Search

In infrastructure planning and construction, modeling the subsoil and its associated uncertainty is a fundamental task of geotechnical engineers. However, probabilistic methods and tools for quantifying and displaying the uncertainty of the subsoil models are rarely used in practice where deterministic interpolation dominates. In digital planning using Building Information Modeling (BIM), the probabilistic approach supports creating a discipline model in which the uncertainties of the spatial layer structure are statistically quantified to evaluate the georisks in the design and execution of civil constructions. This article presents a case study using a combination of Sequential Gaussian Simulation (SGSIM) and Sequential Indicator Simulation (SISIM) to account for uncertainties in soil layer geometry. In a case study at the Munich Town Hall, a geostatistical approach is applied and validated based on 70 bore logs, whereby the probabilities for the occurrence of a particular layer are spatially quantified. The case study illustrates the methodology‘s great potential and benefits compared to the conventional deterministic approach based on interpolation procedures. [ABSTRACT FROM AUTHOR]

Implementing probabilistic subsoil models in IFC 2x3 and 4.0 Predicting uncertainties in 3D subsoil models for BIM improves risk assessment and decision‐making and enables a more economical and sustainable planning and execution of construction measures. Based on open‐source software, an approach for implementing probabilistic ground models in the Industry Foundation Classes (IFC) data schema is proposed. The basics of IFC, which are necessary for creating discipline‐specific object geometries as well as their georeferencing and attribution, are explained. Two probabilistic 3D models created with bore‐log and Cone Penetration Test (CPT) data, respectively, serve as application examples; these show the predicted geometry of the soil layers with the associated uncertainties based on volume pixels (voxels). As long as voxel models are not integrated into IFC, isosurfaces provide a viable intermediate solution for representing soil layers and uncertainties. Consistent georeferencing ensures correct positioning in the coordination model. The modeling of subsoil and geotechnical data is shown for different IFC versions. The current IFC version 4 improves surface modeling and reduces data redundancy. The presented approach enables a customized implementation of probabilistic subsoil models in IFC and a more efficient collaboration of the experts involved in creating the BIM model. [ABSTRACT FROM AUTHOR]

Biocrusts play an essential role in maintaining ecosystem stability, which is common in arid and semi‐arid areas. Although there have been some previous studies on the stoichiometry of biocrust subsoil in grazing systems, further research is needed to assess the effects of varying grazing intensities. Four grazing gradients were established to investigate the change mechanism of biocrust subsoil stoichiometry under grazing conditions, considering its seasonal response. These findings revealed that biocrusts' coverage and their chlorophyll content showed a parabolic trend of increasing and then decreasing with the increase in grazing intensity. At the same time, their standard response thresholds to grazing intensity ranged from 2.67 to 5.33 sheep/ha. Moreover, the premise that the biocrust is damaged by grazing trampling has become a consensus; our study found that the biocrust still played an important role, although its structure was destroyed because of its greenness (BG) increased. The influence of grazing intensity on the biocrust subsoil stoichiometry is unquestionable; in addition, they are influenced by a combination of vegetation (10% and 19%) and environmental influences (6% and 18%). Furthermore, it was observed that these changes did not compensate for the reproduction and development of biocrusts in grazing‐induced trampling damage. In this study, the integrated consideration of biocrusts into the grazing system fully affirmed its essential role. Additionally, it clarified the pathways and effect of grazing on biocrusts subsoil stoichiometry, providing a new perspective and reference for developing grazing strategy on the Loess Plateau. [ABSTRACT FROM AUTHOR]

AbstractThe Bekker apparatus is an important tool for measuring soil bearing capacity; however, it is not entirely suitable for deep-sea sediments, and the size of the loading plate can affect the accuracy of the Bekker bearing parameters. This paper employs the Coupled Eulerian-Lagrangian (CEL) method to explore how different conditions impact Bekker bearing parameters. As the size of the loading plate gradually increases, the soil compression mechanism and load path reach a relatively stable state, leading to the stabilization of Bekker bearing parameters. The study proposes a range of plate sizes for deep-sea soils with varying strengths, noting that the physical mechanisms of low-strength soils are relatively simple, making them more consistent with the ideal conditions described by Bekker’s theory. Furthermore, an analysis of the relationship between Bekker bearing parameters and penetration depth reveals that the parameters corresponding to different strength soils vary almost parallel with depth. This is attributed to the same settlement path, where the distribution of loads and the geometrical shapes of the supporting structures remain unchanged, resulting in a similar trend in the variation of Bekker parameters. The research findings provide a theoretical basis for analyzing the bearing capacity characteristics of soft deep-sea soils. [ABSTRACT FROM AUTHOR]

In the geotechnical engineering field, the rapid speed of urbanization triggers the need for direct measurements of sub-soil parameters through in situ testing, accompanied by instant results. At this juncture, the cone penetration test (CPT) is selected for this study. Here, an attempt is made to develop a correlation between cone penetration resistance (qc) and standard penetration blow count (SPT N) in order to predict a reference range of qc for cohesive (silty clay/clayey silt) sub-soil of different SPT-based consistencies. In this context, 25 CPT were conducted adjacent to conventional boreholes accompanied by SPT tests at eight important locations in West Bengal (WB) and Odisha (OR), India, focusing on infrastructure development. Primarily, sub-soil is characterized by bulk unit weight (γ) along with soil behavior type index (IC) estimated from the CPT and compared with the sub-soil profile identified from conventional boreholes. Further, a comparison of qc with SPT N is made to establish a correlation. Also, an attempt is made to tally the established correlation with the earlier correlations established for different regions. This study quantitatively establishes a quadratic correlation (R2 = 0.84) between qc and SPT N, which is found to be in good agreement with the previous correlations. Overall, the key findings of this study, i.e., the predicted range of qc, reveal a reliable method for assessing the consistency of cohesive sub-soil by virtue of the qc. However, this correlation is limited to soft to very stiff silty clay/clayey silt sub-soil formation. [ABSTRACT FROM AUTHOR]

Background and Aims Root system architecture (RSA) plays a key role in plant adaptation to drought, because deep rooting enables better water uptake than shallow rooting under terminal drought. Understanding RSA during early plant development is essential for improving crop yields, because early drought can affect subsequent shoot growth. Herein, we demonstrate that root distribution in the topsoil significantly impacts shoot growth during the early stages of rice (Oryza sativa) development under drought, as assessed through three-dimensional image analysis. Methods We used 109 F12 recombinant inbred lines obtained from a cross between shallow-rooting lowland rice and deep-rooting upland rice, representing a population with diverse RSA. We applied a moderate drought during the early development of rice grown in a plant pot (25 cm in height) by stopping irrigation 14 days after sowing. Time-series RSA at 14, 21 and 28 days after sowing was visualized by X-ray computed tomography and, subsequently, compared between drought and well-watered conditions. After this analysis, we investigated drought-avoidant RSA further by testing 20 randomly selected recombinant inbred lines in drought conditions. Key Results We inferred the root location that most influences shoot growth using a hierarchical Bayes approach: the root segment depth that impacted shoot growth positively ranged between 1.7 and 3.4 cm in drought conditions and between 0.0 and 1.7 cm in well-watered conditions. Drought-avoidant recombinant inbred lines had a higher root density in the lower layers of the topsoil compared with the others. Conclusions Fine classification of soil layers using three-dimensional image analysis revealed that increasing root density in the lower layers of the topsoil, rather than in the subsoil, is advantageous for drought avoidance during the early growth stage of rice. [ABSTRACT FROM AUTHOR]

Biopores formed by the actions of decaying roots of plants and soil fauna are essential for providing preferential growth pathways into deeper soil when the subsoil is compacted. Biopores help with rapid transportation of oxygen which increases microbial activity. These positive impacts help to increase the yield of crops even in adverse environmental conditions. However, the impact of biopores depends on various climatic and soil conditions. Understanding the mechanisms of different factors controlling the influences of biopores on the growth and development of plant roots is essential for getting more benefits in crop production. While several reviews have explored biopore-root interactions in crop production, there remains a lack of systematic studies on the factors influencing these interactions. In this review, we discussed different factors affecting the impacts of biopores on various crops in different situations based on current literature. It is also explained how we can maximize these impacts for getting benefits in sustainable crop production. Biopore improves the soil structure which has vital role on the growth of crops. On the other hand, clumping of roots within the biopores was also observed which may negatively affect crop growth. Similarly, biopores increase water infiltration as well as the leaching of nutrients. The influences of biopores depend on pore characteristics, abundance of biopores, moisture content, management practices, edaphic conditions, plant species etc. Understanding the factors influencing biopore-root interaction can contribute to improve root accessing into the deeper soil, enhancing their adaptation in stressful soil conditions. [ABSTRACT FROM AUTHOR]

Field observations and centrifuge tests indicate that progressive column bending failure accompanies most instabilities of rigid-column-supported and geosynthetic-reinforced (RCGR) embankments. However, recognized guidelines specifically for evaluating the overall stability of such systems featuring bending failure remain limited. A general methodology to calculate the factor of safety (FS) for RCGR embankments using the limit equilibrium method is presented in this article. The focus is on deep-seated slope failures, wherein rigid columns progressively fracture due to subsoil overstressing. The concentric arches model, along with tensioned geosynthetic analysis, informs the determination of vertical and horizontal loads on the column heads. The column's resisting moment stems from its flexural and compression resistance. A mobilization factor for the net thrust on each column is defined to capture the progressive failure. The methodology involves an iterative computational procedure to identify the critical slip surface and the FS using the Fellenius' method. The solution was validated using three case studies, including both centrifuge models and field tests, as well as finite-element analysis. The results indicate that the soil mass contributes the most to resisting sliding and overall stability, followed by columns and geosynthetics. In addition, axial force mainly provides the resisting moment of columns. [ABSTRACT FROM AUTHOR]

Experimental studies on the influence of geogrids in unbound base layers In railroad construction, base layers of unbound coarse‐grained material are usually installed between the existing subsoil and the rail track. Geosynthetics, in particular geogrids, are used to improve the system behaviour. The reduction of the base layer thickness by the geogrid is based on empirical approaches. The influence of the geogrid on the load‐bearing behavior of a base course is to be quantified by experimental investigations. The investigation is performed using a downscaled base course material and geogrid. For this purpose, monotonic and cyclic triaxial tests were performed to demonstrate the failure and the cyclic loading behaviour. In the monotonic triaxial tests the specimens were sheared to failure. The positive influence of the geogrids compared to the unreinforced specimens could be quantified. Since the in‐situ stresses are mainly in the service load range and thus the failure state is not reached, but the stress follows a high number of load cycles, cyclic triaxial tests were performed. The test specimens were loaded cyclically in order to investigate the influence of the geogrid on the deformation accumulation. The cyclically loaded specimens thus show the influence of the geogrid on deformation accumulation. As a result, a reduction in deformation accumulation due to the geogrid could be demonstrated. [ABSTRACT FROM AUTHOR]

Verification of sufficient anchor lengths with the FEM for double back anchoring The article analyses the necessity of the minimum length of grouted anchors for excavation walls. The required verification of a sufficient anchor length is to be carried out according to current standards with the verification of stability in the lower failure plane. Here, calculations using the finite element method (FEM) are not intended. The future Europe‐wide standardisation will foreseeably lead to an increased use of the FEM for stability verifications, without all details of these verifications having already been defined. The verification of the sufficient anchor length of single back‐anchored excavation walls using the FEM has already been analysed. A stepwise reduction of the shear parameters of the soil was identified as the most suitable method. However, this does not correspond to the procedure specified in the current German standard of a comparison of the existing anchor force with a possible anchor force from an investigation of the lower failure plane. The article uses an example to investigate whether the method of stepwise reducing the shear parameters of the soil also leads to plausible results for double‐anchored excavation walls. Here, the determination of the failure mechanisms in the subsoil is of high importance. One question is whether a variation of both anchor lengths results in different failure mechanisms, as it is the case applying classic methods. [ABSTRACT FROM AUTHOR]

Designing an ash pond for the High Concentrated Slurry Disposal (HCSD) in hilly terrains poses a unique set of challenges. In such regions, the availability of barren land adjacent to the project sites is limited, making it difficult to locate suitable sites for ash pond construction. Furthermore, the hilly terrain and complex topography demand careful planning and design to ensure the long-term stability and safety of the ash pond and associated infrastructure. This paper discusses the design considerations for the construction of ash pond dykes in a hilly region of Vietnam for the HCSD disposal. The case study highlights detailed geotechnical design investigations, such as soil type, slope stability and groundwater conditions. In addition, geotechnical instrumentation to monitor the performance of ash pond dykes and the subsoil supporting it during and after construction is also discussed. The paper also examines the environmental and hydrological design aspects of the ash pond, including the development of drainage and channelization concept along the hilly terrain to manage storm water and prevent the mixing of rain water with ash slurry. Such mixing could otherwise create an environmental hazard. [ABSTRACT FROM AUTHOR]

A settlement analysis of a new high-rise building, the Nivy Tower, in Bratislava, Slovakia, is presented in this paper. A 3D finite element model was prepared. A non-linear elasto-plastic material model with double hardening and increased stiffness in a small-to-very-small strain range was adopted for the Tertiary (Neogene) subsoils. Due to the lack of an appropriate in-situ test, the results from a 1D compression test were used for the calibration of the soil input parameters. However, the results from these tests, especially in the primary loading, are often biased due to the effects of soil disturbance during the preparation of the sample. Therefore, a different procedure has been proposed, in which the stiffness parameters were obtained from unloading-reloading branches of 1D compression tests. It could be concluded that the predicted and measured settlements are in a reasonable match for all the points measured. The computed distributions of the vertical displacements and those measured by sliding micrometres show greater differences from a depth of twenty meters beneath the foundation slab. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the effects of soil penetration resistance, tillage depth, and operating speeds on the deformation and fatigue of the subsoiling shovel based on the real-time measurement of tractor-operating conditions data. Various types of sensors, such as force, displacement, and angle, were integrated. The software and hardware architectures of the monitoring system were designed to develop a field operation condition parameter monitoring system, which can measure the tractor's traction force of the lower tie-bar, the real-time speed, the latitude and longitude, tillage depth, and the strain of the subsoiling shovel and other condition parameters in real-time. The time domain extrapolation method was used to process the measured data to obtain the load spectrum. The linear damage accumulation theory was used to calculate the load damage of the subsoiling shovel. The magnitude of the damage value was used to characterize the severity of the operation. The signal acquisition test and typical parameter test were conducted for the monitoring system, and the test results showed that the reliability and accuracy of the monitoring system met the requirements. The subsoiling operation test of the system was carried out, which mainly included two kinds of soil penetration resistances (1750 kPa and 2750 kPa), three kinds of tillage depth (250 mm, 300 mm, and 350 mm), and three kinds of operation speed (4 km/h low speed, 6 km/h medium speed, and 8 km/h high speed), totaling 18 kinds of test conditions. Eventually, the effects of changes in working condition parameters of the subsoiling operation on the overall damage of subsoiling shovels and the differences in damage occurring between the front and rear rows of subsoiling shovels under the same test conditions were analyzed. The test results show that under the same soil penetration resistance, the overall damage sustained by the subsoiling shovels increases regardless of the increase in the tillage depth or operating speed. In particular, the increase in the tillage depth increased the severity of subsoiling shovel damage by 19.73%, which was higher than the 17.48% increase due to soil penetration resistance and the 13.07% increase due to the operating speed. It should be noted that the front subsoiling shovels consistently sustained more damage than the rear, and the difference was able to reach 16.86%. This paper may provide useful information for subsoiling operations, i.e., the operational efficiency and the damage level of subsoiling shovels should be considered. [ABSTRACT FROM AUTHOR]

Load transfer platform (LTP) plays an important role in load transfer between piles and subsoil in pile-supported embankments over soft soils. This study conducted spring-based trapdoor tests to investigate the load transfer mechanisms of LTPs with unreinforced and geosynthetic-reinforced river sand and lightweight aggregate (LWA) subjected to differential movement. Spring-based trapdoor tests were used to simulate the differential movement below the LTP under fill placement and surface footing loading to investigate the mobilization and degradation of soil arching and tensioned membrane effects above the trapdoor (simulating the subsoil settlement). To evaluate the trapdoor rigidity effect, both rigid (one-segment) and flexible (three-segment) trapdoors were utilized. Test results revealed that LWA, when utilized as an LTP material, could effectively improve the mobilization of soil arching, hinder the degradation of soil arching, and reduce the trapdoor settlement. LWA was proven to be a good alternative LTP fill material in pile-supported embankments. Geosynthetic reinforcement was beneficial to minimize degradation of soil arching. In the rigid trapdoor tests, the tensioned membrane effect was progressively mobilized with the applied footing pressure. However, the flexible trapdoor tests showed rapid mobilization of the tensioned membrane effect, followed by a sustained mobilization, and then a rapid arching degradation after a certain applied pressure was reached and continued. Under surface footing loading, the embankment with the LWA as the LTP fill material showed an inverted tower-shape deformation pattern, whereas that with the river sand as the LTP material exhibited a rectangular deformation pattern. [ABSTRACT FROM AUTHOR]

Abstract Water clarity on the inshore Great Barrier Reef (GBR) is greatly influenced by terrestrial runoff of suspended particulate matter (SPM). Catchment sediment tracing studies often do not extend into the marine environment, preventing the analysis of preferential marine transport. This study employs novel collection and sediment tracing techniques to examine the transport of the terrigenous ‘mineral’ component of plume SPM within the GBR lagoon for two flood events. Utilising geochemical, radionuclide and clay mineral analysis, we trace terrigenous mineral sediments > 100 km from the river mouth. We show that the SPM geochemistry is highly influenced by particle-size fractionation, desorption, and dilution within the plume, rendering traditional tracing methods unviable. However, the ratios of rare earth elements (REE) to thorium (Th) provide stable tracers of mineral SPM transported across the catchment to marine continuum and allow the identification of discrete catchment sources for each flood event. Plume sediment radionuclides are also stable and consistent with sub-surface erosion sources.

The self-healing capacities of a GCL with natural bentonite (NB) as core (NB-GCL) and a GCL with a polymerized bentonite (PB) as core (PB-GCL) were investigated under simulated field conditions, i.e. geomembrane-GCL-a clayey subsoil layer composite liner system with a damage hole on the geomembrane and the GCL. The clayey subsoils tested had initial water contents of 22.2% and 26.8%. The liquids used were deionized (DI) water and 0.3 M NaCl solution. The test results indicate that for both the PB-GCL and NB-GCL only hydrated on the subsoils for 1–3 months, a damage hole of 15 mm in diameter was almost not self-healed. For cases of applying a constant liquid head on the top of the geomembrane of 100 mm, the sizes of damage holes were self-healed in term of diameter is about half of the values reported in the literature for tests with plenty liquid supply to the damaged GCLs. Further, for the conditions tested and for the cases self-healed, DI water leaked into the subsoil was less than about 60 g, and 0.3 M NaCl solution leaked was less than 150 g. • Self-healing capacity of GCLs was newly studied under a simulated field condition. • GCLs hydrated on clayey subsoils had very limited self-healing capacity. • Self-heling capacity of GCLs with limited liquid supply was clarified. • Leakage through a hole on GCL before it was self-healed was novelly investigated. [ABSTRACT FROM AUTHOR]

Biogas slurry is increasingly adopted as a substitute for chemical fertilizer to improve soil fertility and control soil degradation. But little is known about its long-term effects on different soil layers. This study aims to test if biogas slurry substitution alters soil nutrients and aggregates differently in different layers and how the effects are influenced by straw return. A five-year field trial of a winter wheat–summer maize rotation was established to evaluate the effects of biogas slurry substitution [treatments: control without fertilizer (CK); chemical fertilizer (CF); 50% biogas slurry substitution (BSCF); 100% biogas slurry substitution (BS)] on two soil layers (0–20 and 20–40 cm) under equal N, P, and K fertilization in a Fluvisol. The result showed that compared with CK, fertilization was necessary to maintain soil available nitrogen (AN) and available potassium (AK) in the 0–20 cm layer. Also, fertilization had positive effects on soil EC, TN, and AP, especially in the topsoil. In terms of increasing the degree of water-stable macroaggregation, improving aggregate stability and reducing their crushing rates, CF was superior to biogas slurry substitution because of the greater accumulations of soil N, the most important physicochemical factor regulating soil macroaggregation and stability. The effects of biogas slurry substitution changed with soil layers. In surface soil, BD, water-stable macroaggregates, and aggregate stability significantly increased due to the positive regulatory effects of straw, AP, and EC; whereas in subsoil, they decreased. Inorganic fertilization with straw return functions well in soil structural degradation control and N fertility improvement, especially in the topsoil. Whereas in fields without straw return, biogas slurry substitution may be a feasible and economical choice to improve topsoil structure and also an excellent supplement to provide P and K. [ABSTRACT FROM AUTHOR]

Background and aim: Deep roots are important for crops to access water when the topsoil is dry. Root anatomy and activity play an important role in water uptake. However, little is known about the effects of root distribution and anatomical structure on water uptake and grain yield under different water conditions. This study aimed to reveal the contribution of deeper roots, root anatomy and root activity on grain yield and water use efficiency. Methods: A field experiment and Rhizobox experiment were performed to evaluate the effects of changes in root distribution, root anatomy and root activity on grain yield and water use efficiency under three water conditions. Three dryland wheat cultivars (BM1, CH58 and CH1) were compared. Results: BM1 formed a root system, which limited the acquisition of water in the subsoil, resulting in lower grain yield and water use efficiency in field and rhizobox experiments. In contrast, cultivars CH58 and CH1 exhibited greater root biomass and root length density in the subsoil, optimizing subsoil water uptake, thereby increasing grain yield and water use efficiency. CH58 had a smaller root diameter and vessel diameter, thicker cortex thickness, higher root cortex thickness-to-diameter ratio and higher root activity. Conclusion: This study demonstrated that, deeper roots, root anatomy and root activity are important traits in selecting wheat cultivars that maintain yield under low water conditions. Therefore, wheat crop development and breeding to improve grain yield should also consider optimizing root anatomy and improving root activity while promoting deep root development. [ABSTRACT FROM AUTHOR]

To address the problem of large tractive resistance in traditional subsoiling methods, this paper designed a pulse-type gas explosion subsoiler, as well as an air-blown double-ended chisel type subsoiling shovel and a conduit. The mathematical equation of the influence of the structural parameters of the subsoiler on the groove profile is established. The EDEM 2022 software was used to simulate the subsoiling operation process. The soil disturbance law of the chisel subsoiler was analyzed by the change of soil particle velocity. The optimum value interval of quadratic regression orthogonal rotation combination test factors was determined by using the steepest climb test, with specific tillage resistance and filling power as evaluation indicators. Based on the Box–Behnken design test, a second-order regression model of response value and significance parameter was obtained, and an optimal combination was found by optimizing the significance parameter. The effects of subsoiling air pressure, pulse width and pulse interval on evaluation indicators were analyzed by the response surface method; the test results show that when the air pressure was 0.8 MPa, the pulse width was 0.17 s and the pulse interval was 0.12 s, and the specific tillage resistance was 0.4421 N/mm2 and the filling power was 18.5%; a comparative test between the pulse-type gas explosion subsoiler and a continuous gas explosion subsoiler was carried out, and the specific tillage resistance was reduced by 12.2% and the filling power was reduced by 10.5%; the comparative test shows that the pulse-type gas explosion subsoiler has smaller tractive resistance per unit area and smaller disturbance to soil. The research results provide a theoretical basis and reference for the optimization and improvement of gas explosion subsoilers. [ABSTRACT FROM AUTHOR]

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

To achieve high maize (Zea mays L.) yields and quality grain, it is necessary to develop stress-resistant cultivars and related cultivation practices, aiming to maximize efficiency. Thus, our objectives were (i) to investigate the impact of tillage practices and maize hybrids (which have improved over time) on yield and its components, and (ii) to characterize the response pattern of maize hybrid grain nutrient quality components to subsoiling. To achieve this, we conducted field trials with five maize hybrids from different eras under two tillage practices: rotary tillage and subsoiling. We compared grain yield, nutritional quality, and other indicators across different tillage conditions from the 1970s to the 2010s. The main results of this study are as follows: under rotary tillage conditions, the 2010s hybrid (DH618) significantly increased yields (9.37–55.89%) compared to hybrids from the 1970s–2000s. After subsoiling, the physiologically mature grains of all hybrids exhibited minimal changes in crude protein and fat content, while there was a significant reduction in the total soluble sugar content of the grains. After subsoiling, there was a substantial 8.14 to 12.79 percent increase in total starch accumulation in the grain for all hybrids during the period of 47–75 days post-anthesis. Furthermore, during the period of 47–75 days after anthesis, the consumption of grain crude protein significantly contributed to the accumulation of total starch in the grains. Ultimately, subsoiling significantly increased the yield of each hybrid and enhanced the total grain starch content at physiological maturity of all hybrids, with the 2010s hybrid (DH618) performing exceptionally well. [ABSTRACT FROM AUTHOR]

Water clarity on the inshore Great Barrier Reef (GBR) is greatly influenced by terrestrial runoff of suspended particulate matter (SPM). Catchment sediment tracing studies often do not extend into the marine environment, preventing the analysis of preferential marine transport. This study employs novel collection and sediment tracing techniques to examine the transport of the terrigenous ‘mineral’ component of plume SPM within the GBR lagoon for two flood events. Utilising geochemical, radionuclide and clay mineral analysis, we trace terrigenous mineral sediments > 100 km from the river mouth. We show that the SPM geochemistry is highly influenced by particle-size fractionation, desorption, and dilution within the plume, rendering traditional tracing methods unviable. However, the ratios of rare earth elements (REE) to thorium (Th) provide stable tracers of mineral SPM transported across the catchment to marine continuum and allow the identification of discrete catchment sources for each flood event. Plume sediment radionuclides are also stable and consistent with sub-surface erosion sources. [ABSTRACT FROM AUTHOR]

Introduction: To address issues related to shallow soil tillage, low soil nutrient content, and single tillage method in maize production in the Western Inner Mongolia Region, this study implemented various tillage and straw return techniques, including strip cultivation, subsoiling, deep tillage, no-tillage, straw incorporation with strip cultivation, straw incorporation with subsoiling, straw incorporation with deep tillage, and straw incorporation with no tillage, while using conventional shallow spinning by farmers as the control. Methods: We employed Xianyu 696 (XY696) and Ximeng 6 (XM6) as experimental materials to assess maize 100-grains weight, grain filling rate parameters, and grain nutrient quality. This investigation aimed to elucidate how tillage and straw return influence the accumulation of grain material in different maize varieties. Results and discussion: The results indicated that proper implementation of tillage and straw return had a significant impact on the 100-grains weight of both varieties. In comparison to CK (farmer's rotary rotation), the most notable rise in 100-grains weight was observed under the DPR treatment (straw incorporation with deep tillage), with a maximum increase of 4.84% for XY696 and 6.28% for XM6. The proper implementation of tillage and straw return in the field resulted in discernible differences in the stages of improving the grain filling rates of different maize varieties. Specifically, XY696 showed a predominant increase in the filling rate during the early stage (V1), while XM6 exhibited an increase in the filling rates during the middle and late stages (V2 and V3). In comparison to CK, V1 increased by 1.54% to 27.56% in XY696, and V2 and V3 increased by 0.41% to 10.42% in XM6 under various tillage and straw return practices. The proper implementation of tillage and straw return had a significant impact on the nutritional quality of the grains in each variety. In comparison to CK, the DPR treatment resulted in the most pronounced decrease in the soluble sugar content of grains by 25.43% and the greatest increase in the crude fat content of grains by 9.67%. Conclusion: Ultimately, the proper implementation of soil tillage and straw return facilitated an increase in grain crude fat content and significantly boosted grain weight by improving the grouting rate parameters at all stages for various maize varieties. Additionally, the utilization of DPR treatment proved to be more effective. Overall, DPR is the most promising strategy to improve maize yield and the nutritional quality of grain in the long term in the Western Inner Mongolia Region. [ABSTRACT FROM AUTHOR]

The research conducted in the north Steppe of Ukraine throughout 2020-2022 studied such elements of corn growing technique as the basic tillage method and mineral fertilization for corn hybrids of different ripeness groups. It was found that the highest yield among all hybrids under experiment was achieved as a result of using turning plowing method. The LG 31377 hybrid showed itself as the most productive with the result of 8.91 t/ha. Change from turning plowing to subsoiling led to insignificant yield reduction, which constituted 1.7% and 1.9% for middle-early LG 31272 and Adevey hybrids and to minor but essential 3.5% for middle-ripe LG 31330 and LG 31377 hybrids. Growing corn after shallow tillage caused yield losses of 15.5-24.0%. While studying the impact of fertilizers on corn hybrid productivity, it was concluded, that the lowest yield was harvested on plots with no mineral fertilization. Within the range of hybrids under research, in case of no fertilizers used, the lowest productivity 7.33 t/ha was registered for the LG 31377 hybrid, while the highest yield of 7.48 t/ha was formed by the LG 31272. The application of mineral fertilizers in the amount of N30P30K30 contributed to the yield growth by 10.1-17.2% among the hybrids under research, which constituted 0.76 t/ha for the LG 31272, 1.04 t/ha for the Adevey, 1.08 t/ha for the LG 31330 and 1.26 t/ha for the LG 31377 hybrid. The increase of mineral fertilizers amount to N60P60K60 resulted in further yield growth of 0.6-2.2% only. In case of application of N30P30K30 and N60P60K60 the LG 31377 had the highest yield among other hybrids -- 8.59 and 8.78 t/ha. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Actual Problems of Jurisprudence / Habaršy. Zan̦ Seriâsy is the property of Al-Farabi Kazakh National University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article is devoted to the study of the problems of the institute of reclamation of lands that were violated due to the extraction of minerals and geological study of the subsoil. The article analyzes the legal regulation of land reclamation in Ukraine and the reclamation of lands that have been violated as a result of mineral extraction and geological exploration of the subsoil, the ways of improving the legal regulation of the said institute are established. The article states that mining activity has significantly changed the surrounding natural environment, including some natural regions of Ukraine. It was established that mining and geological exploration of the subsoil caused significant changes in the geological environment of the country. It was found that one of the main factors of negative impact on the environment is the extremely high concentration of mining enterprises and the consequences of mineral extraction. It has been established that one of the necessary steps contributing to the improvement of the condition of lands that have been disturbed as a result of mining is land reclamation. The choice of the method and methods of reclamation of disturbed lands depends on the type of mineral, the method of its extraction, and the soil conditions of the region. It was found that the processes of reclamation of disturbed lands in the field of subsoil use are divided into: mining and biological stages. It is noted that the legal definition of reclamation of disturbed lands does not fully reflect the content of the said institution and its legal nature. The article defines the reclamation of lands disturbed as a result of mining operations and geological study of the subsoil and substantiates the expediency of supplementing the legislation with the specified concept. The article proposes: to supplement Chapter VI of the Law of Ukraine «On Land Protection» with the provision «land protection during the geological study of the subsoil and mining operations», to adopt the Law of Ukraine «On Land Reclamation», one of the sections of which should be a section devoted to «land reclamation during geological study of the subsoil and mining operations». It was concluded that the institute of reclamation of damaged lands is important for improving the condition of soils, as one of the important means of land protection. It has been proven that the reclaimed territories should constitute an optimally formed and ecologically balanced landscape area with mandatory landscape mapping. [ABSTRACT FROM AUTHOR]

The high number of grapevine (Vitis vinifera L.) cultivars grown world-wide are described and identified according to detailed morphological and morphometric descriptor lists. The grapevine leaf is of utmost importance in characterization, despite its traits being very sensitive to environmental factors. In this study, the effect of irrigation/drought stress on the individual leaf morphology and morphometry of the 'Hárslevelű' grapevine (Vitis vinifera L.) cultivar was examined. To verify the effect of the applied irrigation methods (drip and subsoil irrigation) on the plant's water status, water potential measurements were carried out during the 2022 season. The effect of the applied treatments on the vegetative growth was evaluated according to point quadrat and a multichannel LiDAR analysis in order to describe the width of the canopy area, row volume, and area coverage index. The individual leaf morphology was assessed via traditional morphometry and colorimetry. Our results showed that rainfed plants had a significantly lower stem ψ compared to the drip- and subsoil-irrigated plants at all examined dates. The point quadrat results indicate that the leaf layer number was significantly (p < 0.05) influenced by the position, while the treatment showed no effect on the leaf layer number. The leaf colorimetry showed a difference among the samples, as significant alterations were found in 28 out of the 32 examined color properties. Within the traditional morphometric analysis, 54 traits were evaluated, and 14 of the traits were significantly altered due to the different water management systems. [ABSTRACT FROM AUTHOR]

We present an integrated site investigation of a proposed estate with a view to generating baseline data required for safe design and construction of structures and groundwater schemes, installation and protection of utilities, and post-construction environmental issues. An electrical resistivity survey involving 1D and 2D imaging techniques was involved. The 1D resistivity imaging involved the Schlumberger Vertical Electrical Sounding (VES) with half current electrode spacing of 1–125 m, whose data were interpreted for layer resistivities and thicknesses using segment-by-segment curve matching and 1D forward modeling with W-Geosoft/WinSev 5.1 code. The 2D dipole-dipole resistivity imaging utilized 20 m dipole length and an expansion factor (n) ranging from 1 to 5. The 2D data were inverted to 2D resistivity images with DIPRO software. The 1D and 2D interpretation models delineated five subsurface layers comprising topsoil, fill, laterite, weathered basement, and fresh basement. The weathered basement is the main aquifer with thicknesses ranging from 11.9 to 64.4 m with prospect for groundwater development. The essentially lateritic subsoils in the upper 10 m with resistivity values generally > 450 Ωm are adjudged moderately to highly competent. The low-porosity/permeability lateritic layer overlying the weathered layer aquifer constitutes a sealant against infiltrating pollutant with the groundwater significantly protected. Except within the stream channel, the soils/subsoils are practically non-corrosive. [ABSTRACT FROM AUTHOR]

The high-speed rail networks are engineered to enable rapid and effective transit. They are expected to be fully functional even during adverse operational conditions such as heavy rain, fluctuating water level, and the dynamic nature of external loadings. However, several case histories and recent research development exhibited the limitations of the effectiveness of embankment stability confronted with severe and prolonged precipitation and adverse saturated subsoil conditions. Besides, the mechanism of shear reinforcement and the effects of soil–water characteristics on the dynamic stability of embankment needs to be better understood. Therefore, conducting dynamic analyses for high-speed railways (HSR) considering fluctuating saturated subsoil conditions is vital for railway embankment's structural robustness and operational serviceability. The presented study focuses on the dynamic analysis of an HSR embankment, considering the intricate interaction between pore pressure dynamics and associated deformations. The embankment positioned alongside the railway track is subjected to varying levels of precipitation and groundwater exposure. The analysis commences with a gravitational assessment, probing the embankment's behavior under the influence of both elastic and plastic properties inherent to the constituent soil layers. Employing a 2D dynamic inelastic framework, the study rigorously integrates the reciprocal influence of pore-pressure dynamics and deformation effects. This sophisticated analysis methodology leverages the OPENSEES framework. Implications of interaction between the degree and extent of saturation in the subsoil and associated embankment deformation are also discussed. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) persistence is predominantly governed by mineral protection, consequently, soil mineral-associated (MAOC) and particulate organic carbon (POC) turnovers have different impacts on the vulnerability of SOC to climate change. Here, we generate the global MAOC and POC maps using 8341 observations and then infer the turnover times of MAOC and POC by a data-model integration approach. Global MAOC and POC storages are 975 964 987 Pg C (mean with 5% and 95% quantiles) and 330 323 337 Pg C, while global mean MAOC and POC turnover times are 129 45 383 yr and 23 5 82 yr in the top meter, respectively. Climate warming-induced acceleration of MAOC and POC decomposition is greater in subsoil than that in topsoil. Overall, the global atlas of MAOC and POC turnover, together with the global distributions of MAOC and POC stocks, provide a benchmark for Earth system models to diagnose SOC-climate change feedback. Separating soil organic carbon into mineral-associated and particulate organic carbon enables a more accurate prediction of soil vulnerability to climate change. The authors generate the global atlas of stocks and turnover times of these two fractions. [ABSTRACT FROM AUTHOR]

Background: This study unveils the intricate functional association between cyclic di-3',5'-adenylic acid (c-di-AMP) signaling, cellular bioenergetics, and the regulation of lipopolysaccharide (LPS) profile in Porphyromonas gingivalis, a Gram-negative obligate anaerobe considered as a keystone pathogen involved in the pathogenesis of chronic periodontitis. Previous research has identified variations in P. gingivalis LPS profile as a major virulence factor, yet the underlying mechanism of its modulation has remained elusive. Methods: We employed a comprehensive methodological approach, combining two mutants exhibiting varying levels of c-di-AMP compared to the wild type, alongside an optimized analytical methodology that combines conventional mass spectrometry techniques with a novel approach known as FLATn. Results: We demonstrate that c-di-AMP acts as a metabolic nexus, connecting bioenergetic status to nuanced shifts in fatty acid and glycosyl profiles within P. gingivalis LPS. Notably, the predicted regulator gene cdaR, serving as a potent regulator of c-di-AMP synthesis, was found essential for producing Nacetylgalactosamine and an unidentified glycolipid class associated with the LPS profile. Conclusion: The multifaceted roles of c-di-AMP in bacterial physiology are underscored, emphasizing its significance in orchestrating adaptive responses to stimuli. Furthermore, our findings illuminate the significance of LPS variations and c-di-AMP signaling in determining the biological activities and immunostimulatory potential of P. gingivalis LPS, promoting a pathoadaptive strategy. The study expands the understanding of c-di-AMP pathways in Gramnegative species, laying a foundation for future investigations into the mechanisms governing variations in LPS structure at the molecular level and their implications for host-pathogen interactions. [ABSTRACT FROM AUTHOR]

The porcine epidemic diarrhea virus (PEDV) infection inflicted substantial economic losses upon the global pig-breeding industry. This pathogen can infect all pigs and poses a particularly high fatality risk for suckling piglets. The S1 subunit of spike protein is a crucial target protein for inducing the particularly neutralizing antibodies that can intercept the virus-host interaction and neutralize virus infectivity. In the present study, the HEK293F eukaryotic expression system was successfully utilized to express and produce recombinant S1 protein. Through quantitative analysis, five monoclonal antibodies (mAbs) specifically targeting the recombinant S1 protein of PEDV were developed and subsequently evaluated using enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA), and flow cytometry assay (FCA). The results indicate that all five mAbs belong to the IgG1 isotype, and their half-maximal effective concentration (EC50) values measured at 84.77, 7.42, 0.89, 14.64, and 7.86 pM. All these five mAbs can be utilized in ELISA, FCA, and IFA for the detection of PEDV infection. MAb 5-F9 exhibits the highest sensitivity to detect as low as 0.3125 ng/mL of recombinant PEDV-S1 protein in ELISA, while only 0.096 ng/mL of mAb 5-F9 is required to detect PEDV in FCA. The results from antigen epitope analysis indicated that mAb 8-G2 is the sole antibody capable of recognizing linear epitopes. In conclusion, this study has yielded a highly immunogenic S1 protein and five high-affinity mAbs specifically targeting the S1 protein. These findings have significant implications for early detection of PEDV infection and provide a solid foundation for further investigation into studying virus-host interactions. [ABSTRACT FROM AUTHOR]

To date, Hessdalen lights (HLs) are misunderstood; nevertheless, these phenomena are surprisingly ignored by most of the scientific community. However, a few researchers, such as Erling Strand and Massimo Teodorani, have paved the right path by showing that experimental methods of physics can be applied to study HLs. Additionally, we believe that matter cannot simply be brushed aside and that it deserves a serious examination. Recently, we proposed a possible origin of HLs (Pascoli, 2021). The basic idea--a micrometric wormhole manifestation--is promoted here, and we suggest that the Hessdalen-type lights, seen pretty much everywhere in the world, may eventually be interpreted as a symptom of an unsuspected phenomenon deep in the subsoil of the considered site. The idea of a geological origin for the Hessdalen lights has already been proposed (Teodorani, 2004, 2014); however, this interesting suggestion is being reconsidered from an entirely new perspective. The present paper has to be seen as a working hypothesis, in which the main interests are to foster thinking on underlying physics and to suggest a full series of experiments that can be performed on these very enigmatic Hessdalen lights. Regardless of the strength of a hypothesis, the experiment is the final arbiter in science. [ABSTRACT FROM AUTHOR]

No-tillage of summer maize after the harvest of winter wheat is the primary agricultural practice on the North China Plain. However, prolonged no-tillage without deep tillage practices negatively impacts soil properties, which is detrimental to the growth and yield of summer maize. In this study, Xianyu 688 and Jifeng 2 were used as test maize materials, no-tillage and surface fertilizing with normal nitrogen (N) (BC240), no-tillage and surface fertilizing with N reduction (BC180), subsoiling layered fertilization with normal N (FC240) and subsoiling layered fertilization with N reduction (FC180)were designed, in order to assess root distribution, N utilization and grain yield of summer maize. In the two maize cultivars, the FC240 and FC180 treatments significantly reduced soil bulk density in the 10–50 cm depth soil layer compared to the other two treatments, and also increased total N content in the 20–50 cm depth soil layer. Compare BC 240 treatment, the FC240 treatment significantly increased root length in the 20–40 cm soil layer and root rap bleeding. Additionally, the FC240 and FC180 treatments enhanced dry matter and N accumulation, grain yield, N uptake efficiency and N fertilizer partial factor productivity. In various treatment, Xianyu 688 exhibited increased grain yield, N uptake efficiency and N fertilizer partial factor productivity compare with Jifeng 2. When employing a total N application level of 180–240 kg N/hm2, the synergistic improvement of summer maize grain yield and N efficiency can be achieved by incorporating subsoiling combined with layered nitrogen application. [ABSTRACT FROM AUTHOR]

Visco‐hypoplastic material model for tertiary soils in Frankfurt am Main The subsoil conditions in the city centre of Frankfurt am Main are characterized by tertiary over‐consolidated clays and clayey marls with embedded limestone banks and sand layers, whose thickness varies considerably depending on the location. In a research project, the time‐dependent material response of these tertiary clays, which significantly influence the deformation behaviour of buildings, was investigated with a comprehensive laboratory test program and a set of parameters for the visco‐hypoplastic AVISA model was determined. This article summarizes the findings obtained for the tertiary Frankfurt clays. In addition, a concept is proposed with which the system permeability and the system stiffness of the heterogeneous tertiary layers taking into account embedded limestone banks and sand layers can be realistically modelled in 3D coupled pore pressure‐displacement analyses with the finite element method. [ABSTRACT FROM AUTHOR]

Odontarrhena corsica was grown for three months on Chrome loam topsoil and subsoil from near Reisterstown, MD, to examine the effects of varying soil masses (2.8 and 5.6 kg pot−1) and soil layers (topsoil vs. subsoil) on plant growth and Ni accumulation. The subsoil position effect was simulated by placing a pot of topsoil on top of a pot filled with subsoil. Shoot Ni concentrations were similar for all treatments at 7 g Ni kg−1. Shoot yield was significantly higher in the 5.6 kg treatments compared to the 2.8 kg treatments (>18 g pot−1vs. ∼12 g pot−1) and also greater in the topsoil treatment compared to the subsoil treatment (24.0 g pot−1vs. 18.6 g pot−1), resulting in significantly higher phytomining. Soil depth had no statistically significant effect on shoot and root yield. Subsoil fertilization increased yield (25.8 g pot−1vs. 19.7 g pot−1), enough to suggest that further research is warranted to optimize Ni phytomining. This study confirms the importance of soil volume and root access to the subsoil when evaluating the potential for Ni phytomining by Odontarrhena species. The use of small pots may lead to an underestimation of phytomining potential. Prior studies have demonstrated that greater soil volume enhances Ni phytomining by Odontarrhena Ni hyperaccumulators. This study investigated Ni phytomining in both serpentine subsoil and topsoil, and examined the role of soil volume in this context. Our findings indicate that root access to Ni-rich serpentine subsoil significantly enhances Ni phytomining. [ABSTRACT FROM AUTHOR]

The site investigation is a key part of the design of tunnel construction projects, as it provides accurate geotechnical parameters. A systematic site investigation, which consists of mainly in situ tests and laboratory sample tests, was conducted for the Haimen-Taicang river-crossing tunnel project on Yangtze River. This paper aims to analyze and compare the piezocone penetration testing (CPTU) and dilatometer test (DMT) results of both onshore and under-river subsoils to provide insights into the interpretation of the in-situ tests. The accuracy of well-documented interpretation methods based on CPTU and DMT was discussed. Current empirical correlations between in-situ test results and unit weight, undrained shear strength and constrained modulus of the subsoils were checked, and their site adaptability was discussed in detail. A series of site-specific correlations were derived based on the analysis of the in-situ tests and the comparison between the in situ tests interpretation and the laboratory results. In order to reduce the errors between testing locations caused by soil variability and get the consistent understanding of soil behaviors, CPTU–DMT correlations were reviewed and improved based on local testing results. [ABSTRACT FROM AUTHOR]

Large-scale digital soil maps are essential for rational and sustainable land management as well as accurate fertilizer application. This study focuses on digital mapping of soil properties, namely soil organic carbon (SOC), pH, nitrogen (N), phosphorus (P), and potassium (K) in Chernozem topsoil and subsoil. The study was conducted on two arable fields in the Cis-Ural forest-steppe zone of the Republic of Bashkortostan (Russia). The random forest algorithm in combination with terrain attributes and Sentinel-2A satellite data was applied for spatial prediction of soil properties. The root-mean-square error (RMSE) and coefficient of determination (R2) were used to determine the model performance. According to the Pearson correlation, a significant positive relationship between SOC and N content was found at all sites and depths (R = 0.76–0.92). A cross-validation revealed that SOC (R2 = 0.22–0.62, RMSE = 0.35–0.89%) and N (R2 = 0.16–0.60, RMSE = 21.11–36.6 mg kg−1) were best predicted among other properties at all depths using remote sensing data, whereas the performance of predictive models decreased with depth. However, a relationship between the content of some soil properties and their spatial distribution at study depths was observed, which can be used as an additional explanatory variable. We suppose that digital mapping of soil properties at the arable field scale should not be limited to topographic and remote sensing variables. Based on this information, the use of auxiliary variables, such as collocated soil information in combination with relief and remote sensing data can be effective in more accurately estimating the spatial distribution of properties across arable fields at different depths. Overall, this study provides valuable insights into spatial modelling of the vertical distribution of soil properties, highlighting the significance of remote sensing data at the arable field scale. The findings can be valuable for land managers, agronomists, and policymakers seeking sustainable land management practices and efficient fertilizer application, as well as for developing further mapping procedures for arable fields. [ABSTRACT FROM AUTHOR]

Purpose: Straw incorporation is an important management practice in global agriculture. However, present straw returning usually focus on returning straw into the topsoil, while neglecting the amendment of subsoil. The study aims to investigate the effect of different straw returning strategies on soil quality and wheat productivity, and to develop recommendations regarding sustainable agriculture. Methods: A 2-year field experiment was conducted to evaluate the effects of five straw returning strategies on the soil quality and wheat yield in a winter wheat-summer maize cropping system in the North China Plain. Soil quality is defined as an index approach, including soil physical, chemical, and biological properties. The five treatments were straw removal (SR), straw mulching (SM), straw incorporation into topsoil (SI), deep-ploughing straw incorporation (DP-SI) and deep-injected straw incorporation (DI-SI). Results: Our results showed that straw returning improved soil quality across 0–40 cm depth relative to SR. The DP-SI and DI-SIa (above straw cluster) significantly increased topsoil quality by 20.5–26.2% and 13.6–19.0% compared with SI and SM. The DI-SIa also enhanced the subsoil quality, which was characterized by a significant increase in soil nutrients, compared to other straw returning strategies. The soil quality of 0–40 cm layer under DP-SI and DI-SI was significantly higher than that of other treatments. In addition, a positive correlation between soil quality and wheat yield was observed. Thus, the higher soil quality under DP-SI and DI-SI improved the average wheat yield by 9.6% and 10.7% compared with SI, respectively. Conclusion: These results indicates that DI-SI may improve subsoil properties and wheat yields and is likely an effective measure for sustainable development of a wheat-maize rotation system. [ABSTRACT FROM AUTHOR]

After the 2010 Maule earthquake (Mw 8.8) major changes were made in seismic regulations at the national level. One of the most interesting aspects was the change in the methodology for the soil classification in the NCh433 design standard. In summary, there was a transition from the use of soil strength parameters to soil dynamic parameters, such as the harmonic average of the shear wave velocity in the first 30 m of the subsoil (Vs30) and the predominant period (Tg), whose incorporation is under review. In this study, results from 4 teams exploring the same 6 sites using various sensors, geometries, and procedures are compared, all of them using Surface Wave Methods (MOS, for its initials in Spanish). It is concluded that, in general, the estimation of Vs30 and Tg are quite robust, but important variations are observed in the shear wave velocity profiles obtained. For that reason, it is necessary the comparison of these results with the stratigraphy. These results point to the limitations and potential of MOS to estimate the dynamic properties of sites. [ABSTRACT FROM AUTHOR]

Determination of tipping points in nitrogen (N) isotope (δ15N) natural abundance, especially soil δ15N, with increasing aridity, is critical for estimating N‐cycling dynamics and N limitation in terrestrial ecosystems. However, whether there are linear or nonlinear responses of soil δ15N to increases in aridity and if these responses correspond well with soil N cycling remains largely unknown. In this study, we investigated soil δ15N and soil N‐cycling characteristics in both topsoil and subsoil layers along a drought gradient across a 3000‐km transect of drylands on the Qinghai–Tibetan Plateau. We found that the effect of increasing aridity on soil δ15N values shifted from negative to positive with thresholds at aridity index (AI) = 0.27 and 0.29 for the topsoil and subsoil, respectively, although soil N pools and N transformation rates linearly decreased with increasing aridity in both soil layers. Furthermore, we identified markedly different correlations between soil δ15N and soil N‐cycling traits above and below the AI thresholds (0.27 and 0.29 for topsoil and subsoil, respectively). Specifically, in wetter regions, soil δ15N positively correlated with most soil N‐cycling traits, suggesting that high soil δ15N may result from the "openness" of soil N cycling. Conversely, in drier regions, soil δ15N showed insignificant relationships with soil N‐cycling traits and correlated well with factors, such as soil‐available phosphorus and foliage δ15N, demonstrating that pathways other than typical soil N cycling may dominate soil δ15N under drier conditions. Overall, these results highlight that different ecosystem N‐cycling processes may drive soil δ15N along the aridity gradient, broadening our understanding of N cycling as indicated by soil δ15N under changing drought regimes. The aridity threshold of soil δ15N should be considered in terrestrial N‐cycling models when incorporating 15N isotope signals to predict N cycling and availability under climatic dryness. [ABSTRACT FROM AUTHOR]

Before beginning construction on any civil structure, it is imperative to conduct a soil investigation to determine the soil's parameters and to learn about the subsoil's behavior. A thorough analysis must be performed, taking into account the foundation's cost-effectiveness and any potential overdesign. In the early stages of a soil investigation, geophysical testing is used to find out about the subsurface. This is because geophysical tests are fast, easy to do, do not cause damage, and are cost-effective. In this study, subsurface profiling is performed using the inverse slope approach after resistivity tests are performed at numerous sites on varying terrain types. We generate a subsurface profile using inverse slope electrical resistivity testing and compare it with bore log data to identify any discrepancies. The results of the inverse slope method and the bore log data are comparable at different depths; further, the range of agreement of both results is determined by Bland–Altman analysis. [ABSTRACT FROM AUTHOR]

Soil–structure interaction (SSI) refers to the dynamic interaction between a structure and the surrounding soil on which it rests. The behavior of the soil can significantly affect the response of the building structure. In the context of civil engineering and structural analysis, SSI becomes particularly important when considering the response of structures to dynamic loads such as earthquakes or so-called paraseismic loads, e.g., mining tremors. Several factors contribute to SSI. Soil and building structure material properties, foundation type, and loading conditions are the most important parameters. The article concerns SSI in the case of mining rock bursts in Poland. The influence of changes in site material conditions and building material properties on the SSI phenomenon was investigated. A few variants of different properties of typical construction materials (brick, reinforced concrete, and cellular concrete) in the case of selected representative building structure were considered. The subsoil material properties from the wide range were also taken into account. Numerical three-dimensional finite element method (FEM) analysis was applied. The adopted models of the soil-structure system were verified by data from in situ experimental vibration measurements. A significant influence of the subgrade material and the building structure material on the SSI was demonstrated. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) is a soil health indicator and understanding dynamics changing SOC stocks will help achieving net zero goals. Here we present four datasets featuring 11,750 data points covering co-located aboveground and below-ground metrics for exploring ecosystem SOC dynamics. Five sites across England with an established land use contrast, grassland and woodland next to each other, were rigorously sampled for aboveground (n = 109), surface (n = 33 soil water release curves), topsoil, and subsoil metrics. Commonly measured soil metrics were analysed in five soil increments for 0–1 metre (n = 4550). Less commonly measured soil metrics which were assumed to change across the soil profile were measured on a subset of samples only (n = 3762). Additionally, we developed a simple method for soil organic matter fractionation using density fractionation which is part of the less common metrics. Finally, soil metrics which may impact SOC dynamics, but with less confidence as to their importance across the soil profile were only measured on topsoil (~5–15 cm = mineral soil) and subsoil (below 50 cm) samples (n = 2567). [ABSTRACT FROM AUTHOR]

Many design guidelines have been proposed for piled embankments, most of which consider piles or columns as rigid inclusions. In this study, a small-scale physical model test was performed to investigate the load transfer mechanism of a geotextile-reinforced sand layer over a soft subsoil improved by semirigid columns. A multi-stage load was applied at the top of the sand layer until the columns started to yield. When the columns yielded, a reverse load transfer was observed. Vertical stresses were measured and analyzed in terms of efficacy and stress reduction ratio (SRR) with a comparison of existing design guidelines for assessing soil arching. Among the reviewed guidelines, the approach recommended by the Dutch guidelines provided the closest results to the experimental data, whereas the one adopted by the American guidelines predicted well the change in efficacy and SRR under different surcharge loads. However, the load transfer mechanism after the yielding of columns is beyond the scope of the existing design guidelines. In addition, it was found through regression analysis that the increment of vertical stresses on columns and surrounding soil followed an inclined line under partially undrained conditions during loading stages and a curve during consolidation. [ABSTRACT FROM AUTHOR]

Aphids are insect pests that suck phloem sap and introduce salivary proteins into plant tissues through saliva secretion. The effector of salivary proteins plays a key role in the modulation of host plant defense responses and enhancing aphid host adaptation. Based on previous transcriptome sequencing results, a candidate effector cyclin-dependent kinase-like (CDK) was identified from the grain aphid Sitobion avenae. In this study, the function of SaCDK in wheat defense response and the adaptation of S. avenae was investigated. Our results showed that the transient overexpression of SaCDK in tobacco Nicotiana benthamiana suppressed cell death triggered by mouse pro-apoptotic protein-BAX or Phytophthora infestans PAMP-INF1. SaCDK, delivered into wheat cells through a Pseudomonas fluorescens-mediated bacterial type III secretion system, suppressed callose deposition in wheat seedlings, and the overexpression of SaCDK in wheat significantly decreased the expression levels of salicylic acid and jasmonic acid signaling pathway-related genes phenylalanine ammonia lyase (PAL), pathogenesis-related 1 protein (PR1), lipoxygenase (LOX) and Ω-3 fatty acid desaturase (FAD). In addition, aphid bioassay results showed that the survival and fecundity of S. avenae were significantly increased while feeding on the wheat plants carrying SaCDK. Taken together, our findings demonstrate that the salivary protein SaCDK is involved in inhibiting host defense response and improving its host adaptation, which lays the foundation to uncover the mechanism of the interaction of cereal aphids and host plants. [ABSTRACT FROM AUTHOR]

This article examines how indigenous ontologies of gold, land, and rivers shape extractive practices, based on ethnographic field work in Ghana. I draw from political ecology to account for how invisible properties of the subsoil become entangled with social realities. In Ghana, understandings of the subsoil as more-than-material worlds inform rituals, taboos, and other protocols. Through such protocols, chiefs, spiritualists, and others emerge to govern subterranean access. This research shows that subterranean sovereignty extends beyond the state to include invisible forces of extractive landscapes, presenting ontological challenges to neoliberal land acquisition and gold privatization processes. The study also shows that mineral matters have resisting and intentional capacities that are constituted through resource making. Such resisting capacities contradict dominant views of resources, generating new understandings of resources as things that do not always become. The study suggests the need to attend to complicated forces of extraction and mining regulations. Such an approach is not merely epistemological intervention for addressing the subsoil's invisible properties but provides important insights to reimagine contemporary extractive practices as ontological struggles over the subsoil wherein indigenous persons produce and challenge claims to land through more-than-material relationships with the environment. [ABSTRACT FROM AUTHOR]

Soil organic matter (SOM) is a critical player in the global carbon cycle and a common paleoclimate archive, yet the mechanisms governing its evolution, particularly in subsoil (>30 cm) systems, remain less well understood. To better characterize subsoil SOM dynamics, we investigated the isotopic compositions of SOM in fine (<2 μm) and coarser (>2 μm) grain‐size fractions of the top 2 m of a soil profile developing in eolian sediments on the Chinese Loess Plateau. We found that in the subsoil, SOM in the fine fraction, characterized by lower C/N and higher δ13C, exhibits consistently younger radiocarbon ages than those in the coarser fraction. Such offsets suggest that organo‐mineral interactions facilitate fresh carbon input to the fine fraction rather than preventing SOM decomposition. We then developed a mass‐balance model to interpret the radiocarbon data. The results suggest continual carbon input from the above‐ground biosphere to the 2‐m deep subsoil. The active subsoil organic carbon cycling can lead to significant variations in δ13CSOM under an environment that experienced substantial vegetation changes, resulting in time‐averaged signals when using δ13CSOM for paleoenvironmental reconstructions. Our study underscores the dynamic nature of the subsoil carbon pool, emphasizing its potentially underestimated role in the contemporary carbon cycle. Plain Language Summary: Soil organic carbon (SOC) plays a key role in the global carbon cycle and serves as an important material for studying past climates. However, the processes involved in its breakdown, transformation, and interaction with soil minerals, especially in deep soils, are not fully understood. To gain better understanding of the vertical movement of SOC within soils, we analyzed the radiocarbon activities of SOC in different particle‐size fractions from a 2‐m deep soil profile located on the Chinese Loess Plateau. Based on the radiocarbon data and a mass balance model, our results suggest that the deep soils (30–200 cm) receive significant and continuous input of fresh carbon from the soil surface, which then closely interact with fine‐grained minerals and microorganisms. The transport of biospheric carbon into deep soils highlight an active subsoil SOC pool in the modern carbon cycle. On the other hand, the constantly evolving SOC might modify its original geochemical signals, posing challenges for reconstructing past climates from these soil records. Key Points: Soil organic carbon in a 2‐m soil profile was systematically analyzedSubsoil organic matter is dominated by mineral‐associated microbial productsBiospheric carbon continually fuels the subsoil organic carbon pool [ABSTRACT FROM AUTHOR]

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