Search Results (185)

Tea garden irrigation suffers from time delays, nonlinear interference, and phenological biomass fluctuations caused by plucking, leading to the failure of traditional Proportional–Integral–Derivative (PID) and fixed-threshold models in precise water supply. This study proposes a precision irrigation system for smart tea gardens integrating Phenology-Aware Collaborative Decision-Making and an Adaptive Gain Predictive Super-Twisting Sliding Mode Control (AG-PSTC) algorithm. A “temperature–time–water” phenological reference model was constructed, and Crop Water Stress Index (CWSI) was introduced to decouple shoot density changes into phenology-driven and water stress components, realizing dynamic target soil moisture (W_target) setting. The AG-PSTC algorithm combined an improved Smith predictor for phase compensation and a barrier function-based adaptive super-twisting term for chattering elimination and finite-time convergence. Simulations showed AG-PSTC reduced rise time by 78% and steady-state error by four orders of magnitude compared with PID, with robust performance under ±40% time-delay perturbation. Field tests confirmed the system suppressed false irrigation during plucking, with soil moisture standard deviation within 1.51%. This study provides a vertical integration framework from crop physiological models to precision control, promoting the transition of tea garden irrigation from experience-based to demand-based. Full article

To investigate the bearing characteristics of super-long and large-diameter cast-in-place piles with combined pile-end and pile-side post-grouting, double-load-box self-balanced static-load tests were conducted on two such piles of the Yellow River Bridge Project on Jiaoping Expressway both before and after grouting. This study aims to provide technical insights for the design and construction of similar pile foundations. The test results indicate that, after grouting, the ultimate bearing capacities of test piles SZ1 and SZ2 increased by 123.1% and 72.8%, respectively, with a significant reduction in pile top settlement under the same load level. Under each load level, the axial force of the pile shaft reaches its maximum near the upper load box, presenting a triangular distribution curve. Furthermore, the side frictions of SZ1 and SZ2 enhanced by 87.73% and 83.59%, respectively, after grouting, while their ultimate end resistances are improved by 362.6% and 120.6%. These findings demonstrate that post-grouting effectively optimizes the mechanical properties of the pile–soil interface and enhances the structural stiffness of the surrounding soil. Specifically, the grout hardens at the pile end, solidifies the sediment there, increases the density of the pile-end soil layer, and improves the bearing rigidity of the bearing stratum. This research validates the effectiveness of the combined pile-end and pile-side post-grouting technology in improving the bearing performance of super-long and large-diameter cast-in-place piles, providing valuable technical support for the safe and efficient construction of the Yellow River Bridge on the Jiaoping Expressway and similar engineering projects. Full article

Advances in affordable genetic engineering have accelerated the creation and large-scale environmental release of genetically modified microorganisms (GMMs). While beneficial applications exist, GMMs may present unique, long-term risks to human and environmental health. Unlike static chemicals, GMMs are biologically active, self-replicating entities capable of rapid mutation and global dispersal. Current regulatory frameworks place responsibility on each country to regulate GMMs, without a clear, coordinated international policy. This review details critical risk scenarios, including horizontal gene transfer to native species and the possible disruption of vital human microbiomes (gut, oral, and infant), which could increase resistance to degradation, promote traits that expand a microbe’s range of hosts or ecological niches, and enhance the production of novel metabolites with unexpected biological activity. In soil, GMMs may support the emergence of “super bugs” or destabilize carbon sequestration cycles, potentially impacting climate resilience. Engineered microbial enzymes in the food supply may also act as environmental drivers of autoimmunity. Given the limited understanding of microbial ecology, we propose a decision-based biosafety workflow emphasizing pre-release risk assessment and continuous post-release monitoring. We urge national and international regulators to adopt the precautionary principle to better protect human health and the environment from the potential negative outcomes of GMMs. Full article

Rural cut-slope construction constitutes a typical trigger of geological hazards in mountainous regions of developing countries, a risk exacerbated under climate change with the increased frequency and intensity of extreme rainfall events. This study developed an early identification framework for assessing landslide hazard potential associated with such construction, based on the Comprehensive Index Method (CIM). Using Fujian Province, China, as a case study, seven core influencing factors—including slope-wall distance, cut-slope height, and slope gradient—were selected to establish a differentiated weighting system. By integrating multi-source geospatial data, the framework enables automatic identification of potential hazards and risk classification. Results indicate that of the more than 144,000 potential hazard sites identified across the province, 21.20% were classified as medium-risk or higher-risk. High-risk sites display marked spatial clustering, predominantly located in inland counties of northwestern, central, and western Fujian, characterized by steep topography, frequent cut-slope activities, and extensively distributed clay soil layers—conditions highly sensitive to rainfall infiltration. Structural parameter analysis reveals that the vast majority of potential hazard sites exhibit typical engineering geological characteristics, including narrow slope-wall distance, steep cut-slope gradients, and moderate cut-slope height, collectively increasing the susceptibility to rainfall-induced instability. Validation based on two heavy rainfall events in 2024 (Super Typhoon Gaemi and the 9 June Wuping-Shanghang event) yielded identification match rates of 91.8% and 79.98%, respectively, with Kappa coefficients of 0.85 and 0.72, confirming the reliability and practical applicability of the method under extreme weather scenarios. The proposed framework offers valuable support for regional landslide prevention and climate adaptation planning in the context of ongoing climate change. Full article

The field experiment was carried out in the fields of the Experimental Variety Testing Station in Chrząstów, belonging to the Central Research Centre for Cultivated Plants in Słupia Wielka. The aim of the present study was to determine the effect of residual nitrogen (N_res) remaining in the soil after cultivation of three varieties of common maize fertilized with different types of nitrogen fertilizers on nitrogen-use-efficiency indicators in subsequent crops of winter and spring common wheat. Nitrogen accumulation in both wheat cultivation systems showed a significant response to the interaction between maize varieties and the type of nitrogen fertilizer applied. Urea proved to be the most consistent source of nitrogen in the grain, regardless of the maize variety used as the preceding crop or the form of nitrogen applied. Variability in nitrogen accumulation under the U + N-Lock, Super N-46, and SG Stabilo treatments was primarily associated with a marked decrease in the SC maize variety. The SC + Roots Power maize variety left the soil in a condition highly favourable for nitrogen accumulation in wheat grain across two consecutive growing seasons. Maize variety was the primary factor influencing the proportion of fertilizer-derived nitrogen in the total nitrogen accumulated in the grain. The highest recovery of fertilizer nitrogen over the two-year production cycle was obtained in the SC + Roots Power treatment fertilized with SG Stabilo. Notably, urea demonstrated the strongest residual effect on nitrogen availability to winter wheat. Full article

Climate change and the impacts related to nonbiodegradable synthetic materials highlight the need for sustainable alternatives. Biopolymers from renewable sources show great potential for producing hydrogels, which are three-dimensionally crosslinked materials with high water absorption. In this work, super-absorbent biodegradable hydrogels were produced via single-step reactive extrusion using mixtures of starch, gelatin, cellulose, and xanthan gum, with glycerol as a plasticizer, and citric acid as a crosslinking agent. Pelleted hydrogels were obtained with water absorption between 290% and 363%. Reactive extrusion promoted the formation of new ester and amide bonds, confirmed by FT-IR. Citric acid was effective as a crosslinker, and higher citric acid content (3%) produced samples with greater swelling, supported by the porous internal structure observed. Preliminary agricultural tests showed that the formulation with the highest citric acid content, when added to soil at 5%, significantly increased water-holding capacity and resulted in the highest germination rate of maize seeds. Overall, the extrusion process proved efficient, scalable, and environmentally friendly for producing biodegradable hydrogels for agricultural applications. Full article

The SDG 15.3.1 framework provides a standardized approach using land use/land cover (LULC) change, land productivity, and soil organic carbon (SOC) dynamics to assess land degradation. However, SDG 15.3.1. faces limitations like coarse resolutions of Landsat-8 and Sentinel-2, particularly for fine-scale studies. Accordingly, this paper integrates Very Deep Super-Resolution (VDSR) for downscaling Landsat-8 imagery to 1 m resolution and the Vegetation Health Index (VHI) into SDG 15.3.1 to enhance detection in the heterogeneous Loiret region, France—a temperate agricultural hub featuring mixed croplands and peri-urban interfaces—using 2017 as baseline and 2024 as target. Results demonstrated that 1 m resolution detected more degraded LULC areas than coarser scales. SOC degradation was minimal (0.15%), concentrated in transitioned zones. VHI reduced overestimation of productivity declines compared to the Normalized Difference Vegetation Index by identifying more stable areas and 2.69 times less degradation in integrated assessments. The “One Out, All Out” rule classified 2.6% (using VHI) and 7.1% (using NDVI) of the region as degraded, mainly in peri-urban and cropland hotspots. This approach enables metre-scale land degradation mapping that remains effective in heterogeneous landscapes where fine-scale LULC changes drive degradation and would be missed at lower resolutions. However, future ground validation and longer timelines are essential to enhance the presented methodology. Full article

To achieve sustainable agriculture development in arid regions, it is imperative to improve the soil quality of arid sandy soils. This study explored the effects of the combined application of organic–inorganic fertilizers with soil conditioners on the physiological characteristics, yield, and quality of rapeseed in arid sandy lands. The aim was to provide a technical reference for improving sandy soil and increasing rapeseed yield in arid regions. This field study designed six treatments (control group: organic fertilizer + chemical fertilizer (CK); T1: organic fertilizer + chemical fertilizer + super absorbent polymer (SAP); T2: organic fertilizer + chemical fertilizer + humic acid (PI); T3: organic fertilizer + chemical fertilizer + attapulgite (PII); T4: organic fertilizer + chemical fertilizer + PI + PII; HF: chemical fertilizer) to evaluate their effects on the nutrient absorption, physiological characteristics, yield, and quality of rapeseed. The results showed that the combination of organic–inorganic fertilizers with SAP, PI, PII, or PI + PII could significantly reduce the salinity of sandy soil while increasing the nutrient content in various parts of rapeseed. Among the combinations, the SAP treatment (T1) had the most significant effect, with the following specific impacts: (1) Alleviation of salt stress: The SAP treatment increased the root potassium ion content by 63.09% and reduced sodium ion content by 60.16% compared with CK, significantly increasing the potassium/sodium ratio. (2) Physiological improvement: The SAP treatment increased the total chlorophyll content (TCC), superoxide dismutase/catalase activity, and dry matter accumulation by 86.85%, 161.58%, and 376.8%, respectively, compared with CK. (3) Yield and quality enhancement: The SAP treatment increased rapeseed yield and the crude protein content in stems and leaves by 148.32% and 86.05%, respectively, but decreased crude fiber content by 43.59% compared with CK. (4) Economic benefits: The net revenue (NR) of the SAP treatment reached 197.62 USD per hectare, which was significantly higher than that of other treatments. A comprehensive evaluation showed that the combined application of organic–inorganic fertilizers with SAP enhanced plant antioxidant enzyme activity and photosynthetic efficiency, synergistically enhancing the yield and quality of rapeseed in sandy areas. This study provides an economically efficient solution for sustainable agricultural development in arid regions. Full article

The tensile strength of stabilized clayey soil is a key indicator of its resistance to cracking and directly governs its performance when used as subgrade fill. In this study, ordinary Portland cement and polyacrylate-based super-absorbent polymers (SAP) were combined to stabilize four typical high-water content clayey soils sourced from Northern Bavaria. The optimal SAP content was determined based on absorption capacity by the tea-bag method. Subsequently, the effects of cement content and curing period on the Brazilian tensile strength (BTS) of clayey soils were investigated, and the correlation between Brazilian tensile strength and unconfined compressive strength (UCS) was discussed. The results indicated the following: the optimal SAP content was 0.3%; the BTS increased significantly with higher cement content and a longer curing period; the failure modes of BTS specimens were revealed, including multiple non-through fracture, non-central fracture, and central fracture; a strong linear correlation was established between BTS and UCS, with the proportional coefficient ranging from 0.129 to 0.233. The findings of this study can provide a valuable reference for the design and application of cement-SAP stabilized soils in practical engineering. Full article

The extensive development of urban underground space increases the risk of deformation to adjacent structures during deep excavations. This study investigates the response of three low-strength strip-foundation buildings (#4, #8, and #11 of the Ninggong Apartment) in Nanjing, China, affected by the excavation of an adjacent super-long, narrow subway station. The site is located in a typical soft alluvial area of the Yangtze River, characterized by highly compressible and sensitive soil, which poses substantial challenges. Pre-construction ground improvement was implemented to mitigate the impacts of diaphragm wall trenching; however, monitoring data indicated that buildings’ settlements of this stage still reached 28.2%, 24.8%, and 27.2% of their final values, with extensive influence zones. Subsequent excavation of the eastern and middle sections induced further cumulative and differential settlements, raising safety concerns and necessitating structural strengthening before adjacent western excavation. An integrated underpinning system, combining anchor static pressure steel pipe piles with a raft foundation, was adopted. Although short-term settlement increased during pile and raft installation, post-strengthening settlement rates decreased significantly. The adjacent western excavation caused only 13.3% of the settlement to be observed during the middle section’s excavation. All buildings were ultimately protected from excessive deformation. The protective strategies and lessons learned provide practical guidance for similar projects. Full article

Plant growth-promoting bacteria (PGPB) have a wide range of applications in agriculture and environmental management. They act as biostimulants and biofertilizers to enhance crop quality and yields in a more sustainable way. The present research aimed at isolating three active strains from the arid rhizosphere soil to act as biofertilizer. The plant growth-promoting features were evaluated in vitro and their implementation on pepper growth and yield were assessed and measured. Regarding IAA and ammonia production, the three designated isolates (P21, P22-1 and P58) showed patterns of high IAA production, producing 154.47 µg/mL, 155.03 µg/mL, and 188.65 µg/mL, respectively. Furthermore, considerable amounts of ammonia were detected in the supernatant of peptone water medium after 72 h of growth. Isolate P21 produced the maximum amount and generated 17.38 μmol/mL, whereas both P22-1 and P58 displayed lower amounts (15.47 and 15.92, respectively), without significant differences. P-solubilization efficacy calculated 18.7% (isolate P21), 64% (isolate P22-2), and 54% (isolate P58) when compared with un-inoculated medium. The molecular identification by 16S rRNA displayed that the three isolates belonged to Pseudomonas alkylphenolica strain P21 (PX257452), Pantoea agglomerans strain P22-1 (PX257453), and Pantoea brenneri strain P58 (PX257454). Applying the selected strains with sweet pepper in the presence of rock phosphate (RP) was assessed under greenhouse conditions. Three treatments (adding bacterial suspension at 0, 10 and 20 days after transplanting) from P21, P22-1, and P58 strains revealed that P21(3), P21(2), P22-1(3), and P58(3) treatments are considered the most promising treatments related to plant height, root length, leaf area, number of leaves per plant, leaf P-uptake, and stem P-uptake in addition to total plant P-uptake. In addition, the PCA biplot showed that MSP (mono-super phosphate), P22-1(3), and P58(3) are closely associated with high phosphorus uptake, indicating their effectiveness in enhancing phosphorus absorption by solubilizing insoluble forms. Eventually, PGPB will help the environment by improving soil fertility and structure, decreasing the need for toxic chemical fertilizers, and improving ecosystem health overall. Full article

Peatlands are vital carbon reservoirs, but their ecological roles are increasingly being compromised by land use change. While tropical peatlands are often associated with lowlands, distinct highland peatlands also occur, they remain insufficiently explored. The Humbang Hasundutan peatlands formed on the southern flank of the Toba caldera following the ~74 ka super-eruption, where persistent waterlogging in cool, wet uplands enabled accumulation of predominantly woody peats. This study investigated the effects of recent land use changes on the chemical and biological properties of peat soils in Humbang Hasundutan (elevation 1350–1430 m.a.s.l.), comparing forests, open lands, and cultivated areas. Soil samples were collected from three sub-districts (Dolok Sanggul, Pollung, Lintong Nihuta) at two depths (10 cm and 40 cm) and analysed for carbon (C), nitrogen (N), pH, and microbial respiration. Results revealed the significant degradation in cultivated lands, with C content dropping to 10–15%, compared to 57.30% in forests. Nitrogen levels were highest in Dolok Sanggul (1.38% in cultivated land) and Pollung (1.32% in open land). C:N ratio varied from 66 in forests to 34 in cropping lands. Soil pH varied by land use, with cultivated areas showing elevated pH (5.09) due to mineral soil mixing, while natural forests retained acidic conditions (pH 3.9–4.4). Microbial respiration was highest in forests (5.49 mg CO₂/day) but decreased in disturbed areas. These results stress the climate-mitigation value of intact highland peat forests and the urgency of tailored restoration via rewetting and native revegetation, alongside cautious agroecological management. Full article

Cadmium and arsenic co-contamination found in mining actions indicates major effluence in adjacent farmland soils, disturbing the plant physiology and soil’s microbial community. Phosphorus (P) plays a vital role in reducing soil contamination from Cd and As bioavailability and uptake by plants. However, the right P sources for remediation approaches are critical and still require further research in Cd- and As-contaminated soil. This study aimed to explore the effects of different phosphorus fertilizer sources on Lolium perenne growth and its physiological and rhizosphere microbial diversity under combined contamination with Cd and As. Pot experiments were performed with seven treatments including SSP (single super phosphate), DAP (diammonium phosphate), MAP (monoammonium phosphate), CaP (calcium phosphate), HighCaP (high calcium phosphate), RP (rock phosphate), and no phosphorus fertilizer application (CK) with five replications in the RCB design. The SSP treatment showed the greatest plant height (15.7 cm), hay yield (3567.6 kg·ha⁻¹), and enhanced antioxidant defense activities. It also achieved the highest phosphorus accumulation rate (0.63 g·kg⁻¹) with reduced Cd and As uptake. In addition, SSP promoted higher non-protein sulfhydryl (NPT) and phytochelatin synthetase (PCs) contents along with γ-glutamylcysteine synthetase (γ-ECS) activity, and enriched the rhizosphere microbial community, where the Sphingomonas abundance was 7.08% higher than for other treatments. Therefore, this result indicates that SSP can improve the yield and physiology in L. perenne, as well as soil the rhizosphere microbial community structure, while reducing Cd and As accumulation in plants under Cd and As stress. Full article

Sustainable irrigation in water-limited regions requires timely, field-scale estimates of soil water content (SWC). Yet, field-scale SWC studies leveraging near-daily satellite imagery of regenerative systems—particularly cotton under Mediterranean conditions—are lacking, and explainable integrations of Planet SuperDove with agrometeorological inputs remain underexplored. In this study, we evaluated a machine learning framework that integrates near-daily multispectral features from Planet SuperDove with agrometeorological variables to estimate the daily SWC of regenerative cotton under Mediterranean conditions across two seasons (2023–2024). Six regression models were compared; extreme gradient boosting achieved the highest accuracy (R² = 0.73 ± 0.08; RMSE = 4.60 mm ± 0.81; nRMSE = 0.035 ± 0.01), with limited bias and stable performance across the years and moisture conditions. The model interpretability via SHAP indicated that agrometeorological drivers contributed over half of the predictive power, while the NDVI and NIR provided the most informative satellite inputs, followed by the NDRE and PSRI. The results show that combining high-frequency satellite data with meteorological inputs can deliver accurate and interpretable SWC estimates at the homogeneous plot level, supporting irrigation optimization of regenerative systems. This approach is practical, transferable, and suited for operational decision-making where frequent, high-resolution observations are available. Full article

Laser-induced breakdown spectroscopy (LIBS) has been used to explore the chemistry of three regions of Mars on respective missions by NASA and CNSA, with CNES contributions. All three LIBS instruments use ~100 mm diameter telescopes projecting pulsed infrared laser beams of 10–14 mJ to enable LIBS at 2–10 m distances, eliminating the need to position the rover and instrument directly onto targets. Over 1.3 million LIBS spectra have been used to provide routine compositions for eight major elements and several minor and trace elements on >3000 targets on Mars. Onboard calibration targets common to all three instruments allow careful intercomparison of results. Operating over thirteen years, ChemCam on Curiosity has explored lacustrine sediments and diagenetic features in Gale crater, which was a long-lasting (>1 My) lake during Mars’ Hesperian period. SuperCam on Perseverance is exploring the ultramafic igneous floor, fluvial–deltaic features, and the rim of Jezero crater. MarSCoDe on the Zhurong rover investigated for one year the local blocks, soils, and transverse aeolian ridges of Utopia Planitia. The pioneering work of these three stand-off LIBS instruments paves the way for future space exploration with LIBS, where advantages of light-element (H, C, N, O) quantification can be used on icy regions. Full article