soils were artificially contaminated with Hg and then incubated under controlled conditions for 21 days. Digestate and fly ash were applied to both soils in a dose of 10 and 1.5 %, respectively, and soil samples were collected after 1, 7, 14, and 21 days of incubation. The presence of Hg in both soils negatively affected to processes such as nitrification, provoked a decline in the soil microbial biomass C (soil microbial biomass C (MBC)), and the microbial activities (arylsulfatase, and β-glucosaminidase) in both soils. Meanwhile, the digestate addition to Chernozem and Luvisol soils contaminated with Hg improved the soil chemical properties (pH, dissolved organic carbon (DOC), N (Nₜₒₜ), inorganic–N forms (N–NH₄ ⁺ and N–NO₃ ⁻)), as consequence of high content in C and N contained in digestate. Likewise, the soil MBC and soil microbial activities (dehydrogenase, arylsulfatase, and β-glucosaminidase) were greatly enhanced by the digestate application in both soils. In contrast, fly ash application did not have a remarkable positive effect when compared to digestate in Chernozem and Luvisol soil contaminated with mercury. These results may indicate that the use of organic amendments such as digestate considerably improved the soil health in Chernozem and Luvisol compared with fly ash, alleviating the detrimental impact of Hg. Probably, the chemical properties present in digestate may determine its use as a suitable amendment for the assisted-natural attenuation of mercury-polluted soils.