Abstract Traditional soil stabilizers like cement and lime contribute significantly to greenhouse gas emissions, posing risks to environmental sustainability. In response, biopolymers have emerged as promising alternatives due to their renewable nature, biodegradability, and effective binding properties. This study explores the potential of xanthan gum, a natural biopolymer, as an eco-friendly stabilizer for enhancing the strength characteristics of clayey soil. Various xanthan gum concentrations (0.5%, 1%, 1.5%, 2%, and 3%) with respect to dry weight of soil were mixed with clay and subjected to different curing periods (1, 3, 7, 14, and 28 days) to assess their influence on unconfined compressive strength (UCS). Experimental results demonstrate a notable increase in UCS with both higher xanthan gum content and longer curing times. The optimal xanthan gum dosage for maximum strength enhancement was found to be 1.5-2%. The improvement is primarily attributed to hydrogen bonding between xanthan gum molecules and clay particles. Additionally, the failure behavior transitioned from ductile at early curing stages to brittle at longer curing periods, indicating progressive strength gain and structural transformation. These findings suggest that xanthan gum is an effective and sustainable alternative for soil stabilization, offering significant benefits for environmentally conscious geotechnical engineering applications.

This paper develops a novel erosion law that incorporates the influence of stress state into the mass exchange between the liquid and solid phases for suffusion, using the coupled computational fluid dynamics and the discrete element method (CFD-DEM) simulations. To achieve this, a series of CFD-DEM simulation tests are conducted on gap-graded soil samples, followed by the derivation of a new erosion law that considers the influence of seepage velocity and mechanical conditions. The proposed erosion law is then integrated into a four-constituent framework to enable hydromechanical modeling. Furthermore, a fines-dependent constitutive model based on the critical state concept is implemented to account for the influence of suffusion on the mechanical behavior of the soil. The new model is assessed through a series of laboratory hydromechanical tests, yielding satisfactory estimation results. Subsequently, the model is utilized to investigate the influence of soil initial state, including void ratio, friction angle, fine content, and size ratio, on the evolution of erosion. Finally, the mechanical behavior of soils before and after suffusion is modeled using the proposed framework. The results demonstrate that the CFD-DEM-based erosion law, as well as the hydromechanical model, effectively capture the main characteristics of soils subjected to suffusion.

Ambient noise data from 45 stations of the BRASIS network were analyzed, and the spectral ratio between horizontal and vertical amplitudes as a function of frequency was calculated, allowing site effects to be analyzed. The H/V curves were obtained using the Nakamura technique, which enables the evaluation of soil characteristics. This study allows us to improve the resolution of shallow structures in the region's models, showing a better spatial correlation with known tectonic features. By analyzing these curves, information was obtained on the contact between the basement and the underlying sedimentary basin, and for some stations, a shallower contrast was observed. In general, for stations located on the basins, lower fundamental frequency values were obtained, while for stations located at the basin edges, the frequencies showed high values indicative of firm rock. In the stations located in the Chaco-Paraná basin, the fundamental frequency was determined, representing the response to the contact between the basin and the basement, and a second contrast was observed, possibly linked to a volcanic stratum from the Upper Jurassic-Middle Cretaceous at a depth of 550 meters. In the Pantanal basin, the fundamental frequency presented a similar value. Additionally, two impedance contrasts were observed, the most superficial linked to the interface between an Aeolian deposit from the Pleistocene-Holocene, and an older unit associated with lateral migration channels. These results represent a progress in the seismological knowledge of the Chaco-Paraná, Paraná, and Pantanal basins.

This article presents the results of the suitability assessment and identification of favorable sites for photovoltaic solar power plants connected to the electricity grid in northern Benin. The integration of renewable energies into Benin's energy park constitutes a major challenge for which those in power are seeking an optimal solution. The north of the country has strong solar potential, we based our study on this region in order to evaluate the technical and economic feasibility of photovoltaic power plants. The method adopted consists first of analyzing the opportunity to choose potential sites through the combination of a geographic information system (GIS) and a hierarchical analytical process (AHP) approach. In this process, nine (9) factors were weighted, namely solar irradiation, grid connection infrastructure, topography, land cover and use, surface and soil characteristics, environmental risks, flooding, restricted areas and distances from the road and power grid to determine potential sites. Then thanks to the Technique of Order of Preference by Similarity with the Ideal Solution (TOPSIS), the distances were optimized for the identification of the most favorable sites. The results of the application of the selection criteria applied to the northern zone around the substations of the Beninese Energy Electrical located in Bembereke, Djougou, Kandi, Natitingou and Parakou made it possible to identify 25 potential sites then 15 favorable sites. This hybrid method has the advantage of determining both favorable sites and the capacities of the resulting power plants.

Advances and the growing deployment of in-situ soil sensing has the potential to deliver new insights into soil system dynamics. However, it also calls for the development of efficient data analysis methods that can extract interpretable information from continuous data. This study utilises an automated, changepoint-based method for analysing soil moisture time series data. The method is used to autonomously detect wetting events and dynamically estimate parameters describing the drydown characteristics of the soil moisture following the event. Information can then be extracted from the output of the changepoint analysis. This provides an indication of how soils are responding to wetting events, and here we explore if this information corresponds with soil characteristics. In an illustration using soil moisture data from nine different field sites in the United States, different drydown characteristics were observed from the distributions of the estimated parameters. We find that these features can be associated to the climatic regimes and the soil texture of the sites. The potential for identifying changes in soil properties and processes based on shifts in drydown characteristics over time is discussed.

Background/Objective: In irrigated areas, accumulation of salt restricts plant growth, reduces or even stops seed germination, and encourages poor seedling establishment. When the soil's salinity drops, the plants can absorb water and nutrients. A reduction in the growth rate of plants is the initial indication of the plant's response to salinity, which is linked to several metabolic alterations identical to those induced by water stress in plants. This stress significantly impairs crop yield by restricting plant growth. Method: The ultrasonic velocity and density of Arginine in water and 0.2N solutions of Magnesium sulphate, Potassium sulphate, and Sodium sulphate have been measured as a function of concentration at temperatures of 313.15 K and 318.15 K. This fundamental data has been utilized to calculate various thermo-physical parameters of the specified systems. Findings: This study evaluated the impact of Arginine on saline salts, particularly sodium sulphate, magnesium sulphate, and potassium sulphate. The outcome validates the role of Arginine in saline solutions and introduces a novel strategy that improves synthesis through ultrasonic techniques. The degree of interaction is greater for Arginine with magnesium sulphate. It follows that Arginine has greater effectiveness with magnesium sulphate saline solution. It can improve the physical characteristics of saline soil. Novelty: The application of chemical fertilizers adversely affects the physical properties of soil. The application of amino acids in place of harmful fertilizers is sustainable. As a fundamental component of protein, it cannot disrupt the natural balance of soil. The ultrasonic approach is non-destructive, which allows it to determine the type of interaction with greater precision. Keywords: Saline soil, Hydrogen bonding, Solute-solvent interaction, Amino acids, Ultrasonic velocity

Abstract. Plant diversity promotes soil organic carbon (SOC) gains through intricate changes in root-soil interactions and their subsequent influence on soil physical and biological processes. We assessed SOC and pore characteristics of soils under a range of switchgrass-based plant systems 12 years after their establishment. The systems represented a gradient of plant diversity with species richness ranging from 1 to 30 species. We focused on soil biopores as indicators of the legacy of root activity and explored biopore relationships with SOC accumulation. Biopores were measured using X-ray computed micro-tomography. Plant functional richness explained 29 % of bioporosity and 36 % of SOC variation, while bioporosity itself explained 36 % of the variation in SOC. The most diverse plant system (30 species) had the highest SOC, while long-term bare soil fallow and monoculture switchgrass had the lowest. Of particular note was a 2-species mixture of switchgrass (Panicum virgatum L.) and ryegrass (Elymus canadensis), which exhibited the highest bioporosity and achieved SOC levels comparable to those of the systems with 6 and 10 plant species, and were inferior only to the system with 30 species. We conclude that plant diversity may enhance SOC through biopore-mediated mechanisms and suggest a potential for identifying specific plant combinations that may be particularly efficient for fostering biopore formation and, subsequently, SOC sequestration.

Abstract Environments can shape the occurrence and extent of disease outbreaks in wildlife. We studied the effects of environmental features on the occurrence of treponeme‐associated hoof disease (TAHD), an emerging infectious disease of free‐ranging elk ( Cervus canadensis ), in southwestern Washington, USA. During the 2016–2022 harvest seasons, successful elk hunters returned mandatory harvest reports and noted the presence or absence of hoof abnormalities indicative of TAHD. We used generalized linear models and an information‐theoretic approach to model selection to relate (1) the spatial distribution of hoof abnormalities to features of landscapes (land cover, topography, and soil characteristics) and (2) the temporal distribution of hoof abnormalities to precipitation during the year preceding the harvest season. The probability of hoof disease increased with soil clay content and proportion of agricultural land (88% of model weight). We found no conclusive evidence for an effect of precipitation on the occurrence of TAHD, but this could relate to relatively high annual precipitation (>140 cm) in the study area. Nevertheless, disease cases may have been negatively associated with precipitation during February–June (55% of model weight). Soils and land management practices may increase the risk of hoof disease by promoting the survival of pathogens that cause TAHD, the susceptibility of elk to infection, or the intensity of pathogen transmission among elk when congregated. Focusing on areas where the risk of disease is greatest may facilitate the detection of TAHD during surveillance. Likewise, removing infected elk and dispersing uninfected elk from areas with the greatest risk of disease may enhance the effectiveness of efforts to reduce transmission. Basing this work on the knowledge that disease risk is modified by factors of hosts, pathogens, and environments, this study serves as an application of the epidemiological triad framework to better understand the ecology and epidemiology of an emerging infectious disease in wildlife.

Radon exhalation rate and emanation factor values in relation to different soil characteristics.

Invasive alien species pose significant threats to biodiversity and ecosystem functioning in protected areas (PAs) worldwide. This study examines ecological impacts of invasive weeds Lantana camara and Mesosphaerum suaveolens on plant species diversity, community composition and soil chemical properties in Parsa and Shuklaphanta National Parks (NPs), Nepal. In total, we sampled 180 pairs of 5 m × 5 m plots, comprising 45 pairs (3 sites × 15 pairs) for each invasive species in each NP. Across all sampling sites, these weeds consistently reduced species diversity (Shannon, Simpson indices), despite the species- and site-specific variations in species richness and soil characteristics. Non-metric multidimensional scaling and Canonical correspondence analysis revealed substantial modifications in plant species composition, along with shifts in indicator species and an increase in the relative cover of established alien plants in invaded plots. While the effects of invasions on soil properties were inconsistent, L. camara significantly increased soil organic carbon and total nitrogen in Parsa, whereas M. suaveolens had no measurable impact on soil parameters except soil pH in either PA. These results suggest that species diversity indices and changes in species composition serve as reliable ecological indicators for assessing impacts of invasive weeds and monitoring ecological restorations. The decline in species diversity and alterations in plant community composition can have cascading effects on ecosystem processes and livelihoods of local communities. Given the increasing threats of plant invasions in Nepal's PAs, urgent and effective management interventions are needed to prevent further spread, mitigate ecological and socio-economic impacts, and restore invaded habitats.

Exploration of potential ecosystem service trade-offs when establishing trees in different urban substrates.

A new green protocol for selecting translocation sites for coastal cliff endemic plants: a case study from southern Italy.

Impact of forest fires on water quality and nutrient dynamics in burned streams in Patagonia.

Structural and water stability characteristics of surface soil over shallow-buried coal seams: Spatial variability and co-inertia analysis.

Effects of microplastics on the hydraulic properties and pore characteristics of compacted soil

Soil utilization of solid waste: Small strain characteristics of coastal cement soil modified by oyster shell powder under freeze-thaw cycle

Abstract A laboratory study was carried out to investigate how incorporating compost derived from yellow maize cobs at rates of 0, 2, 4, 6, and 8% influences the physical characteristics of gypsiferous soils. The soils, with gypsum contents ranging between 59.5 and 525 g kg −1 , were sampled from surface horizons (0–10 cm to 60–70 cm depth) at the Agricultural Research Station, College of Agriculture, University of Tikrit. The gypsum levels in the seven collected soil types (G1–G7) were as follows: 59.5, 147.3, 226.5, 313.7, 391.2, 453.9, and 525 g kg −1 respectively. Compost was produced from crushed, air-dried yellow corn cobs (4 mm), enriched with nitrogen (urea, 1.4 kg), phosphorus (DAP, 1.4 kg), poultry manure (5.6 kg), and 8.5 kg of fertile soil to support microbial activity and decomposition. Each soil sample was air-dried, ground, and sieved to 2 mm, then mixed with the compost at the designated rates (2–8%) along with a non-amended control (0%). Samples were incubated for two months to allow proper interaction between compost and soil. After incubation, all soil samples were air-dried and sieved again. For analysis, samples from G1–G7 were subjected to pressure levels of 0, -4, -33, -100, -200, -500, -1000, and -1500 kPa using metal cores (60.2 mm diameter, 20 mm height) to estimate the moisture description curve and calculate the values of water available to the plant. Also, the data of the moisture description curve were used to calculate the pore size distribution. The addition of compost improved the soil moisture retention curve by increasing available water content and enhancing mesopore development, resulting in better pore size distribution across all gypsum levels.

Restoring plant diversity on Loess Plateau mining slopes: effects of artificial soil and slope characteristics with management strategies.

Abstract In the autumn of 2024, the Agricultural Research and Experiment Station was the location of a field experiment that was carried out, at University of Kirkuk, to investigate maize response to moisture depletion and tillage depth under drip irrigation utilizing GR and T-Tape emitters. The experiment encompassed three variables: moisture depletion levels (45% and 65%), tillage depths (20 and 30 cm), and emitter types, structured as a split-split-plot design nested within a randomized complete block design (RCBD). The evaluation of the drip irrigation system was conducted before planting. Post-cultivation evaluation presented that GR emitter was achieved the lowest coefficient of variation (C.V %) at 0.0651% and highest field emission uniformity (FEU %) at 95.735%, compared to T-Tape. Moisture depletion at 45% of available water reduced bulk density and increased saturated water conductivity, reaching 1.35 Mg m −3 and 1.52 cm h −1 , respectively, compared to 65% depletion. Tillage at 30 cm depth promoted deeper root growth, as maize roots extended beyond 30 cm, reducing soil compaction and enhancing water and nutrient uptake. This improved plant height and grain yield, reaching 230.88 cm plant −1 and 13.323 Mg ha −1 , respectively, compared to 20 cm tillage. The findings suggest that the integration of 45% moisture depletion, 30 cm tillage, and GR emitters improves soil characteristics and maize yield under drip irrigation. These findings underscore the practical applicability of GR-type emitters and deep tillage techniques in drip-irrigated maize production. Integrated techniques can markedly improve water distribution efficiency, diminish soil compaction, and augment crop production, rendering them appropriate for implementation in water-scarce agricultural settings.

Unraveling depth-dependent patterns of soil physicochemical properties: the role of integrated fertilization regimes in apple orchard profiles.