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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]

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]

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]

Mining waste creates challenging soil conditions that hinder tree establishment for boreal forest restoration. This study investigated the effects of adding topsoil or ramial chipped wood (RCW) on the physicochemical properties of waste rock and the growth and survival of planted native tree species. A randomized-block setup with four replications of four treatments was established on a gold mine site in western Quebec, Canada in 2018, and planted with Pinus banksiana and Abies balsamea. Results demonstrated that topsoil addition significantly improved height and diameter growth, aerial and root biomasses, survival, and nutrient uptake (N, P, and S) in conifer seedlings. Concomitantly, water content increased, pH lowered and nutrient concentrations increased in the substrate with a topsoil layer. However, multivariate analysis revealed that these improved soil conditions alone did not determine the survival and growth of conifer seedlings. In contrast, the application of RCW-based treatments had no discernible impact on the growth and survival of the planted trees. Additionally, topsoil amendment effectively reduced the concentration of potentially phytotoxic elements in soil and needles, particularly arsenic. The total arsenic concentration in the mineral substrate (84.1 to 507 µg.g− 1) emerged as a growth-limiting factor for both conifer species. The total concentration of arsenic in the waste rock correlated positively with arsenic accumulation in the tree needles, indicating potential root uptake of this element. This study emphasizes the significance of addressing arsenic availability during reclamation efforts at mine sites. Nonetheless, further research is required to determine the phytotoxic thresholds of arsenic on conifers and its potential metabolic effects. [ABSTRACT FROM AUTHOR]

The effects of mulch on the dissipation of S-metolachlor-SMOC, foramsulfuron-FORAM, and thiencarbazone-methyl-TCM and the formation of their main degradation metabolites were studied here. The herbicides were jointly applied in preemergence of maize on two separate occasions to two agricultural soils under conventional tillage (CT) and non-tillage (NT) over two wheat-maize cycles. Herbicide concentrations were determined in topsoil samples at different times after both applications, and they were fitted to kinetic models. The half-life (DT50) values for SMOC were higher under CT management than under NT (mean values: 25.6 and 7.38 days, respectively) in both soils over the two years. The faster herbicide dissipation with mulch could be because it is partially intercepted and strongly adsorbed/retained through different potential pathways, especially biodegradation, which was supported by the detection of SMOC-ESA and SMOC-OA metabolites. The mean DT50 values for FORAM (6.15 and 6.07 days, respectively) were very close for both soils under NT and CT management over the two-year experiment. The mulch had a lesser impact than for SMOC due to the former's higher water solubility and lower adsorption, with dissipation being controlled mainly by biodegradation and likely also by leaching. TCM recorded intermediate DT50 values (mean value 20.8 days) in both soils+CT in the two-year experiment compared to SMOC and FORAM. The mulch effect on TCM dissipation was observed only after the second application because the DT50 values were higher in soils+NT after the first application (mean value: 26.9 days) than after the second one (mean value: 5.9 days). The amount of soil surface covered by the mulch controlled the herbicide dissipation, and soil and herbicide properties determine their adsorption behaviour by both mulch and soils. [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]

Evaluating the impact of vegetation types and reclamation methods on soil organic carbon and nitrogen in carboniferous spoil heaps is critical for selecting the best vegetation type and reclamation method to improve ecosystem services in a changing climate. This paper presents the relationship between vegetation types (woodland, forbland, and grassland) and reclamation techniques (barren rock, topsoil application, succession, and cultivation) on soil organic carbon (SOC) and total nitrogen (TN) in developing soils on carboniferous rocks in coal mine heaps. Soil samples were collected from the litter layer (Oi + Oe) and the A horizons (0–10 cm). The results revealed that vegetation types and reclamation methods significantly affected SOC and TN stocks. Woodland exhibited higher SOC and TN in the Oi + Oe horizons than other vegetation types. Topsoil application and cultivation resulted in the highest SOC and TN stocks in the A horizons (0–10 cm) under woodland and forbland compared to succession on bare carboniferous rock. In grassland, there was no significant difference in SOC stock under topsoil application and cultivation; however, significantly higher TN stock was observed in the 0–10 cm areas with topsoil application compared to succession on bare carboniferous rock. Based on the results, topsoil application is recommended to improve SOC if the mining site is restored using woodland. Conversely, grassland exhibits a similar amount of SOC stock with or without topsoil application. Considering the difficulty of obtaining topsoil, we suggest that grasses are optimal for SOC stock in the studied mining sites, followed by forbs. [ABSTRACT FROM AUTHOR]

Mountain regions play a crucial role in maintaining global biodiversity, with altitude exerting a significant influence on soil microbial diversity by altering plant diversity, soil nutrients, and microclimate. However, differences in microbial community composition between topsoil (0–10 cm deep) and subsoil (10–20 cm deep) remain poorly understood. Here, we aimed to assess soil microbial diversity, microbial network complexity, and microbial community assembly in the topsoil and subsoil layers of the dry–hot Jinsha River valley in southwestern China. Using high-throughput sequencing in soil samples collected along an altitudinal gradient, we found that bacterial diversity in topsoil decreased with increasing altitude, while bacterial diversity in subsoil showed no altitude-dependent changes. Fungal diversity in topsoil also varied with altitude, while subsoil fungal diversity showed no change. These findings suggest that microbial diversity in topsoil was more sensitive to changes in altitude than subsoil. Bacterial community assembly tended to be governed by stochastic processes, while fungal assembly was deterministic. Soil bacterial and fungal network complexity was enhanced with increasing altitude but reduced as diversity increased. Interestingly, the presence of woody plant species negatively affected bacterial and fungal community composition in both soil layers. Soil pH and water content also negatively affected microbial community composition, while organic carbon and total nitrogen positively influenced the microbial community composition. Simultaneously, herb and woody plant diversity mainly affected soil bacterial diversity in the topsoil and subsoil, respectively, while woody plant diversity mainly affected soil fungal diversity in subsoil and soil nutrients had more effect on soil fungal diversity. These findings suggest that altitude directly and indirectly affects microbial diversity in topsoil, subsequently influencing microbial diversity in subsoil through nutrient availability. [ABSTRACT FROM AUTHOR]

A comprehensive study of environmental magnetism and magnetic mineral morphology of topsoils from Dhanbad of Jharkhand, India is attempted to appraise the amount of magnetic minerals in topsoils and possible sources. This indicates that local anthropogenic sources greatly influence the topsoils. It reveals that the pseudosingle domain, fine-grained, low-coercive magnetite controls the magnetic mineralogy in topsoils, due to coal combustion-related activities and moderate vehicular movements. These results are accompanied by scanning electron microscopy with energy-dispersive X-ray spectroscopic analyses, suggesting the occurrence of principally spherule and accessorily angular anthropogenic magnetic grains in topsoils, indicating that local anthropogenic sources influence topsoils. The environmental magnetic and morphological characters of topsoils positively complement each other and conclude that magnetic grains from different sources show distinctly dissimilar morphologies. Some porous polygonal spherule-shaped magnetic grains are also identified, which could host potentially toxic elements and pose a threat to locals in the form of cardiovascular, respiratory and neurological health consequences. These anthropogenic magnetic grains stand distinctive in pollution source identification, where coal combustion and related infrastructure in and around Dhanbad city are recognized as major anthropogenic sources. [ABSTRACT FROM AUTHOR]

Cropland acidification seriously restricts sustainable agricultural development. The main purpose of this study was to determine whether deeper tilling could alleviate topsoil acidification to improve the quality of arable land. A soil column incubation experiment simulating tillage depths (10 cm, 30 cm and 50 cm) and lime addition was conducted to determine their effects on soil acidification improvement. The changes in soil pH, exchangeable acidity, ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), available phosphorus (AP), and microbial phospholipid fatty acids (PLFA) were analyzed. Tillage depth, lime application, and their interaction all had significant impacts on soil pH. T50 (simulated tillage depth of 50 cm) and T50+Lime (simulated tillage depth of 50 cm plus lime) treatments significantly increased the topsoil pH from 5.41 to 6.35 and 7.12, respectively. T50 treatment significantly reduced the soil exchangeable acid content compared to the T10 treatment. The nutrient accumulation along soil column indicated that the T50 and T50+Lime treatments significantly increased NO3−-N and AP content in the >30–50 cm soil layer. Compared with T30, NO3−-N accumulation in the >30–50 cm soil layers of T50 and T50+Lime treatments was 6.62 and 7.93 times higher, respectively. The accumulation of AP in the >30–50 cm soil layers of the T50 and T50+Lime treatments was 1.33 and 1.54 times higher than in the T30 treatment, respectively. These findings imply tillage up to 50 cm without exogenous materials could be a potential measure to reduce topsoil acidification and increase nutrition availability of >30–50 cm soil layers. Tillage of up to 30 cm combined with lime application confers greater benefits, which would particularly impact crops with shallow root systems. Subsequent field experiments will be conducted to further investigate the efficacy of these strategies in enhancing crop yield. [ABSTRACT FROM AUTHOR]

Based on the soil data of four periods in 1982 (the second soil census), 1998, 2008, and 2018, geostatistic and Kriging interpolation methods were used to analyze the spatio-temporal variation characteristics of topsoil organic matter (SOM), total nitrogen (TN), available potassium (AK), and available phosphorus (AP) in Zong′ ai Town of Shouyang County, Shanxi Province. Combined with the center of gravity model, the center of gravity migration direction of nutrients was explored, and the spatio-temporal variation patterns of the soil nutrients and their influencing factors were revealed during the period of 1982—2018 in Zong′ ai Township. The results showed that the average contents of soil SOM, TN and AP, AK increased by by 3.30, 0.19 g·kg-1 and 7.75, 53.13 mg·kg-1, with the increase rate of 26.92%, 26.39%, 131.80% and 70.31%, respectively, from 1982 to 2018. SOM and AP contents showed an increase-decrease-increase trend from 1982 to 2018, while AK and TN contents kept increasing. Compared with 1982, the block-base ratios of SOM, TN, AP, and AK increased in 2018, indicating that the nutrients of the four periods of time were jointly influenced by structural and non-structural factors (random factors) and the degree of influence by non-structural factors gradually increased, and the influence of anthropogenic activity interference became more significant. In 2018, the spatial distribution characteristics of SOM contents in the study area showed a pattern [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]

Reducing fertilizer-N rate, applying a nitrification inhibitor (NI), and incorporating straw are widely recommended to improve N use efficiency of crops and decrease N losses. A field 15N tracer study was conducted to compare their effectiveness on fertilizer-N fates during the maize growing season in Northeast China. The following six treatments were used: (1) no N fertilization (control); (2) 200 kg urea-N ha−1 (100%N); (3) 200 kg urea-N ha−1 and straw (100%N + S); (4) 160 kg urea-N ha−1 (80%N); (5) 160 kg urea-N ha−1 and NI (Nitrapyrin in this study) (80%N + NI); and (6) 160 kg urea-N ha−1, NI, and straw (80%N + NI + S). The results showed that the five N fertilization treatments yielded 16–25% more grain and 39–60% more crop N uptake than the control, but the differences among the five treatments were not statistically significant. Compared with the 100%N, 20% fertilizer-N reduction (80%N) decreased the 15N concentration in topsoil and plant pools but increased the proportion of plant 15N recovery at harvesting (NUE15N, 60% vs. 50%). Compared with the 80%N, NI co-application (80%N + NI) delayed soil nitrification and increased soil 15N retention at harvesting (52% vs. 36%), thereby decreasing NUE15N significantly. Straw incorporation decreased fertilizer-N retention in soil compared with NI co-application because it promoted NUE15N significantly. In conclusion, the results demonstrate that NI and straw additions are efficient strategies for stabilizing fertilizer-N in soils and potentially minimizing N loss; however, their effects on NUE15N vary and the related mechanism must be further clarified in long-term trials. [ABSTRACT FROM AUTHOR]

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]

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In order to study the deflection and deformation law of vertical shafts in deep and thick topsoil layer, the main and secondary shafts of Shandong Guotun Coal Mine are taken as the examples, and the wireline baseline method is adopted to carry out multi-period deformation monitoring. Based on the multi-period monitoring data, the dynamic information of shaft deflection was obtained, and combined with the geological conditions and mining activities, the temporal and spatial characteristics of shaft deflection and deformation were investigated to analyze the changes of the local parameters of the shaft, compare the differences in shaft deflection, and reveal the deflection and deformation law of the shafts in deep topsoil layer, which provides a reliable basis for demonstrating the mechanism of shaft deflection and the management of the shafts. The study shows that: the time characteristics of wellbore deflection in vertical wells affected by mining and grouting activities can be divided into three phases of “increasing-decreasing-stabilizing”, and the spatial characteristics are mainly manifested in that the bedrock layer is less deflected, while the topsoil layer shows a function-like significant change, and the dynamics of wellbore and its deflection in the topsoil layer are approximately equal, with the area of the largest wellbore deflection converging to the wellhead; the main and auxiliary wells are inclined to the northwest of the mining area and there is a difference in orientation. The overall inclination of the wellbore in the east-west direction accounts for more than 97%, while that in the north-south direction is only less than 20%, which is highly correlated with the working face direction in terms of the distance between the workings; the horizontal displacement of the deep topsoil layer triggered by the mining disturbance increases with the height of the wellbore, which is the main reason for the deflection of the wellbore.

Healthy soil is crucial for sustainable agriculture with soil microbiomes being key to soil health. However, comprehensive assessments of soil health and microbial community structures under different wheat yields have not been made. Therefore, soil samples were collected from wheat fields with differing yields at depths of 0-15 and 15-30 cm. The yields were categorized as low (Y1, 3.75 t·ha-1), medium (Y2, 6.00 t·ha-1), high (Y3, 8.25 t·ha-1), and maximum (Y4, 10.1 t·ha-1), and soil health and microbial communities determined. The results showed that both yield category and soil depth significantly influenced SOC, TN, mineral nitrogen, AP and AK, enzyme activity, and soil bacterial communities. The soil health index in Y4 (0.51-0.87) was significantly higher than in Y3 (0.39-0.63), Y2 (0.27-0.45), and Y1 (0.21-0.52) at both 0-15 and 15-30 cm (expect Y1). Significant correlation was only found between soil health index at 0-15 cm and wheat yield, not at 15-30 cm. The bacterial and fungal network structure in Y4 was more complex and densely connected. Actinobacteria, Thaumarchaeota, and Ascomycota were identified as key drivers of soil health. Based on these results, the regulation of microbes has the potential to improve soil health and crop yields. [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.

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]

A four-step dividing algorithm of sampling points for artificial neural networks is presented to select a representative training subset for modelling the spatial distribution. The chromium and manganese contents in the topsoil in Tarko-Sale and Noyabrsk cities (Russian subarctic zone) were used as raw data. The spatial distributions of the content of elements in the topsoil layer were performed using a multilayer perceptron (MLP) with sigmoid and hyperbolic tangential activation functions. The root means squared error (RMSE) was calculated for each element content and area. The MLP with hyperbolic tangential activation function showed better accuracy for both subarctic cities and model areas. For Noyabrsk, the model with a hyperbolic tangent was about 10% better. For Tarko-Sale, the improvement of RMSE was around 200%. We have identified three classes of points: «elite», «middle», and «useless». Given this information when dividing the raw set, the accuracy of the models will increase. [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]

The main aim of this study was to assess the amount of carbon (C) stored in the upper 30 cm layer of mineral soils in eucalypt plantations in Portugal, with a Mediterranean-type climate. Soil sampling data (2468 samples), field evaluations (soil profile description) and relevant information on the particle size distribution, climate, bedrock and reference soil group were accomplished. Bulk density per sample was assessed using pedo-transfer functions and soil C stock was estimated. The results showed an average of 41.2 t C ha−1 stored in the soil. In the northern regions of Portugal, the coldest and wettest areas of the country with better stand productivity, a higher soil organic carbon (SOC) is achieved (median SOC of 39.2 g kg−1 and soil C stock of 55 t ha−1) than in southern and inland regions, with a warmer and drier climate (median SOC of 15.2 g kg−1 and soil C stock of 28 t ha−1). The assessment of mean soil C stock per bedrock type revealed higher C stored in granites followed by conglomerates, coal shales and clay shales. Regarding soil type, the results showed a higher C stock in Cambisols, Leptosols and Fluvisols (>50 t C ha−1), whereas Regosols and Luvisols stored less, following the same trend presented for reference soil groups in Europe. Comparing the geographic distribution of the C stock in the upper layer of the mineral soils with the amount of C in eucalyptus stands (root and aboveground biomass—data from national forest inventory), the mineral soil pool can represent more than two-thirds of the total C stored in eucalyptus plantations in Portugal. Further studies should focus on the evolution of C stocks in eucalypt plantations during different stages of stand growth and under different management practices. [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]

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]

Background and Objective: Heavy metals are regarded as serious contaminants due to their toxicity, persistence in natural conditions, and ability to enter and accumulate (bioaccumulation and biomagnification) in food chains. The aim of this study was to investigate the concentrations of the heavy metals Pb, Cd, Cu, Zn, Cr, Fe and Ni in surface agricultural soils of the Miandoab landfill area. Materials and Methods: In this study, 57 soil samples were collected from a depth of 0-20 cm. After preparing and digesting in the laboratory, the samples were analyzed using a inductively coupled plasma spectrometer (ICP-OES). The Ecological Risk Potential Index (EPRI), Earth Accumulation Index (Igeo), Principal Components Test (PCA) Pearson's Correlation, Cluster Analysis, and One-T-test were utilized. Statistical processing was conducted using SPSS software. Results: According to the results of the single T-test, the average concentrations of Pb, Cd, Cu, Zn, Cr, Ni did not significantly differ from their background concentration in the soil (p≥0.05). A significant difference was pbserved only for Fe (p<0.05), indicating a geological origin for this element. The EPRI was within the low-risk range, with an average value of 46.95. PCA revealed that the first factor was positively associated with Cr, Pb and Fe; the second factor with Zn and Cu; and the third factor with Cd. Cluster analysis showed that Fe was predominantly influenced by natural resources. According to the land accumulation index, all metals, except Cu, were classified non-polluted or slightly polluted at stations 2 and 4. Conclusion: The origin of elements is related to both natural and human factors. Specifically, Cr, Pb and Cd are more likely to originate from man-made sources, while Fe primarily comes from natural sources. The decrease in the concentration of metals can be attributed to continuous and annual ploughing, inactivity of the landfill, biological absorption by crops, soil leaching and transporting to lower depths. [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]

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]

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]

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]

[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]

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]

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]

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.

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]

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 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]

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]

Assessment of subsoil corrosivity was conducted within the University of Cross River State, Calabar, Calabar Campus, Southern Nigeria. The study employed electrical resistivity methods. The results from vertical electrical sounding revealed that the topsoil of VES1 and VES3 was slightly corrosive at depths of 2.20m and 0.70m while that of VES2 and VES4 were practically non-corrosive at depths 0.60m and 1.00m. The electrical resistivity tomography across the VES2 and VES4 showed a low resistivity at horizontal distances between 5.0m and 10.0m at a depth of 3.75m, indicating very strongly corrosive. Other areas of the profile with resistivity from 19.0 Ώm to 38.0 Ώm at a depth of between 6.38m and 19.8m indicate moderately corrosive and 75.0 Ώm which is slightly corrosive. A resistivity of 148.0Ώm to >580Ώm at the top layer indicates practically non-corrosive at depths 6.38m and 19.4m. Hence, metallic pipes should be buried at depth 3.0m. [ABSTRACT FROM AUTHOR]