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Soil degradation has led to a continuous decline in the quality of phaeozem, which is seriously threatening the foundation of national food security. Therefore, precisely evaluating the health status of phaeozem resources and their spatial and temporal variations are crucial for ensuring the effective implementation of soil degradation prevention and control strategies. In this study, soil data from 140 sites were collected, and eight physical and chemical indices (sand content, silt content, pedon thickness, organic matter, total potassium, total nitrogen, total phosphorus, and pH) were utilized to assess the soil health status of phaeozem in Liaoning Province. The results showed the following: (1) The minimum data set is aligned with previous research findings and effectively mirrors the soil's health condition. (2) The substantial coefficients of variation observed for pedon thickness, sand content, and silt content across regions suggest notable differences, likely influenced by climatic variations, parent material differences, and anthropogenic activities. (3) The study area's average soil pH of 6.39 indicates an overall acidic nature, potentially attributed to intense soil weathering and suboptimal fertilization practices. (4) The soil health index (SHI) ranged from 0.33 to 0.91, with an average of 0.62, which indicates that the majority of the phaeozem in Liaoning Province are in a sub-healthy state (SHI < 0.6 = unhealthy, SHI 0.6–0.8 = sub-healthy, SHI ≥ 0.8 = healthy). These sub-healthy areas are primarily located in hills, mountains, and the Liaohe Plain, and are significantly impacted by rainfall and wind erosion. Meanwhile, unhealthy areas are concentrated in the south and center of the province, characterized by fragile ecological environments and challenging agricultural conditions. [ABSTRACT FROM AUTHOR]

We study studied the alpine meadow soil in Gannan Prefecture. Geostatistical analysis showed that Circular [soil total nitrogen (STN), soil total potassium (STK), soil available phosphorus (SAP)] model, index [bulk density (BD), soil water content (SWC), soil organic carbon (SOC), soil available nitrogen (SAN)] model and Gaussian [soil total phosphorus (STP), soil available potassium (SAK)] model is universal Kriging Method semi-variation function optimization fitting model. In the model, the spatial correlation is weak to medium, and SOC, STN, STP, STK, SAN, SAP, SAK, and SWC have specific spatial trend effects. Then principal component analysis was used to obtain three key factors (SOC, BD, and SWC) affecting soil quality, which accounted for 81.91% of the total variation of soil quality. These factors were taken as the minimum data set (MDS) and soil quality index (SQI) was calculated. According to SQI, the whole region was divided into three soil management zones (SMZs). Recommendations are made for different management areas to ensure resource conservation and reduce environmental footprint. [ABSTRACT FROM AUTHOR]

Soil degradation has led to a continuous decline in the quality of phaeozem, which is seriously threatening the foundation of national food security. Therefore, precisely evaluating the health status of phaeozem resources and their spatial and temporal variations are crucial for ensuring the effective implementation of soil degradation prevention and control strategies. In this study, soil data from 140 sites were collected, and eight physical and chemical indices (sand content, silt content, pedon thickness, organic matter, total potassium, total nitrogen, total phosphorus, and pH) were utilized to assess the soil health status of phaeozem in Liaoning Province. The results showed the following: (1) The minimum data set is aligned with previous research findings and effectively mirrors the soil’s health condition. (2) The substantial coefficients of variation observed for pedon thickness, sand content, and silt content across regions suggest notable differences, likely influenced by climatic variations, parent material differences, and anthropogenic activities. (3) The study area’s average soil pH of 6.39 indicates an overall acidic nature, potentially attributed to intense soil weathering and suboptimal fertilization practices. (4) The soil health index (SHI) ranged from 0.33 to 0.91, with an average of 0.62, which indicates that the majority of the phaeozem in Liaoning Province are in a sub-healthy state (SHI < 0.6 = unhealthy, SHI 0.6–0.8 = sub-healthy, SHI ≥ 0.8 = healthy). These sub-healthy areas are primarily located in hills, mountains, and the Liaohe Plain, and are significantly impacted by rainfall and wind erosion. Meanwhile, unhealthy areas are concentrated in the south and center of the province, characterized by fragile ecological environments and challenging agricultural conditions.

Terroir is a concept referring interactions of natural (topography, lithology, climate, soil etc.) and human (economic conditions, traditions, cultivation practices, etc.) factors; therefore, terroir is spatially delimited and subjected to environmental, socio-economic, and temporal changes. The geoecological background of wine districts are considered more stable among them, but, because of its natural diversity and the spatial changes of production sites, changes in abiotic terroir components might occur too. In this study the spatial changes of grape production sites in Eger Wine District (Hungary) across two and a half centuries (1784 to 2018), and their consequences on the composition of the geoecological factors (lithology, topography, soil characteristics) were analyzed. Modernization of cultivation, urbanization and increase of builtup areas around the central settlement resulted in decreased concentration, i.e. increased spatial dispersion to more remote vineyards further from Eger. It also has consequences on the lithological and topographical composition of the production sites. Besides the slightly increasing extent of vineyards (from 5346 ha to 7413 ha) we found a distinct decrease of vineyards at higher elevations and a substantial increase at lower elevations. Distribution according to slope gradient changed also remarkably, with the share of vineyards on <5% slopes from 38% to 65%. These changes resulted in transformations of pedological characteristics according to the comparison of vineyard’s extent with soil map data: vineyards shifted to slightly acidic, more fertile (i.e. deeper soil layer with higher organic carbon content) soils. The share of vineyards with different lithology and parent material also changed: loose, calcareous Tertiary sediments decreased almost to half, and the share of vineyards over acidic volcanics and their weathered regoliths almost doubled. Comparing these two dominant lithological types and soil profiles derived from them, different pedological characters and taxonomic status were found (Phaeozems and Vertisols). However, comparison of these two lithological types based on main topsoil characteristics (pH, SOC, carbonates, depth of fertile soil layer, N, P, K content) according to 25 randomly chosen surficial soil samples at production sites, showed no significant differences.. In the case of this particular wine district, spatial changes of the production sites affected mostly the distribution by elevation, by slope gradient, but did not alter significantly the surface soil character of the terroir. [ABSTRACT FROM AUTHOR]

Understanding the relations between soil features and plant responses is important for agricultural production and nature conservation. The aim of this study was to investigate the importance of the influence of soils’ physical and chemical features on the composition of plant species and richness in grasslands studied on the limestone massif in eastern Serbia (Mt. Rtanj). The data set included 22 phytosociological releves, the same number of corresponding mixed soil samples (0-10 cm depth) and 8 soil profiles. Two vegetation types were distinguished by numerical classification as Saturejion montanae and Festucion valesiacae. The results of detrended correspondence analysis (DCA) indicated that the most important soil parameters affecting species composition in dry grasslands were humus, the content of calcium, soil exchange capacity and base saturation, in addition to total acidity, pH and soil depth. The communities of both vegetation types are developed on Leptosols and Phaeozems. Under similar physical and chemical conditions of the soil, the grassland vegetation exhibits differences in floristic composition.

The study objective was to determine the relationship of selected enzyme activities with carbon sequestration and N, P, K, Mg, Zn and Cu contents in Phaeozem soils. Soil samples were taken from a 10 ha area. A selection of their physical and chemical properties and the contents of the available forms of selected macro- and microelements were determined. The activities of dehydrogenases (DEH), catalase (CAT), peroxidases (PER), alkaline (AlP) and acid (AcP) phosphatase, β-glucosidase (BG) and proteases (PR) were also determined. The relationship between enzymatic soil fertility indices (AlP/AcP, BIF, GMea, TEI, BA12 and BA13) and selected soil parameters was also determined. The research used principal component analysis (PCA) to distinguish significantly correlated parameters of a Phaeozem used for agricultural purposes. The study area showed low TOC and K contents and average P and Mg contents. Significant positive correlations were found between the TOC content and activity of the tested enzymes, evidencing that soil enzymes are an important parameter in carbon sequestration and soil nutrient dynamics. [ABSTRACT FROM AUTHOR]

The rising level of pollutant emissions is becoming one of the most pressing environmental problems of our time. Therefore, this work is focused on evaluating Cd and Ni contamination of soils and assimilatory organs of two native (Acer platanoides L., Taxus baccata L.) and two non-native (Negundo aceroides Moench, Thuja occidentalis L.) woody species in urban parks of SW Slovakia. The contents of Cd and Ni in soils were determined by the AAS method and, in the assimilatory organs of trees, by the AAS-ETA method. The studied soils (Fluvisol, Phaeozem) have neutral soil reactions and a moderate organic matter content. Cadmium soil contamination is considerable to very high; in the case of Ni, it is moderate to low. Cadmium levels detected in leaves were 31% higher than in needles, while Ni levels were 27% lower. Significant ecological factors in relation to the studied woody species were evaluated using PCA. The first three principal components of PCA significantly correlated with Cd (PC1) and Ni (PC3) contents in soils and Cd content in assimilatory organs (PC2), thus suggesting that these elements could especially originate from industrial and vehicular sources. Knowledge of the factors affecting the accumulation of risk elements in the assimilatory organs of park woody species can be successfully used, especially in the assessment of the quality of the urban environment and the selection of suitable cultivars for planting in areas with air pollution. [ABSTRACT FROM AUTHOR]

The rising level of pollutant emissions is becoming one of the most pressing environmental problems of our time. Therefore, this work is focused on evaluating Cd and Ni contamination of soils and assimilatory organs of two native (Acer platanoides L., Taxus baccata L.) and two non-native (Negundo aceroides Moench, Thuja occidentalis L.) woody species in urban parks of SW Slovakia. The contents of Cd and Ni in soils were determined by the AAS method and, in the assimilatory organs of trees, by the AAS-ETA method. The studied soils (Fluvisol, Phaeozem) have neutral soil reactions and a moderate organic matter content. Cadmium soil contamination is considerable to very high; in the case of Ni, it is moderate to low. Cadmium levels detected in leaves were 31% higher than in needles, while Ni levels were 27% lower. Significant ecological factors in relation to the studied woody species were evaluated using PCA. The first three principal components of PCA significantly correlated with Cd (PC1) and Ni (PC3) contents in soils and Cd content in assimilatory organs (PC2), thus suggesting that these elements could especially originate from industrial and vehicular sources. Knowledge of the factors affecting the accumulation of risk elements in the assimilatory organs of park woody species can be successfully used, especially in the assessment of the quality of the urban environment and the selection of suitable cultivars for planting in areas with air pollution.

Agricultural practices can affect root-associated microbiota, but the effect of fertilization is still poorly examined. The aim of this study was to obtain 16S and ITS metagenomic profiles of tomato rhizosphere and root endosphere under mineral (NPK) fertilization in the open field experiment in the south of West Siberia. We found 6 bacterial and 3 fungal phyla in the roots and 24 bacterial and 16 fungal phyla in the rhizosphere. Proteobacteria and Actinobacteria together contributed 90% of the total number of sequence reads in roots and 50% in the rhizosphere, whereas Ascomycota ultimately prevailed in OTUs’ richness and abundance in both biotopes. Fertilization changed the relative abundance of 32 bacterial and 14 fungal OTUs in the rhizosphere and of 7 bacterial and 3 fungal OTUs in roots. The revealed root bacteriobiome response to conventional mineral NPK fertilization by the dominant taxa at the high taxonomic level (class) illustrates well the role of NPK-changed plant metabolism in shaping endophytic microbiota and hence fertilization potential in enhancing plant growth-promoting microorganisms and mitigating plant pathogens. Using fertilization rate gradient in further research may bring a more detailed understanding of how to modify and even fine-tune root-associated microbiomes in order to enhance crops’ health and yields.

Returning corn straw to soil improves soil carbon sequestration in the Phaeozem regions of Northeast China. This research was to investigate the changes in soil carbon fractions of Phaeozem derived from loess and laterite PM with corn straw incorporation and quantify the influence of the key factors on soil carbon accumulation in order to improve the soil carbon stabilization efficiency. A simulative laboratory incubation experiment was conducted over 12 months using Phaeozem derived from loess and laterite PM and eight corn straw doses. Results showed that the clay mineral of Phaeozem was dominated by a mixed-mineral illite-smectite layer, illite, vermiculite, kaolinite, and smaller amounts of montmorillonite. Clay mineral species of topsoil were identical with its PM. The LOC and HOC of six soils increase with increase in straw incorporation level. The promoting effectiveness of straw incorporation on C accumulation declined when the C inputs reached a certain level. At 15% straw incorporation levels, the LOC and HOC of six soil increased by 1.86–3.01 g kg−1 and 1.33–2.22 g kg−1 than CK, respectively. The increment of LOC and HOC of six soils followed the trend of LHAp > LLAp > RHAp > RLAp > LC > RC. At 15% straw incorporation levels, the RLOC of RC (419%) and LC (296%) was greater than topsoil (103–254%) and the RHOC of RC (90%) and LC (61%) was much greater than topsoil (9–26%). Further analysis suggested that C input, TSOC, and clay content were the most influential variables on carbon sequestration efficiency. They accounted for about 73% of the variations of RLOC and RHOC. The relative contributions of 2:1 clay to RLOC and RHOC were about 10% and 15%, respectively and that of 1:1 clay were about 4.4% and 3.5%, respectively. In conclusion, both the topsoil and PM of Phaeozem have considerable C-stabilizing capacity and the C sequestration efficiency of topsoil and PM derived from loess was greater than those for topsoil and PM derived from laterite. [ABSTRACT FROM AUTHOR]

An increasing rate of the use of nanoparticles necessitates regarding them as a new class of toxicants. Nanodiamonds hold a special position because of their use in consumer goods, such as fuels and lubricants, which increases the risk of soil pollution with these nanoparticles. The goal of this study was to assess the effects of water-soluble soil components on the electrokinetic potential (ζ-potential) and size of detonation nanodiamonds. Water extracts from 15 zonal soil samples were studied. Addition of nanodiamonds to soil water extracts caused an increase in the weighted average hydrodynamic diameter of nanodiamonds from 24 to 69–683 nm and a drop in absolute ζ-potential from –22 to –(11.2–19.50) mV; an increase in the absolute ζ-potential to –34.5 mV was observed in one case. The highest increase in the size of nanodiamonds was detected in the extracts with high pH values and high Ca/(Fe + Al) ratio. The observed inverse correlation of the ζ-potential of nanodiamonds with the extinction coefficient of the dissolved soil organic matter and the iron content in water extracts suggested that the stability of nanodiamonds could increase in soil solutions in the presence of low molecular weight components of dissolved soil organic matter and at high iron concentrations. Generally, the obtained results allow us to assume that coagulation of nanodiamonds and a decrease in their mobility in soil are due to their interaction with water-soluble soil components. Water extracts from solonetzes are an exception, because the mobility of nanodiamonds in them may increase. [ABSTRACT FROM AUTHOR]

A comparative study of mountain-meadow and mountain-forest soils was performed within the entire Dolgorukovskaya Yayla—a plateau on the northern macroslope of the Main Ridge of the Crimean Mountains—in the altitudinal range from 560 to 975 m a.s.l. Soil morphology, texture, acidity, exchangeable cations, nonsilicate iron content, parameters of the humus status, and optical characteristics of soils were studied. Forest soils on the entire slope are assigned to acid and dark burozems (Cambisols, Luvisols); they are characterized by similar morphological properties and profile patterns of clay, humus, and nonsilicate iron. Mountain-meadow, mountain-meadow chernozem-like, and residual-carbonate soils (Phaeozems) are formed under meadow vegetation in the upper part of the plateau, and soils transitional to piedmont chernozems (Chernozems) are located in its lower part. Humus reserves in the 0- to 50-cm-thick soil layer varied from 16.6 to 42.2 kg/m2 under meadows and from 10.7 to 18.8 kg/m2 under forests. Soils under forest and meadow vegetation were characterized by an increase in acidity and a decrease in base saturation with the increase in the altitude. Acidity was generally higher in forest soils, while the difference in this parameter between forest and meadow soils in the upper part of the plateau was minimal. In soils under meadows, the content of oxalate-extractable iron also increased with the altitude, and its mean content in the A horizon (226 ± 67 mg/100) was higher than that in forest soils (183 ± 41 mg/100 g). More intense color of soils under grass vegetation as compared to soils under forests is mainly explained by the differences in the rate of organic matter humification and optical density of humic acids, the total humus content being similar in both groups of soils. [ABSTRACT FROM AUTHOR]

Changes of inorganic phosphorus forms and the characteristics of phosphorus adsorption and desorption were studied under a long-term fertilization experiment in black soil. Results showed that the forms of inorganic phosphorus ranged as O–P < Ca2–P < Ca8–P < Al–P < Ca10–P < Fe–P. Therefore, Fe–P was the main inorganic phosphorus form in this study. The capacity of phosphorus adsorption with phosphate treatments was higher than with no-phosphorus treatments. The optimal fitted equation was the Langmuir equation. Phosphorus desorption was related to the binding energy. Positive correlation between phosphorus adsorption and desorption without phosphorus addition was found; however, negative correlations among the phosphate treatments had been observed. [ABSTRACT FROM AUTHOR]

Abstract—: A comparative analysis of organic matter in the mountainous soils under the main plant communities of the Crimea was performed. The humus state of burozems and mountainous meadow soils under natural meadow vegetation and planted forests was studied using traditional methods and 13C-NMR spectroscopy for the determination of the contents of total organic carbon, carbon of humic acids and optical density of humic acid solutions. The highest humus content in the A horizon was found in the dark burozem under the beech-hornbeam forest on the Chatyr-Dag Plateau. The meadow soils of the Ai-Petri Plateau were significantly inferior in terms of humus content than the dark burozem and meadow soils of other Crimean plateaus due to the intensive anthropogenic impact on these lands until the 1970s. The lowest humus content was found in the meadow soils of the forested Ai-Petri areas because of the strong degradation of the grass cover after planting trees. The investigation of humic acids using the 13C-NMR method showed that humic acids of Crimean mountainous soils were characterized by the elevated hydrogen content, which well agreed with the content of alkyl fragments. The structural molecular composition of humic acids was dominated by aliphatic components, aromatic components being weakly expressed. At the same time, the aromaticity was somewhat higher in the cases when the soil was formed in the meadow ecosystem; it was lower in the upper soil horizons of the forest ecosystems. The degree of aromaticity of humic acids is intermediate between that of podzolic and chernozem soils, which is typical for soils of semihumid regions. The substitution of herbaceous vegetation in the course of natural overgrowing or afforestation of areas with meadow soils has led to an increase in their acidity, but it had no noticeable effect on the elemental and structural composition of humic acids. [ABSTRACT FROM AUTHOR]

Vast areas of land in the forest-steppe of West Siberia are occupied by birch forests, the most common ecosystems there. However, currently, little is known about the microbiome composition in the underlying soil, especially along a sequence of soil genetic horizons. The study aimed at inventorying microbiome in genetic horizons of a typical Phaeozem under undisturbed birch forest in West Siberia. Bacteria and fungi were studied using 16S rRNA genes’ and ITS2 amplicon sequencing with Illumina MiSeq. Proteobacteria and Acidobacteria together accounted for two-thirds of the operational taxonomic units (OTUs) numbers and half of the sequences in each genetic horizon. Acidobacteria predominated in eluvial environments, whereas Proteobacteria, preferred topsoil. The fungal sequences were dominated by Ascomycota and Basidiomycota phyla. Basidiomycota was the most abundant in the topsoil, whereas Ascomycota increased down the soil profile. Thelephoraceae family was the most abundant in the A horizon, whereas the Pyronemataceae family dominants in the AEl horizon, ultimately prevailing in the subsoil. We conclude that soil genetic horizons shape distinct microbiomes, therefore soil horizontation should be accounted for while studying undisturbed soils. This study, representing the first description of bacterio- and mycobiomes in genetic horizons of the Phaeozem profile, provides a reference for future research.

Common bean (Phaseolus vulgaris L.) is one of the most important grain legumes in East Africa, but its yield has remained below the genetic potential. Declining soil fertility is among the primary constraints to bean production in most East African bean producing regions. Often existing recommendations are generic and inept to guide farm level decision making on nutrient replenishment. A greenhouse nutrient omission study was conducted to determine the limiting nutrients in three soils of Masaka District, commonly cropped to beans: "Liddugavu" a Phaeozem, "Limyufumyufu" a Cambisol and "Luyinjayinga" an Umbrisol soil. Nine treatments; (i) complete nutrient treatment, (ii) N omitted, (iii) P omitted, (iv) K omitted, (v) Mg omitted, (vi) S omitted, (vii) Ca omitted, (viii) Micronutrients omitted and (ix) control without nutrients. Each treatment was randomly assigned to the three soils and replicated three times using a completely randomised design. Nitrogen, phosphorus and potassium were limiting nutrients for bean production in Umbrisol (Luyinjayinja) while in Cambisol ('Limyufumyufu), common bean production was most limited by soil acidity. The performance varied with soil types, with beans grown on the Phaeozem registering greater leaf number and growth, confirming both scientist's and local farmer's knowledge that this soil has greater potential than the other two soils. [ABSTRACT FROM AUTHOR]

Soil deterioration during the Anthropocene is a result of human activities such as misuse of chemical compounds like herbicides and inadequate agricultural management practices. Atrazine is the most widely used herbicide in maize (Zea mays) crops around the world. Its application is used for improving agricultural yields. However, it also represents a risk factor towards environmental contamination and human health. The objective of this work was to evaluate the adsorption-desorption capacity of atrazine in three types of soils under different agricultural management: (i) Andosol under rainfed agriculture; (ii) Phaeozem under conventional tillage (LC) and under zero tillage (LZ); and (iii) Vertisol under rainfed agriculture (VT), and Vertisols irrigated with raw wastewater during 56 and 100 years (V56 and V100). Standard batch experiments were performed on samples of each soil type with and without organic matter (OM). Adsorption capacity was higher in the soil samples containing OM. The following distribution coefficients (Kd) were obtained: the highest Kd value was obtained in the Andosol (19 L/kg), followed by the Vertisol (3 to 11 L/kg), and the lowest was in the Phaeozem (1 L/kg). We found that the larger affinity of the herbicide for the organic fraction of the soil is not only related to the organic content, but also due to its chemical composition (degree of aromaticity). This depends mainly upon the agricultural management practices such as crop rotation and the incorporation of residues at the end of the crop cycle. Also, the use of wastewater during irrigation and the type of tillage performed are additional factors that affect the quality of soil organic matter. Therefore, the atrazine retention capacity of the soil, contributes to the soil buffering function and to the environmental destination of the herbicide. [ABSTRACT FROM AUTHOR]

• 90 years of WW-irrigation effect on soil structure was evaluated. • Aggregates stability and microstructural pore space were chosen as indicators. • At macrostructure, long-term WW irrigated soils had greater soil aggregates stability. • The pore space characteristics of WW had less dispersion than rainfed soils. • More samples are needed to understand WW effect on microstructural pore space. Wastewater (WW) agricultural irrigation is becoming a common practice as an alternative to water scarcity. However, WW irrigation may affect the soil structure at different hierarchical levels. This issue was tackled by evaluating the long-term (>90 years) WW irrigation effects on soil structure. Samples of Ap and Ah horizons from eight rainfed and eight WW-irrigated plots were collected for physicochemical characterization. Undisturbed samples were analyzed for aggregate stability, and the pore space of small macroaggregates (0.5–1 mm) from Ah horizons of three rainfed and three WW-irrigated plots was analyzed by x-ray microtomography. Long-term WW-irrigated plots had higher contents of C (Ap = 2.54%; Ah = 1.64%) and N (Ap = 0.24%; Ah = 0.16%) compared to rainfed soils, as well as higher aggregates stability (mean weight diameter = 23.6 mm, p = 0.001). However, soil organic matter accumulation was not the main driver of the higher aggregate stability in WW-irrigated soils (Spearman correlation coefficients of 0.467 and 0.476 for organic C and total N, respectively). It was proposed that a combination of factors including SOM and easily degradable OM (C/N = 2.10) input from WW was the reason for this higher stability. The results did not allow one to conclude on the long-term effect of WW irrigation on the microstructural pore space because the scatter in the data of the rainfed samples was high. Considering a higher number of samples may address this problem. Nevertheless, the findings of this research improve our understanding of the effects of WW irrigation on soil structure and provide a better assessment of the benefits and risks associated with this practice. [ABSTRACT FROM AUTHOR]

The Phaeozem region is an important grain production base in China and soil fertility has declined under long-term cultivation. Studying soil organic carbon (SOC) change in the upland phaeozem of Northeast China under different tillage modes has great theoretical and practical significance for reducing greenhouse gases emissions, increasing soil carbon stocks, and ensuring food security. This study applied the DAYCENT model to simulate six long-term experimental sites in the phaeozem region, and through calibration and validation analysis, it concluded that the DAYCENT model could effectively simulate the dynamic change of SOC in the upland phaeozems; hence, the relevant parameters of each site were determined. Under future climate scenarios (Representative Concentration Pathway 4.5, RCP 4.5), SOC change in agricultural soils (0-20 cm topsoil) of four different management scenarios (fertilizer application, manure amendment, straw return, no-tillage) was simulated. The overall simulated trend was no-tillage > straw return > manure amendment > fertilizer application. Fertilizer had no evident effect on increasing SOC, but the effect would be better if combined with manure; both straw return and no-tillage had the general effect of improving SOC and the simulated values rose rapidly with a large increasing rate within a short period; however, the increasing rate became gentle after 2050, reached a relatively stable level after 2080, then gradually reached carbon saturation. Untill 2100, the SOC content of each site reached a relatively higher level by adopting the no-tillage treatment, where the SOC contents of Harbin, Hailun, Nehe, Dehui, Gongzhuling and Lishu were 2.36 g/100 g, 2.81 g/100 g, 2.22 g/100 g, 2.38 g/100 g, 1.97 g/100 g and 2.01 g/100 g, respectively. The SOC contents increased by 52.47% when compared with the initial value, and the simulated average annual increase of SOC for 84 years was 0.0082 g/100 g. [ABSTRACT FROM AUTHOR]

Adding compost to degrade acetochlor in soil is an important way to reduce its impact on the environment. The addition of conditioner improved the generation of compost products with specific effects. Thus, in order to determine a better composting conditioner for degradation of acetochlor, the dissipation of acetochlor in unmodified and different composting conditioners (zeolite, biochar, zeolite + biochar) was studied by pot experiment. The effects of residual concentrations of acetochlor (1.02, 1.56 and 2.08 mg·kg−1) and soil types (phaeozem and stagnic soil) on the dissipation of acetochlor were evaluated. The community structure of microbial fungi and bacteria in soil was determined by high-throughput sequencing to evaluate the change of microbial community in the soil with acetochlor residue. The results showed that compost types, soil types and the concentration of acetochlor residue in soil had different effects on the dissipation of acetochlor in soil. The addition of biochar and zeolite could significantly increase the degradation rate of acetochlor in soil. When the same compost was added, the degradation of acetochlor was fastest in phaeozem with a degradation rate of 95.13%. The degradation rate of acetochlor in black soil was higher than that in stagnic soil. High throughput sequencing results showed that the application of organic fertilizer changed the structure of soil microbial community. Luteibacter , Sagenomella and Remersonia had the highest correlation with the degradation of acetochlor in soil. The analysis of microbial community showed that· Luteibacter (24.49%),· Sagenomella (1.55%) and Remersonia (3.14%) played important roles in the degradation of acetochlor. Artificial neural network analysis showed that the sensitivity of acetochlor degradation rate to the conditioner in the soil was biochar (60.07%) > biochar + zeolite (21.19%) > blank (13.97%) > zeolite (4.77%). These results showed that biochar compost was more conducive to the dissipation of acetochlor in soil after application, and the application of organic fertilizer affected the soil microbial community structure. [Display omitted] • Organic fertilizer effectively promoted acetochlor degradation in soil. • Biochar was the most effective for acetochlor degradation in soil. • Organic fertilizer increased the abundances of acetochlor-degrading bacteria. • Bacteria and fungi may be involved in acetochlor degradation. [ABSTRACT FROM AUTHOR]

Acute laboratory toxicity tests were carried out to assess the individual and combined toxic effects of metals including cadmium (Cd), lead (Pb) and the metalloid arsenic (As) in Phaeozem on the seed germination and seedling growth of soybean, Glycine max Seeds were exposed to varied concentrations of Cd, Pb and As individually and in mixtures including Cd + Pb, Cd + As, Pb + As and Cd + Pb + As. The sum of toxic units (TU) for medium effective concentration of the mixture (EC50mix) was calculated based on the dose (TU-based)-response relationship using the Trimmed Spearman-Karber method. Binary metal combinations of Cd + Pb, Cd + As and Pb + As produced additive, synergistic and antagonistic effects, respectively, on shoot growth and synergistic, synergistic and antagonistic effects on root growth. Ternary combination of Cd + Pb + As had a synergistic effect on shoot growth and an additive effect on root growth. Bioaccumulation of metals was observed in soybean and inhibited or enhanced bioaccumulations of individual metals were found in mixtures due to different combinations of metals.

Control samples of scintillation liquids – Phaeozem soil mixtures were prepared with different scintillation liquids as the support electrolyte, Install Gel ® XF, (Ultima Gold AB™ and Ultima Gold XR™), to construct the polarization curves, and to select the cell potential with the highest mass transfer to remove 24 Na (15 h) and 99m Tc (6 h) as radiotracers from polluted Phaeozem soil. During the electrokinetic treatment (EKT), the removal of radionuclides contained in scintillation liquids absorbed in Phaeozem soil, liquid phase was characterized by Gas Chromatography coupled with a Flame Ionization Detector (GC-FID) and Fourier Transform Infrared Spectrometry (FTIR), solids by FTIR, before and after the application of cell potential. In this sense, the support electrolyte was selected based on the highest current generated (1 mA), as in the case of scintillation liquid 50% Ultima Gold XR™ + 50% Water (1:1), which was used for 6 h in the presence of a mesh and a titanium rod, as anode and cathode, respectively. Finally, the removal percentage accumulated in the liquid phase after the EKT of Phaeozem soil polluted by 99m Tc was 61% close to the anode after 4 h. It was also 61% for 24 Na close to cathode after 2 h, and after 4 h it was 71.8%. [ABSTRACT FROM AUTHOR]

Carbon and nitrogen compounds and the emission of CO, CH, and NO were studied in the ancient buried and modern background soils developed from different parent materials in the Arkaim Reserve of Chelyabinsk oblast. The studies were performed after an 18-year-long period of absence of anthropogenic loads on the local ecosystems. Element contents in the humus horizons of the chernozems of the former plowland and pastures and of the forest soil reach 28-45.6 g/kg for C, 2.5-4.5 g/kg for N, 140-423 mg/kg for labile carbon (C), 32-73 mg/kg for labile nitrogen (N), 350-952 mg/kg for carbon of microbial biomass (C), and 38-85 mg/kg for nitrogen of microbial biomass (N). The contents of different forms of C and N depend on the soil type and texture and on the type of land use, including that before reservation of the territory. The emission of greenhouse gases was examined in this area for the first time. The production of CO by the soil buried about 4000 years ago is an order of magnitude lower than that by the modern soil. The emission and sink of NO are small in both modern and ancient soils. The behavior of methane is clearly different in the automorphic and hydromorphic soils: the former serve as methane sinks, whereas the latter act as methane sources. The rate of the CO emission from the soils is controlled by many factors, including the soil type, texture, degree of hydromorphism, composition of parent materials, and type of land use. [ABSTRACT FROM AUTHOR]