Search Results (657)

To address the issue of poor film–soil separation in traditional subsoil residual film recovery machines, which leads to recovered film containing excessive soil, a film–soil conveying and separation device was designed. By establishing a mechanical model for the balanced conveyance of the film–soil composite, the range of conveyor chain inclination angles enabling stable transport was determined. Using RecurDyn 2023 simulation software, a sensitivity analysis was conducted on the effects of vibrating wheel speed, vibrating wheel mounting distance, and conveyor chain inclination angle on vibration characteristics. This analysis revealed that vibrating wheel speed and mounting distance have a significant impact on the vibrating mechanism. Based on the DEM–MBD (Discrete Element Method—Multi-Body Dynamics) coupling approach, a discrete element simulation model was built for the film–soil vibrating conveyor device, residual film, and soil. Using the primary conveyor chain speed, vibrating wheel speed, and mounting distance as experimental factors, and soil content rate and film leakage rate as experimental indicators, single-factor tests and a three-factor, five-level orthogonal rotational composite design test were performed. The results showed that, at a primary conveyor chain speed of 1.61 m/s, a vibrating wheel speed of 186.2 r/min, and a mounting distance of 688.2 mm, the soil content rate was 18.11% and the film leakage rate was 7.61%. The film–soil conveying and separation process was also analyzed via simulation. Field validation tests using the optimal parameter combination yielded relative errors of 3.43% and 5.51%, respectively, demonstrating effective film–soil separation. This research provides a theoretical foundation and equipment support for addressing residual film pollution in the cultivated layer of Xinjiang region. Full article

High-standard farmland fertility enhancement projects can lead to the sustainable utilization of arable land resources. However, due to difficulties in project implementation and uncertainties in costs, resource allocation efficiency is constrained. To address these challenges, this study first analyzes the impact of geography and engineering characteristics on cost indicators and applies principal component analysis (PCA) to extract key influencing factors. A hybrid prediction model is then constructed by integrating the Northern Goshawk Optimization (NGO) algorithm with a Backpropagation Neural Network (BP). The NGO–BP model is compared with the RF, XGBoost, standard BP, and GA–BP models. Using data from China’s 2025 high-standard farmland fertility enhancement projects, empirical validation shows that the NGO–BP model achieves a maximum RMSE of only CNY 98.472 across soil conditioning, deep plowing, subsoiling, and fertilization projects—approximately 30.74% lower than those of other models. The maximum MAE is just CNY 88.487, a reduction of about 32.97%, and all R² values exceed 0.914, representing an improvement of roughly 5.83%. These results demonstrate that the NGO–BP model offers superior predictive accuracy and generalization ability compared to other approaches. The findings provide a robust theoretical foundation and technical support for agricultural resource management, the construction of projects, and project investment planning. Full article

Non-Native Tree Species (NNTs) play crucial roles in global and European forests. However, in the Czech Republic, NNTs represent a tiny fraction of the forested areas due to limited research on their potential use. The country is actively afforesting abandoned agricultural lands; NNTs which are already tested and certified could enhance the country’s forestry system. This study aimed to evaluate the initial growth of Castanea sativa, Platanus acerifolia, and Corylus colurna under three soil treatments on abandoned agricultural soil, evaluate the survival and mortality of the tree species, and further compare the soil dynamics among the three ecosystems to describe the initial state and short-term changes in the soil environment. The research plot was set in the Doubek area, 20 km East of Prague. Moreover, soil-improving materials, Humac (1.0 t·ha⁻¹) and Alginite (1.5 t·ha⁻¹), were established on the side of the control plot at the afforested part. The heights of plantations of tree species were measured from 2020 to 2024. Furthermore, 47 soil samples were collected at varying depths from three ecosystems (afforested soil, arable land, and old forest) in 2022. A single-factor ANOVA was run, followed by a post hoc test. The result shows that the Control-C plot (Castanea Sativa + Platanus acerifolia + Corylus colurna + agricultural soil without amendment) had the highest total growth (mean annual increment in the year 2024) for Castanea sativa (KS = 40.90 ± a21.61) and Corylus colurna (LS = 55.62 ± 59.68); Alginite-A (Castanea Sativa + Platanus acerifolia + Corylus colurna + Alginite) did best for Platanus acerifolia (PT = 39.85 ± 31.52); and Humac-B (Castanea Sativa + Platanus acerifolia + Corylus colurna + Humac) had the lowest growth. Soil dynamics among the three ecosystems showed that the old forest (plot two) significantly differs from arable soil (plot one), Humac and Platanus on afforested land (plot three), Platanus and Alginite on afforested land (plot four), and Platanus without amendment (plot five) in horizon three (the subsoil or horizon B) and in horizon four (the parent material horizon or horizon C). Results document the minor response of plantations to soil-improving matters at relatively rich sites, good growth of plantations, and initial changes in the soil characteristics in the control C plot. We recommend both sparing old forests and the afforestation of abandoned agricultural soils using a control treatment for improved tree growth and sustained soil quality. Further studies on the species’ invasiveness are needed to understand them better. Full article

Increasing soil organic carbon (SOC) storage is essential for improving soil fertility and mitigating climate change. The priming effect, which is regulated by physical, chemical and microbial interactions, plays a pivotal role in SOC turnover. However, the fate of both native and newly added carbon under different tillage regimes remains unclear. To address this gap, a ¹³C-glucose labelling incubation experiment was conducted to assess SOC mineralization and priming effects under long-term tillage practices, including subsoiling with straw mulching (ST), no tillage with straw mulching (NT), and conventional tillage with straw removal (CT). The results demonstrated that conservation tillage (NT and ST) significantly reduced total SOC mineralization and glucose-derived CO₂ release compared to CT. Notably, the priming effect under CT was 19.5% and 24.7% higher than under NT and ST, respectively. In the early incubation stage, positive priming was primarily driven by microbial co-metabolism, while during days 1–31, microbial stoichiometric decomposition dominated the process. In addition, NT and ST treatments significantly increased the proportion of >250 μm aggregates and their associated carbon and nitrogen contents, thereby enhancing aggregate stability and physical protection of SOC. The priming effect observed under conservation tillage was strongly negatively related to aggregate stability and aggregate associated carbon content, whereas it was positively related to the β-glucosidase/Peroxidase ratio (BG/PER) and the subtraction value between carbon/nitrogen (R_C:N) and the carbon–nitrogen imbalance of the available resources (TER_C:N). Overall, our findings highlight that conservation tillage enhances SOC stability not only by improving soil physical structure but also by alleviating microbial stoichiometric constraints, offering a synergistic pathway for carbon retention and climate-resilient soil management. Full article

A new method for finite element simulation analysis of the interaction between complex structured tillage implements and soil was established in this study. This method accurately analyzes soil fragmentation during subsoiling using tillage tools with complex structures. It also accurately reflects the force on bionic subsoilers during cultivation, the interaction law between the subsoiler and the soil, and the impact of subsoiling operations on the soil properties. Bionic subsoilers were introduced to establish a dynamic analysis model for subsoiling cultivation. The novelty lies in introducing bionic subsoilers inspired by mole claws to reduce draft force and optimize soil failure patterns. Experiments have shown that compared with standard subsoilers, the stress distribution of the bionic subsoiler-H is significantly reduced, with a maximum stress reduction of 52.96%. The stress distribution of the subsoilers after subsoiling cultivation was directly proportional to the wear of the subsoiler, and the draft force of the subsoiler was inversely proportional to the size of the soil block at the front of the subsoiler. Compared with the soil model with a plough layer, the average stress values of the standard subsoiler, bionic subsoiler-H, and bionic subsoiler-C in the models without a plough pan layer were reduced by 13.97%, 6.67%, and 7.1% lower, respectively. Abaqus finite element analysis could not only effectively reflect the actual situation of soil in the field, but also accurately simulate and analyze the effect of soil fragmentation in the subsoiling process via tillage tools with complex structures, providing a digital analysis foundation for the collection of intelligent tillage information. Full article

Deep tillage is a conservation tillage method that aims to break the plow pan layer. It provides significant benefits, including enhanced root development, improved soil quality, and substantial increases in crop yields. The depth of tillage is a crucial factor in assessing the effectiveness of deep tillage operations. Accurate regulation of tillage depth in deep tillage equipment is vital for ensuring the high-quality and efficient execution of these practices. The distribution of mechanical resistance within the soil can effectively indicate the location of the plow pan layer and serves as the main reference for setting the tillage depth for machinery. This paper examined the current state of research on tillage depth control technology for deep tillage operations. It focused on three main technical areas: soil mechanical resistance detection, tillage depth measurement, and tillage depth regulation. The report discussed the working principles of various technologies and compared the existing methods. Additionally, the paper analyzed the challenges faced in the development of tillage depth control technology in China and offers recommendations for future advancements. It highlighted that leveraging information and digital technologies to determine the distribution of the soil plow pan layer, along with the integration of efficient and intelligent control technologies for precise tillage depth regulation, represented a key direction for the future development of deep tillage operations. Full article

Labile organic carbon (OC), a dynamic component of soil organic carbon (SOC), is essential for improving soil health, fertility, and crop productivity, particularly when organic and inorganic amendments are combined. However, limited research exists on the best amendment strategies for restoring degraded gleyic solonetz soggy sodic (GSSS) soils in West Africa’s coastal zones. A three-year field study (2017–2019) assessed the effects of various combinations of organic (mature or composted cow dung, with or without biochar) and inorganic inputs on soil organic carbon fractions, total carbon stocks, and the Carbon Management Index (CMI) in GSSS soils of Sege, Ada West District, Ghana. The results showed that organic and inorganic combinations outperformed the sole inorganic NPK treatment and the control, particularly in the topsoil. Composted cow dung with mineral fertilizer (CCfert) was especially effective, significantly increasing labile OC, SOC stock, and CMI by 35.3%, 140.5%, and 26% in the topsoil compared to the control and by 28%, 77.8%, and 4.3% compared to NPK alone. In the subsoil, mature cow dung-based treatments performed better. These findings highlight the potential of integrated organic and inorganic strategies, especially those based on composted manure, to rehabilitate degraded sodic soils, build carbon stocks, and improve soil quality for sustainable agriculture in coastal West Africa. Full article

Understanding how elevation gradients and soil depths influence soil organic carbon stocks (SOCS) and total nitrogen stocks (TNS) is essential for sustainable forest management (SFM) and climate change mitigation. This study investigated the effects of elevation and soil depth on SOCS and TNS in the Mount Kenya East Forest (MKEF). A stratified systematic sampling approach was applied, involving collection of 38 soil samples from two depths (0–20 cm and 20–40 cm) across three elevation zones: Lower Forest (1700–2000 m), Middle Forest (2000–2350 m), and Upper Forest (2350–2650 m). Samples were analysed for bulk density (BD), pH, texture, soil organic carbon (SOC), and total nitrogen (TN), using standard laboratory methods. In topsoil (0–20 cm), SOCS ranged from 109.28 ± 23.41 to 151.27 ± 17.61 Mg C ha⁻¹, while TNS varied from 8.89 ± 1.77 to 12.00 ± 2.46 Mg N ha⁻¹. In subsoil (20–40 cm), SOCS ranged from 72.03 ± 19.90 to 132.23 ± 11.80 Mg C ha⁻¹, with TNS varying between 5.71 ± 1.63 and 10.50 ± 1.90 Mg N ha⁻¹. SOCS and TNS increased significantly with elevation (p < 0.05), exhibiting the following trend: Lower Forest < Middle Forest < Upper Forest. Topsoil consistently stored significantly higher SOCS than subsoil (p < 0.05), emphasizing the critical role of surface soils in carbon sequestration. Regression analysis revealed a significant positive relationship between SOCS and TNS (R² = 0.84, p < 0.001). Both SOCS and TNS were positively correlated with elevation, SOC, TN, and total annual precipitation (TAP), but negatively correlated with BD and mean annual temperature (MAT). These findings provide baseline data for monitoring SOCS and TNS in the MKEF, offering insights into sustainable forest management strategies to improve soil health and enhance climate change mitigation efforts. Full article

Crop rotation and simplified tillage affect soil properties and consequently crop yields. The use of heavy machinery in the tillage can affect soil degradation and reduce soil productivity. The aim of this study was to investigate the effect of soil packing and different soil tillage methods applied before the sowing of maize cultivated after grassland and in monoculture on soil compaction, soil organic carbon content, and maize yield. A strip–split–plot experiment was conducted on-farm in northeastern Poland from 2017 to 2021. The soil compaction was measured in the soil layers: 0–10, 10–20 and 20–30 cm in the leaf development stage (BBCH 19), the flowering stage (BBCH 67) and the maize kernel development stage (BBCH 79). The experimental factors were as follows: 1. preceding crop—grassland, maize; 2. degree of soil packing—without soil packing, soil packing after harvesting the preceding crop; 3. different soil tillage—conventional plough tillage method, reduced tillage method. Maize cultivation following a multi-species grassland resulted in a modest 1.47% increase in soil organic carbon content compared to continuous maize monoculture. In monoculture maize, all investigated reduced tillage methods led to increased soil compaction by 0.61–0.67 MPa. However, this adverse effect was mitigated by prior grassland cultivation. Maize grown after a multi-species grassland exhibited 14% higher silage mass yields. Considering the reduction in soil compaction and the enhanced yield potential, this preceding crop is recommended for maize cultivation. Although soil packing did not significantly impact maize yields, reduced tillage methods, such as subsoiling at 40 cm, medium ploughing at 20 cm, and passive tillage, led to a significant reduction in silage mass compared to other treatments. Full article

Understanding the complex phenomena of interactions between the elements of a combined piled raft foundation (CPRF) is essential for the proper design of such foundations. To evaluate the effects of mutual influence among the CPRF’s elements, a series of long-term measurements of selected physical quantities related to the performance of the foundation were conducted on a building with a frame structure, stiffening walls, and monolithic technology, consisting of seven aboveground stories and one underground story. The analysis distinguishes the real deformations resulting from temperature changes and from stress strains resulting from load changes. The two types of deformations were subjected to further interpretation of only changes in the stress and strain over time. Changes in stress values in the subsoil, as well as strain measurements in the vertical direction of concrete columns, were recorded to assess the load distribution between the CPRF’s components. The numerical analysis results obtained for a fragment of the monitored foundation were compared with actual measurement results to verify the numerical model of interaction between the structure and the soil. Field monitoring and FEA methods were used to compare the long-term deformation analysis, and they helped to minimize the monitoring time. This comparison also served to supplement and simultaneously expand the dataset of test results on a real-world scale. Full article

Soil amendments such as limestone and gypsum can influence microbial carbon use efficiency (CUE) by altering nutrient stoichiometry, particularly nitrogen (N) and phosphorus (P). However, their effects beyond the topsoil, especially under no-till systems, remain unclear. This study assessed microbial CUE through substrate use efficiency (SUE) following glucose addition as a factor influencing carbon (C) sequestration potential. Two experiments were conducted in tropical soil. The first evaluated the addition of ¹⁴C-glucose (G) to soil treated with lime, lime + gypsum, and a control, with or without the addition of N. The second compared limestone + gypsum and control treatments, incorporating G with N and P. Soil microbial respiration (CO₂ emission) was measured after 14 and 42 days. In the surface soil (0–10 cm), CUE increased with limestone or limestone + gypsum when N was applied. In the subsoil (40–60 cm), these amendments enhanced CUE compared to untreated soil in the absence of N. Treatments with G+N+P or G+P improved CUE in the surface soil. At the same time, G+N+P increased CUE in the subsoil regardless of acidity alleviation. Differences in ¹⁴CO₂ evolution indicated higher microbial CUE with acidity correction. Balanced N and P applications significantly enhanced CUE, highlighting the importance of both soil acidity correction and nutrient availability for microbial carbon processing. Full article

Coastal saline–alkali soils, characterized by poor structures and low fertility, limit sustainable agricultural development. This study aimed to investigate how green manure application influence soil aggregate stability and soil organic carbon (SOC) sequestration in such coastal saline soils. Field experiments were conducted by comparing the following five treatments: (1) control (CK); (2) ryegrass full incorporation (RF); (3) ryegrass mulching (RM); (4) alfalfa full incorporation (AF); (5) alfalfa mulching (AM). The results demonstrated that green manure application significantly increased large macroaggregate (>2 mm) proportions by 20.60–56.70% while reducing microaggregates (<0.25 mm) by 24.35–68.43%. SOC increased across 0–40 cm soil depth, primarily driven by large macroaggregates and microaggregates, which contributed 23.7–73.5% and 34.8–91.4% of the total increase, respectively. Mulching treatments (AM/RM) increased surface SOC sequestration, while full-incorporation practices (AF/RF) boosted subsoil SOC stocks. These results highlight green manure application as an effective strategy to rehabilitate coastal saline soils by enhancing aggregate stability and SOC sequestration, providing technical guidance for saline soil rehabilitation in coastal saline regions. Full article

The coastal region of Ceará, Brazil, is expected to host offshore wind farms aimed at producing green hydrogen (GH₂) through electrolysis. However, the viability and cost of these developments may be affected by the mechanical behaviour of the marine subsoil, which is largely composed of carbonate sands. These sediments are known for their complex and variable geotechnical properties, which can influence the foundation performance. This study investigates the geotechnical characteristics of carbonate sands in comparison with quartz sands to support the design of offshore wind turbine foundations. Field testing using the Ménard pressuremeter and laboratory analyses, including particle size distribution, microscopy, X-ray fluorescence, calcimetry, direct shear, and triaxial testing, were performed to determine the key strength and stiffness parameters. The results show substantial differences between carbonate and quartz sands, particularly in terms of the stiffness and friction angle, with notable variability even within the same material type. These findings highlight the need for site-specific characterisation in offshore foundation design. This study contributes data that can improve geotechnical risk assessments and assist in selecting appropriate foundation solutions under local conditions, supporting the planned offshore wind energy infrastructure essential to Ceará’s green hydrogen strategy. Full article

Below the central nave of the Gothic Cathedral of Palencia (14th to 16th centuries) lies the Crypt of San Antolín, which represents the remains of a Visigothic building from the mid-7th century. The crypt itself has suffered recurrent episodes of flooding over the centuries. However, the latest flooding, which began in mid-2021 and ended in mid-2023, is one of the most long-lasting episodes on the historical record. To establish the origin of these flooding episodes, the geological and hydrological properties of the subsoil have been determined by direct prospecting techniques (drilling) and indirect geophysical techniques (Electrical Resistivity Tomography). The prospecting has determined that the aquifer in the area has a basin-like geometry, which favors the accumulation of water below the crypt. This work has shown that the recurrent floods suffered by the crypt prior to 2021 are related to episodes of intense rainfall. However, after 2021, there is a direct relationship between the persistent flooding and the onset of landscaping at the Plaza de San Antolín, one of the squares near the cathedral. In addition, previous archaeological excavations carried out in 1965 in that same square had disrupted the stratigraphic column, easing the percolation of water. We conclude that the increase in landscaped areas in archaeological environments may modify the hydrogeological dynamics of the subsoil and affect the surrounding buildings. Full article

The semi-arid region of North China has undergone extensive afforestation to prevent land degradation. Although afforestation was considered an effective way to improve soil water retention, the mechanism by which it affects soil hydraulic properties remained uncertain. In this study, soil water retention curve (SWRC), soil water-stable aggregates, and other soil physicochemical properties were determined in short-term abandoned cropland (AC), shrubland (SL), and woodland (WL) that had been converted from cropland for 1, 8, and 24 years, respectively. Pearson correlation analysis and partial least-squares structural equation modeling methods were used to identify the main factors affecting soil hydraulic properties. Results showed that the SWRCs of all three land uses were well-fitted by a double-exponential model. The WL and SL land uses exhibited higher soil field capacity (0.33–0.37 cm³ cm⁻³), wilting point (0.20–0.23 cm³ cm⁻³), and available water content (0.13–0.15 cm³ cm⁻³). Surface soil exhibits a more pronounced trend in water retention capacity changes compared to subsoil under vegetation restoration. The WL and SL land uses showed more soil macroaggregates and intra-aggregate pores at surface layers, which mainly explained the variations in hydraulic properties. The main factors influencing soil hydraulic properties were soil aggregates, matrix and structural porosity, soil organic carbon (SOC), and soil bulk density (BD). Overall, afforestation can improve soil hydraulic properties and could be an effective practice for soil and water conservation in the semi-arid region of North China. Full article