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The aim of this study is to investigate the distribution of lanthanum, thorium, and uranium content in soils from the Mitrovica region in the Republic of Kosovo. For this purpose, 156 samples of topsoil (0–5 cm) were considered in a sampling network of 1.4 × 1.4 km2. The soil samples were prepared using the aqua regia digestion method and analyzed using inductively coupled plasma mass spectrometry. The contents of La, Th, and U in the soil of the study area were determined to be 19, 4.8, and 0.84 mg/kg, respectively. The enrichment factor values for La, Th, and U ranged from 3.8 to 7.9, 3.2 to 7.0, and 2.0 to 7.0, respectively, indicating moderate to substantial enrichment. The geo‐accumulation index values of all elements were less than zero, indicating uncontaminated levels. The spatial distribution patterns of La, Th, and U content showed that the values are elevated in the north‐eastern and western parts of the study area, where Miocene latites and quartz latites predominate (average contents of 35, 2.4, and 2.1 mg/kg, respectively). These areas are located in rural areas, suggesting that the high La, Th, and U contents in the soil are related to the lithology of the study area and there is no influence of possible anthropogenic sources. This study contributes to the database of La, Th, and U contents in the soils of the Mitrovica region and allows an assessment of the relationship between geochemistry and ecosystem health. [ABSTRACT FROM AUTHOR]

Mining activities have resulted in a substantial accumulation of cadmium (Cd) in agricultural soils, particularly in southern China. Long-term Cd exposure can cause plant growth inhibition and various diseases. Rapid identification of the extent of soil Cd pollution and its driving factors are essential for soil management and risk assessment. However, traditional geostatistical methods are difficult to simulate the complex nonlinear relationships between soil Cd and potential features. In this study, sequential extraction and hotspot analyses indicated that Cd accumulation increased significantly near mining sites and exhibited high mobility. The concentration of Cd was estimated using three machine learning models based on 3169 topsoil samples, seven quantitative variables (soil pH, Fe, Ca, Mn, TOC, Al/Si and ba value) and three quantitative variables (soil parent rock, terrain and soil type). The random forest model achieved marginally better performance than the other models, with an R2 of 0.78. Importance analysis revealed that soil pH and Ca and Mn contents were the most significant factors affecting Cd accumulation and migration. Conversely, due to the essence of controlling Cd migration being soil property, soil type, terrain, and soil parent materials had little impact on the spatial distribution of soil Cd under the influence of mining activities. Our results provide a better understanding of the geochemical behavior of soil Cd in mining areas, which could be helpful for environmental management departments in controlling the diffusion of Cd pollution and capturing key targets for soil remediation. [ABSTRACT FROM AUTHOR]

This study was conducted on the distribution of manganese content in the soils of the city of Mitrovica and its surroundings in Kosovo. A total of 156 topsoil samples were taken in the entire study region (sampling grid of 1.4 × 1.4 km2). The average Mn content of the entire study area is 1600 mg/kg (range 170–17000 mg/kg), which is 4.2 times higher than the EU average and 3.3 times higher than the global average. The spatial distribution maps show that the higher Mn contents occur mainly in soils from Miocene latite as well as quartz-latite and from Triassic volcanic-sedimentary formations in the eastern and north-eastern part of the study area. The lower values were found in the Flysch and Cretaceous flysch outcrops. It was found that the increased Mn contents in soils from this area are mostly of lithogenic origin. The values of the enrichment factor (EF) show that the soils of the entire study area are very highly enriched with Mn (20 < EF < 40). The values of the geo-accumulation index (1< I-geo ≤ 2), show that the soils of the entire study area are moderately contaminated with Mn. [ABSTRACT FROM AUTHOR]

Fast regrowth from deep roots and rhizomes makes it difficult to mechanically control the perennials Cirsium arvense and Tussilago farfara respectively. It is, however, not clear whether new shoots originate mainly from fragments of roots/rhizomes in upper soil layers or from an intact system below depth of soil cultivation. Here we present results from three experiments with natural infestations of C. arvense, and two with both C. arvense and T. farfara. Plots of 1 m2 were excavated to different depths (13–25 cm), all below‐ground plant parts in the topsoil were collected and thereafter fragments were either returned to or removed from the plots. Regrowth from disturbed plots with removed or returned fragments was compared. The origin of regrown shoots, that is, whether they originated from seeds, intact below‐ground root/rhizome systems or returned fragments, was examined. More C. arvense shoots originated from the intact root system (48%–84%) than from root fragments (16%–52%). The final aboveground biomass was not affected by removal of the top‐soil fragments. For T. farfara, a small proportion (3%) of new shoots originated from the intact rhizome system, and the rest from fragments. We conclude that the intact root system of C. arvense contributes at least as much as root fragments to regrowth after soil cultivation, which might imply that time of treatment and depth of cultivation are crucial for the effect of mechanical control. For T. farfara, the results suggest that tillage equipment with high capacity to fragment the rhizome system will contribute to efficient control. [ABSTRACT FROM AUTHOR]

Plant propagules are crucial flora memory materials in restoration practice. Awakening flora memory from plant propagules (i.e. seeds, root fragments, rhizomes, corms, and tubers) in the translocated topsoil from a donor site is a rapid method for forest restoration on degraded sites globally. However, it remains unclear to what extent manageable measures, such as light reduction and watering, affect flora memory awakening. We employed a quadratic saturation D‐optimal design in a forest topsoil translocation experiment to quantify the effects of light reduction and watering on flora memory awakening. We used the cumulative number and richness of plantlets emerging from plant propagules to represent the extent of flora memory awakening. Our results show that any combinations of light reduction and watering significantly increased both the cumulative number and richness of plantlets across different life forms. Light reduction had a significantly more positive effect on flora memory awakening than watering. Different life forms exhibited different parabolic or positive linear relationships in responses to light reduction and watering. Light reduction of about 60% of the degraded site and watering of about 80% of the donor site resulted in the highest number and richness of plantlets. We concluded that light reduction and watering combinations were effective in kick‐starting the flora memory awakening in a semiarid subtropical forest after topsoil translocation. [ABSTRACT FROM AUTHOR]

Reflecting recent advances in our understanding of soil organic carbon (SOC) turnover and persistence, a new generation of models increasingly makes the distinction between the more labile soil particulate organic matter (POM) and the more persistent mineral-associated organic matter (MAOM). Unlike the typically poorly defined conceptual pools of traditional SOC models, the POM and MAOM soil fractions can be directly measured for their carbon content and isotopic composition, allowing for fraction-specific data assimilation. However, the new-generation model predictions of POM and MAOM dynamics have not yet been validated with fraction-specific carbon and 14 C observations. In this study, we evaluate five influential and actively developed new-generation models (CORPSE, MEND, Millennial, MIMICS, SOMic) with fraction-specific and bulk soil 14 C measurements of 77 mineral topsoil profiles in the International Soil Radiocarbon Database (ISRaD). We find that all five models consistently overestimate the 14 C content (Δ14 C) of POM by 69 ‰ on average, and two out of the five models also strongly overestimate the Δ14 C of MAOM by more than 80 ‰ on average, indicating that the models generally overestimate the turnover rates of SOC and do not adequately represent the long-term stabilization of carbon in soils. These results call for more widespread usage of fraction-specific carbon and 14 C measurements for parameter calibration and may even suggest that some new-generation models might need to restructure or further subdivide their simulated carbon pools in order to accurately reproduce SOC dynamics. [ABSTRACT FROM AUTHOR]

Evaluating the impact of land‐use intensification on soil microbial communities is essential for recognizing the implications on microbiome stability and ecosystem function. The microbial biomass and enzyme activity in the topsoil have been found to decrease as a consequence of natural forest conversion; however, the impact of land‐use conversion on the microbes in subsoil remains largely unclear. Here, we examined the effect of primary forest conversion to plantations and cultivated lands on microbial communities at three sites with similar soil, climate, and landform. The forest conversion was set as the experimental treatment, and the primary forest as the control. A linear mixed‐effect model was applied to investigate the role of environmental parameters in shaping the soil microbial biomass and community determined by the phospholipid fatty acids analysis in both the topsoil (0–20 cm) and subsoil (20–40 cm). Compared to the primary forest, the total microbial biomass, β‐1,4‐N‐acetylglucosaminidase, leucine aminopeptidase, acid phosphatase activities, and labile organic C fraction contents in both topsoil and subsoil were reduced in cultivated lands. The ratios of gram‐positive bacteria to gram‐negative bacteria and arbuscular mycorrhizal fungi to saprotrophic fungi in subsoil decreased by 45%–53% and increased by 29%–151%, respectively, following the primary forest conversion to cultivated lands. The response ratio (the percentage of microbial and enzyme indicator response to the primary forest conversion) ranged from −80% to 140% depending on the soil depth, specific microbial group, and converted land‐use type. Microbial biomass and enzyme activity are primarily controlled by the labile organic C content and nutrients availability in both topsoil and subsoil. This study suggests that the primary forest conversion exerts an adverse effect on the microbial biomass, enzyme activity, and substrate availability in both topsoil and subsoil, highlighting the degradation of subsoil health in subtropical China. [ABSTRACT FROM AUTHOR]

Seed-based restoration in dryland environments is commonly limited by low and sporadic rainfall, extreme temperatures, and degraded soils. These challenges are exacerbated in dryland mine restoration sites where species are seeded onto mine waste substrates due to limited availability of topsoil. Native grasses are focal dryland and mine restoration species, though the ability to deliver seeds to targeted sites presents further constraints to seed-based restoration due to complex seed morphology and site attributes. Seed enhancement technologies (SETs) may help to mitigate environmental stressors and improving seed handling. In this study, SETs which promote seedling recruitment and/or address edaphic challenges while also improving seed morphology and handling were tested in four Australian native grasses (Cymbopogon ambiguus, C. obtectus, Eulalia aurea, and Eriachne obtusa). Flash flaming or acid digestion (depending on species), extruded seed pellets with or without the addition of topsoil, and flaming or acid digestion used in combination with extruded pellets (with or without topsoil) were evaluated on topsoil and mine waste substrates. Material treated with either flash flaming or acid digestion tended to produce similar maximum emergence (week 3), final emergence (week 14), and above-ground biomass (week 14) on both topsoil and mine waste when compared to the un-enhanced ('control') treatment. Extruded pellets enhanced emergence (maximum and final) on both soil types, though had no effect on biomass. Extruded pellets containing topsoil and/or when used in combination with flash flamed or acid digested florets, provided the most significant benefits to seedling emergence, particularly on mine waste soil. However, SETs were unable to mitigate the detrimental effects of mine waste substrates on seedling biomass. This study shows promise for improving seed-based restoration in post-mine and dryland environments using SETs, though also highlights potential limitations and the importance of understanding long-term (i.e., beyond emergence) plant recruitment outcomes in SET applications. [ABSTRACT FROM AUTHOR]

Transferring topsoil to severely degraded areas, such as mined areas, is an effective restoration technique. However, topsoil from pristine areas is a limited resource, making it important to seek techniques that optimize its use. Thus, this study assessed the effects of adding a small topsoil volume (10 L/m2 or 1 cm layer), a seed mix of 14 species, and litter (30 L/m2) alone and in different combinations in the restoration of a rupestrian grassland area degraded by bauxite mining. The substrate in the degraded area was turned prior to applying treatments. Vegetation cover, density of individuals, and species richness were measured 30 months after the experiment was set up. The isolated use of each material and the simultaneous addition of topsoil to the seed mix were not effective. The simultaneous use of topsoil, litter, and seed mix provided the best result, presenting the highest vegetation coverage (60%), density (67 ind/m2), and species richness (26 in 12 m2). Although, to a lesser extent, the combination of seed mix and litter also presented satisfactory results. The combination of the three materials promoted the revegetation of an area that had been without vegetation for around 50 years, presenting a density of individuals and species richness comparable to those obtained with the use of thick topsoil layers (15–30 cm). Furthermore, the topsoil volume used was optimized. [ABSTRACT FROM AUTHOR]

High levels of soil water repellency (SWR) can hinder water infiltration and increase surface soil erosion risk and runoff. Although SWR occurs naturally in many areas, it is often patchy and does not impede water movement. However, fire can increase the connectedness and extent of SWR leading to topsoil loss, nutrient limitations, increased root water stress, and ultimately slower ecosystem recovery. This study examines the naturally hydrophobic soils of Oregon's Deschutes National Forest following the 2020 Green Ridge Fire to (1) examine the relationship between SWR and management‐relevant burn severity classes, (2) quantify an appropriate spatial scale over which to evaluate SWR properties, and (3) determine which environmental factors drive patterns in SWR. We found that the top 1–3 cm of soil became less hydrophobic after fire, while the profile to about 10 cm became more uniformly hydrophobic. This could indicate that surface soil is more prone to post‐fire erosion in burned areas. However, predicting SWR is still challenging. While burn severity and environmental metrics did statistically account for some variation in SWR following fire, the range of SWR spatial autocorrelation was at best a few meters. Due to this fine‐scale variation, future work should focus on determining an efficient post‐fire soil evaluation protocol with adequate density and scale of sampling while also incorporating the influence of environmental factors to inform management decisions. Core Ideas: Naturally occurring hydrophobicity complicates predicting post‐fire hydrology.Fire increased the homogeneity of water repellency in only some burn severities.Variability makes predicting hydrophobicity or scaling up incredibly difficult.The top 1–3 cm of soil across all burn severities may have highest erosion risk. [ABSTRACT FROM AUTHOR]

Pálava is a complex of prominent limestone hills in South Moravia, with extensive traces of prehistoric activities. This study presents the results of a long-term metal-detecting survey of the Pálava Hills and their surroundings. It focuses on findings dated to the Bronze Age and especially to the Urnfield period with 673 from the topsoil recovered artefacts. The study monitors the functional composition of the items within the dataset, as well as the spatial distribution of individual artefacts. The data from the surveys allow comparisons between the enclosed sites at the Stolová hora, Kotel, and Děvín hills, and the open satellite settlements in the hinterland. The results are also used for a comparison with other Moravian Bronze Age sites that have been surveyed with the same method. The study also includes a metallographic analysis of 177 objects. The results create a picture of an intensively used hillfort at Stolová hora, which in the Urnfield period represented a centrepiece of a broader agglomeration, and at some point, also probably of the whole region. [ABSTRACT FROM AUTHOR]

Slope orientation significantly influences soil's physicochemical properties and the soil hydrological environment. However, the regulatory mechanisms and effects, particularly in semi-arid highlands, remain poorly understood. This study investigated soil physicochemical and hydrological properties on shaded and sunny slopes. Results indicated that in the 0–20 cm soil layer, the water-holding capacity was higher on sunny slopes, while water retention in the 10–20 cm layer was significantly higher on shaded slopes. This suggests that vegetation on shaded slopes experiences less soil erosion due to higher topsoil water retention. Additionally, slope orientation altered soil properties: the electrical conductivity (EC) of the 0–20 cm soil layer was significantly higher on shaded slopes. Nutrient elements such as Ca, Cu, and Zn were also relatively higher on shaded slopes, whereas soil organic matter was significantly lower compared to sunny slopes. Overall, soil water-holding capacity and supply were primarily controlled by EC, followed by capillary porosity and nutrient elements like Ca, Mn, and Fe. Therefore, slope orientation has a significant effect on soil hydrological properties, with stronger topsoil water retention on shaded slopes. These findings offer valuable insights for vegetation restoration in semi-arid highland ecosystems. [ABSTRACT FROM AUTHOR]

Composts are increasingly used to enhance soil health and agricultural sustainability, but their impacts on nitrogen (N) availability are unclear. In a 3‐year field experiment with subsurface drip‐irrigated tomatoes (Solanum lycopersicum), we investigated the effects of food waste and green waste co‐compost (FW) and green waste compost (GW) on yield, nitrogen‐use efficiency (NUE), nitrate leaching potential, and fertilizer N retention. Various combinations of compost rates (0, 9, or 18 t ha−1) and fertilizer N levels (0%, 70%, 85%, and 100% of the recommended rate) were examined, and 15N‐labeled fertilizer was used. In Years 2 and 3, FW and GW either maintained or increased crop yield compared to no compost when 0% or 70% N was applied; however, lower NUE was observed in the compost treatments compared to no compost when 70% or 85% N was supplied. Postharvest, FW showed greater fertilizer N retention in topsoil than GW and controls, while no difference in nitrate leaching potential was found among treatments, except for Year 2 during which FW exhibited the lowest potential. These results suggest that compost can immobilize fertilizer N, reducing its uptake by crops but enhancing soil retention, potentially acting as an N source or a primer of soil N mineralization. Future research is needed to assess compost's impact on N gaseous emissions and distinguish its dual roles as an N source and a soil N mineralization primer. This is essential for developing nutrient management guidelines to minimize N losses. Core Ideas: Combined application of compost and N fertilizer sustained and/or increased tomato yield.Compost served as a N source and/or primed soil N mineralization, while retaining fertilizer N.Combined application of compost and N fertilizer has potential to minimize nitrate leaching. [ABSTRACT FROM AUTHOR]

This study aims to develop models for estimating topsoil properties by analyzing both the parametric and textural features extracted from Sentinel-1 C-SAR (VV, VH) images. Field measurements were collected from 13 soil samples in the Laylan region of Kirkuk City, Iraq, and utilized to develop and validate the models. The study employed classification algorithms, including the random forest (RF) and maximum likelihood (ML) classifiers, using specific indicators derived from Sentinel-1 data. Additionally, a soil triangle was constructed using three axes to represent the predicted target parameters, facilitating the identification of five distinct soil groups in the study area. The findings reveal that the soil triangle enables the delineation of five subcategories of soil characterized by varying proportions of sand and silt. Each soil sample was categorized into one of five predefined classes based on its clay content, ranging from 0% to 14.48%. The performances of the ML and RF algorithms were assessed, demonstrating their effectiveness in estimating percentage labels despite limited training data, with ML exhibiting higher accuracy than RF. The developed models showed promising potential; however, their applicability should be tested across diverse geographic regions with varying climatic conditions. Future research could focus on utilizing these models to generate soil texture maps, potentially enhancing soil parameter estimation in different environments. [ABSTRACT FROM AUTHOR]

[Objective] The aim of this study is to explore the accuracy and applicability of different machine learning models for predicting the spatial distribution of surface soil organic carbon density (SOCD) with limited samples, which can provide a references for the study of watershed scale carbon pool in the Chinese Loess Plateau. [Methods] In this study, we compared the accuracy and stability of the predicted SOCD in topsoil (0-20 cm) by four machine learning models, namely Multiple Linear Stepwise Regression (SR), Random Forest (RF), Extreme Gradient Boosting (XGB) and Support Vector Machine (SVM), based on the limited measured samples in a sub-watershed of Yanhe River in the Chinese Loess Plateau. [Results] (1) Under the condition of limited samples, all models successfully and appropriately predicte the spatial distribution of SOCD, among which the SVM model has the best model performance, and the average RMSE, R² and MAE of 50 predictions is 0.74. 0.43 and 0.64, respectively. (2) The average SOCD of different land use types are consistent between measured and predicted values but shows significant difference among land use types. SOCD decreases in the order: shrubland forestland > grassland > cropland. The total organic carbon of cultivated land in the study area is 2.39×106t (0-20 cm). (3) The evaluation of feature importance shows that terrain factors, NDVI max, near-infrared surface reflectance (B5) and Brightness index have significant contributions to the accuracy of predictions. [Conclusion] Under the condition of limited samples, the machine learning model combined with controlling features can be effectively applied to the prediction of the spatial distribution of topsoil SOCD at the watershed scale in the Chinese Loess Plateau. [ABSTRACT FROM AUTHOR]

Background: Undoubtedly the biggest single cause of pollution, automobile emissions have a variety of negative occupational and human health impacts. Chemicals, paints, primers, and other hazardous products are frequently used in auto workshops' operational procedures. Substances like petrol, diesel, solvents, lubricants, and grease can be unintentionally or purposely release/exposed to the terrestrial environment. Numerous rock oil products consist of organic compounds that are capable of causing significant risk to soil, organisms, and humans due to their high toxicity. Objectives: The study aims to assess the occupational and toxicological risk of exposure to toxic elements (TEs) in topsoil from residentially situated automobile workshops (AWs) in Abeokuta, Ogun State, Nigeria. Methods: 12 composite soil samples were strategically collected and transported to the laboratory. 1 g of the processed sample was digested using aqua regia, namely a mixture of nitric acid and hydrochloric acid, optimally in a molar ratio of 1:3, while toxic elements analyses were done using an atomic absorption spectrometer (AAS). Results: The result showed the presence of arsenic (As = 0.67 – 5.63 mg/kg), cadmium (Cd = 8.92 – 134 mg/kg), cobalt (Co = 6.21 – 71.22 mg/kg), nickel (Ni = 1.89 – 9.18 mg/kg), and lead (Pb = 32.6 – 211 mg/kg) in the soil. The concentrations of Cd and Pb in 66.7% and 58.3% of the sample are higher than the Canada soil guideline value (CSGV) (for Cd 22 and for Pb 140 mg/kg) respectively. Contamination factors (CF) indicate very high soil contamination from Cd and Pb, and the significant association between the TEs (Pb, Cd, Co, Ni and As) p < 0.01, suggests an emergence from an anthropogenic origin. Hazard index (HI) values for the TEs were < 1, except for Pb (27.8) in the children, indicating a significant non-cancer-related effect on exposure, while the total cancer risk (TCR) value was within the threshold limit. Conclusions: The investigated topsoil is polluted with Cd and Pb, and there is a non-cancer-related effect on children with prolonged exposure to Pb. Therefore, AWs should be cited away from residential homes, while remediation of the polluted soil should be considered.

Soil structure dynamics during a season depend on management practices and environmental factors. A lightweight autonomous robot (total mass: 3300–4100 kg, wheel load: 700–1200 kg, contact areas: 0.125 m2, inflation pressures: 60–280 kPa) was used for sowing (October 2021) and weeding (May 2022) operations on an annually plowed sandy loam field. We took 579 cm3 soil cores at 10‐ to 18‐cm depth in the crop area and wheel tracks before and after the operations to assess the impact from traffic and the potential recovery of topsoil structural properties. We measured air permeability and effective air‐filled porosity in the laboratory, and X‐ray CT scanned the samples to evaluate soil pore functionality. The first operation (conducted on a moist seedbed) had the largest impact, significantly compacting and reducing the air‐filled porosity by 42% (from 0.21 to 0.12 m3 m−3) and decreasing air permeability by 75.8% (from 130 to 31.5 µm2). After 7 months, the crop area and wheel track showed signs of soil consolidation due to environmental factors but not decompaction. The second operation occurred on drier (water content 0.06 g g−1), stronger soil conditions (degree of compactness 100.8%), and recompaction of the wheel track was not observed. Traffic in weak soils can result in seasonal topsoil compaction despite the lighter wheel loads. However, due to the milder impacts, recovery rates might be faster for lightweight machinery than for heavy tractors. Multi‐season studies are needed to assess the real potential of lightweight robots to minimize soil compaction risk. [ABSTRACT FROM AUTHOR]

PT Putra Perkasa Abadi site PT Bukit Asam Tbk is a company engaged in the mining sector with business processes including topsoil removal, overburden removal, haul road maintenance, road construction, pit service, equipment rental, coal getting and coal hauling. The purpose of the study is to analyze the influence of SAP digitalization on the improvement of the occupational safety system, identify the benefits and challenges in the process of digitizing the occupational safety system, and formulate strategies and recommendations to optimize the implementation of the digitalization of the occupational safety system. This research method uses a qualitative approach with data collection methods through literature studies, field observations, in-depth interviews, document analysis, and surveys. One of the steps taken to improve the implementation of the work safety system is the digitalization of the Safety Accountability Program (SAP) of Partners. Based on data obtained through primary data sources from 30 respondents, namely supervisors from 9 Partners of PT Putra Perkasa Abadi site PT Bukit Asam Tbk, and analysis using the Likert scale, it was concluded that SAP digitalization has a great influence on the role of management with an average score of 91, Conditions and workplaces with an average score of 93, awareness and quality of workers with an average score of 91, project performance with an average score of 92. Research Results: SAP digitalization has been proven to improve the effectiveness of occupational safety systems through increased efficiency, data accuracy, and better decision-making. However, there are several challenges faced, such as resistance to change and system integration. Recommended strategies include improved training, effective communication, and the development of adequate IT infrastructure. This means that, overall, it is very influential in improving the safety system of PT Putra Perkasa Abadi's partner, PT Bukit Asam Tbk with an average score of 92. [ABSTRACT FROM AUTHOR]

Forest ecosystems and urban parks are an integral part of the natural environment and the natural system of a city, where they form a mosaic of habitats resulting from the variation in soil cover due to human activities. The study was conducted in urban forests in five urban parks in Upper Silesia (southern Poland) and investigated the chemical properties and content of potentially toxic metals (PTMs) in the topsoil, which had an average thickness of 15 cm for all samples. The soil reaction ranged from acidic (pH = 4.7–5.1, in KCl) to slightly acidic (pH = 5.6, to neutral—6.6–7.2) at most sites. The organic carbon (OC) content was relatively high at all sites, ranging from 1.19 to 14.3%, with the highest total nitrogen (Nt) content being 0.481%. The average total phosphorus (Pt) content in the parks ranged from 310 mg kg−1 to 684 mg kg−1, while the highest values were 1840 mg kg−1. The total Cr, Cu, Co and Ni content was within acceptable limits, while the Zn, Pb, Cd, As, Sr and Ba exceeded acceptable standards. In terms of content, Zn dominated the PTMs at each site (Zn > Pb > Ba > Sr > Cu > Cr > As > Ni > Cd > Co), while Ba and Pb alternated in taking second place (Zn > Ba > Pb > Sr > Cu > Cr > Ni > As > Co > Cd). Environmental indicators, such as the geoaccumulation index (Igeo), enrichment factor (EF) and potential ecological risk index (RI), showed that the analyzed soils are highly contaminated with PTMs. Among the sources of pollution in the urban forest are low emissions from coal combustion, industrial activities, water runoff from streets and proximity to transportation routes. Identification of PTM levels in urban parks will provide valuable information on the behavior of these metals, which is important in sustainable development and can help evaluate the local spatial development plans of urbanized areas. [ABSTRACT FROM AUTHOR]

[Objective] Soil organic carbon (SOC) is not only an indicator of soil health but also plays a crucial role in feedback interaction between global warming and carbon stock in terrestrial ecosystems. Its dynamics is modulated by a multitude of interactive abiotic and biotic factors. In this paper, we analyze the spatial distribution of SOC in the plough layer and its correlation with soil texture and other geochemical properties in the region of Zhengzhou in Henan province. [Method] Soil samples were taken from a grid network in the region. SOC, bulk density, soil texture and other geochemical properties in each soil sample were measured. The correlation between SOC and soil nutrients, including nitrogen, phosphorus, potassium and micronutrients in the soil, was analyzed using the GeoChemStudio software. [Result] The calcareous skeletol soil in the region has the highest SOC, reaching 2.307%. The SOC content varied from 0.1%-11.6% across the region, and was normally distributed with a mean of 1.134%. The SOC was positively correlated with N, P2O5, Fe, Mn, Zn, Cu, Mo and B, and their associated correlation coefficients were 0.804 5, 0.223 0, 0.156 3, 0.119 1, 0.223 8, 0.263 4, 0.162 8 and 0.191 1, respectively. Negative correlations were found between SOC and K2O and pH, and their associated correlation coefficients were -0.088 8 and -0.195 7, respectively. The average SOC content in the plough layer in the region was 1.09%. Spatially, SOC was rich in Xinmi, Dengfeng and Gongyi in the southwest of the region. In terms of soil texture, SOC is higher in skeletol soil and calcareous cinnamon soil than in other soils. SOC stored in the topsoil in the whole region was 1 012.87x104 t, with 523.13x104 t stored in the cinnamon soils and calcareous cinnamon soils, accounting for 51.64% of the total topsoil SOC in the region. [ABSTRACT FROM AUTHOR]

Soil health assessments aim to quantify soil health status using indicators linked to ecosystem services such as yield, nutrient cycling, water cycling, or carbon storage. Many indicators are related to soil biological processes, which can be challenging to interpret because they are sensitive not only to management, but also to nonmanagement variables such as soil inherent properties, topography, and climate. Existing studies address this challenge by grouping similar soils by taxonomy, geography, or a combination of these and other variables for soil health assessment. We investigated whether grouping soils based on multiple quantitative topsoil properties could be an alternative to taxonomic or geographic groups. We used an unsupervised classification algorithm, k‐means, to cluster publicly available soil and climate data for Minnesota. Clustering into eight conceptual groups ("clusters") based on 10 topsoil properties was determined to be the optimal algorithm output. We evaluated the ability of our soil clusters and other grouping methods to explain variance in eight soil health indicators. We found the combination of Major Land Resource Area (MLRA) and soil cluster performed best, explaining as much or more variance than other groupings for five of the eight indicators. The clusters distinguish zones of topsoil variation at the field scale, and MLRAs account for broader scale variation in climate and other landscape factors. The approach we describe is flexible and could be applied at different locations and scales to produce conceptual soil groups and associated maps to support soil health test sampling and interpretation at the field scale. Core Ideas: Case study explores utility of cluster analysis to group similar soils and aid in soil health indicator interpretation.K‐means classification simplified >6500 soil map units into eight clusters based on 10 topsoil properties.Soil clusters represent an intermediate level of complexity between map units and general soil associations.Major Land Resource Area and soil cluster together were most useful for stratifying soils.Clustering method is adaptable, and public soils databases make similar analyses possible in other regions. [ABSTRACT FROM AUTHOR]

Soil bacterial communities play a remarkable role in nutrient cycling, significantly affecting soil organic material content, soil fertility, and, in an indirect way, plant succession processes. Conversely, vegetation type influences microbial soil life. The present study compared the bacterial microbiome composition, diversity and catabolic activity profile of topsoil samples collected under three different forest types (a twice-coppiced black locust stand, a young, naturally reforested, and a middle-aged mixed pedunculate oak stand) planted on former arable land in the early 20th century. Diversity indices determined during 16S ribosomal RNA sequencing-based metagenome analysis indicated that the black locust stand had the highest soil bacterial community diversity. At the phylum level, Acidobacteriota, Actinobacteriota, Proteobacteria, Verrucomicrobiota, Bacteroidota, and Gemmatimonadota were the most abundant taxa in the forest soils. Concerning soil parameters, redundancy analysis revealed that pH had the highest impact on bacterial community structure and pH, and soil organic carbon content on the samples' respiration patterns. As for catabolic activity, the recently clearcut oak forest showed the lowest substrate-induced respiration, and citrate was the main driver for the inter-stand variability of microbial activity. Our results confirm that soil parameters and forest type influence the composition and functioning of the soil bacterial microbiome. [ABSTRACT FROM AUTHOR]

In this work, we evaluated the changes that occurred by the deposition of the tailings, and the consequences after the implementation of rehabilitation procedures, in a stretch of the Gualaxo do Norte River, Brazil. The deposition occurred after the largest environmental disaster in the history of Brazil, the rupture of the Fundão dam, which dumped tons of ore tailings into the environment, producing several losses in the Doce River Basin. We carried out three surveys with laser scanner in the area: the first with airborne laser scanner in 2011, before the dam collapse; and two with terrestrial laser scanner after the disaster, in 2016 and 2018. The cloud points were aligned and evaluated regarding their positional accuracy using Global Navigation Satellite System control points. The changes in sediment volume as well as the material gains or losses among the periods were assessed according to differences in the coordinate Z. The siltation affected both the Gualaxo do Norte channel and the river terraces, with the study area suffering a deposition of almost 40 thousand m3 of sediments. It was also possible to identify zones where the deposition of sediments predominated over removal/erosion, with 68% of the study area in 2016 recording accumulation of tailing layers in relation to the pre-rupture situation. In 2018, the deposition zones corresponded to almost 80% of the study area (in relation to the situation in 2016), and the most material accumulated was associated with topsoil deposition through rehabilitation interventions. Laser scanner technology proved to be promising to estimate the volume of tailings and identify areas with accretion or removal of sediments, being a great tool to direct environmental recovery initiatives in the Fundão dam most affected areas. [ABSTRACT FROM AUTHOR]

Successful reclamation and revegetation of disturbed sites depends on the availability of sufficient topsoil. Current regulations in western Canada require the replacement of =80% of the original topsoil depth (TRD) to restore pre-disturbance productivity. However, salvaged topsoil at many legacy and other disturbed sites is often insufficient to achieve the 80% TRD (TRD80). This 5-year study examined vegetation responses to 50% TRD without organic amendment (TRD50) or amended with either peat (PTRD50) or biochar (BTRD50), relative to the TRD80 treatment, following borrow site reclamation in northeastern Alberta, Canada. Amendments were applied once at rates calculated to bring organic carbon in the topsoil to concentrations approximating those in the TRD80 treatment. Tree and shrub seedling mixes were transplanted following amendment application and vegetation attributes were measured annually thereafter. Results showed that PTRD50 performed as well as TRD80 and outperformed BTRD50 with respect to native species' canopy cover and tree seedling height. Canopy covers of forb and non-native species decreased significantly whereas those of graminoid and native species increased over time for all treatments. Across treatments, native plant species richness increased by 5% per year while nonnative species richness decreased by 19% per year. Overall, peat showed a satisfactory rate of recovery and a trajectory toward the natural boreal forest, indicating its potential to improve reclamation success at disturbed boreal sites where salvaged soil is insufficient to attain equivalent land capability. This finding will provide an additional tool for regulators seeking to refine land reclamation guidelines for such sites in boreal forest regions. [ABSTRACT FROM AUTHOR]

The stability of soil organic matter (SOM) that governs soil organic carbon (SOC) storage depends on its characteristics and components, but little is known about how tree species in forest ecosystems affect SOM components and characteristics. In this study, we used FTIR spectroscopy to investigate plantations of two ecologically and economically significant tree species—namely, spruce (Picea spp.) and sycamore (Acer pseudoplatanus)—in order to determine how the different litter inputs and root-microbe interactions of these two plantations affect the functional groups, components, and characteristics of their SOM. Soil samples were taken from the topsoil (0–10 cm) and subsoil (10–20 cm). In the 0–10 cm soil depth, the SOM's hydrophilic, hydrophobic, and aromatic components differ between the spruce and sycamore plantations. The hydrophobic components constitute the primary constituents of the SOM of the two forest plantations, in contrast to the expected predominance of the hydrophilic component of the SOM. Also, the high hydrophobicity (hydrophilic/hydrophobic) in the subsoil of the spruce plantations was attributed to a decrease in hydrophilic components and a subsequent increase in hydrophobic components of the SOM. The sycamore plantations exhibited a higher SOM aromaticity and a greater degree of decomposition than the spruce plantations. The aforementioned distinctions emphasise the contrasting mechanisms involved in transforming and turnover of the two-tree species' soil organic matter (SOM). [ABSTRACT FROM AUTHOR]

Organic amendment is an effective method to reclaim salt-affected soil. However, in coastal land with shallow saline groundwater, it is limited known about the mechanism of organic amendment on soil desalinization. Thus, to examine the effect of topsoil organic matter content on soil water/salt transport and distribution, two-year field observations in Bohai coastal land, North China, and soil column experiments simulating salt accumulation and salt leaching were conducted, respectively. There were different organic fertilizer amendment rates in 0–20 cm topsoil, 0% (CK), 50% (OA 0.5), and 100% (OA 1.0) (w/w) for soil column experiments. Field observation showed that after organic amendment (OA), the soil's physical structure was improved, and less of the increase in topsoil salt content was observed, with more salt accumulated in deep soil layers during the dry season. In addition, OA greatly promoted salt leaching during the rainy seasons. The results of the soil column tests further indicated that OA treatments significantly inhibited soil evaporation, with less salt accumulated in the topsoil. Although there was no difference in soil water distribution between the CK and OA 0.5 treatment, the topsoil EC for the OA 0.5 treatment was significantly lower than that for CK. During soil water infiltration, the OA 0.5 and OA 1.0 treatments significantly increased the infiltration rates, enhanced the wetting front, and promoted salt leaching to deeper soil layers, compared with CK. The improvement of soil organic amounts could make the soil more self-resistant to the coastal salinization. The findings of this study provide some insights into soil water/salt regulation in heterogeneous soil masses and on the permanent management of coastal saline farmland. [ABSTRACT FROM AUTHOR]

Soil bulk density (BD) serves as a fundamental indicator of soil health and quality, exerting a significant influence on critical factors such as plant growth, nutrient availability, and water retention. Due to its limited availability in soil databases, the application of pedotransfer functions (PTFs) has emerged as a potent tool for predicting BD using other easily measurable soil properties, while the impact of these PTFs' performance on soil organic carbon (SOC) stock calculation has been rarely explored. In this study, we proposed an innovative local modeling approach for predicting BD of fine earth (BDfine) across Europe using the recently released BDfine data from the LUCAS Soil (Land Use and Coverage Area Frame Survey Soil) 2018 (0–20 cm) and relevant predictors. Our approach involved a combination of neighbor sample search, forward recursive feature selection (FRFS), and random forest (RF) models (local- RFFRFS). The results showed that local- RFFRFS had a good performance in predicting BDfine (R2 of 0.58, root mean square error (RMSE) of 0.19 gcm-3 , relative error (RE) of 16.27 %), surpassing the earlier-published PTFs (R2 of 0.40–0.45, RMSE of 0.22 gcm-3 , RE of 19.11 %–21.18 %) and global PTFs using RF models with and without FRFS (R2 of 0.56–0.57, RMSE of 0.19 gcm-3 , RE of 16.47 %–16.74 %). Interestingly, we found that the best earlier-published PTF (R2 = 0.84, RMSE = 1.39 kgm-2 , RE of 17.57 %) performed close to the local- RFFRFS (R2 = 0.85, RMSE = 1.32 kgm-2 , RE of 15.01 %) in SOC stock calculation using BDfine predictions. However, the local- RFFRFS still performed better (ΔR2 > 0.2) for soil samples with low SOC stocks (< 3 kgm-2). Therefore, we suggest that the local- RFFRFS is a promising method for BDfine prediction, while earlier-published PTFs would be more efficient when BDfine is subsequently utilized for calculating SOC stock. Finally, we produced two topsoil BDfine and SOC stock datasets (18 945 and 15 389 soil samples) at 0–20 cm for LUCAS Soil 2018 using the best earlier-published PTF and local- RFFRFS , respectively. This dataset is archived on the Zenodo platform at https://doi.org/10.5281/zenodo.10211884 (S. Chen et al., 2023). The outcomes of this study present a meaningful advancement in enhancing the predictive accuracy of BDfine , and the resultant BDfine and SOC stock datasets for topsoil across the Europe enable more precise soil hydrological and biological modeling. [ABSTRACT FROM AUTHOR]

The successful restoration of endangered habitat types at a low cost is of vital importance. We tested how successful and cost‐effective six combinations of restoration treatments were in the Cape Floristic Region of South Africa. Treatments were applied to an area that was primarily covered invasive alien grasses. Treatments that tested combinations of burning, direct sowing of seed, and planting of seedlings, aimed to test the synergistic effect of three treatment factors. Topsoil translocation aimed to determine if this, combined with planting, can restore native shrub cover and whether the addition of mulch and seed can improve overall success. The mechanical removal of invasive grasses, sowing and planting, were tested in the absence of fire. Both topsoil translocation treatments and the treatment that had been burned, sown and planted ("Burn‐sow‐plant") led to plant species richness resembling near‐pristine plots and approximately 30% higher than the burn‐only treatment ("Burn"). Native shrub cover was the highest for treatments which included planting. Survival for planted species was 36–41% higher for Burn‐sow‐plant. The contribution of sowing was low, with 9–16% of species sowed being present across treatments. We show that topsoil translocation can be successful if combined with planting. Burn‐sow‐plant was most successful at a reasonable cost, despite planting being expensive, whereas Burn and Burn‐sow were less successful, but cheaper. The treatment in which grass was removed before sowing and planting was the least successful and most expensive. We conclude that the most successful treatments are not necessarily the most expensive. [ABSTRACT FROM AUTHOR]

Yeasts are an obligate component of the microbial communities of both undisturbed natural soils and disturbed soils in urban ecosystems. In urban environments changes occur in the yeast complexes in the soil that largely depend on the intensity of the prevailing anthropogenic influences. Yeasts in urban topsoil in playgrounds have been little studied so far. However, even these studies show that opportunistic and pathogenic species of the genera Candida and Cryptococcus can occur there. The presence of such yeasts can pose a serious threat to children whose immune system is not yet sufficiently developed and to adults whose immunity is weakened. We analysed the topsoil (0–15 cm) of ten playgrounds in the city of Moscow throughout the year for the presence of opportunistic and pathogenic Candida yeasts included in the "WHO fungal priority pathogens list" in 2022 (WHO FPPL). In addition, the susceptibility profile of the isolated strains to three conventional antifungal agents was evaluated: Fluconazole, Voriconazole and Amphotericin B. Two opportunistic Candida species, C. parapsilosis and C. tropicalis, were observed during the study period. Resistance to fluconazole was detected in 41% of C. parapsilosis strains and in 54% of C. tropicalis strains; resistance to voriconazole was detected in 18% of C. parapsilosis strains and in 12% of C. tropicalis strains, and the lowest percentage of resistant strains was detected to amphotericin B, namely 3% and 1% of C. parapsilosis and C. tropicalis strains, respectively. Thus, urban topsoil in playgrounds can be considered as a reservoir for the maintenance and spread of yeasts with potential health risks for children and adults. [ABSTRACT FROM AUTHOR]

The studies of heavy metal input and output fluxes from farmland soils will contribute to sustainable agricultural practices. However, debate on the primary pollution to crops has not resulted in the emergence of practical remediation strategies. Hence, the flux should be identified with precision for targeted pollution control. In this study, a catchment downstream of a metal mining area was selected for investigation of Cadmium pollution in the topsoil of farmlands, including the input and output fluxes in different environmental media. The results showed that irrigation was the main input source of Cd to soil, accounting for more than 75%, in which the contribution of dissolved Cd in water was 1–2 orders of magnitude higher than that of Cd adsorbed on suspended particles. Crop harvesting, surface runoff, and leaching were the main Cd output pathways from this area. The dynamic prediction results under different scenarios showed that Cd in farmland soil would be in a cumulative state in the following years by 2050. Straw removing could significantly reduce Cd accumulation in farmland soil. In addition, the substantial increase of crop yield in the future would increase the Cd output flux. This work revealed the accumulation pattern of Cd in farmland soils, and will aid in the development of remediation strategies for cadmium contamination of agricultural soils. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a topsoil with ecological functionality to meet mine rehabilitation and reestablishment of the desired final ecosystem considering different technosols bioremediation configurations. The substrates were amended with compost and malt residue to provide the organic fraction of the soil. In terms of nutrient requirements for fertile soils to sustain plant cover, the best configurations were attained, and this implies that the different amendments were necessary in influencing soil properties. The presence of Eragrostic tef ensured absence of metal mobilisation and an improved soil structure. The results showed that amendments and pH have direct linear correlations to plant growth. It was identified that dolomite (3%), calcite (5%) and gypsum (4%) are indicative of both higher biomass accumulation and degree of germination. Technosols have an improved soil-plant-water relations compared to that of stockpiled soil, therefore displaying potential for land rehabilitation and repurposing of coal waste. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to assess the spatial distribution of carbon reserves in the surface of organic and mineral soil layers, in a carbon landfill. The studied areas are located within the broad-leaved forests of the Southern Urals. Methods: The analysis of the forest carbon cycle was conducted in early spring on trees, shrubs, and grass vegetation. Soil gas flux measurements were performed using a Smart Chamber connected to a LI-COR 7810 gas analyser. CO2 flux emission from the soil surface reached up to 493.2 Gf a day, under the tree canopy and did not exceed 471.8 Gf in uncovered areas (glades). Results: Thus, in early spring, the CO2 flux emissions from the soil surface in forest stands is higher in absolute terms, than in uncovered areas. It can presumably be explained by the difference in vegetation cover, along with the size, depth, and spatial distribution of roots from trees, shrubs and herbaceous plants. Conclusion: Forest litter and humus, mainly composed of potassium, nitrogen, and phosphorus, are critical for maintaining the carbon balance in forest areas. [ABSTRACT FROM AUTHOR]

The continuous rise in global warming and dramatic changes in precipitation patterns have resulted in frequent extreme weather events, biodiversity loss, and ecosystem degradation. This has resulted in varying degrees of mortality in desert mosses, a ground cover type that maintains desert stability and provides important ecological functions. There is, however, a lack of research on the effects of moss mortality on soil multifunctionality (SMF) and microbial interactions in temperate deserts. This study compared and analyzed the soil nutrient content, enzyme activities, and the associated microbial community structure between living and dead moss crusts in the temperate Gurbantunggut Desert. The results indicated that moss mortality improved SMF by increasing the soil carbon content, nitrogen, phosphorus, and enzymatic activity. However, the mortality also considerably reduced the total biomass and abundance of bacteria and fungi in the topsoil, having no significant effect on their diversity. Additionally, a significant decrease in the connectivity and complexity of the soil bacterial and fungal networks was observed when compared to living moss crusts. This was especially noted in the fungal networks, where fungi were more sensitive than bacteria to moss mortality. Although the natural mortality of mosses increases SMF, there is also an increased risk of nutrient loss, thereby threatening ecosystem sustainability. It is, therefore, imperative to consider the causes of crustal degradation while developing management and restoration processes for degraded desert ecosystems. [ABSTRACT FROM AUTHOR]

Robusta coffee production can be sucessed by using high-quality seedlings that have good growth performance. One of several keys to success in seedling production is the choosing best planting medium and providing exogenous growth regulators. These include using cocopeat planting media and giving coconut water. This research aims to determine whether using cocopeat planting media and providing coconut water can increase the growth of robusta coffee seedlings. The experiment used a randomized complete group design with six treatments and four replications; each experimental unit consisted of three robusta coffee seedlings. The six tested treatments were control (topsoil 100%); cocopeat 50% + topsoil 50%; cocopeat 100%; topsoil 100% + coconut water 200 mL; cocopeat 50% + topsoil 50% + coconut water 200 mL; and cocopeat 100% + coconut water 200 mL. This study indicated that cocopeat and coconut water could increase the growth of robusta coffee seedlings. The composition of cocopeat 100% and the combination of topsoil 50% + cocopeat 50% had an improvement effect on the growth of robusta coffee seedlings. [ABSTRACT FROM AUTHOR]

Alpine areas worldwide are under heavy land‐use pressure and degradation. Active restoration treatments can contribute to accelerating recovery of degraded areas. However, monitoring data are needed to understand the contribution of restoration treatments to long‐term management and to predict time to recovery (TR). In this study, we used monitoring data on removed roads in an alpine area in Norway to investigate TR of three vegetation‐based indicators. Four restoration treatments were tested: 1) removal of added gravel down to original terrain surface, and stirring of topsoil; 2) adding fertilizer to the stirred topsoil; 3) adding seeds to the fertilized topsoil; and 4) no removal of added gravel, but stirring of top layer (gravel and soil). The restoration of roads took place in 2002, and monitoring of permanent plots was carried out in 2004, 2009, 2014, and 2019. Reference plots in intact vegetation next to removed roads were monitored in 2014 and 2019. We used species composition and species richness of vascular plants as well as total vegetation cover as indicators of restoration outcome and investigated predicted TR for these indicators under different restoration treatments. Species composition changed significantly with time since restoration in all treatments, approaching that of the reference vegetation. The recovery of species composition was slowest in fertilized and seeded plots, where estimated TR was 2–3 times longer (> 45 years) than in the other treatments (< 20 years). Species richness of vascular plants was restored quickly (< 5 years) within all restoration treatments, whereas recovery of vegetation cover varied more (20–30 years). Our study confirms that vegetation recovery in alpine environments is a long‐term process, but that adding seeds and nutrients is unnecessary for, and even inhibits, the recovery of narrow, disturbed sites such as former roads. [ABSTRACT FROM AUTHOR]

Rewetting drained agricultural peatlands aids in restoring their original ecosystem functions, including carbon storage and sustaining unique biodiversity. 30–60 cm of topsoil removal (TSR) before rewetting for Sphagnum establishment is a common practice to reduce nutrient concentrations and greenhouse gas emissions, and increase water conductivity. However, the topsoil is carbon-dense and preservation in situ would be favorable from a climate-mitigation perspective. The effect of reduced TSR on Sphagnum establishment and nutrient dynamics on degraded and rewetted raised bogs remains to be elucidated. We conducted a two-year field experiment under Sphagnum paludiculture management with three TSR depths: no-removal (TSR0), 5–10 cm (TSR5), and 30 cm (TSR30) removal. We tested the effects of TSR on Sphagnum establishment and performance, nutrient dynamics, and hotspot methane emissions. After two years, TSR5 produced similar Sphagnum biomass as TSR30, while vascular plant biomass was highest in TSR0. All capitula nitrogen (N > 12 mg/g) indicated N-saturation. Phosphorus (P) was not limiting (N/P < 30), but a potential potassium (K) limitation was observed in year one (N/K > 3). In TSR0, ammonium concentrations were > 150 µmol/l in year one, but decreased by 80% in year two. P-concentrations remained high (c. 100 µmol/l) at TSR0 and TSR5, and remained low at TSR30. TSR30 and TSR5 reduced hotspot methane emissions relative to TSR0. We conclude that all TSR practices have their own advantages and disadvantages with respect to Sphagnum growth, nutrient availability and vegetation development. While TSR5 may be the most suitable for paludiculture, its applicability for restoration purposes remains to be elucidated. Setting prioritized targets when selecting the optimal TSR with peatland rewetting is pivotal. [ABSTRACT FROM AUTHOR]

This paper presents the agroproductive differences between two luvisol units at the Preajba Experimental Center, Gorj, Romania, under the influence of surface erosion. Thus, two soil profiles were comparatively executed, one on the plateau on a slope of 2-5%, on a typical luvisol characterized by an Aţel, Ao, AE, El, Bt1, BC, C profile, and another in the lower third of the slope on a 10-15% where a stagnic eroded luvisol was identified. The latter had gradually removed its upper horizons due to slow surface geological erosion, exhibiting a shorter profile with the AoEl, El, Bt1w, Bt2w sequence. By washing the fertile topsoil year after year, the physical and chemical properties of the soil worsened. In this regard, the bonitation sheets were drawn up, the potential yields achieved under natural conditions were determined, and following the application of specific hydro-ameliorative measures and the execution of enhanced bonitation based on them, it was observed that the bonitation scores increased, the favourability classes decreased, and the yields increased directly proportional to the value of the enhanced bonitation score. [ABSTRACT FROM AUTHOR]

Nitrogen (N) and phosphorus (P) are the two most important macronutrients supporting forest growth. Unprecedented urbanization has created growing areas of urban forests that provide key ecosystem services for city dwellers. However, the large‐scale patterns of soil N and P content remain poorly understood in urban forests. Based on a systematic soil survey in urban forests from nine large cities across eastern China, we examined the spatial patterns and key drivers of topsoil (0–20 cm) total N content, total P content, and N:P ratio. Topsoil total N content was found to change significantly with latitude in the form of an inverted parabolic curve, while total P content showed an opposite latitudinal pattern. Variance partition analysis indicated that regional‐scale patterns of topsoil total N and P contents were dominated by climatic drivers and partially regulated by time and pedogenic drivers. Conditional regression analyses showed a significant increase in topsoil total N content with lower mean annual temperature (MAT) and higher mean annual precipitation (MAP), while topsoil total P content decreased significantly with higher MAP. Topsoil total N content also increased significantly with the age of urban park and varied with pre‐urban soil type, while no such effects were found for topsoil total P content. Moreover, topsoil N:P ratio showed a latitudinal pattern similar to that of topsoil total N content and also increased significantly with lower MAT and higher MAP. Our findings demonstrate distinct latitudinal trends of topsoil N and P contents and highlight a dominant role of climatic drivers in shaping the large‐scale patterns of topsoil nutrients in urban forests. [ABSTRACT FROM AUTHOR]

Improved understanding of land use derived changes in soil organic matter (OM) compartments stabilized to different degrees against microbial decomposition is required for outlining efficient land use strategies aimed at improving soil ecosystem functions that are strongly coupled to gains and losses of soil organic carbon (OC). However, such data is scarce, particularly in subsoil environments. Consequently, in this study, we analyzed OC storage in topsoils and subsoils, as well as OM fractions with different OC turnover dynamics, including particulate (free and occluded), water-extractable, and mineral-associated OM. We sampled soils under native prairie (10 sites) and long-term arable use (> 40 years, 10 sites) to a depth of 3 m in the central U.S. Our results showed that the arable bulk soils had significantly lower OC content in the A horizon and across all analyzed OM fractions compared to native prairie soils. This reduction was primarily derived from OC losses in the mineral-associated OM (arable: 7.2 ± 0.5 g kg−1; native prairie: 12 ± 0.7 g kg−1), which retained the most significant portion (50–56 %) of bulk soil OC among all fractions. No significant impact of land use on OC storage in the bulk soil and fractions was observed in the subsoil B and C horizons, except for water-extractable OM, which had lower amounts in arable soils in the C horizon than native prairie soils. This underscores the relevance of this fraction for the translocation of OC across the soil profile in undisturbed systems. Our results highlight the crucial role of mineral-associated OM for soil OC storage, but also its sensitivity to land use change, especially in the topsoil, suggesting this fraction is highly relevant for strategies aiming at restoring pre-disturbance soil OC levels.

IntroductionSoil microbial communities, including biological soil crust microbiomes, play key roles in water, carbon and nitrogen cycling, biological weathering, and other nutrient releasing processes of desert ecosystems. However, our knowledge of microbial distribution patterns and ecological drivers is still poor, especially so for the Chihuahuan Desert.MethodsThis project investigated the effects of trampling disturbance on surface soil microbiomes, explored community composition and structure, and related patterns to abiotic and biotic landscape characteristics within the Chihuahuan Desert biome. Composite soil samples were collected in disturbed and undisturbed areas of 15 long-term ecological research plots in the Jornada Basin, New Mexico. Microbial diversity of cross-domain microbial groups (total Bacteria, Cyanobacteria, Archaea, and Fungi) was obtained via DNA amplicon metabarcode sequencing. Sequence data were related to landscape characteristics including vegetation type, landforms, ecological site and state as well as soil properties including gravel content, soil texture, pH, and electrical conductivity.ResultsFilamentous Cyanobacteria dominated the photoautotrophic community while Proteobacteria and Actinobacteria dominated among the heterotrophic bacteria. Thaumarchaeota were the most abundant Archaea and drought adapted taxa in Dothideomycetes and Agaricomycetes were most abundant fungi in the soil surface microbiomes. Apart from richness within Archaea (p = 0.0124), disturbed samples did not differ from undisturbed samples with respect to alpha diversity and community composition (p ≥ 0.05), possibly due to a lack of frequent or impactful disturbance. Vegetation type and landform showed differences in richness of Bacteria, Archaea, and Cyanobacteria but not in Fungi. Richness lacked strong relationships with soil variables. Landscape features including parent material, vegetation type, landform type, and ecological sites and states, exhibited stronger influence on relative abundances and microbial community composition than on alpha diversity, especially for Cyanobacteria and Fungi. Soil texture, moisture, pH, electrical conductivity, lichen cover, and perennial plant biomass correlated strongly with microbial community gradients detected in NMDS ordinations.DiscussionOur study provides first comprehensive insights into the relationships between landscape characteristics, associated soil properties, and cross-domain soil microbiomes in the Chihuahuan Desert. Our findings will inform land management and restoration efforts and aid in the understanding of processes such as desertification and state transitioning, which represent urgent ecological and economical challenges in drylands around the world.

Numerous plastic products are used in agriculture, including containers, packaging, tunnels, drip irrigation tubing, and mulches. Large amounts of plastics are used as mulches on the soil surface for vegetable and fruit production (tomato, cucumber, watermelon, strawberry, and vine) to reduce weed competition, increase water and fertilizer use efficiency, and enhance crop yield. Portugal uses around 4500 t/year of polyethylene to cover approximately 23,000 ha of agricultural land, and only a small amount is recovered for recycling or secondary uses because of issues of contamination with the soil, vegetation, pesticides, and fertilizers. Cleaning and decontaminating polyethylene mulch are costly, and commercial technology is often not accessible or economical. Most plastic mulch is composed of polyethylene that degrades slowly and produces a large quantity of residues in the soil, with a negative impact on the environment. In the present study, the effects of long-term cultivation of blueberry using green 100% high-density polyethylene mulch in the south Portugal were evaluated for soil chemical and biological changes. High-density green plastic mulch did not contaminate the topsoil with di(2-ethylhexyl) phthalate, and heavy metals, buttotal nitrogen, organic carbon concentrations, electric conductivity, and microbial activity were significantly reduced in the planting row compared with the bare soil without mulching. Furthermore, the presence of plastic mulch did not negatively affect the presence of nematodes, and the number of Rhabditida (bacterial feeders) increased in the planting and covered row.

The deployment of remote sensing platforms has facilitated the mapping of soil properties to a great extent. However, the accuracy of these soil property estimates is compromised by the presence of non-soil cover, which introduces interference with the acquired reflectance spectra over pixels. Therefore, current soil property estimation by remote sensing is limited to bare soil pixels, which are identified based on spectral indices of vegetation. Our study proposes a composite mapping approach to extend the soil properties mapping beyond bare soil pixels, associated with an uncertainty map. The proposed approach first classified the pixels based on their bare soil fractional cover by spectral unmixing. Then, a specific regression model was built and applied to each bare soil fractional cover class to estimate clay content. Finally, the clay content maps created for each bare soil fractional cover class were mosaicked to create a composite map of clay content estimations. A bootstrap procedure was used to estimate the standard deviation of clay content predictions per bare soil fractional cover dataset, which represented the uncertainty of estimations. This study used a hyperspectral image acquired by the Airborne Visible/Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) sensor over cultivated fields in South India. The proposed approach provided modest performances in prediction ( R v a l 2 ranging from 0.53 to 0.63) depending on the bare soil fractional cover class and showed a correct spatial pattern, regardless of the bare soil fraction classes. The model's performance was observed to increase with the adoption of higher bare soil fractional cover thresholds. The mapped area ranged from 10.4% for pixels with bare soil fractional cover >0.7 to 52.7% for pixels with bare soil fractional cover >0.3. The approach thus extended the mapped surface by 42.4%, while maintaining acceptable prediction performances. Finally, the proposed approach could be adopted to extend the mapping capability of planned and current hyperspectral satellite missions. [ABSTRACT FROM AUTHOR]

Flue gas desulfurization gypsum (FGDG) is a by-product generated in the combustion of coal. This solid residue has the potential to be applied to the soil and help to reduce acidity and provide nutrients to soils impacted by surface coal mining. Thus, the objective of this work was to evaluate nutrients and heavy metals in soil and plant tissue and the development of ryegrass in two soils impacted by coal mining under FGDG application. Thus, an experiment was conducted under controlled conditions with two materials used for the construction of the recovered soil profile after mining, topsoil and overburden, after 10 years of coal mining in southern Brazil. The treatments consisted of control treatments and application of FGDG at a dose considered to correct soil acidity in the constructed mine soil materials under ryegrass (Lolium multiflorum) cultivation. It was observed that the application of FGDG increased the availability of potassium (+ 25%) and calcium (+ 38%) in the topsoil. In the overburden, FGDG increased the availability of phosphorus (+ 33%), calcium (+ 25%) and Mg (+ 31%). The FGDG was important in reducing the active and potential acidity of the soil, increasing the dry matter of ryegrass plants cultivated in the overburden (+ 31%). Thus, the use of FGDG contributes to reduce soil acidity, increasing nutrient availability and ryegrass development without increasing the levels of heavy metals in the soil and in the plant tissue, indicating that its application in the constructed mine soil constitutes a suitable alternative of use of this residue. [ABSTRACT FROM AUTHOR]

Land use plays a crucial role in the stock of soil organic carbon (SOC) and soil nitrogen (SN). The aim of this study was to assess and characterize the effects of various soil management practices on the physicochemical properties of soil in a Mediterranean region in southeastern Spain. Texture, soil moisture, bulk density, pH, electrical conductivity, equivalent CaCO3 (%), soil organic matter and carbon, and Kjeldahl nitrogen were determined for the surface topsoil (0–5 cm, 180 samples) under three types of land cover: cropland, grassland, and urban soil. The main soil textures were silt, silt loam, and sandy loam with low percentages of soil moisture in all soil samples and lower bulk density values in cropland and grassland areas. The pH was alkaline and the electrical conductivity as well as the equivalent calcium carbonate content were moderate to high. Organic matter estimated using the LOI and WB methods varied in the order cropland > grassland > urban soil. The results obtained for SOC and SN indicate that cropland presented the highest stocks, followed by grassland and urban soil. The values determined for the C/N ratio were close to 10 in cropland and grassland, indicating that organic matter readily undergoes decomposition at these sites. Our results emphasize the importance of evaluating the effects and identifying the impacts of different soil management techniques, and further research is needed to better understand the potential to improve soil organic carbon and nitrogen storage in semiarid regions. [ABSTRACT FROM AUTHOR]

Western Anhui is an important precision agricultural area in China, characterized by diverse landforms and multiple soil types. To determine the spatial distribution of soil nutrient elements and their controlling factors, we analyzed 5 nutrient indicators by collecting 1295 groups of shallow soil (0-20cm) samples and conducted a comprehensive soil nutrient geochemical grade evaluation on the basis of single indicator analysis. The results show that soil nutrients are poor in the cultivated lands of the northern region. The use of fertilizer should be adjusted as needed to balance the soil nutrients in some areas, and the management of farmland nutrients is suggested for improving the agricultural yield. [ABSTRACT FROM AUTHOR]

Solid-liquid partition coefficients (Kd) of Ra-226 and Po-210 were measured for five agricultural soils in five fields in the south of Vietnam. Rice, maize, water spinach and tomato were grown on Fluvisols, while sweet potato – on Arenosols. The obtained values were very different between radionuclides, cultivation types, and agricultural practices. For Ra-226, they were 2783, 1189, 907, 431, and 1117 L kg–1 in soils under rice, maize, water spinach, sweet potato, and tomato, respectively. The values of 826, 332, 409, 217, and 451 L kg–1 were estimated for Kd in soils under rice, maize, water spinach, sweet potato, and tomato. For a particular soil, the Kd of Ra-226 was higher than that of Po-210. It proves that in the solid phase of the soil, Po-210 was absorbed more strongly than Ra-226. In this study, a new method for determining the leaching rates of Ra-226 and Po-210 from the topsoil to the deeper layer of soil was introduced. It was based on the Kd value and the leaching rate of water for a specific soil type. The leaching rates of 7.4, 37, 63, 36.6, and 61 were estimated for Ra-226 in rice, maize, water spinach, sweet potato, and tomato soils respectively. Similarly, the leaching rates of 22.1, 111, 111, 69.1, and 133 were estimated for Po-210 in rice, maize, water spinach, sweet potato, and tomato soils respectively. The long-term assessment of Ra-210 and Ra-226 in the selected soil was based on the mass balance between the daily input and output of radionuclides in topsoil. It was found that activity concentrations of Ra-226 and Po-210 increase significantly in some soil soils for example under sweet potato and tomato soil. [ABSTRACT FROM AUTHOR]

Agricultural practices that lead to soil carbon sequestration may be a win–win strategy for mitigating global warming and improving soil fertility and resource use efficiency. The mechanisms through which soil organic carbon (SOC) concentration affects crop yields are numerous but difficult to separate. The objective of this study was to disentangle these processes and estimate to what extent the yield response to SOC is mainly driven by changes in physical or biochemical properties and processes. This was achieved by analysing the response of yields in continuous maize to SOC concentrations during 20 years (2000–2019), which had evolved in 14 experimental treatments in a Swedish long‐term field experiment at Ultuna since 1956, ranging from 0.94% to 3.65% in the topsoil (0–20 cm). Average maize yields during this period varied between 1.9 and 8.4 Mg dry mass per hectare in the different treatments. The treatments comprise applications of different mineral nitrogen (N) fertilizers and organic amendments and combinations thereof. Our analysis showed that maize yield in the treatments that were not severely limited by nitrogen supply or soil acidity increased by 16% for each percentage unit increase in SOC. We applied the widely used concept of critical N concentration in plant biomass to diagnose the N status in maize in the different treatments (N nutrition index [NNI]) and parameterized a response function between yield and pH (RpH). Dry soil bulk density (BD) was used as a proxy for soil physical properties. These three variables NNI, RpH and BD explained 95% of the variation in maize yields among treatments. Further analysis of the relationship between BD, SOC and plant available water capacity revealed that about two thirds of the yield increases in response to SOC change could be ascribed to associated changes in soil physical properties. Our analysis suggests that the extra storage capacity of water, which increased by up to 15 mm in the topsoil for each unit percentage increase in SOC, was the main driver for the observed yield responses. We conclude that measures for increasing SOC in soils most likely are an effective adaptation strategy for reducing the risk of crop damage during dry spells, which probably are becoming more frequent in the future due to climate change, even in relatively humid climates as in Sweden. [ABSTRACT FROM AUTHOR]

Grassland degradation can substantially reduce soil carbon sequestration capacity. However, the effects of grassland degradation on soil organic carbon (SOC) density remain unquantified in high‐altitude alpine meadows. In this study, the response and controlling mechanisms of topsoil (0–20 cm) organic carbon were explored in a field survey involving 11 pairs of healthy versus severely degraded plots of high‐altitude (above 4000 m) alpine meadows, as well as three short‐term (3–5 years) fencing restoration projects, across the source of the Yellow River in August of 2020 and 2021. The results showed that 0–20 cm root biomass, SOC content (SCC), and density (SCD) of healthy meadows averaged 533.7 ± 291.9 g/m2 (mean ± S.D), 21.17 ± 9.36 g/kg, and 4.54 ± 1.64 kg C/m2, respectively. Root biomass, SCC, and SCD were markedly reduced by 63.0%, 33.2%, and 17.6% in severely degraded grassland compared with healthy meadows. The SCC and SCD averaged 7.92 ± 2.21 g/kg and 2.2 ± 0.9 kg C/m2 in fencing plots, respectively, and were not significantly different from severely degraded meadows, suggesting a limited improvement in SOC from short‐term fencing restoration. Analysis of a piecewise structural equation model revealed that the effect of degradation on SCD (indicated by the difference in SCD between paired healthy and degraded meadows) was jointly regulated by the differential surface root biomass and site altitude, with a total positive effect of 0.39 and 0.26, respectively. Our findings indicate the losses of topsoil organic carbon stock caused by grassland degradation are root biomass‐ and altitude‐dependent, supporting the notion that antecedent prevention of degradation, more than subsequent restoration, should be the highest priority in the adaptive management of alpine meadows in harsh high‐altitude regions. [ABSTRACT FROM AUTHOR]

Rare earth elements (REE) are essential components in various modern technologies. Mining activities, in contrast, severely destabilize the adjacent ecological systems. The soil transformation environmental issue in mining areas is inextricably linked to process techniques. Inconsistencies in harm and serviceability arise from different mining techniques. This study was conducted in Fujian, China, which has abundance of ion adsorption type rare earth resources (IAT-Res). We investigated the soil interaction effects of two mining techniques (heap leaching and in-situ leaching). After eight years of restoration, soil destruction and nutrient imbalance remain significant in the heap leaching mining regions. The effects of heap leaching are distinct, whereas pollution caused by in-situ leaching is hidden. Although the in-situ leaching technique resulted in less soil erosion, its potential environmental risk cannot be ignored. The greater number of (NH4)2SO4 leachate residues left over after in-situ leaching contaminate the surrounding ecosystem as they are easily translocated. Through this study, we demonstrate the ecological impacts of different mining techniques in mining areas. As a result, to obtain accurate protection and contaminant control management. However, additional interests should address the leachate and REE pollution caused by in-situ leaching in a larger region. [ABSTRACT FROM AUTHOR]