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Soil is an important reservoir of innumerable natural and biological resources fundamental to the sustainability of life and the earth's functionality. The soil is complex due to changing biodiversity, physicochemical characteristics, disturbances, and pedogenesis, which are constituent indices required for the measurement of its healthiness. Hence, there is a need to concertedly protect the soil by consciously promoting practices and behaviors that optimize its priority functions in delivering ecosystem services. It is further significant for crop yield, hence the need to pay more attention to its health. Soil healthiness is also a reflection of its capacity to support biogeochemical processes, abiotic communities, and plant and animal productions. However, agronomic studies, until recently, focused more on the use of chemical indicators in determining soil health, despite the versatile ecophysiological role of microorganisms in soil formation, resource cycling, and management. These biological phenomena expressed by soil microbial communities form the basis for the conversion of diverse organic matters into bioutilizable resources for plants' healthy development. This review, therefore, explored the underlining mechanisms, particularly climate change-related, that caused divergent soil properties and how this impacted the microbial composition of healthy soil. Likewise, several pieces of agronomic literature on the physical characteristics, ecological services, and functions of a healthy soil were compared toward innovative best management practices for improving soil health. [ABSTRACT FROM AUTHOR]

AbstractMineral weathering played a critical role in removing highly concentrated carbon dioxide (CO2) from the Precambrian atmosphere. Currently, it plays an important role in biogeochemical cycles and soil formation in terrestrial ecosystems. We aimed to fix CO2 by crystallizing carbonated minerals obtained from weathered rocks into calcium carbonate (CaCO3). In this study, we isolated a new Enterobacter bacteria (UT18) species from soil containing many rocks and plants by comparing the ability of the isolated bacteria to decrease pH. In combination with the results of high-performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP-MS), we demonstrated that UT18 participates in mineral weathering by secreting gluconic acid and acetic acid. These organic acids can release Ca, Al, and Si from anorthite. Traces of weathering on the anorthite surface were observed using scanning electron microscopy (SEM). The released Ca ions can be recrystallized by the addition of Na2CO3 into the formation of CaCO3 in the form of aragonite. Our study describes a new characteristic of acid production in UT18 and demonstrates an example of an H+-releasing pattern in microbial mineral weathering. This study will help elucidate the mechanism of microbial mineral weathering and can be applied to soil improvement and greenhouse effect mitigation. [ABSTRACT FROM AUTHOR]

The article reports on the discovery of megalithic tombs in the Ahlen-Falkenberger Moor in Germany. As part of a research project, three passage graves were examined, in which well-preserved elements of the burial constructions were found. Various burial activities of the Funnel Beaker Culture could be identified and dated. The excavations and scientific analyses provide insights into the complex architecture and use, as well as the environmental development around the megalithic grave Wanna 1592. Various identifiable phases are presented, including the construction of the monument, the burial level and activities in the entrance area, human impacts in the surroundings, destruction and sealing of the chamber, disturbance of the outer stone packing, and the disappearance in the bog. The text describes archaeological finds and soil analyses at a burial mound in Wanna. Two deposits were found, one outside the chamber and one inside the chamber, which can be dated to the Late Bronze Age. Ceramic fragments and flint artifacts were also discovered. The soil analyses show that the burial mound was built on a Luvisol surface, which has transformed into a Podsol outside the mound. Micro-morphological analyses were also conducted, revealing further details about the soil development. The article describes the results of an investigation of megalithic graves in Ahlen-Falkenberg, Denmark. It is noted that the graves have similar construction features and fit into the regional distribution of passage graves. It is speculated that the graves were built in a continuous working process, with social aspects playing a role in the choice and construction of the megaliths. The graves were likely built within a short construction period, and the materials came from the immediate surroundings. The graves were used during the Early Neolithic period and later abandoned in the Late Neolithic period. In Schleswig-Holstein, the entrance of a dolmen was destroyed in the Late Neolithic period. With the continuous rise of the bog water level, Wanna 1591 and 1592 were situated in wet contexts at the end of the Neolithic period, and Wanna 1588 at the latest in the EBA. Human activities increasingly focused on the higher Ahlen Geests, which included landscape clearances. The last practices were carried out during the transition from the Bronze Age to the Iron Age in Wanna 1588, when pottery vessels were placed between two capstones. In conclusion, it can be said that the megalithic landscape of Ahlen-Falkenberg has been well-preserved thanks to peat growth over the past thousands of years, providing insights into the original building elements and techniques, as well as burial practices of the FBC megaliths in the Neolithic period. Further excavations are necessary to clarify open questions. [Extracted from the article]

The results of a field study of the erosion–accumulative patterns of the soil cover of a key area in the zone of dark chestnut soils (Kastanozems) are presented, and the information content of multitemporal remote sensing data on the bare soil surface for its identification and mapping is analyzed. The site is located on the Millerovo–Morozovskaya inclined plain within the Don–Donetsk hilly-ridge plain, in Oblivsky district of the Rostov region. The soil cover of the key area is represented by a combination of low-contrasting soils on convex and concave surfaces within an elongated ridge and its slopes, including agro-dark chestnut solonetzic and nonsolonetzic soils, agrozems (washed away soils that have lost the middle-profile xerometamorphic horizon), and stratozems (aggraded soils). The development of this soil cover pattern is determined by a combination of mesorelief landforms and two types of soil-forming rocks. The map of the C coefficient of the multitemporal soil line reveals the heterogeneity of the soil cover related to the activity of erosion/deposition processes. In the key area, three groups of contrasting soil combinations differ significantly in the form of different variations and combinations-variations forming a kind of framework of the soil cover. Combinations of eroded and aggraded soils located between the above three groups of soil combinations significantly differ from their neighbors, but their interpretation has an increased uncertainty. [ABSTRACT FROM AUTHOR]

How to determine the unusual stratum load for metro tunnel under the influence of ground fissure is a major challenge faced by the construction of Xi'an Metro in China. In this paper, based on the theories of Bierbaumer and Terzaghi, a limit equilibrium form of stratum holding effect principle is proposed as an alternative solution for calculating the unusual stratum load experienced by metro tunnels crossing ground fissures at different intersection angles. Our methodology uses the movement mode of stratum-tunnel induced by active ground fissure to construct the analysis model, while considering soil properties and strength, holding force, tunnel buried depth, segment diameter, and the intersection angle between tunnel and ground fissure. Fundamental formulae for the development of soil fracture angle during this movement process are also derived and analyzed. The methodology is also illustrated and validated by two representative examples, and the sensitivity of parameters affecting the results is discussed as well, providing some design suggestions for practical engineering. The presented alternative way of calculating the unusual stratum load in the active ground fissure site might be helpful for the design of metro engineering to meet the necessary degree of safety. [ABSTRACT FROM AUTHOR]

The article presents an analysis of the thickness of humus horizons in chernozems and gray forest soils measured at more than a thousand survey sites on three plots with an area of about 10000 ha each in the northern (Orel oblast), central (Kursk oblast), and southern (Belgorod oblast) forest-steppe on the Central Russian Upland. The measured thicknesses of the humus horizons were compared with the model thicknesses. The thickness of humus horizons was simulated with the consideration of the rates of soil erosion and self-restoration. We used erosion models WaTEM/SEDEM (rainfall erosion) and that of the State Hydrological Institute modified by Larionov (snowmelt erosion) and Krasnov, which were previously verified on small catchments on the studied plots or near them. Land use history was reconstructed using historical maps. The approach enabled us to model with sufficient accuracy mean erosion losses of soils and calculate the mean modern thickness of the humus horizon. The obtained results of comparisons of measured and simulated thicknesses of the humus horizon clearly indicate the significant role of soil self-restoration in formation of erosion–accumulation patterns of the soil cover. Insufficient consideration of soil self-restoration results in a significant underestimation of the calculated thickness of the humus horizon and, as a consequence, in an overestimation of the degree of soil erosion. The rate of self-restoration of chernozems and (Luvic Retic Greyzemic Phaeozems) about 0.4 mm/yr, which corresponds to published data of case studies. There is an increase in differences between the model and measured thicknesses of the humus layer in the sequence chernozem–dark gray forest soil–gray forest soil–(Luvic Greyzemic Phaeozems). Plowing of gray forest soils obviously favors an increase in the flow of dissolved humus, as well as pedoturbation, which could potentially contribute to errors in the measurement of the thickness of the humus horizon in terrain conditions and to underestimation of the degree of degradation of the soil cover in the northern forest-steppe. [ABSTRACT FROM AUTHOR]

The study investigated the reinforcing effect of vetiver root on soil by conducting outdoor planting tests and indoor root tests. The cracking indexes of soil specimens with varying root contents were analyzed, and a statistical model was established to determine the relationship between the cracking indexes, the number of dry and wet cycles, and the root content. The study revealed the crack evolution law of vetiver-reinforced expansive soil. The study explored the mechanism of the vegetation root in inhibiting the cracking of expansive soil and determined the optimal planting density of vetiver grass through outdoor planting tests. The results indicate that: The surface crack rate (CR), total crack length (CL), and crack number (CN) in the root-soil specimen exhibited exponential growth with an increase in the number of wet and dry cycles. This growth was more pronounced during the first and second cycles. The vetiver root could effectively reduce soil crack formation, and the specimen's cracking resistance is positively correlated with the root content. With the root content increased, the CR, CN, and CL decreased. The logistic model is suited to the CL of added root soil. The logistic model is more suitable for the growth model of the CR of the expansive soil with low root content, while the Boltzmann model is more suitable for the growth model of the CR of the expansive soil with high root content. Width of crack (CW) is better suited to the DoseResp growth model. The Boltzmann model is more applicable to the CN in expansive soils with low reinforcement, while the logistic growth model is more suitable for the development of CN above 0.21% root content. The development of the crack network was influenced by two key factors: the root content and the number of wet and dry cycles. Under the condition of planting roots, the development of crack networks in expansive soil differs from that of expansive soil with added roots, and there is no clear pattern to follow. The inhibitory effect of the vetiver root on cracking of expansive soil is related to the planting density of vetiver. [ABSTRACT FROM AUTHOR]

In root research, hydroponic plant cultivation is commonly used and soil experiments are rare. We investigated the response of 12‐day‐old barley roots, cultivated in soil‐filled rhizotrons, to different soil water potentials (SWP) comparing a modern cultivar (cv. Scarlett) with a wild accession ICB181243 from Pakistan. Water potentials were quantified in soils with different relative water contents. Root anatomy was studied using histochemistry and microscopy. Suberin and lignin amounts were quantified by analytical chemistry. Transcriptomic changes were observed by RNA‐sequencing. Compared with control with decreasing SWP, total root length decreased, the onset of endodermal suberization occurred much closer towards the root tips, amounts of suberin and lignin increased, and corresponding biosynthesis genes were upregulated in response to decreasing SWP. We conclude that decreasing water potentials enhanced root suberization and lignification, like osmotic stress experiments in hydroponic cultivation. However, in soil endodermal cell suberization was initiated very close towards the root tip, and root length as well as suberin amounts were about twofold higher compared with hydroponic cultivation. [ABSTRACT FROM AUTHOR]

Plant-parasitic nematode research in the Middle East and North Africa (MENA) region faces significant challenges rooted in a need for proper assembly, diversity, and a unified and purpose-driven framework. This led to exacerbating their detrimental effects on crop production. This systematic review addresses the current situation and challenges that require targeted interventions to sustainably manage plantparasitic nematodes and reduce their detrimental impact on agriculture production in the MENA region. We analyzed the nematode-related research conducted within the region over the past three decades to assess available resources and promote diverse research approaches beyond basic morphology-focused surveys. We show that crops are attacked by a diverse spectrum of plant-parasitic nematodes that exceed the global economic threshold limits. In particular, Meloidogyne species exceed the threshold limit by 8 - 14-fold, with a 100% frequency of occurrence in the collected soil samples, posing a catastrophic threat to crop production and the economy. We highlight detrimental agriculture practices in theMENA region, such as transferring soil from established fields to barren land, which enhances the dissemination of plant-parasitic nematodes, disrupting soil ecology and causing significant agricultural challenges in newly cultivated areas. Looking into the behavior of farmers, raising awareness must be accompanied by available solutions, as more practical alternatives are needed to gain the confidence of the farmers. We propose integrating microbial-based products and soil development practices in hygienic farming as resilient and sustainable solutions for nematode management. Increased emphasis is required to diversify the nematode-related research areas to bridge the gaps and facilitate the transition from fundamental knowledge to practical solutions. A cohesive network of nematologists and collaboration with national and international entities is crucial for exchanging knowledge related to legislation against invasive species. [ABSTRACT FROM AUTHOR]

The search for novel substances that promote the establishment of a microbial community and facilitate optimal humification processes while increasing soil organic matter content offers an opportunity for land restoration. The objective of study was to determine the abundance of ecological and trophic groups of soil microorganisms and the intensity of microbiological processes when subjected to probiotic treatment at various concentrations and doses in typical black soil. The eco-trophic groups of soil microorganisms were identified by inoculating dilutions of soil suspensions onto selective nutrient media. The direction and intensity of soil microbiological processes were assessed using the mineralization-immobilization, oligotrophy, and pedotrophy indexes. The results demonstrate that probiotics has a positive impact on the microbiological activity of the soil, leading to an increase in the number of ecological and trophic groups of soil microorganisms during both spring and autumn seasons. Notably, a significant effect on the soil microorganism conditions was observed after 30 days of probiotic treatment. Probiotics exhibit a favorable influence on microbiological processes within the soil, fostering conducive conditions for the development of soil microorganisms and the formation of humus. The most effective concentration of probiotics for promoting the functionality of microbial communities in black soils is determined to be 10%, accompanied by a dose of 100 l ha-1. Consequently, the application of probiotic treatment at a concentration of 10% and a dose of 100 l/ha-1 holds the potential to enhance the biological state of the soil, restore soil microbial diversity, and serve as an environmentally safe fertilizer. [ABSTRACT FROM AUTHOR]

In urban conditions, the soil is exposed to a number of adverse factors that have a great impact on its hydrophobic and hydrophilic properties. The water-repellent properties of urban dust and soils were determined with the water drop penetration time (WDPT) test. Hydrophobization of Albic Retisols in the conditions of a megalopolis was modeled, and its rate was estimated. Three dust samples with different values of the WDPT test from 420 to 850 seconds were studied. According to the results of the model experiment, with an increase of solid atmospheric fallout in the Retisols, the level of their hydrophobicity also increases. The rate of the increase depends on the water-repellent properties of the dust. During pollution with the most hydrophobic dust, the maximum hydrophobization of the humus-accumulative soil horizon is achieved upon a 70-year-long impact. For other dust samples, an increase in the time of absorption of a drop was observed up to the maximum period of aerial soil contamination within the model experiment (200 years). Values of the WDPT test for the studied soil horizons ranged from 2.4 s to 1493.5 s for background soil and urban soil forming near a major highway for 90 years, respectively. In the soil of forty-year-old residential area, the value was 237.1 s. The correspondence of the levels of hydrophobicity, the degree of anthropogenic load and the residence time in the urban environment in the model experiment and in the samples of real urban soils indicates that solid atmospheric fallouts are a component of humus-accumulative horizons of urban soils and have a significant impact on their water-repellent properties. [ABSTRACT FROM AUTHOR]

The Ryshkovo paleosol of the Mikulino Interglacial (MIS 5e), Late Moscow loess (MIS 6), and buried small erosional landforms were studied in the Taneyev Quarry of Kursk oblast, in the center of the East European Plain. Macro- and micromorphological and palynological analyses of the soil samples were carried out, and the OSL age and physicochemical properties were determined. The history of erosional landforms, soils, and landscapes was reconstructed on the basis of the facial analysis of the paleosol catena. It was concluded that the differentiation of the paleosol profile into the Ah–E–Bt horizons was developed during the Mikulino Interglacial, whereas the initial heterogeneity of the parent material had been formed earlier, during the Late Moscow (Saalian) Glaciation, under the impact of slope and cryogenic processes. The lithological matrix of the Ryshkovo paleosol did not remain unchanged due to the different history of interaction of eolian and slope (solifluction and colluvial) processes, initial pedogenesis, and interglacial soil formation. [ABSTRACT FROM AUTHOR]

Iron in soil exists in various valence states and is prone to changes with alterations in soil environmental conditions. Its migration and transformation are crucial for soil formation and understanding soil evolution. This study focuses on Quaternary red soils found in woodland, sparse forest grassland, grassland, and cultivated land located in the semi-humid region of the middle temperate zone. For comparison, buried Quaternary red soil was also examined. A soil reconstruction model was used to quantitatively calculate the variation of different forms of iron in order to analyze various forms of iron composition, migration, and transformation within the soil profile, as well as the evolutionary traits of Quaternary red soils influenced by diverse land use activities. This study found that after exposure and use, iron from the topsoil of buried Quaternary red soil migrated to the subsoil, altering the iron distribution. Free iron and crystalline oxides decreased in the topsoil but increased in specific subsoil layers, with woodland and grassland showing the most significant changes. Silicate-bound iron pooled in the soil weathered to form free iron under different land uses, and poorly crystalline iron oxides transformed into crystalline oxides, with grassland exhibiting the highest transformation intensity. Conversion processes predominated over iron migration in the Quaternary red soils. The evolution of Quaternary red soils can be divided into three stages, marked by changes in iron composition and crystallization due to anthropogenic land use activities. Initially, during 140−94 ka BP, iron composition was stable. Then, between 94–24 ka BP, plant decomposition formed iron–metal complexes, releasing and crystallizing poorly crystalline iron oxides. Finally, from 24 ka BP to the present, anthropogenic activities intensified, increasing the formation and conversion rates of these oxides. This study quantifies iron migration and transformation in Quaternary red soils, providing insights for sustainable soil management, especially in regions where human activities have accelerated iron evolution. Based on these findings, the following policy recommendations are proposed: implement sustainable land use practices, encourage land management strategies that preserve natural vegetation, promote research on soil management techniques, develop and implement regulatory policies, and support educational programs to maintain the health and stability of Quaternary red soils, particularly in regions prone to accelerated iron evolution due to anthropogenic activities. [ABSTRACT FROM AUTHOR]

Open-ended pre-stressed high-strength concrete (PHC) pipe piles are susceptible to progressive distortion and even failure in the vicinity of the pile toe during driving into stiff soil or rock strata. This paper presents an experimental investigation conducted as part of a power plant construction in Huainan, China. After 50 piles were driven in the initial phase, the toe of 9 piles were detected as damaged using the sonic echo testing method. In the second construction phase, four piles were instrumented with longitudinal and circumferential fiber optic cables, as well as discrete strain gauges. The recorded responses of pipe piles throughout their driving process are analyzed to reveal the causes of damages. The results show that a maximum circumferential tensile stress developed at a distance of 1/6 pile length above the pile toe, with its value three times greater than that in other cross-sections. This high circumferential stress results in transverse cracks and the failure of open-ended PHC piles and is believed to be related to the formation of soil plugs. The findings provide valuable insights into performance evaluation of driven open-ended PHC piles. [ABSTRACT FROM AUTHOR]

After a wildfire event, ash is a newly formed surficial soil layer with microscale properties such as roughness, morphology, and chemical composition that may impact how ashes form fabrics in situ and so affect the overall hydrological conditions of a burned area (infiltration capacity, permeability, etc.). To examine the effects of ash microscale properties on macroscale behavior, eight wildfire ash samples from California were characterized physically (specific gravity, specific surface area, particle size, etc.), chemically (elemental composition, organic and inorganic carbon content, etc.), and geotechnically (strength, compaction, saturated hydraulic conductivity, etc.). The tested ashes were found to contain predominantly organic unburned carbons and carbonates derived from the combustion of calcium-oxalate rich fuels in temperatures likely ranging from 300°C to 500°C. Ashes had high specific surface areas because morphologically, particles had highly texturized and porous surfaces. Additional water was necessary to coat the particle surfaces, which led to high liquid limits and compaction optimum moisture contents. Hydraulic conductivity values were within range for silty sands (10−5–10−3 cm/s), and specimens had friction angles near 30°. However, tested ashes consistently demonstrated high void ratios and low bulk densities during testing for strength, hydraulic conductivity, and compaction. These anomalies were attributed to unusual carbonate morphologies; the high interparticle friction of these phases allowed ashes to form looser fabrics than a typical silty sand and contributed to the measured high void ratios, low maximum dry unit weights, and high friction angles. Overall, we hypothesize that the relative amounts of inorganic versus organic constituents in our wildfire ash samples affected how the ashes formed fabrics and so affected their geotechnical properties. Practical Applications: The role of wildfire ash in the postfire hydrological response of a catchment is not perfectly understood. Ash is a very heterogenous material whose properties are directly related to its formation environment (fuel type and accessibility, fire duration, and fire temperature, to name a few). This newly formed surface soil layer has unusual properties compared to natural soils, including low bulk densities and high porosities (sometimes up to 70% or more) in situ, but there is currently not enough information on ash properties in the literature to fully explain why. This study addresses this gap by providing physical, chemical, and geotechnical information about wildfire ashes. This is one of the first studies to specifically test wildfire ash maximum density, Atterberg limits, and shear strength. It provides geotechnical data to the community as well as information about ash chemical and physical properties. We hope that this study not only supplements the current literature on postwildfire landscapes but also informs researchers, engineers, and policy makers about how the formation environment of ash can influence its engineering behavior, such as strength, compressibility, and permeability. [ABSTRACT FROM AUTHOR]

Background: Food and nutritional security remain a major thrust area in the under developed and developing countries. These problems are exaggerated by the unprecedented challenges of climate change. Aims: The aim of this study was to assess the impact of climate change on grain quality of wheat and rice genotypes as well as their effect on soil aggregate fractions and aggregate associated carbon. Methodology: In the context, the present study was formulated by considering four predicted climate scenarios, namely, T0C0 (ambient condition), T0C1 (approx. 25% higher CO2), T1C0 (2°C higher temperature) and T1C1 (25% higher CO2 + 2°C higher temperature) and their impact on grain quality of wheat (HD2967, HD2733, DBW17, and HD3093) and rice (IR83376‐B‐B‐24‐2, IR84895‐B‐127‐CRA‐5‐1‐1, R Bhagwati, and IR64) genotypes as well as soil aggregate fractions and aggregate associated carbon. Results: The result revealed that T0C1 has a negative impact on grain nitrogen and protein content. On an average, nitrogen content in wheat and rice showed a decrease of about 15.55% (5.52%–25.32%) and 11.44% (3.33%–23.86%), respectively. Interestingly, the concurrent effect of elevated CO2 and temperature resulted in higher nitrogen and protein content as compared to other climate conditions. Further, P (P) content in the wheat and rice grains also improved under the elevated CO2 condition, whereas the content of potassium was not significantly influenced. Apart from major nutrients, micronutrients (Zn and Fe) were significantly influenced by climatic variables. The study revealed that grain Zn and Fe content of both the crops were reduced due to elevated CO2. The data on soil aggregate fractions revealed that elevated CO2 favors the formation of macro‐aggregate, whereas an increase in temperature favors micro‐aggregate fractions in the soil. Further, the elevation of CO2 also resulted in the accumulation of more carbon in the macro‐aggregates. Conclusion: We conclude that elevated CO2 and temperature cause specific changes in soil aggregate formation and grain nutrient quality. Based on molar ratio of P/Zn and P/Fe, we identified varieties of rice (IR83376‐B‐B‐24‐2) and wheat (HD2733) with higher bioavailability to address the nutritional security with changing climate in developing countries. [ABSTRACT FROM AUTHOR]

Slag nikel is a by-product of nickel ore smelting through the pyrometallurgical process, which contains silica (> 50 %). This suggests that nickel slag, possessing pozzolanic properties, which potentially to be used as a binding material in construction projects dealing with low soil bearing capacity, such as soil improvement for road foundation. Pozzolanic reactions are greatly influenced by the chemical bonds formed between the binding material and the soil, causing mechanical characteristic changes in the soil. This study aims to examine the effect of adding nickel slag to soft soil based on changes in its physical, mechanical and chemical properties. Physical and mechanical property tests were conducted according to ASTM standards, while the changes in chemical structure in the soil were analyzed based on X-Ray Diffraction (XRD) test results. In this study, nickel slag percentages of 3, 6, 9 and 12 % were used based on the weight ratio of clay soil, at optimum water content (wopt). Furthermore, the test specimens were cured for 14, 28 and 56 days to observe the effect of time on the increase of crystal phases in each variation. The results showed that the presence of nickel slag in the soil can affect its physical and mechanical properties. The nickel slag content in the soil of 3, 6, 9 and 12 % reduces the plasticity index by 16.69, 12.02, 8.86 and 6.38 %, respectively. Meanwhile, the density values increased by 10.97, 11.27, 11.68 and 12.01 kN/m³, respectively. The changes in physical and mechanical properties can be explained by the XRD analysis results, showing changes in the spectrum curve and peak intensity of X-Ray Diffraction in the soil with the addition of nickel slag. This explanation clarifies the transformation of the soil's atomic structure from an amorphous state to a crystalline form, which is stabilized by nickel slag. [ABSTRACT FROM AUTHOR]

The emerging upward shield method (USM) for constructing vertical shafts has been used in various projects, including the Midosuji utility tunnel in Japan. A scaled-down model testing system, featuring a geometric similarity ratio of 1:30, was developed specifically for studying the USM. This system incorporates sand inflow control, propulsion control, data acquisition, and water level control. It facilitates detailed observation and recording of parameters such as vertical displacement of surface soil layers, support force at the excavation face, and earth pressure within the model box. Consequently, it enables investigation into the excavation face instability process, modes, and the formation and evolution of the soil arch zone above the excavation face during upward shield tunneling. Additionally, through the application of particle image velocimetry (PIV) technology and GeoPIV-RG software v1.1, quantitative analysis of soil displacement fields during excavation face instability is conducted, capturing microscopic displacements and deformations of soil planes. This approach more accurately elucidates the accuracy of understanding the dynamic response of soil. Pre-test research using the model testing system explores the variation patterns of excavation face load displacement, vertical earth pressure within the failure zone, surface displacement, and internal soil displacement during the instability process. Analysis reveals that excavation face load variation typically progresses through three stages: rapid growth, slow growth, and descent. Moreover, vertical earth pressure shifts upward in tandem with excavation face displacement, while overall surface displacement initially shows slight settlement followed by accelerated uplift. [ABSTRACT FROM AUTHOR]

The main applications of civil explosives in soils are soil compaction, mass excavation, and in situ pile creation. The suitability of explosives for each of these applications strongly depends upon the explosive properties and the soil properties. For those reasons, a reliable estimation or process simulation regarding cost efficiency and explosive work ability in the soil with known soil parameters is relevant. This paper presents a numerical simulation study of different types of soil (different amounts of gravel, sand, silt, and clay) under a blast load modeled using Ansys 2020 R1 Autodyn 2D hydrocode, with different types of explosives. The calculated results from the Ansys 2020 R1 Autodyn 2D and the experimental results obtained from the in situ cavity formation caused by blasting are presented. The Jones–Wilkins–Lee (JWL) equation of state parameters was calculated using EXPLO5 V7.01.01 supported by experimental data, while the soil and explosive properties were measured in laboratory and in situ. [ABSTRACT FROM AUTHOR]

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A dense concentration of old‐growth forest and a wet, cold climate promote mineral weathering and leaching in coastal temperate rainforest soils. Our objective was to assess soil development and soil organic carbon (SOC) distribution across 18 soil profiles in remote, upland terrain of southeast Alaska where pedon data are sparse. We made soil morphological observations, collected samples, and completed laboratory analyses to measure SOC content, pH, and particle size distribution. The survey of upland backslope soils included north‐ and south‐facing hillslopes derived from three lithologies (slate, metavolcanic, and phyllite). The soils across all sites were very gravelly (51.8 ± 20.4% coarse fragments), acidic (mineral soil pH 4.85 ± 0.45), and moderately deep (96.56 ± 37.80 cm); thin, broken E horizons were underlain by thick, carbon‐rich spodic horizons. Soil development was relatively consistent as demonstrated by the Profile Development Index with values from 15 to 26 and Podzolization Index values spanning 8 to 14. A mean pedon SOC stock of 198.02 ± 81.42 Mg C ha−1 (n = 18) was calculated using data collected for all upland organic and mineral soils from our work. The accumulation of SOC was similar among soils formed from contrasting lithologies with averages of 182 ± 15.70 Mg C ha−1 for slate, 188 ± 53.80 Mg C ha−1 for metavolcanic, and 218 ± 124 Mg C ha−1 for phyllite. Our work contributes to soil morphological observations, laboratory data, and SOC stock estimates required to better constrain and model pedogenic processes and SOC stock in remote forests where data sets are limited. [ABSTRACT FROM AUTHOR]

Satellite remote sensing is currently an established, effective, and constantly used tool and methodology for monitoring agriculture and fertilisation. At the same time, in recent years, the need for the detection of livestock manure and digestate spreading on the soil is emerging, and the development of spectral indices and classification processes based on satellite multispectral data acquisitions is growing. However, the application of such indicators is still underutilised and, given the polluting impact of livestock manure and digestate on soil, groundwater, and air, an in-depth study is needed to improve the monitoring of this practice. Additionally, this paper aims at exposing a new spectral index capable of detecting the land affected by livestock manure and digestate spreading. This indicator was created by studying the spectral response of bare soil and livestock manure and digestate, using Copernicus Sentinel-2 MSI satellite acquisitions and ancillary datasets (e.g., soil moisture, precipitation, regional thematic maps). In particular, time series of multispectral satellite acquisitions and ancillary data were analysed, covering a survey period of 13 months between February 2022 and February 2023. As no previous indications on fertilisation practices are available, the proposed approach consists of investigating a broad-spectrum area, without investigations of specific test sites. A large area of approximately 236,344 hectares covering three provinces of the Emilia-Romagna Region (Italy) was therefore examined. A series of ground truth points were also collected for assessing accuracy by filling in the confusion matrix. Based on the definition of the spectral index, a value of the latter greater than three provides the most conservative threshold for detecting livestock manure and digestate spreading with an accuracy of 62.53%. Such results are robust to variations in the spectral response of the soil. On the basis of these very encouraging results, it is considered plausible that the proposed index could improve the techniques for detecting the spreading of livestock manure and digestate on bare ground, classifying the areas themselves with a notable saving of energy compared to the current investigation methodologies directly on the ground. [ABSTRACT FROM AUTHOR]

The article addresses anthropogenic and geological conditions related to the development of soil subsidence in the western zone of Recife (Brazil). Over the past 50 years, human activity has intensified in areas previously affected by soft soils (clay, silt, and sandstone) resulting in subsidence due to additional loads (landfills and constructions). The duration of the settlement process can be significantly influenced by the specific characteristics of the soil composition and geological conditions of the location. This work presents, for the first time, accurate InSAR time series maps that describe the spatial pattern and temporal evolution of the settlement, as well as the correlation with the geological profile, and validation with Global Navigation Satellite System (GNSS) data. Persistent Scatterer Interferometry (PS-InSAR) was employed in the analysis of Single Look Complex (SLC) images generated by 100 ascending COSMO-SkyMed (CSK) and 65 PAZ (32 ascending, and 33 descending) from the X-band, along with 135 descending Sentinel-1 (S1) acquisitions from the C-band. These data were acquired over the period from 2011 to 2023. The occurrence of subsidence was identified in several locations within the western region, with the most significant displacement rates observed in the northern, central, and southern areas. In the northern region, the displacement rates were estimated to be approximately −20 mm/year, with the Várzea and Caxangá neighborhoods exhibiting the highest rates. In the central region, the displacement rates were estimated to be approximately −15 mm/year, with the Engenho do Meio, Cordeiro, Torrões, and San Martin neighborhoods exhibiting the highest rates. Finally, in the southern region, the displacement rates were estimated to be up to −25 mm/year, with the Caçote, Ibura, and Ipsep neighborhoods exhibiting the highest rates. Additionally, east–west movements were observed, with velocities reaching up to −7 mm/year toward the west. These movements are related to the lowering of the land. The study highlights that anthropogenic effects in the western zone of Recife contribute to the region's vulnerability to soil subsidence. [ABSTRACT FROM AUTHOR]

Climate warming is causing widespread deglaciation and pioneer soil formation over glacial deposits. Melting glaciers expose rocky terrain and glacial till sediment that is relatively low in biomass, oligotrophic, and depleted in nutrients. Following initial colonization by microorganisms, glacial till sediments accumulate organic carbon and nutrients over time. However, the mechanisms driving soil nutrient stabilization during early pedogenesis after glacial retreat remain unclear. Here, we traced amino acid uptake by microorganisms in recently deglaciated high-Arctic soils and show that fungi play a critical role in the initial stabilization of the assimilated carbon. Pioneer basidiomycete yeasts were among the predominant taxa responsible for carbon assimilation, which were associated with overall high amino acid use efficiency and reduced respiration. In intermediate-and late-stage soils, lichenized ascomycete fungi were prevalent, but bacteria increasingly dominated amino acid assimilation, with substantially decreased fungal:bacterial amino acid assimilation ratios and increased respiration. Together, these findings demonstrate that fungi are important drivers of pedogenesis in high-Arctic ecosystems that are currently subject to widespread deglaciation from global warming. [ABSTRACT FROM AUTHOR]

The vacuum preloading technique is extensively employed for ground improvement, particularly for slurry ground characterized by high‐water content and low strength. Such ground frequently exhibits a delay in pore water pressure dissipation when treated with prefabricated vertical drains. To clarify the drainage and consolidation behaviour of high‐water content slurry ground under vacuum preloading, this study proposed a two‐stage combined model that integrates both filtration and consolidation processes. Initially, an axisymmetric filtration model was used to describe the formation of the soil column through the radial migration and compaction of the particles. The end‐of‐filtration radial distributions of void ratio, permeability coefficient, and effective pressure served as initial conditions for the consolidation stage analysis. This stage was depicted using a large strain consolidation model based on the free strain condition. The results showed the necessity of incorporating the filtration stage to capture the overall drainage mechanism and characteristics of slurry ground with vacuum preloading treatment. [ABSTRACT FROM AUTHOR]

Analysis of the stable carbon isotopic composition (δ13C) of soil organic matter is important for assessing past climate changes and the response of landscape components to them. Soils of nine soil-sedimentary sequences formed in various landscape and geomorphological conditions of western Transbaikalia have been studied. The time of their formation covers the last 15 kyr. The phases of pedogenesis within genetically different landforms were rather synchronous, which enabled us to suppose that they were caused by regional landscape-climatic changes, which also affected δ13C of soil organic matter. The range of variations in δ13С values is from –20.99 to –27.00‰. Changes in δ13С over time are the most contrasting for sections formed under driest steppe conditions and are the smallest for sections in taiga landscapes with the greatest precipitation. However, in general, the trends of changes in δ13С in different landscape zones over time are similar: the lowest δ13С values are typical for organic matter of Late Glacial paleosols formed 14–15 and 12 kyr BP, as well as for soils of the Late Holocene (3.5–2.0 and 1.0–0.3 kyr BP). Organic matter of soils of the Middle Holocene (9.0–4.0 kyr BP) and of the time interval of 13–14 kyr BP is enriched in 13C. Based on the identified dependence of δ13C in organic matter of modern soils in the region on the amount of precipitation, we have quantitatively reconstructed precipitation during the past growing seasons. The data obtained enable us to estimate the time intervals of 11.7–10.0 and 4.0–1.5 kyr BP as the most optimal for the formation of soils in Western Transbaikalia. An increase in temperatures and a decrease in atmospheric humidity in Transbaikalia and adjacent areas in the Middle Holocene exerted a negative impact on the pedogenesis intensity. [ABSTRACT FROM AUTHOR]

Evidence has suggested that either labile organic carbon (OC) or stable OC play a role in improving aggregate stability. Therefore, this study determined the OC fractions in water stable aggregates (WSA) and their contribution to the formation of the WSA in paddy soils, on the Central Plain of Thailand. Analysis of the OC fractions in the WSA was determined using wet oxidation with hydrogen peroxide (H2O2). The chemical composition of the organic compounds in the WSA was investigated using Fourier transform mid-infrared (FT-IR) spectroscopy. The results showed that the WSA content of the studied soils significantly increased with increasing organic and inorganic cementing/flocculating agents, such as soil organic carbon, clay, polyvalent cations, and sesquioxides. The labile OC and stable OC contents in the WSA also significantly increased with increased WSA content, suggesting the physical protection of OC fractions against microbial decomposition. The FT-IR analysis revealed that labile OC in the WSA, both before and after wet oxidation with H2O2, was dominated by polysaccharides, supporting the physical protection of labile OC by the WSA. Paddy soils containing higher organic and inorganic cementing/flocculating agents had higher stable OC, such as hydrophobic aromatic compounds, in the WSA, compared to paddy soils containing lower organic and inorganic cementing/flocculating agents. In turn, the WSA content of the soils in this study significantly increased with increases in the hydrophobic aromatic compounds in the WSA, suggesting the important role of stable hydrophobic organic compounds in enhancing the formation and stabilization of soil aggregates in these paddy soils. [ABSTRACT FROM AUTHOR]

Data on the contents of eleven polycyclic aromatic hydrocarbons (PAHs) in soils of single-time and repeatedly burnt areas of different ages in taiga landscapes of the Khamar-Daban Ridge (southern Baikal region, Buryatia) are presented. Morphological soil features inherited from the fires are identified: charcoal layer (pyr), ash layer (Cpyr), charred forest litter, (Opyr) and pyrogenic humus horizon (Apyr). The post-fire variability of the soil cover within burnt areas is related to the presence of areas with six degrees of burning of litter material. The content of PAHs in soils decreases with increasing fire intensity, as well as in the case of repeated fires on the already burnt area. Background soils of forests not disturbed by fire have a higher content of PAHs compared to that in soils of 42-year-old burnt area and one-year-old intensely burnt area. Four groups of PAHs differing in their origin have been identified using factor analysis: polyarenes of pyrogenic autochthonous origin formed in situ (naphthalene, tetraphene, pyrene, chrysene, anthracene, naphthalene, to a lesser extent benzo(a)pyrene and benzo(ghi)perylene); polyarenes of pyrogenic allochthonous origin that accumulated in soils due to atmospheric transport of ash material (benzo(a)pyrene and benzo(ghi)perylene); polyarenes of biochemical origin (fluorene and biphenyl); and polyarenes of biochemical and petrogenic origin accumulating in the deep soil horizons (phenanthrene). [ABSTRACT FROM AUTHOR]

The main objective of protecting ecosystems and enhancing the supply of ecosystem services (ESs) is to quantify the value of ecological services. This article calculates the ecological service value (ESV) of the Tarim Basin over the past 40 years using the improved benefits transfer method of satellite remote sensing data, such as Landsat, analyzes the spatiotemporal evolution characteristics of ESV, and studies the driving mechanism of ESV changes using GeoDetector. Finally, the FLUS model was selected to predict the ecosystem service value until 2030, setting up three scenarios: the Baseline Scenario (BLS), the Cultivated Land Protection Scenario (CPS), and the Ecological Protection Scenario (EPS). The results indicate that (1) the ESV in the Tarim Basin decreased by USD 1248.21 million (−2.29%) from 1980 to 2020. The top three contributors are water bodies, wetlands, and grassland. (2) Waste treatment and water supply functions had the highest service value, accounting for 44.53% of the total contribution. The rank order of ecosystem functions in terms of their contribution to the total value of ESV was as follows, refining from high to low importance: water supply, waste treatment, biodiversity protection, climate regulation, soil formation, recreation and culture, gas regulation, food production, raw material. (3) The spatial differentiation driving factors of ESV were detected, with the following Q-values in descending order: net primary productivity (NPP) > normalized difference vegetation index (NDVI) > precipitation > aspect > temperature > slope > soil erosion > GDP > land use intensity > per capita GDP > population > human activity index. (4) The ESVs simulated under the three scenarios (BLS, CPS, and EPS) for 2030 were USD 51,133.9 million, USD 53,624.99 million, and USD 54,561.26 million, respectively. Compared with 2020, the ESVs of the three scenarios decreased as follows: BLS (USD 4209.33 million), CPS (USD 1718.24 million), and EPS USD (−781.97 million). These findings are significant for maintaining the integrity and sustainability of the large-scale ecosystem, where socioeconomic development and the fragile features of the natural ecosystem interact. Additionally, the study results provide a crucial foundation for governmental decision-makers, local residents, and environmental researchers in northwest China to promote sustainable development. [ABSTRACT FROM AUTHOR]

Aims: Our understanding of the rhizosphere is limited by the lack of techniques for in situ live microscopy. Current techniques are either destructive or unsuitable for observing chemical changes within the pore space. To address this limitation, we have developed artificial substrates, termed smart soils, that enable the acquisition and 3D reconstruction of chemical sensors attached to soil particles. Methods: The transparency of smart soils was achieved using polymer particles with refractive index matching that of water. The surface of the particles was modified both to retain water and act as a local sensor to report on pore space pH via fluorescence emissions. Multispectral signals were acquired from the particles using a light sheet microscope, and machine learning algorithms predicted the changes and spatial distribution in pH at the surface of the smart soil particles. Results: The technique was able to predict pH live and in situ within ± 0.5 units of the true pH value. pH distribution could be reconstructed across a volume of several cubic centimetres around plant roots at 10 μm resolution. Using smart soils of different composition, we revealed how root exudation and pore structure create variability in chemical properties. Conclusion: Smart soils captured the pH gradients forming around a growing plant root. Future developments of the technology could include the fine tuning of soil physicochemical properties, the addition of chemical sensors and improved data processing. Hence, this technology could play a critical role in advancing our understanding of complex rhizosphere processes. [ABSTRACT FROM AUTHOR]

Ground reaction curves (GRCs) are increasingly used to simulate the progressive development of soil arching resulting from differential movement in soil. In this study, 20 single, double, and multiple trapdoor tests were conducted under a simultaneous displacement mode (i.e., trapdoors settle simultaneously), while 8 double trapdoor tests were carried out under a successive displacement mode (i.e., trapdoors settle successively) to examine the evolution of soil arching including the parameters related to the GRCs. This study identified and analyzed the key parameters of the GRCs. For the trapdoor tests conducted under the simultaneous displacement mode, an increase of the fill height led to a decrease in the minimum pressure and its corresponding trapdoor displacement. Furthermore, the ultimate normalized pressure and recovery rate exhibited a decreasing trend with an increase of the fill height. As compared to the single and double trapdoor tests, the multiple trapdoor tests had similar initial soil arching, minimum normalized pressure, and its corresponding trapdoor displacement but a relatively lower stress recovery rate. In the trapdoor tests conducted with the successive displacement mode, the pressure on the first settled trapdoor decreased while it increased on the later settled trapdoor during the settlement of the first settled trapdoor. Conversely, during the settlement of the later settled trapdoor, the pressure on the first settled trapdoor increased, while it decreased on the later settled trapdoor. Analyzing the GRCs on the later settled trapdoor under the successive displacement mode revealed that the initial slope and ultimate pressure of the GRC decreased as the fill height increased. [ABSTRACT FROM AUTHOR]

The soil mantle of the tropical karstic landscapes of Southern Mexico was shaped by specific processes of pedogenesis and long‐term human impacts of ancient Maya agriculture. To understand the interaction between natural and human‐induced soil‐forming processes in the calcareous mountains of Chiapas state, we studied soil toposequences around the Classic Maya site of Budsilhá and related them to the archaeological evidence of settlement and land‐use distribution. Soil chemical analysis, micromorphological observations, and clay mineral identification were carried out in key soil profiles at the main geoforms. Limestone hills are occupied by shallow Rendolls which are usually perceived as incipient soils. However, high content of silicate clay composed of kaolinite and vermiculite and ferruginous clayey soil material observed at macro‐ and microscale backed the hypothesis that these soils were formed from the residues of thick Terra Rossa after their erosion. Swampy lowlands are occupied by thick clayey gleyic soils with clay mineral assemblages similar to those in the upland Rendolls. We suppose that the mineral matrix of the lowland soils is largely derived from the pedosediments of eroded upland Terra Rossa, which lost original ferruginous pigmentation and aggregation due to redoximorphic processes. Some wetland soils contain neoformed gypsum that is atypical for humid tropics; sulfide‐sulfate transformation under fluctuating redox conditions could promote gypsum synthesis. Ancient Maya land use was closely related to soil‐geomorphic conditions: settlements with homegardens occupied calcareous hills, whereas the primary agricultural domain was developed on lowland soils after their drainage by artificial canals. [ABSTRACT FROM AUTHOR]

Drilosphere is the zone of interaction between earthworms and soil environments. Besides contributing to soil microporosity, the drilosphere provides habitat for a wide array of micro-organisms. There is growing evidence that the impact of earthworms on soil functions is mediated by microbial populations in the soil. It is important for agroecosystems that the soil quality is maintained for processes like decomposition, soil formation, and several other soil ecological properties. This review focuses on the structure and function of the Drilosphere, as well as its significance as a microbial 'hotspot'; which contributes to the agroecosystem earthworm-driven Drilosphere is a key to agroecosystem, boosting soil health and productivity through improved water movement, enhanced fertility, and nutrient cycling. Their mucus stabilizes soil and promote microbial activity, while interactions with plant roots supports nutrient exchange. Leveraging these dynamics can advance sustainable farming and yield higher agricultural productivity. [ABSTRACT FROM AUTHOR]

In our study, we examined the influence of slope gradient on erosion processes and present soil formation and change on loess hills. We analysed data from the two study areas and found that slope gradient is a significant factor influencing soil depth as well as humus horizon thickness. At the Báb locality, we observed a negative correlation between slope gradient and soil depth (r = –0.206, p < 0.05) and a negative correlation between slope gradient and humus horizon thickness (r = –0.227, p < 0.01). At the Nová Vieska locality, there was a negative correlation between slope gradient and soil depth (r = –0.334, p < 0.02), as well as between slope gradient and humus horizon thickness (r = –0.356, p < 0.01). These findings confirm that slope gradient is a key factor influencing soil formation in loess hills, and has a significant impact on its depth and soil profile. The analysis revealed that a critical slope of 3° significantly influences soil formation, with shallower soils and a thinner humus horizon occurring on steeper slopes. Our findings have important implications for planning erosion control measures and soil management depending on the location and slope gradient. Overall, our work provides insights into soil formation processes in loess hills and contributes to a better understanding of the interactions between slope gradient and erosive processes. [ABSTRACT FROM AUTHOR]

Many scholars have used samples of drying soil to observe the amount of soil condensation water, which may have exaggerated the amount of regional condensation water, as the soil water content in the natural state was not considered. To analyze the effect of soil moisture content on soil condensation in the natural state, the soil condensation volume in loess and sandy soil under different gravimetric moisture content conditions was measured in the autumn of 2022 and spring of 2023 using micro-lysimeters combined with the weighing method at the groundwater and environment site of Chang'an University, Guanzhong Basin, China. The results showed that the average daily condensation of loess under 0%, 3%, 7%, 11%, and 15% moisture content conditions was 0.34, 0.09, 0.01, −0.05, and −0.07 mm with the condensation days of 54, 40, 24, 21, and 16, respectively, and that of sandy soil was 0.21, −0.02, −0.28, −0.82, and −1.35 mm with condensation days of 54, 24, 2, 3, and 1, respectively. Under the same moisture content conditions, loess had more condensation and condensation days than sandy soil. Soil condensation water occurred mainly when the water content was less than 7%, and it was negatively correlated with soil water content. The quantity of soil condensation water was positively correlated with relative humidity and negatively correlated with air temperature–dew point differences. Relative humidity exceeding 60% and air temperature–dew point differences below 8 °C were more favorable for the formation of soil condensation water. This study provides a reference for the assessment of soil condensation in the natural state. [ABSTRACT FROM AUTHOR]

In addition to traditional isotopes, non-traditional isotopes have gradually been applied in the hydrosphere, such as lithium, strontium, magnesium, etc. Magnesium is one of the main elements in the earth's crust and participates in most geophysical and chemical processes. In seawater, the δ26Mg value is -0.82‰ and relatively constant, which determines that the magnesium isotope composition of terrestrial water from seawater recharge is relatively consistent. This provides a constant initial isotope scale for studying water cycle processes and can be used as an ideal tracer element for groundwater research. Through comparative analysis of magnesium isotope composition characteristics and water cycle processes it is shown that the fractionation range of magnesium isotopes can reach 3.5‰, and they have different compositional characteristics in surface water and groundwater. In the process of groundwater rock interaction, magnesium isotopes undergo fractionation, providing valuable information for identifying mineral phase evolution. Magnesium isotopes follow the law of mass dependent fractionation. Therefore, in the process of groundwater infiltration and runoff, magnesium isotope fractionation caused by ion exchange and cohesive soil formation is easier for lighter magnesium isotopes to migrate to heavier magnesium isotopes. This provides the potential for magnesium isotopes to be used to study salt transport and the formation process of clay minerals. [ABSTRACT FROM AUTHOR]

Arable soils significantly contribute to atmosphere pollution through N2O emissions due to the massive use of N-based fertilizers and soil managements. N2O formation in the soil occurs mainly through nitrification and denitrification processes, which are influenced by soil moisture, temperature, oxygen concentration, pH, and the amount of available organic carbon and nitrogen. This review synthetically presents the mechanisms of N2O formation and emission in arable land and some of the current strategies to improve crop nutrient use efficiency. Biological nitrification inhibitor-based agronomic strategies are also presented as future prospects for the sustainable management of crops, which is missing in most of the reviews. [ABSTRACT FROM AUTHOR]

The tropical grasslands of the Central Nicobar Islands have long been perceived as anthropogenic formations, which has influenced their conservation and management in the region. Despite their ecological and cultural significance, these grasslands have received limited scholarly attention, rendering them vulnerable to alternative land uses and conversion. This study aims to address these knowledge gaps through an extensive vegetation survey, soil analysis, and ethnographic research. The outcomes of the vegetation survey and soil analysis reveal that these grasslands are the result of serpentine soil formations, managed by Nicobari communities by fire. The ethnographic research reveals the cultural importance of the grassland commons and its governance through the tuhet system. Further, the study shows that the access regimes have undergone a rapid transformation during post-tsunami resettlement, endangering local instuitions and the sustainability of the grassland commons of the Nicobars. [ABSTRACT FROM AUTHOR]

Natural and climatic features of the soil cover formation of Turkestan region of the Republic of Kazakhstan are identified by a set of hydrological and bioclimatic factors serving as important environment-forming functions, which are reflected in the landscape organization of the territory. When assessing soil resources of agricultural landscapes, integrated index of soil fertility was applied – the “soil index,” which takes into account the reserves of humus, mineral elements, and hydrolytic acidity. Based on monitoring observations (1996–2019) of soil fertility in agricultural landscapes (agricultural lands) of Turkestan region, assessment of soil resources was performed, which showed that in general, the generalized “soil index” ranges from 1.086 to 4.800 units depending on natural features of the territory. It is found that the “soil index” in agricultural landscapes is significantly less than its maximum value (20.000 units), which suggests a pronounced humus deficiency, showing low soil fertility in all agricultural landscapes. To assess the soil resources of agricultural landscapes in Turkestan region, a new approach was applied, which is based on the assessment of energy costs for the soil formation process, which enables to quantitatively reflect the radiation balance of the earth surface, heat, and moisture supply of agricultural land for 1941–1960 and 2001–2020. The indicators applied are subject to the law of vertical zonation and change from the mountain to the arid zone, where the potential energy costs for soil formation range from 82.2–101.9 to 129.4–135.5 kJ/cm2, and natural energy costs energy costs for soil formation from 17.2–21.7 to 121.7–125.2 kJ/cm2.

Cavity formations by soil dissolution or underground collapses are at the origin of large surface subsidence that constitutes a risk of damage or failure for infrastructures. Soil reinforcement with geosynthetics positioned at shallow depth is an economical and functional solution to reduce the induced surface settlements. Previous research has mainly focused on the load transfer mechanism and the arching effect in cohesionless reinforced backfills when the cavity opens. Experimental and numerical studies dealing with cohesive soils are very rare, although this situation is commonly found in practice. To overcome this lack of knowledge, a numerical study based on Discrete Element Modelling is carried out to better understand the load transfer mechanisms that are mobilized in cohesive embankments prone to underground cavity opening. The results are compared with experimental data obtained on a small-scale laboratory model in terms of vertical and horizontal displacements of both soil and geosynthetics. The numerical results focus on the collapse mechanisms of the cohesive embankment, the load transfer mechanisms, the shape of the vertical load distribution acting on the geosynthetic layer, the strain and traction forces within the geosynthetic sheet. • A numerical DEM model is proposed to analyse the load transfer in geosynthetic reinforced cohesive soil at the failure • The experiments and the numerical results exhibit a backfill failure mechanism as a rigid trapezoidal-shaped block of soil • Displacements and strains of the membrane show a frictional and sliding mechanism of the anchorage areas near the cavity • The membrane shows a flatness in the central part of the cavity due to the presence of the collapsed rigid block onto it. All the mechanisms are different from those observed e case of a geosynthetic reinforced granular soil addressed in the literature [ABSTRACT FROM AUTHOR]

The use of carbonaceous materials such as biochar has been considered an innovative solution in agriculture, especially to mitigate dry events caused by climate change. Biochar can improve water holding capacity, physical and chemical properties of soil, and increase the productivity of agricultural systems. However, underlying physiological mechanisms remain poorly understood. Mineral supplementation with potassium nitrate (KNO3) via foliar application is another promising strategy in agricultural management under irrigation deficit. Thus, we investigated the combined effects of biochar and foliar application of KNO3 on growth, yield, and physiology of tomato plants under different irrigation regimes. Results did not indicate a synergistic effect of biochar and foliar application of KNO3. Biochar application alleviated tomato plant stress under deficit irrigation, with plants showing better functioning of photosynthetic apparatus, higher yield, and better fruit quality, as well as increased water use efficiency. Coffee husk biochar (K-rich feedstock) fully met the tomato plant's demand for K and partially met the demand for some other elements (P, Mg, Fe, Zn, Mn, and Cu). Although positive effects of KNO3 application was verified for some physiological and fruit quality components, overall, foliar application of KNO3 did not improve tomato yield. It is concluded that biochar soil amendment can be a promising practice to increase yield and quality of tomato fruits under deficit irrigation. Therefore, biochar-based fertilizer can be an alternative K source that also provides stable carbon to soil and helps to mitigate stress caused by prolonged drought. [ABSTRACT FROM AUTHOR]

The limit support pressure significantly influences the stability of the shield tunnel face and deformation control during tunneling. Current research predominantly focuses on soils under dried or saturated conditions. However, unsaturated soils, which are more commonly encountered in engineering practice and widely distributed, have not been as extensively studied. Based on limit equilibrium theory, a modified analytical wedge-prism model is proposed in this paper to predict the limit support pressure acting on the shallow shield tunnel face in unsaturated sandy soil where the soil arching effect is considered. Taking advantage of finite-element software ABAQUS (version 2021), a series of numerical trapdoor tests are conducted first to study the failure behavior of unsaturated sandy soil. Then, by combining the rotation trajectory of major principal stress with the shear strength theory of unsaturated soil, the loosening earth pressure solution above the shallow trapdoor can be derived analytically. The limit support pressure can be finally obtained through a force equilibrium analysis of the wedge body. The accuracy of the proposed model is validated by comparing the calculated results with current model tests and numerical simulations. Parameter analysis results reveal that both the loosening earth pressure and limit support pressure initially decrease and then increase with the rising degree of soil saturation. A critical saturation point is identified where the loosening earth pressure and the limit support pressure reach their minimum values, attributed to the full development of the soil arching effect. [ABSTRACT FROM AUTHOR]

Mollisols are highly fertile soils and function as significant carbon reservoirs. However, determining their ages and formation processes is challenging due to extensive pedoturbation, which undermines conventional dating methods. Here, we employed luminescence, a light‐sensitive property of minerals widely used in geological dating, to investigate and quantify soil mixing. We analyzed over 2,400 luminescence ages of individual K‐feldspar grains from a Mollisol profile in Northeast China, and for the first time, we were able to determine the intensity of pedoturbation in the Mollisol profile over the past 50,000 years. The results showed that the current pedoturbation can penetrate to a depth of approximately 80 cm, with the intensity decreasing with depth. By identifying a significant intensification in historical pedoturbation, we inferred that the paleoenvironment might be suitable for the formation of Mollisols 16,400 years before present. Plain Language Summary: Mollisols, also known as a type of black soils, are highly fertile soils characterized by a thick, dark surface layer rich in soil organic matter. Mollisols are not only crucial for food security but also serve as a significant carbon pool. To predict the future evolution of these valuable soil resources, it is important to understand when and how they formed. However, due to intensive mixing by animals, plants, and freeze‐thaw processes, it is challenging to accurately obtain soil ages using traditional dating methods that rely on undisturbed sedimentation layers. Here, we utilized luminescence, a light‐sensitive property of minerals, to address the challenge of soil mixing. We analyzed more than 2,400 luminescence ages of individual K‐feldspar grains from a Mollisol profile in Northeast China. The results showed that the upper 80 cm of the soil body is currently mixed, with the mixing intensity being most intense at the soil surface and decreasing with depth. Additionally, we observed evidence of historical soil mixing over the past 50,000 years. The intensity of soil mixing increased around 16,400 years ago. We infer that the paleoenvironment might be favorable for forming Mollisols since then. Key Points: Single‐grain luminescence was used to quantify the intensity of pedoturbation in the Mollisol profile over the past 50,000 yearsDust accumulation fostered the formation of the thick, dark, humus‐rich surface layer of the Mollisol profileThe formation processes of the Mollisol profile were traced back to 16,400 years before present [ABSTRACT FROM AUTHOR]

The heterogeneous composition of fungi plays an indispensable role in the foundation of the multifunctionalities of ecosystems within drylands. The precise mechanisms that govern fluctuations in soil fungal assemblages in dryland ecosystems remain incompletely elucidated. In this study, biological soil crusts (biocrusts) at different successional stages in the Gurbantunggut Desert were used as substrates to examine the characteristics and driving factors that influence fungal abundance and community dynamics during biocrust development using qPCR and high-throughput sequencing of the ITS2 region. The findings showed that the physicochemical properties changed significantly with the development of biocrusts. In particular, total nitrogen increased 4.8 times, along with notable increases in ammonium, total phosphorus (2.1 times) and soil organic carbon (6.5 times). Initially, there was a rise in fungal abundance, which was subsequently followed by a decline as the biocrust developed, with the highest abundance detected in lichen crust (2.66×107 copies/g soil) and the lowest in bare sand (7.98×106 copies/g soil). Ascomycetes and Basidiomycetes emerged as dominant phyla, collectively forming 85% of the fungal community. As the biocrust developed, noticeable alterations occurred in fungal community compositions, resulting from changes in the relative proportions of Dothideomycetes, Lecanoromycetes and unclassified ascomycetes. Nitrogen, phosphorus, organic carbon content, and pH of biocrusts were identified as direct or indirect regulators of fungal abundance and community structure. The complexity of fungal networks increased as biocrusts developed as revealed by network analysis, but reduced in the stability of fungal communities within algal and lichen crusts. Keystone species within the fungal community also underwent changes as biocrust developed. These results suggested that shifts in interspecies relationships among fungi could further contribute to the variation in fungal communities during the development of biocrusts. [ABSTRACT FROM AUTHOR]

Soil parent material is a fundamental natural resource for the generation of new soils. Through weathering processes, soil parent materials provide many of the basic building blocks for soils and have a significant bearing on the physico-chemical makeup of the soil profile. Parent materials are critical for governing the stock, quality, and functionality of the soil they form. Most research on soil parent materials to date has aimed to establish and measure the processes by which soil is generated from them. Comparatively little work has been performed to assess the rates at which soil parent materials erode if they are exposed at the land surface. This is despite the threat that the erosion of soil parent materials poses to the process of soil formation and the loss of the essential ecosystem services those soils would have provided. A salient but unanswered question is whether the erosion of soil parent materials, when exposed at the land surface, outpaces the rates at which soils form from them. This study represents one of the first to detect and measure the loss of soil parent material. We applied Uncrewed Aerial Vehicle Structure-From-Motion (UAV-SfM) photogrammetry to detect, map, and quantify the erosion rates of an exposed saprolitic (i.e., weathered bedrock) surface on an agricultural hillslope in Brazil. We then utilized a global inventory of soil formation to compare these erosion rates with the rates at which soils form in equivalent lithologies and climatic contexts. We found that the measured saprolite erosion rates were between 14 and 3766 times faster than those of soil formation in similar climatic and lithological conditions. While these findings demonstrate that saprolite erosion can inhibit soil formation, our observations of above-ground vegetation on the exposed saprolitic surface suggests that weathered bedrock has the potential to sustain some biomass production even in the absence of traditional soils. This opens up a new avenue of enquiry within soil science: to what extent can saprolite and, by extension, soil parent materials deliver soil ecosystem services? [ABSTRACT FROM AUTHOR]