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Soil quality index (SQI) helps quantify management practices impacts on the soil, providing information for producers in decision‐making. Through evaluation in sugarcane areas, soil indicators were used to develop SQI to access and quantify the impacts of long‐term vinasse application on the soil. The treatments consisted of two soil types: clayey (490 g kg−1 clay) and sandy (80 g kg−1 clay) and two conditions: with (70 m3 ha−1 year−1) and without vinasse application for 10 years. Soil samples were collected in the 0‐ to 10‐cm, 10‐ to 20‐cm, and 20‐ to 30‐cm layers in each treatment. Four soil functions were developed to calculate SQI: root environment quality (REQ), air/water ratio (AWR), soil chemical quality (SCQ), and soil tolerance to erosion (STE). Twelve soil indicators related to soil fertility and aggregation/structure were used. The long‐term vinasse application increased water storage (32%–58% of soil porosity), sum of bases (11–19 mmolc dm−3) and aggregate stability index (41% vs. 78%) compared to without vinasse treatment in sandy soil. In the clayey soil, vinasse increased (p < 0.05) the REQ, SCQ, and STE functions by 10%, 14%, and 13%, respectively, besides not affecting AWR. The long‐term application of vinasse promoted greater benefits, proportionally, in the sandy soil, with increments (p < 0.05) of 30% in AWR, 25% in SCQ, and 27% in STE. According to the SQI, long‐term vinasse application increased the capacity of the clay soil to perform its functions by 8%, while it increased to the sandy soil was 22%. [ABSTRACT FROM AUTHOR]

Brazil's Fundão dam collapse is one of the world's largest disasters of tailing dam failures. Previous research has evaluated toxic metals and non-metals (Cd, Cr, Ni, Pb, As, Hg) in the same soil samples used in this study, and results have indicated that only Fe and Mn concentrations increased above the original baseline (Melo et al., 2023). Consequently, the present study's focus has shifted towards assessing and integrating changes in soil quality regarding chemical fertility and morphological, physical, and mineralogical attributes in the floodplains post-dam collapse. Soil samples from 0 to 0.2 and 0.2–0.4 m depths, and samples of Urochloa sp. were collected along ten transects, spanning 100 km perpendicular to the Doce River channel. This sampling strategy targeted specific landscape positions including areas affected by deposited iron tailings (DIT), soil tailing mixture (STM), and control soil (CS) devoid of iron tailing interference. Results showed no discernible alterations in Ca, Mg, K, and P concentrations in Urochloa sp., and the most severe negative impacts observed regarded the replacement of kaolinitic pre-disaster matrix for hematitic matrix, reduction in organic carbon, and the prevalence of sand and silt particles. These factors collectively contributed to triggering: (i) decrease in chemical fertility and cation exchange capacity and (ii) significant decline in physical quality, evidenced by increased density and reduced total porosity and macroporosity. Addressing these adverse effects would require the augment of organic matter levels and offset the dominance of the hematitic matrix in the DIT. Furthermore, it is imperative to decompact the DIT by mechanized or plant cultivation means. [ABSTRACT FROM AUTHOR]

Soil moisture is important in many hydrological and ecological processes. However, data sets which are currently available have issues with accuracy and resolution. To translate remotely sensed data to an absolute measure of soil moisture requires mapped estimates of soil hydrological properties and estimates of vegetation properties, and this introduces considerable uncertainty. We present an alternative methodology for producing daily maps of soil moisture over the UK at 2 km resolution ("SMUK"). The method is based on a simple linear statistical model, calibrated with 5 years of daily data from cosmic-ray neutron sensors at ∼ 40 sites across the country. The model is driven by precipitation, humidity, a remotely sensed "soil water index" satellite product and soil porosity. The spatial variation in the parameter describing the soil water retention (and thereby the response to precipitation) was estimated using daily water balance data from ∼ 1200 catchments with good coverage across the country. The model parameters were estimated by Bayesian calibration using a Markov chain–Monte Carlo method, so as to characterise the posterior uncertainty in the parameters and predictions. The approach reduces uncertainty by integrating multiple data sources, all of which have weaknesses but together act as a better constraint on the true soil moisture. The model explains around 70 % of the variance in the daily observations with a root-mean-square error of 0.05 m3 m−3, better than results from more complex process-based models. Given the high resolution of the inputs in time and space, the model can predict the very detailed variation in soil moisture which arises from the sporadic nature of precipitation events, including the small-scale and short-term variations associated with orographic and convective rainfall. Predictions over the period 2016 to 2023 demonstrated realistic patterns following the passage of weather fronts and prolonged droughts. The model has negligible computation time, and inputs and predictions are updated daily, lagging approximately 1 week behind real time. [ABSTRACT FROM AUTHOR]

Understanding the hydraulic properties of soil is essential to solve many management problems in agriculture and the environment. Water quality affects soil hydraulic conductivity. Soil hydraulic properties play an important role in nature's water cycle and are used as basic information in designing irrigation and drainage systems, hydrological issues, and soil quality assessment. In the current study, soil sampling is performed from different areas and its hydraulic conductivity was measured using the drop load method and then predicted using support vector machine (SVM) and least‐squares support vector machine (LSSVM) models. The model inputs were: soil texture (percentage of sand, silt, and clay particles), salinity (electrical conductivity), pH, sodium adsorption ratio, soil porosity, and bulk density and the output was soil hydraulic conductivity. Correlation coefficient, root mean square error (RMSE), mean bias error (MBE), and Nash–Sutcliffe efficiency (NSE) were used to evaluate the models and compare them. Based on evaluation criteria the best performance was obtained for random forest (RF) (R = 0.89, RMSE = 0.53, mean absolute error (MAE) = 0.54, and NSE = 0.72). Following RF, the SVM with (R = 0.69, RMSE = 1.32, MAE = 0.69, and NSE = 0.48) performed better than LSSVM model. [ABSTRACT FROM AUTHOR]

Amendment significantly improves soil structure and promotes crop growth. To combat soil degradation and low crop yields in facility agriculture, it is crucial to study the optimal application rate of amendments. This study analyzed the effects of biochar, vermicompost, and mineral-source potassium fulvic acid on the stability of aggregate structure, soil nutrient content, and tomato yield in cambisols, providing a theoretical basis for improving the soil quality of plastic greenhouses in Southern China. A pot experiment on tomato cultivation was carried out in yellow-brown soil in plastic greenhouses. The experiment included eight treatments: 1% biochar (B1); 3% biochar (B3); 5% biochar (B5); 3% vermicompost (V3); 5% vermicompost (V5); 0.1% mineral-source potassium fulvic acid (F1); 0.2% mineral-source potassium fulvic acid (F2); and the control condition without adding soil amendments (CK). The results showed that the biochar and vermicompost treatments effectively reduced soil bulk density and increased total soil porosity. Compared to the control, treatments with soil amendments significantly increased soil pH and had different effects on soil nutrients: F2 showed the most significant improvement in the content of available nitrogen, available phosphorus, and available potassium, with an increase of 133.33%, 834.59%, and 74.34%, respectively; B3 treatment had the highest increase in dissolved organic carbon (DOC), while B5 treatment had the highest organic matter content. Compared to the CK, the particle size of the biochar treatment was mainly 0.053~0.25 mm, while the V3, F1, and F2 mainly occurred with a particle size > 0.25 mm; and V3 has the best aggregate stability. Biochar, vermicompost, and mineral potassium fulvic acid can all promote tomato yield, with the F2 and V3 treatments having a yield increase effect of over 30%. Furthermore, Pearson's correlation analysis showed a highly significant positive correlation between geometric mean diameter (GMD) and mean weight diameter (MWD), water-stable macroaggregate content (R0.25), and a positive correlation between alkaline-dissolved nitrogen, available phosphorus, dissolved organic carbon content, and aggregate stability indicators. Adding 0.2% mineral-source potassium fulvic acid optimizes cambisols' properties, enhances aggregate formation and stability, boosts tomato yield, and shows great application potential. [ABSTRACT FROM AUTHOR]

Soil steam disinfection technology has significant advantages in preventing and controlling soil borne diseases, and is one of the important means to solve the problem of soil continuous cropping obstacles. The heat transfer characteristics of steam in soil are closely related to the specific physical parameters of the soil. The main physical parameters affecting the heat and mass transfer characteristics of Yunnan unique red soil were determined by drying method, pycnometer method, thermal probe method and Metastability plate method. The soil bulk density was 0.736 g/cm³, the soil moisture content was 26.2%, the soil particle density was 2.398 g/cm², the soil porosity was 69.3%, and the soil thermal conductivity was 0. 296 2 W/(m°C), the specific heat capacity of soil mass was 57.840 3 J/(kg. C). The research results provide preliminary experimental data support for subsequent soil steam disinfection experiments and the construction of heat and mass transfer simulation models. [ABSTRACT FROM AUTHOR]

The organic carbon sequestered by the world's mangrove forests plays a key role in the global carbon cycle and may be central to climate change mitigation. This is because mangroves typically exhibit high rates of net primary production and greater carbon sequestration capacity compared to terrestrial ecosystems. This study investigated the influence of selected soil physicochemical properties on the soil organic carbon (SOC) content of Rekawa mangrove forest, Sri Lanka. The effect of soil pH, salinity, conductivity, moisture content (%), bulk density, porosity, phosphate, and nitrate content on SOC was examined along an intertidal gradient. Results showed, SOC was positively correlated with salinity (r2= 0.74), conductivity (r2= 0.76), moisture content (r2= 0.76), porosity (r2= 0.92), and phosphate content (r2= 0.74) while SOC was negatively correlated with bulk density (r2= -0.92) across the entire intertidal zone. Generalised Linear Model (GLM) resolved SOC to be best predicted as a function of soil porosity and soil moisture content [Akaike Information Criterion (AIC): 142.04], with other soil properties modulating the results within some zones. Overall, the present study shows that specific consideration of soil physicochemical properties could allow improved estimates of total carbon stocks which are becoming increasingly important for carbon accounting and national inventories. [ABSTRACT FROM AUTHOR]

Background and aims: The Brachiaria sp. (synonymous with Urochloa) is one of Brazil's main grass species used in livestock production and has become the focus of breeding genetic programs to enhance its resistance to drought, flooding, and pests, as well as improving its palatability to animals. However, there is a limited understanding of how genetic breeding can affect the soil microbiome and its potential functions. Thus, this study aimed to investigate the impact of four different Brachiaria varieties on the soil prokaryotic and fungal communities, with focus on the N-cycle. Methods: We combined molecular techniques, such as quantitative PCR and amplicon sequencing, to target prokaryotic and fungal communities and traditional soil and plant chemical analyses. The treatments were composed of the varieties of B. brizantha cv. Marandu (BM), B. ruziziensis (BR), Brachiaria spp. cv. Ipyporã (BI), B. brizantha cv. BRS Paiaguás (BP) and control without plants. Results: Our findings revealed that all varieties improved soil porosity, P content, organic carbon, and potential functions as Chemoheterotroph, Aerobic-Chemoheterotroph, and Pathotroph-Saprotroph groups. Soil acidity, nutrient availability, and porosity were the main drivers of the microbial communities. The study also identified the ability of each variety to recruit microbial nitrogen-fixers and ammonia-oxidizers. Conclusion: We highlighted that Brachiaria varieties can favor soil microbial communities related to the release of nutrients, resistance to pathogens, and environmental stress. Also, the BI variety showed a higher potential to improve soil quality by increasing soil porosity and potential AMFs. Besides that, all varieties showed some potential to benefit intercropping and crop rotation systems. [ABSTRACT FROM AUTHOR]

The paper presents a detailed ecological investigation of mangroves (trees and palm) along Carigara Bay in Leyte, Philippines by comparing the diversity, vegetation structure, species composition, and indicator species among forest types (riverine and fringe) and zones (landward, middleward, and seaward/along water) as well as by examining their relationships with environmental variables. A total of 22 mangrove species, belonging to 12 families were documented wherein the most abundant was Sonneratia alba, followed by Nypa fruticans, then by Avicennia rumphiana. It was found that the diversity (Shannon-Wiener) of riverine mangroves (0.94 ± 0.07; 1.20 ± 0.04) was significantly higher than the fringe at the middleward and seaward/along the water (p < 0.001). In the fringe mangrove forests, the mangrove species Aegiceras corniculatum was associated with the middleward zone, and Camptostemon philippinensis, Aegiceras floridum, Rhizophora mucronata, Sonneratia alba, and Lumnitzera littorea were associated with the seaward zone, whereas landward zone of fringe and all the zones in riverine were generally associated by species with low to optimum salt tolerances such as Nypa fruticans, and Avicennia rumphiana as the most abundant. As well, a total of 14 mangroves have been identified as indicator species. Lastly, mangrove species can be generally classified as riverine and fringing based on the environmental factors explaining their distributions, and it has been found that soil porosity, water content, soil salinity, and distance from the sea or river's edge were the most significant environmental factors that determine diversity patterns. [ABSTRACT FROM AUTHOR]

Background Aim Methods Results Conclusions Imaging techniques of analysis in undisturbed soil samples are powerful tools for understanding soil properties and functioning. Although micromorphological analysis has always been applied for studying soil genesis, the modern 3D X‐ray Computed Tomography (CT) approach is mostly used in soil physical studies related to soil functioning and ecological services.In this study, we interpret ancient soil formation of the Late Pleistocene pedosedimentary archive of the Tlalpan sequence in the State of Tlaxcala in Central Mexico, based on soil and sediment porosity distribution in 2D and 3D.In order to interpret ancient soil formation based on the porosity distribution, we applied both micromorphological (2D) and CT (3D) analyses in undisturbed samples of each horizon of the Tlalpan sequence.Our micromorphological observations have shown that pore space arrangement is unique for each soil horizon and that it is predetermined by the dominant pedogenetical processes and their succession, such as bioturbation, clay illuviation, and vertic shrinking/swelling. Most of the channels formed by biogenic agents (roots and mesofauna) subsequently underwent shape deformations and/or refilling. The “accommodating planes” type of voids resulted from the development of features of vertic paleosols that, in some cases, erased the past pedogenic pore space organization. Although biogenic turbation, compaction, and clay illuviation mostly affected the macro‐ and mesopores, shrinking/swelling processes affected macro‐ and mesoporosity distribution. The process that was only reflected at the microporosity level is hydroconsolidation.Despite the common idea that textural pores are more resistant to changes compared to meso‐ and macropores, most of soil formation processes registered in the Tlalpan sequence, including anthropogenic impact, were identified in macro‐ and mesopore space. Moreover, the changes that were registered in pore space transformation by 2D and 3D methods of analysis in undisturbed samples are crucial for identifying the sequence of formation processes and, therefore, for paleopedological interpretation. This study shows that the CT is a useful tool to access the soil formation, and pore space memory studied both in 3D and 2D is an important proxy for paleopedological research. [ABSTRACT FROM AUTHOR]

This study aims to assess the extent of hydrocarbon and heavy metal contamination in soils from specific areas on Azerbaijan's Absheron Peninsula, including Absheron, Suraxanı, and Baku, and to evaluate the impact of this contamination on soil properties. Soil samples were analyzed for Total Petroleum Hydrocarbons (TPH) and heavy metals, including aluminum, arsenic, cadmium, lead, and iron, alongside assessments of soil physical, chemical and biological properties. The results revealed significant contamination across all studied areas, particularly in Suraxanı, where TPH levels reached 190 ± 20 mg/kg, exceeding the environmental standard of 100 mg/kg. Similarly, Suraxanı soils exhibited alarmingly high concentrations of heavy metals, with aluminum at 30,128 ± 1,500 mg/kg, arsenic at 50.94 ± 2.5 mg/kg, and cadmium at 0.153 ± 0.01 mg/kg, all surpassing acceptable limits. These contaminants severely degraded soil health, evidenced by increased bulk density (1.7 g/cm³ in Suraxanı) and reduced soil porosity. Microbial activity, a key indicator of soil fertility, was also markedly lower in contaminated regions, with the total bacterial count in Suraxanı being less than half that of the uncontaminated area. The findings underscore the urgent need for comprehensive soil management practices and stricter environmental regulations to mitigate contamination's adverse effects and protect both ecosystems and public health in Azerbaijan's petroleum contaminated areas. [ABSTRACT FROM AUTHOR]

Sugar beet (Beta vulgaris L.) is a globally significant crop, valued for its economic importance in sugar production. Saline‐sodic soil environments negatively impact sugar beet productivity. This study investigates the effects of using compost, glauconite enriched‐K and their combinations in mitigating the saline‐sodic soil environment, sugar beet productivity and extracted sugar quality. A two‐season field experiment in split‐plot design with the main plots is three doses of compost: control (C0), recommended (100%) dose (C1) and 150% recommended dose (C2). Each group divided into four subplots of glauconite treatments arranged according to the recommended dose of potassium (K) as follows: G0 (no glauconite), G1 (50% K), G2 (100% K, 480 Kg glauconite Fed−1) and G3 (150% K). The results showed that compost and glauconite mitigated adverse soil effects caused by salinity and sodicity. The C2G3 treatment reduced electrical conductivity (EC) and exchangeable sodium percentage (ESP), improved organic matter and enhanced soil bulk density, porosity and penetration resistance. This combination also increased soil nutrients (N, K, Fe, Mn, Zn and Cu). Regarding the sugar beet yield, C2G3 improved root yield, top yield, sugar yield and extracted sugar. The application of glauconite increased root diameter by 20% and root length by 23%, enhanced sugar quality with minimal sugar losses to molasses (2.43%), and reduced impurities of K, α‐amino N and Na. Principal component analysis showed positive correlations between root yield and soil potassium, organic matter, cation exchange capacity and soil porosity, with negative correlations to bulk density, EC, pH and ESP. Two‐way analysis of main (ANOM) illustrated significant effects of compost and glauconite on soil–plant interactions. Multivariate analysis indicated that higher glauconite doses significantly enhanced root yield. The Gag run charts confirmed that compost (100%) and G3 levels explored more homogeneity reducing the ESP%, increasing sugar beet root yield, sugar yield and quality. [ABSTRACT FROM AUTHOR]

[Objective] The aims of this study are to clarify the characteristics and influence of soil water content, soil porosity, soil nutrients and the flue-cured tobacco quality in the condition of different dosage of water retaining agent (Potassium polycalcium), to apply the important supply to relieve drought and enhance the quality of the tobacco. Methods] The random-groups design and the condition of different dosages of water retention agent were adopted to measure the indices of soil water content. soil nutrients and tobacco. quality. [Results] As the dosages of water retention agent increased the soil pH value changed from 7.4 το 7.7. total porosity, capillary porosity, soil saturated water content field capacity, capillary water content first increased then decreased. when the dosage of water retaining agent reached to 150 kg/hm, the value of soil bulk density reached to the lowest value. However, the values of total porosity, capillary porosity, soil saturated water content and capillary porosity reached to the highest values. The value of CEC showed fluctuated changes. With the increased of the dosages of water retention agent, the soil organic carbon, soil total potassium available potassium first increased then decreased. However, the total nitrogen, total phosphorus, alkali hydrolyzed nitrogen and available phosphorus showed the increasing trends. But the bulk density first decreased then increased. The chlorine and total nitrogen of the tobacco leaves showed the trends of the upper leaves < the middle leaves < the lower leaves, and as the concentrations of the water retention agent increased, the content of the chlorine of the tobacco leaves showed the fluctuating change. The potassium of middle and upper leaves of the tobacco leaves were higher than that of the lower leaves. And it increased as the concentrations of the water retention agent increased. The content of nicotine changed as the order: the upper leaves the middle leaves the lower leaves, and there existed the weak correlation between nicotine and the concentration of the water retention agents. The reducing sugar and total sugar showed the similar change trends. The ratio of potassium and chlorine changed as the order: the upper leaves > the middle leaves > the lower leaves, and showed the fluctuating change trends as the concentration of water retention agent increased. However, the ratio of nicotine and total nitrogen and the ratio of sugar and alkaline. showed the order: the upper leaves < the middle leaves < the lower leaves, and the two ratios increased as the concentration of water retention agents increased. Meanwhile, there existed the significant positive correlation between the soil total nitrogen and the chlorine contents, the potassium of the upper leaves, the reducing sugar (p<0.05). Also there existed the significant positive correlation between the soil organic carbon and the chlorine contents, the reducing sugar the potassium of the upper leaves, the nicotine of the lower leaves (p<0.05). [Conclusion Above all, the dosage of 150 kg/hm' is considered as the best dosage to soil amelioration in southwest China. Also this study can supply the basis and data supports to the anti- drought ability and enhance the flue-cured tobacco quality. [ABSTRACT FROM AUTHOR]

The main goal of the study was to establish the influence of various tillage systems on the agrophysical properties of dark-chestnut soil under short-grain crop rotation in the irrigated conditions of southern Ukraine. The research was carried out during 2021-2022 in a stationary experiment on a four-field crop rotation: grain maize - winter rapeseed - winter wheat - soybeans. The experimental field was in the semi-arid steppe climate zone at the Institute of Climate-Smart Agriculture of the National Academy of Agrarian Sciences of Ukraine. Three tillage systems were studied for their influence on soil bulk density, porosity, and water permeability, namely: mouldboard-differentiated ploughing tillage; differentiated chisel tillage; and differentiated ploughless tillage with soil slitting. Soil bulk density was determined using the core method. Soil porosity was calculated as the ratio of total bulk density to solid fraction bulk density. Water infiltration rates, established through the water absorption test method, were used to measure soil water permeability. The results of the study were statistically analysed using the common ANOVA procedure with Fisher's least significant difference test at P<0.05. In addition to the agrophysical parameters of the soil, the energy output of the crop rotation was assessed. It was established that mouldboard tillage did not provide significant benefits in terms of bulk density and soil porosity. However, ploughing showed the best results for soil water permeability across all crops in the rotation. The highest energy output of crop rotation (119.1 GJ/ha) was recorded for the ploughless-differentiated tillage system with soil slitting, whereas the mouldboard ploughing and chisel tillage systems produced somewhat lower energy yields of 112.0 and 108.6 GJ/ha, respectively. Therefore, ploughless-differentiated tillage with soil slitting is the most effective option for short-grain crop rotations in irrigated conditions of southern Ukraine, in terms of creating optimal soil agrophysical properties and achieving the highest crop productivity. [ABSTRACT FROM AUTHOR]

Mountain red soil, as a special type of soil in the South, has received widespread attention for its soil erosion problems. Its pore structure restricts water infiltration, thereby affecting the occurrence and development of soil erosion. In order to systematically obtain the distribution characteristics of the pore structure within the surface mountain red soil, this paper uses non-destructive CT detection technology to scan the soil column samples taken from the typical mountain red soil distribution area in Chenggong District, Kunming City, Yunnan Province. Image processing technology is applied to CT slices, and ImageJ (1.46r) software is used to obtain the distribution characteristics of pores within the soil column, including pore sizes and the number of pores at each depth, the proportion of pore area, roundness, and box-counting dimension. The results show that with the increase in depth, the proportion of pore area decreases linearly from the maximum value of 52.25% at the top to the minimum value of 2.02% at the bottom; the roundness of pores fluctuates between 0.8 and 0.9, overall increasing; the total number of pores generally first increases then decreases, and small pores are predominant, with the least number of large pores in the topsoil layer; the box-counting dimension shows a gradual linear decrease, with a maximum value of 1.7980 and a minimum value of 0.9878. The number of pores affects both roundness and the box-counting dimension, and the proportion of pore area also affects the box-counting dimension. There is a negative correlation between roundness and the box-counting dimension. The 3D visualization reconstruction of pores shows that most are interconnected, with the pore size significantly reducing with increasing depth. The quantitative analysis of parameters and 3D visualization reveal, to some extent, the impact of pore structure on the occurrence and development of soil erosion in mountain red soil. These research findings form the foundation for studying soil erosion in this region and provide a basis for systematically understanding its processes and mechanisms. [ABSTRACT FROM AUTHOR]

Land‐use conversion profoundly influences the soil pore structure, consequently modifying the soil functions. Investigating the variation of multiscale soil pore structure and their associated functions following land‐use change is critical for evaluating land management strategies. However, this topic has not yet been extensively explored in recent studies. In this study, the pore structure of soil following land‐use conversion was quantitatively investigated by multiscale X‐ray tomography. Intact soil aggregates and undisturbed soil cores were collected from paddy fields (PF) and from vegetable fields were converted from paddy fields for 5 years (VF‐5), 13 years (VF‐13), and 20 years (VF‐20), respectively. Results revealed that the connected porosity of both aggregates and soil cores was significantly increased after land‐use conversion. The isolated porosity of soil aggregates increased, while, conversely, it decreased for soil cores. The variance in pore structure was attributed to the development of new pores, including channels created by vegetable roots, fissures, earthworm holes, and packing pores resulting from the decomposition of soil organic matter and the rearrangement of soil particles. The altered pore structure influenced the soil exchangeability and reservation ability. For aggregates, the isolated porosity of PF and VF‐5 accounted for over 70% of the total imaged porosity. These aggregates displayed a larger water and carbon reservation ability, but limited exchangeability of air, water, and nutrients. The isolated porosity of VF‐13 and VF‐20 aggregates accounted for approximately 50% of the total imaged porosity, suggesting they could effectively balance the exchange and storage of air, water, and nutrients. As for soil cores, isolated pores became negligible (<0.2%) following land‐use conversion, leading to the emergence of a drainable pore system suitable for vegetable plantation. These findings offer insights into the development of pore structures and the prediction of soil function variations at multiple scales, both of which are crucial for optimizing soil management protocols. [ABSTRACT FROM AUTHOR]

Purpose: Chemical immobilization using hydroxyapatite (HAP) is a cost effective and environmentally sound strategy for remediating lead-contaminated soils, such as shooting range soils. Understanding the combined impact of soil chemical and physical properties on enhancing the formation of pyromorphite, a lead-insoluble phase, is crucial for mitigating environmental risks associate with contaminated soil. This study aimed to elucidate the relationship between percolation velocity and lead leaching as well as pyromorphite transformation to optimize pyromorphite formation in water-unsaturated soils. Methods: Two up-flow suction percolation tests were performed: one varying percolation velocity with soil porosity achieved by incorporating clay minerals, and the other varying percolation velocity while keeping soil porosity constant. Results: Application of HAP substantially suppressed lead leaching in both percolation tests. Enhanced pyromorphite formation was observed with higher percolation velocities relative to soil porosity. Pyromorphite formation was more pronounced at lower percolation velocities compared to higher velocities at equivalent soil porosity level. The percentages of lead formed as pyromorphite in HAP-treated soil were higher than those of lead leached in non-HAP-treated soil among the lower percolation velocities. Conclusions: This study provides experimental evidence indicating pyromorphite formation is favored in soils with lower percolation velocities and higher soil porosities. Therefore, considering both soil chemical and physical properties is essential for understanding immobilization mechanisms in contaminated soils. [ABSTRACT FROM AUTHOR]

Rain‐induced landslides are common natural disturbances in forested headwaters that can strongly alter the spatial distributions of hydrological and environmental features. Although many studies have reported the impacts of landslides on the spatial patterns of soil moisture or their environmental controls, studies that have used detailed in situ data sets collected at the same location before and after a landslide are lacking. This study investigated the spatial distribution pattern of the near‐surface soil moisture and environmental controls, including topographic, soil and vegetation features, in a headwater catchment using ground‐based measurements with high spatial resolution after a landslide in 2016. The data set was compared to measurements taken at the same location before the landslide to explore whether the landslide altered the amount, spatial distribution, or potential controlling factors of near‐surface soil moisture. The mean soil moisture decreased across the site after the landslide, even under conditions of greater rainfall input than before the landslide. Spatial variation in soil moisture decreased in the high‐disturbance area but increased in the low‐disturbance area, although autocorrelation distances of soil moisture changed little. The relationships between the spatial mean and standard deviation of soil moisture markedly changed from a convex‐upward shape to a convex‐downward shape in the highly disturbed area. This indicates that the spatial mean of soil moisture exhibited its greatest spatial variation under moderate conditions before the landslide, with the lowest spatial variation occurring after the landslide. Most of the same controlling factors (i.e., slope gradient, topographic wetness index, vegetation density, soil porosity and saturated hydraulic conductivity) were explored after the landslide, but their influence levels greatly decreased or even disappeared. Thus, the landslide weakened the spatial connectedness between soil moisture and environmental features, which has not yet been restored 6 years after the landslide. We suggest that the connectedness between hydrological responses and environmental features is crucial for restoration. Their connectedness can serve as an indicator to identify the stage of ecological succession from the disturbances of a landslide. [ABSTRACT FROM AUTHOR]

With the world's population expanding rapidly, modern agriculture is evolving at a swift pace, leading to a significant increase in food production, primarily through the use of chemical fertilizers. However, this heavy reliance on fertilizers has led to issues such as soil compaction and decrease of earthworm abundance. Herein this study reports a smart soil consisting of conventional soil and carbon dots (CDot) based smart material which is capable of automatically adjusting its porosity and soil aggregate size. Due to the responsiveness, The CDot‐based smart soil can lift its height up to 150% upon humidity stimulation due to the increased porosity which is similar to the effect caused by earthworms. Based on this effect, this smart soil can increase the growth rate of maize seedlings by 40%, thus showing great potentials in agriculture. [ABSTRACT FROM AUTHOR]

Particle density (ρs) and bulk density (ρb) are key factors in the calculation of total soil porosity. However, direct measurements of ρs and ρb are labour‐intensive, time‐consuming, and sometimes impractical. Pedotransfer functions (PTFs) provide alternative methods for indirect estimation of ρs and ρb. In this paper, the accuracy of typical 12 ρs and 9 ρb PTFs was evaluated using easily measurable soil properties (sand, silt, clay, and soil organic matter (SOM) content) from granitic residual soils collected from six study areas in subtropical China, and the accuracy of PTFs constructed based on multiple linear stepwise regression (MSR) and machine‐learned algorithms (backpropagation neural network, k‐nearest neighbour algorithms, random forests, support vector machines, and gradient boosted decision trees) was compared to determine the accuracy of PTFs. The results show that typical PTFs have poor accuracy (R2adjusted < 0.020) and are not applicable to the indirect estimation of ρs and ρb in granitic residual soils. The PTFs constructed by machine learning algorithms all performed better than MSR, with the highest estimation accuracy of the PTFs constructed by the random forest algorithm, with R2adjusted values of 0.923 and 0.933 for the ρs and ρb PTFs, respectively, and root‐mean‐square error of 0.020 g·cm−3 and 0.023 g·cm−3, respectively. Compared with MSR, the random forest algorithm has greater accuracy and eliminates the restriction of PTFs on predictors, which provides support for understanding the changing rules of ρs and ρb in granite residual soils in subtropical regions, evaluating soil quality and improving soil structure. [ABSTRACT FROM AUTHOR]

Straw return is an effective measure to increase soil sustainability. However, few studies have examined the effects of different straw return methods on soil structure, soil organic carbon content and maize yield or the potential relationships between those variables. Therefore, we developed a field orientation experiment to study the effects of different straw return methods on soil porosity, soil aggregate stability, the soil organic carbon content and maize yield. Four treatments were established: flat no-tillage with full straw mulching (FM), ridge no-tillage with full straw mulching (LM), rotary tillage with full straw incorporation (LX), and conventional tillage without straw (CK) as the control treatment. Compared with those of the CK treatment, the soil porosities (f) in the FM, LM and LX treatments significantly increased by 6.7%, 8.8% and 7.9%, respectively; the soil aggregate destruction rates (PAD) decreased by 17.3%, 34.3% and 16.9%, respectively. In addition, the FM, LM and LX treatments effectively increased the mean mass diameters (MWDs) of the soil aggregates and the soil organic carbon content. Compared with those in the CK treatment, the three-year average yields in the FM, LM and LX treatments significantly increased by 5.2%, 7.2% and 4.1%, respectively. Moreover, the f, MWD, soil organic carbon content and corn yield were positively correlated. Our study indicates that the LM treatment was most effective in improving soil structure and increasing soil organic carbon content with corn yield. [ABSTRACT FROM AUTHOR]

Soil porosity and moisture are critical indicators of soil quality. In coal–grain intercropping areas, centuries of coal industry activities have resulted in coal particle contamination, which has affected soil properties; however, its impact on soil porosity and moisture remains underexplored. This study compares coal-contaminated soils (CCS) and coal-free soils (CFS) in Jiaozuo, employing computed tomography (CT) scanning and moisture measurements to analyze how coal pollution influences soil porosity and moisture. Our findings indicate that CCS, compared to CFS, exhibit significant reductions in total porosity (TP), CT-measured porosity (CTP), number of pores (CTN), and the proportion and volume of water–air regulating pores (CTNWA/CTN and CTPWA). These results underscore that coal pollution substantially alters soil porosity and pore numbers. Additionally, coal pollution modifies soil pore morphology, leading to reductions in the number and length of pore throats (Nthroat and Lthroat) and causing the pores to become more flattened and rounded, with an increased inclination angle of interconnected pores (IAic). As coal pollution levels increase, interconnected porosity (Pic) and coordination number (CNic) decrease, while isolated porosity (Pisolated) increases. In terms of moisture parameters, coal pollution diminishes the maximum water holding capacity, soil permanent wilting point, saturated hydraulic conductivity, and moisture evaporation rate. In contrast, field water-holding capacity and maximum effective water content are enhanced. Furthermore, with increased coal pollution, maximum water holding capacity, soil permanent wilting point, and saturated hydraulic conductivity decreased, whereas field water-holding capacity and maximum effective water content increased. Correlation analysis reveals that changes in CTN, Nthroat, and Lthroat significantly influence moisture parameter variations, with most pore parameter changes affecting saturated hydraulic conductivity. The observed effects of coal pollution on soil pore parameters are attributed to the filling and clogging actions of coal particles, while its impact on moisture parameters primarily results from these particles filling and clogging soil pores. This study provides a scientific basis for managing soil moisture in areas affected by coal pollution, particularly in coal–grain intercropping regions. [ABSTRACT FROM AUTHOR]

This review aims to demonstrate how biochar, derived from agricultural wastes can improve soil physical and chemical properties, reduce greenhouse gas emissions, and contribute to increased agricultural productivity and long-term sustainability. In this review, we analyze the effects of biochar on various soil parameters, including soil bulk density, soil porosity, microbial activity, nutrient content, cation exchange capacities, pH, water holding capacity, and infiltration rates. The results highlight the practical importance of utilizing biochar to improve soil physical and chemical properties. Additionally, the results show that biochar is a practical strategy for improving the growth and yield of crops and reducing greenhouse gas emissions. It can be concluded that biochar can significantly contribute to sustainable agriculture and food security in Jordan by improving soil health, enhancing water retention, and mitigating salinity. [ABSTRACT FROM AUTHOR]

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Poplars are crucial for timber supply and ecological protection in China. Enhancing the growth of poplar plantations and improving soil fertility in arid, and semi-arid poor soil regions are key aspects of sustainable forest management. Fertilization (FTL) and drip irrigation (DI) are among the most widely used methods globally for increasing yield and soil productivity. This study conducted field experiments on FTL and DI in a 10-year-old Populus × canadensis 'Zhongliao 1' (cultivation varieties of P. canadensis in northern China) plantation. DI limits were set according to soil moisture at 60% (S1), 70% (S2), and 80% (S3) of field capacity; nitrogen FTL rates were set at 100% of the baseline fertilization amount (100% BFA, N 643.20 g·year−1, P 473.37 g·year−1, and K 492.29 g·year−1) (F1), 70% BFA (F2), 130% BFA (F3), and 160% BFA (F4). The treatments of drip irrigation and fertigation (DIF) were H1 (100% BFA, 60% FC), H2 (100% BFA, 80% FC), H3 (160% BFA, 60% FC), and H4 (160% BFA, 80% FC), along with a control group (CK) without any management, totaling 12 experimental combinations. The results showed that the H4 had the most significant promoting effect on the height, DBH, and volume increments. All treatments had little effect on the soil bulk density of the plantation but significantly impacted soil capillary porosity and pH. Compared to DI, soil nutrient and organic matter content were more sensitive to FTL. Appropriate FTL and DI can increase soil sucrase activity. Soil urease activity tended to increase with higher FTL rates, and higher DI levels also positively influenced urease activity. Excessive or insufficient soil moisture and nutrients negatively impacted soil cellulase and catalase activities. Correlation analysis revealed no significant correlation between the growth of P. × canadensis 'Zhongliao 1' and soil nutrient content, but significant or highly significant correlations existed between growth and soil porosity and related enzyme activities. Comprehensive evaluation using a membership function indicated that high FTL levels (F4) were more conducive to the simultaneous improvement of the growth and soil fertility of the plantation, followed by H4 and F1, suggesting that high FTL is the key factor affecting the growth of 10-year-old P. × canadensis 'Zhongliao 1' plantations and the restoration of stand productivity, with moisture being secondary. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To study how the soils, respond to an earthquake, seismic waves are frequently utilized. The purpose of this work is to build the porosity graphs based on the geotechnical parameters of the soils and forecast the porosity of shallow clay soils using seismic wave velocities that analyze the dynamic features of the soil. Compressional (P) and shear (S) wave velocities, seismic velocity ratio, Poisson ratio, bulk modulus, and shear modulus are the factors used to calculate porosity. In this work, porosity values are calculated using grain and dry densities of core samples taken from different boreholes within the study region, and bulk modulus, shear modulus, and Poisson ratio are calculated using P- and S-wave velocities obtained by utilizing the seismic-refraction method, as well as porosity values. The research region is in Iran; Isfahan Metro Line 2 and mostly consists of clay, silt, sand, and gravel deposits. Based on the values of the Poisson ratio, seismic P-wave velocity, seismic velocity ratio (Vp/Vs), and the stiffness of the clay soils, the data of the clay soils in the region were individually sorted. These characteristics were used to create novel multi-parameter relationships between clay soil porosity, seismic velocities, shear modulus, and the Poisson ratio. Using the error norm approach, the errors in the parameters utilized for each relationship were identified. The error norm technique's findings show that the shear wave velocity and shear module have the lowest error when calculating porosity. Therefore, it is advised to estimate porosity of shallow clay soils using the given correlations. These relationships can be used to assess the porosity of clay soil and to determine if the soil's pores are saturated with liquid. [ABSTRACT FROM AUTHOR]

In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River, this study selected the Xiazangtan super large scale distribution area in Jianzha County as the study area. Through experiments and numerical simulations, plant roots characteristics, soil physical properties and infiltration characteristics of naturally grazed grassland and enclosed grassland with different slope directions were compared and analyzed, and the influence of rainfall on seepage field and stability of the two grassland slopes were discussed. The results show that the highest soil moisture infiltration capacity (FIR) is found on the shady slope of the enclosed grassland (2.25), followed by the sunny slope of the enclosed grassland (1.23) and the shady slope of the naturally grazed grassland (-0.87). Correlation analysis show that soil water content, root dry weight density, total soil porosity, number of forks and root length are positively correlated with infiltration rate (P <0.05), whereas soil dry density is negatively correlated with infiltration rate (P<0.05). The results of stepwise regression analyses show that soil water content, total soil porosity, root length and number of forks are the main factors affecting soil infiltration capacity. And the ability of roots to increase soil infiltration by improving soil properties is higher than the effect of roots itself. After 60 min of simulated rainfall, the safety factors of the shady slopes of naturally grazed grassland and enclosed grassland are reduced by 29.56% and 19.63%, respectively, comparing to those before rainfall. Therefore, in this study, the roots play a crucial role in regulating soil infiltration and enhance slope stability by increasing soil water content, soil total porosity and shear strength while decreasing soil dry density. The results of this study provide theoretical evidence and practical guidance for the effective prevention and control of secondary geological disasters such as soil erosion and shallow landslide on the slope of river banks in the study area by using plant ecological measures. [ABSTRACT FROM AUTHOR]

The implementation of unsuitable tillage practices has the potential to disrupt the structure integrity of the ploughed layer, as well as to influence the physical parameters of the soil. The application of a reasonable tillage method has been demonstrated to result in an improvement in the physical quality of the soil. Three autumn tillage practices have been implemented at the Dongyang Experimental Station of Shanxi Agricultural University since 2016: no-tillage with straw mulch (NTS), autumn rotary tillage with straw incorporation (RTS), and autumn plough tillage with straw incorporation (PTS). The impact of autumn tillage practices on soil physical quality in the 0-30 cm profile of spring corn fields was evaluated following the corn harvest in 2018 and 2019. The results showed that compared to the NTS treatment, the application of RTS was found to have decreased significantly by 9.6%-24.2% in soil bulk density, while it increased significantly by 12.8%-34.0% in total porosity and by 43.5%-146.4% in macroporosity at a depth of 5-10 cm. In comparison to the NTS treatment, the adoption of PTS was found to decrease significantly by 10.7%-30.5% soil bulk density, while it increased significantly by 9.9%-42.7% the total porosity and 23.1%-202.8% the macroporosity at a depth of 0-10 cm. Furthermore, the soil microporosity significantly increase of 7.5%-11.1% under the RTS treatment at the 0-5 cm soil depth and 7.7%-11.2% under the PTS treatment at the 10-20 cm soil depth. Soil physical quality index (SQI) significantly increase under the RTS and PTS treatments, with a 41.26% and 57.57% improvement, respectively, in comparison to the NTS treatment. In summary, the adoption of autumn tillage with straw return (RTS and PTS) demonstrated a reduction in soil bulk density, an increase in soil porosity, macroporosity, and a promotion of capillary porosity, and promoted the improvement of soil physical quality on the Eastern Loess Plateau when compared to no-tillage with straw mulch (NTS). [ABSTRACT FROM AUTHOR]

Soil erodibility (K) refers to the inherent ability of soil to withstand erosion. Accurate estimation and spatial prediction of K values are vital for assessing soil erosion and managing land resources. However, as most K-value estimation models are empirical, they suffer from significant extrapolation uncertainty, and traditional studies on spatial prediction focusing on individual empirical K values have neglected to explore the spatial pattern differences between various empirical models. This work proposed a universal framework for selecting an optimal soil-erodibility map using empirical models enhanced by machine learning. Specifically, three empirical models, namely, the erosion-productivity impact calculator model (K_EPIC), the Shirazi model (K_Shirazi), and the Torri model (K_Torri) were used to estimate K values. Random Forest (RF) and Gradient-Boosting Decision Tree (GBDT) algorithms were employed to develop prediction models, which led to the creation of three K-value maps. The spatial distribution of K values and associated environmental covariates were also investigated across varying empirical models. Results showed that RF achieved the highest accuracy, with R2 of K_EPIC, K_Shirazi, and K_Torri increasing by 46%, 34%, and 22%, respectively, compared to GBDT. And distinctions among environmental variables that shape the spatial patterns of empirical models have been identified. The K_EPIC and K_Shirazi are influenced by soil porosity and soil moisture. The K_Torri is more sensitive to soil moisture conditions and terrain location. More importantly, our study has highlighted disparities in the spatial patterns across the three K-value maps. Considering the data distribution, spatial distribution, and measured K values, the K_Torri model outperformed others in estimating soil erodibility in the plateau lake watershed. This study proposed a framework that aimed to create optimal soil-erodibility maps and offered a scientific and accurate K-value estimation method for the assessment of soil erosion. [ABSTRACT FROM AUTHOR]

To explore the spatial distribution characteristics of soil physical properties and soil erosion in sloping farmland with ridges in the black soil areas of northeast China, sloping farmland with ridges built with woven bags (RW) along the contour lines was selected as the research object, and another sloping farmland was selected as the control (CK). Soil samples were collected from both RW and CK at uniform spatial intervals to measure key indicators of soil properties in the surface layer (0–15 cm), including soil water-holding capacity, soil structure, and annual average soil loss (A). The results showed that: (i) RW exhibited a significantly higher overall field water-holding capacity compared to CK, with soil moisture characteristics more evenly distributed spatially. Soil bulk weight, fractal dimension, and soil aggregate destruction in RW were reduced by 1.09%, 0.65%, and 4.61%, respectively, compared to CK. Additionally, soil total porosity, capillary porosity, mean weight diameter (MWD), and geometric mean diameter (GWD) were more evenly distributed spatially in RW. (ii) On the up-slope, soil water content and DR>0.25 in RW had a higher increase than those of CK. On the mid-slope, soil field water-holding capacity, capillary porosity, MWD, and GWD in RW had a higher increase than those in CK. On the down-slope, RW had a 7.67–10.79% increase in soil water content, saturated water-holding capacity, field water-holding capacity, and capillary water-holding capacity compared to CK, with total soil porosity and soil capillary porosity increasing by 2.84% and 15.51%, respectively. (iii) Annual average soil loss (A) of RW was reduced by 61.85–99.64% compared to CK, based on the China Soil Loss Equation (CSLE). (vi) Soil water-holding capacity and soil structure characteristics of RW showed benefits compared to CK, with the benefits ranging from 1.01 to 1.09, while the benefit of A reached 2.46. This study is significant for understanding the spatial distribution of soil erosion on sloped farmland in black soil areas and for the effective application of soil and water conservation measures. [ABSTRACT FROM AUTHOR]

To clarify the influence range and saturation distribution after the biogas desaturation method is applied, a three-dimensional model is established with TOUGH2 software to analyze the effect of construction parameters such as grouting volume, grouting rate, grouting depth, nitrogen source concentration, and soil porosity. After that, the sensitivity of the parameters on the influence range is determined. The grouting volume and soil porosity are the most sensitive to the lateral and vertical influence range, respectively. This study provides a basis for the engineering practice of treating liquefiable subgrade by the biogas desaturation method. [ABSTRACT FROM AUTHOR]

The issue of interfacial shear damage has been a significant challenge in the field of geotechnical engineering, particularly in the context of diaphragm walls and surrounding soils. Polymer grouting is a more commonly used repair and reinforcement method but its application to interface repair and reinforcement in the field of geotechnical engineering is still relatively rare. Consequently, this paper presents a new polymer grouting material for use in grouting reinforcement at the interface between concrete and soils. The bonding characteristics and shear damage mode of the interface after grouting were investigated by the direct shear test, and the whole process of interface shear damage was investigated by digital image correlation (DIC) technology. Finally, the reinforcement mechanism was analyzed by microscopic analysis. The results demonstrate that the permeable polymer is capable of effectively filling the pores of soil particles and penetrating into the concrete-soil interface. Through a chemical reaction with water in the soil, the polymer cements the soil particles together, forming chemical adhesion at the interface and thereby achieving the desired reinforcement and repair effect. In the shear process, as the normal stress increased, the horizontal displacement and horizontal compressive strain at the distal end of the loading end decreased, while the maximum vertical displacement and maximum vertical strain of the cured soil also decreased. The results of scanning electron microscopy (SEM) demonstrated that the four groups of test polymers exhibited a reduction in soil porosity of 53.47%, 58.79%, 52.71%, and 54.12%, respectively. Additionally, the form of concrete-soil interfacial bonding was observed in the concrete-cohesive layer-cured soil mode. The findings of this study provide a foundation for further research on diaphragm wall repair and reinforcement. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil & Water Conservation (1009-2242) is the property of Institute of Soil & Water Conservation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Soil & Water Conservation (1009-2242) is the property of Institute of Soil & Water Conservation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: The influence of tropical fruticulture that was established in Amazonian dark earth was investigated by considering changes in soil physical and chemical properties. Soil samples were collected at two layers (0–0.1 and 0.1–0.2 m) under two dissimilar conditions: naturalized archaeological site (Amazonian dark earth) vs. tropical fruticulture. Material and methods: We evaluated soil texture (clay, sand, and silt contents), bulk density, soil porosity, soil resistance, carbon stock (C stock), soil moisture, geometric mean diameter, weighted average diameter, average diameter < 2 mm, average diameter > 2 mm, soil pH, exchangeable cations (Al3+, Ca2+, Mg2+, K+), potential acidity, soil organic carbon (SOC), and available P. Results and discussion: Our results emphasized the soil physico-chemical changes as influenced by tropical fruticulture in the Amazonian dark earth. The PCA and SEM showed that the tropical fruticulture had an overall negative effect on available P, Ca2+, GMD, soil aggregation, SOC, C stock, bulk density, and soil resistance. Conclusion: The results of our study highlighted the importance of considering the Amazonian dark earth as an archaeological site, and when necessary for food production, we must consider soil management practices to promote soil ecosystem avoiding soil quality loss. Thus, long-term experiments in the studied sites considering soil management may exploit different feedback among tropical fruticulture and the Amazonian dark earth. [ABSTRACT FROM AUTHOR]

The glomalin-related soil protein (GRSP) is an important component of soil organic carbon (SOC), which plays an important role in maintaining soil structural stability, soil carbon (C), and nitrogen (N) fixation. However, little is known about the GRSP content in soil and its contribution to soil nutrients in plantations of different tree species. In this study, we determined the soil physicochemical characteristics and GRSP contents in different soil layers of four kinds of plantations, including Acacia mangium (AM), Pinus caribaea (PC), Eucalyptus urophylla (EU), and Magnoliaceae glanca (MG), to address how the plantation types affected the GRSP in different layers of soil in southern China. The results showed that with an increase in soil depth, the GRSP content decreased linearly, and the contribution rate of GRSP to SOC and total nitrogen (TN) in deep soil was 1.08–1.18 times that in surface soil. The tree species significantly affected the vertical distribution of GRSP in soil. Among the four plantations, the conifer species PC had the highest level of GRSP, while the N-fixing species AM had the lowest level. However, SOC, soil capillary porosity (CP), TN, soil water content (SWC), and total phosphorus (TP) were important factors regulating soil GRSP content. Additionally, the regulation effects of soil properties on GRSP were various in surface and deep soil among different plantations. In order to improve soil quality and C sequestration potential, conifer species can be planted appropriately, or conifer species and N-fixing species can be mixed to increase soil nutrient content and enhance soil structure and function in afforestation of southern China. [ABSTRACT FROM AUTHOR]

In this subsection, a simulation model of underground pipeline leaks was created. Modeling the flow fields of overhead pipelines and underground pipelines with different soil porosity was conducted. The influence of the underground environment and soil porosity on the pipeline leakage field was analyzed. The influence of changes in the underground environment and soil porosity on the loss of kinetic energy at gas leakage was defined. Thus, the law of change in the characteristics of the sound signal of a leak on the pipe wall was obtained. Based on the results of study, it was determined the area of damage to a gas pipeline which is depended on proportionality of the diameter of the gas jet. As the gas is released from a crack in the gas pipeline and with different porosity of the pipe material, the gas diffusion occurred. As a result, the explosion zone increased which ultimately the release of gases into the environment under the influence of pressure increased. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse the physical quality of a Planosols in the semi-arid environment under integrated and conventional agricultural production systems after eight years of management and to observe if the physical properties of the soil under grazing respond differently to the production systems assessment. The experiment has been carried out since 2015 in Alagoinha, Paraíba, on a Planosols. The treatments were composed of: Urochloa decumbens + Ipê (BI); Ur. decumbens + Gliricídia (BG); Ur. decumbens + sabiá (BS); Ur. decumbens + milho (L) and Ur. decumbens (B). Soil samples were collected in 2022 in the 0-10, 10-20 and 20-30 cm depth layers to determine soil bulk density (Bd), total porosity (TP), macroporosity (Mac), microrosity (Mic) and saturated hydraulic conductivity (K0). The data was subjected to analysis of variance and principal component analysis (PCA) (p<0.05). The results showed that there was no difference (p<0.05) between the treatments evaluated, but BI and B showed considerable K0 on the surface 7.5 and 3.1 cm h-1, respectively. Mac was restrictive in all treatments in the 0-10 cm layer, with average values <0.10 m3 m-3. It can be concluded that the physical quality of the soil under grazing is the same between integrated and conventional (pasture) agricultural production systems after a period of eight years. [ABSTRACT FROM AUTHOR]

In the Cerrado Biom, a commonly used intercropping is between corn species and Urochloa, however, there are alternative grasses able to improve the corn intercropping, such as those of genus Panicum. Studies show that diversified crop rotation improves the efficiency of the agricultural system. Thus, it was aimed to evaluate the effect of the corn (Zea mays) and Zuri grass (Panicum maximum BRS Zuri) grown in the monoculture or intercropped under conditions with and without soil scarification in chemical and physical soil attributes. For this, an area under Red Oxisoil was used, in which part was scarified up to 30 cm deep and the other was not. In February 2020, corn and Zuri grass were planted in cultivar sole system or intercropped between the two species in compacted and scarified area, creating six evaluation areas. After the crop cycle, with corn harvest and Zuri grass crushing, soil sampling was carried out for evaluations at five points in each area. Corn in monoculture had lower soil moisture and greater resistance to penetration. And the soil without scarification had a higher C stock. The results showed that the Zuri grass using after soil revolving can be applied as a management strategy, looking to dry mass accumulation, bigger carbon stock and soil porosity, improving soil conditions for the summer crop. Besides that, the intercropped used improves the chemical soil conditions. [ABSTRACT FROM AUTHOR]

The article presents a study which assessed the spatial variations in soil textural fractions, bulk density and porosity of the lesser Himalayas in India. Topics include basic statistical values of the research area soil physical property data, reasons for the variation in soil characteristics, and computed semivariogram soil parameter characteristics.

Soil surface cover is one of the most critical factors affecting soil water vapor transport, especially in drylands where water is limited, and the water movement occurs predominantly in the form of vapor instead of liquid. Biocrusts are an important living ground cover of dryland soils and play a vital role in modifying near‐surface soil properties and maintaining soil structure. The role of biocrusts in mediating soil water vapor transport during daytime water evaporation and nighttime condensation remains unclear. We investigated the differences in vapor diffusion properties, vapor adsorption capacity, and water evaporation between bare soil and three types of biocrusts (cyanobacterial, cyanobacterial‐moss mixed, and moss crusts) in the Chinese Loess Plateau. Our results showed that the three types of biocrusts had 5%–39% higher vapor diffusivity than bare soil. At the same level of ambient relative humidity and temperature, the initial vapor adsorption rates and cumulative adsorption amounts of the biocrusts were 10%–70% and 11%–85% higher than those of bare soil, respectively. Additionally, the late‐stage evaporation rate of cyanobacterial‐, cyanobacterial‐moss mixed‐, and moss‐biocrusts were 31%–217%, 79%–492%, and 146%–775% higher than that of bare soil, respectively. The effect of biocrusts on increasing vapor transport properties was attributed to the higher soil porosity, clay content, and specific surface area induced by the biocrust layer. All of these modifications caused by biocrusts on surface soil vapor transport properties suggest that biocrusts play a vital role in reshaping surface soil water and energy balance in drylands. Key Points: Biocrusts increase water vapor diffusion properties, water vapor adsorption amount, and cumulative evaporation amountModified soil properties of biocrust are a key factor influencing water vapor fluxReshaped vapor transport properties of biocrust control soil water and energy balance [ABSTRACT FROM AUTHOR]

In order to cultivate large diameter timber of Phoebe bournei, we conducted a 3-year soil loosening experiment on Phoebe bournei middle-aged stands. The main findings are as follows: loosening the surface soil, causing a decrease in soil bulk density, which increases year by year over time; an increase in soil capillary and non capillary pores, which decrease year by year; an increase in the natural moisture content and maximum water capacity of the soil, and over time, the natural moisture content and maximum water capacity decrease year by year; the growth of stands is accelerated, and the diameter at breast height, tree height, and volume growth are significantly higher than those of forests without loose soil, and the larger the soil loosening area, the better the growth. For cultivating large diameter timber of Phoebe bournei, it is recommended to do soil loosening operation every 3-5 years. [ABSTRACT FROM AUTHOR]

The interface performance between clay–sand mixtures and concrete structures is governed by the mixture's composition and its physical properties. Moisture content and particle-size distribution play important roles in deciding the mixture's arrangement of soil particles, porosity, hydraulic conductivity and behaviour under various mechanical loadings. Application of a polymer interfacial coating can improve the bond performance between soils and concrete mainly via interfacial friction/mechanical interlocking. The present work analyses the development of interfacial strength between clay–sand mixtures and a polymer coating with changes in particle gradation. The multi-scale mechanisms at the interface are investigated, giving primary attention to soil porosity. A 50:50 clay–sand mixture exhibited a greater interfacial adhesive performance compared to other soil mixtures. In addition, the moisture-controlled pores and gradation-controlled pores demonstrated differences in macroscale interfacial strength. Both mercury intrusion porosimetry (MIP) and 129 Xe nuclear magnetic resonance (NMR) were utilized to detect the pore structure of the mixtures. 129 Xe-NMR revealed the pore distribution of the mixtures as ranging from macropores to nanopores, and MIP complemented the pore information by determining the critical pore entry diameter in the macropore regime. Mesopores dominated with increasing fine sand content until a threshold value was reached; thereafter, merging of pores occurred and macropores dominated. [ABSTRACT FROM AUTHOR]

[Objective) The purpose of the paper was to select the best planting mode suitable for improving the soil quality of tobacco-planting paddy soil, as well as the quality and efficiency of tobacco leaves, and effectively integrating flue-cured tobacco with diversified industries in Yunnan province. [Method] Using the flue-cured tobacco variety Yunyan 87 as material, a 3-year field experiment was conducted on paddy soil, and five treatments were set up: Flue-cured tobacco continuous cropping (TI, CK), 2-year alfalfa rotation-1-year flue-cured tobacco rotation (T2), 1-year alfalfa rotation-2-year flue-cured tobacco rotation (T3), flue-cured tobacco intercropping corn (T4), flue-cured to-bacco morchel rotation (T5), to explore the effects of planting patterns on soil physicochemical characteristics, soil microbial quantity, yield and quality of flue-cured tobacco. [Result] Compared with T1 (CK), soil bulk density decreased by 2.47% to 21.77% after rotation and in- tercropping, and soil porosity, cation exchange capacity, contents of organic matter, hydrolyzed nitrogen, available phosphorus and available potassium increased significantly, and soil water soluble chlorine had no significant change. Moreover, it could increase the content of large and medium particle size aggregates and improve the soil structure and stability. The number of fungi, bacteria and actinomyces in rotation and intercropping rhizosphere soil were significantly increased by 61.82%-176.4%, 13.0%-49.73% and 25.38% 130.05%, re- spectively. Meantime, the microbial biomass carbon, nitrogen and carbon nitrogen ratio increased by 13.81% 60.38%, 9.96% 52. 40% and 3.51% -5.48%, respectively. The leaf area, proportion of high-grade, yield and output value of tobacco were significantly increased, and output value of T2 and T5 was the highest, which were significantly increased by 43. 28% and 50.22% compared with T1 (CK), respectively. Compared with T1 (CK), the contents of total sugar, reducing sugar and oxides potassium in T2, T3, T4 and 15 were significantly increased by 13.96%-56.51%, 7.46% -27.91% and 40.76% 52.72%. The contents of total nitrogen and nicotine in tobacco leaf decreased by 4.13% 11.00% and 3.39% -16.41%. [Conclusion] The use of flue-cured tobacco-alfalfa' and flue-cured tobacco-morchella' rotation mode can improve soil fertility, soil permeability, aggregate structure and soil microbial community abundance, which is beneficial to increase tobacco yield and output value, and improve the coordination of tobacco chemical composition. [ABSTRACT FROM AUTHOR]

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The unsaturated permeability of cracked compacted fine soil is a key parameter in geotechnical engineering, particularly when analyzing water flow through the soil in various conditions. The compaction affects the saturated and unsaturated permeability by reducing porosity. However, cracks can appear by shrinkage and growth during desiccation, which obviously leads to macro-porosity (a process during which the soil acquires a high level of double porosity). The development of a crack network influences the suction (as negative water pressure) and then the unsaturated permeability. The current paper aims to analyze the role of the crack network (considered as macropores) on the unsaturated permeability, by quantifying the network based on the Crack Intensity Factor (CIF). The unsaturated permeability is given as a function, separately of CIF and suction. The experimental results may be considered constructive for soil modeling. Regarding the birth of the first crack, it occurred when the suction reached a value near to that of the air entry suction. Since the first crack appeared, primary cracks were developed and then followed by secondary cracks. The obtained experimental results of WRC and Kunsat for cracked compacted clay are beneficial in managing the design of the geotechnical structure stability and the environmental issues of water diffusion. CIF increases with suction, which is augmented during the drying process demonstrating a decrease in the moisture content. After 21 hours of desiccation, CIF ended up reaching a value of 4%. It is generally recognized that cracks create preferential pathways for water flow, whereas their geometry and distribution influence how water moves through the soil. Modeling the impact of cracks on permeability may involve considering factors like crack width, orientation, and connectivity. In this paper, a simple model was proposed to predict the unsaturated permeability as a function of suction with different CIF values with the material being assumed as a double porosity soil. [ABSTRACT FROM AUTHOR]