Search Results (2,026)

Seasonal fertilizer restriction periods (blackouts) are commonly implemented in Florida to reduce potential nutrient losses during the summer rainy season; however, their effects on sports turf performance under traffic stress are not well documented. A two-year field study (2022–2023) was conducted in Citra, FL, to evaluate the influence of nitrogen (N) fertilization timing and frequency on ‘Bimini’ bermudagrass (Cynodon dactylon L. Pers.) traffic tolerance and post-traffic recovery. Treatments included bi-weekly (24.4 kg N ha⁻¹) and monthly (48.8 kg N ha⁻¹) N applications, a pre-blackout (97.6 kg N ha⁻¹) N application, and a non-treated control. Simulated traffic was applied using a modified Baldree traffic simulator for a total of 60 traffic events each year. Turfgrass performance during traffic and recovery was assessed using percent green cover (PGC), dark green color index (DGCI), soil moisture, surface hardness, and rotational resistance. In both years, bi-weekly and monthly N applications consistently resulted in greater PGC and DGCI during traffic and recovery compared to the pre-blackout and non-treated treatments. The pre-blackout treatment provided limited and inconsistent benefits, particularly under prolonged traffic stress. Fertilizer effects on soil moisture and surface hardness varied between years, while rotational resistance was unaffected by treatment. These results indicate that reliance on pre-blackout fertilization alone may be insufficient to maintain bermudagrass traffic tolerance and recovery during periods of sustained traffic stress. Under sustained traffic pressure, applying a single fertilizer treatment just before the restriction period was less effective and produced inconsistent improvements in turfgrass coverage and color compared with staged fertilization during the growing season, reinforcing that routine N fertilization is necessary when turfgrass experiences sustained traffic. Full article

Viscoelastic solutions are developed for the axial dynamic response of single piles in soil profiles that are inhomogeneous both vertically (with depth) and horizontally (with radial distance from the pile). While vertical soil inhomogeneity has been well explored, horizontal inhomogeneity has received limited research attention. In this work, the problem is treated in the realm of linear elastodynamic theory by employing a rigorous finite-element formulation specifically developed by the authors for the problem at hand. The effect of double soil inhomogeneity is investigated with reference to: (1) pile head stiffness; (2) pile-head radiation damping; (3) soil reaction along the pile; and (4) variation of the above with loading frequency. To this end, four different soil profiles are considered in conjunction with different levels of soil inhomogeneity, pile lengths, pile–soil stiffness contrasts, and boundary conditions at the pile tip. It is shown that the effect of inhomogeneity has unique features that cannot be captured by using a substitute homogeneous profile. Modeling an inhomogeneous soil as a homogeneous layer providing equal pile-head stiffness (to be referred in this work to as “stiffness-equivalent soil”) may grossly overestimate wave radiation, leading to dampened estimates of dynamic pile response. Simulations of two field experiments are reported, and implications of radiation damping in design are discussed. Full article

Industrial hemp (Cannabis sativa L.) is versatile and rapidly developing, offering new prospects to producers as a multipurpose crop, yet limited water availability in the Mediterranean area due to climate change makes its sustainable management challenging. Although the plant’s water requirements have been studied, a significant gap remains regarding irrigation management based on the hydraulic properties that govern water movement. The present study elucidates the role of soil hydraulic parameters in water dynamics within the rhizosphere of industrial hemp (Cannabis sativa L., ‘Felina 32’). For this purpose, a pot experiment of three irrigation treatments (100% FC, 80% FC, 60% FC; FC is the field capacity) was set up using two different soil types (clay loam CL and sandy clay loam SCL). SCL soil showed a higher C_max of about 4 cm⁻¹ compared to the C_max of 0.11 cm⁻¹ of CL soil, but dropped drastically within a narrow frame of soil moisture. CL soil resulted in about 12-fold higher diffusivity (D_max ≈ 0.23 cm² min⁻¹) within a wider range of soil moisture compared to the SCL soil (D_max ≈ 0.02 cm² min⁻¹), which facilitated water redistribution at CL, allowing the plant to maximize its water uptake, even at the lowest water input. As a result, the CL soil allowed more flexible scheduling and in contrast, SCL soil necessitated a high frequency irrigation protocol. The integration of hydraulic properties into irrigation planning revealed the potential of CL to apply water to plants efficiently across full and deficit irrigation, showing the peak performance of the irrigation water use efficiency (IWUE) (0.929 g/mm) under the 60% FC regime. The findings provide a framework for linking soil physics–agricultural hydraulics with irrigation strategies in controlled environments. Full article

Increasing frequency and intensity of extreme precipitation events, together with altered soil saturation dynamics, have significantly increased the occurrence of shallow landslides. These processes are closely linked to climate change and increasingly affect mountainous and hilly regions worldwide, where rainfall-induced pore pressure variations and transient infiltration govern slope instability. Despite growing recognition of climate-driven slope failures, most conventional geomechanical analyses still rely on static assumptions and simplified boundary conditions, which are insufficient to capture the pronounced temporal variability of hydro-climatic forcing. To address this gap, this study introduces a conceptual and methodological framework for a proactive landslide cadaster, developed within the Climate Adaptive Resilience Evaluation (CARE) framework. Rather than serving as a static inventory of past events, the proposed cadaster functions as a structured, updatable repository of climate–geomechanical parameters that directly support advanced landslide analyses. The core innovation lies in the formalization of the climate–geomechanical interface, which enables the transformation of climatic and hydrological variables into parameters directly applicable in geomechanical modeling. These parameters encompass climatic, hydrological, geomechanical, and thermo-hydraulic processes and are assigned to spatially referenced locations, complemented by documented landslide occurrences. Their spatial distribution forms a network of reference points that allows interpolation, continuous updating, and reuse across multiple analyses. In this way, the cadaster becomes a proactive, process-based data infrastructure, serving as the foundational input for scenario-based landslide susceptibility, hazard, and risk assessments within the CARE analytical workflow. The conceptual framework is illustrated through an example from Slovenia, focusing on the Visole area near Maribor, where selected data types and workflow steps are presented for demonstration purposes. Full article

Measurement results of train-induced vibrations are evaluated for characteristic frequencies, amplitudes and spectra, leading to a prediction which is based on transfer functions of the vehicle–track–soil system, the soil, and the building–soil system. The characteristic frequencies of train-induced vibrations are discussed following the propagation of vibrations from the source to the receiver: out-of-roundness frequencies of the wheels, the sleeper passage frequency, the vehicle–track eigenfrequency, the car-length frequency and multiples, axle-distance frequencies, bridge eigenfrequencies, the building–soil eigenfrequency, and floor eigenfrequencies. Amplitudes and spectra are compared for different train and track types, for different train speeds, and for different soft and stiff soils, where high frequencies are typically found for stiff soil and low frequencies for soft soil. The ground vibration is between the cut-on frequency due to the layering and the cut-off frequency due to the material damping of the soil, but the dominant frequency range also changes with distance from the track. The frequency band of the axle impulses due to the passing static loads obtains a signature from the axle sequence. The high amplitudes between the zeros of the axle-sequence spectrum are measured at the track, the bridge, and also in the ground vibrations, which are even dominant in the far field. A prediction software is presented, which includes all three parts: the excitation by the vehicle–track interaction, the wave transmission through the soil, and the transfer into a building. Full article

Global Navigation Satellite System Interferometric Reflectometry (GNSS-IR) provides a low-cost, all-weather approach for continuous soil moisture content (SMC) retrieval. However, in single-constellation, multi-satellite applications, the optimal satellite number and the combined effects of multiple environmental factors on retrieval accuracy and stability remain insufficiently quantified. To address these issues, this study develops a dual-frequency GNSS-IR SMC retrieval framework that explicitly incorporates multiple environmental factors. Entropy-based fusion (EFM) is used to adaptively weight dual-frequency phase-delay observations, and a marginal-gain criterion is introduced to determine a suitable number of participating satellites. On this basis, univariate linear regression (ULR) and random forest (RF) models are established, and the Normalized Difference Vegetation Index (NDVI), temperature, and precipitation are incorporated into the RF model to improve retrieval robustness and quantify the relative contributions of environmental factors. The results show that multi-satellite combinations significantly improve SMC retrieval performance, while the incremental gain exhibits clearly diminishing returns and converges when the number of participating satellites reaches about 5–6 within a single constellation. Dual-frequency fusion consistently outperforms single-frequency schemes across different GNSS constellations, demonstrating the complementary value of multi-frequency information under multi-satellite conditions. In addition, the environmentally informed nonlinear model achieves higher accuracy and stability than the linear model, and the dominant environmental drivers differ across stations. Overall, this study provides quantitative support for configuring single-constellation multi-satellite GNSS-IR soil moisture monitoring schemes and for improving retrieval robustness under complex environmental conditions. Full article

Permafrost regions serve as sensitive indicators of global warming due to their ecological sensitivity and role as climate archives. To study how soil microbial communities in seasonal permafrost respond to freeze–thaw alternations, we analyzed composition and diversity during freezing, freeze–thaw, and thawing stages, identifying key taxa and environmental drivers. Our results identified 11 known fungal phyla and 13 dominant genera in permafrost regions. Most dominant fungi showed stable abundance during soil warming. However, the genera Inocybe and Sebacina were significantly suppressed when transitioning from frozen to freeze–thaw conditions. Fungal species diversity gradually increased with rising temperature and freeze–thaw frequency, with thawed soil showing higher richness and evenness. Frozen, freeze–thaw, and thawed soil were respectively associated with 90.48%, 71.43%, and 66.67% of node species. Adjacent stages shared 57.14% of coexisting species. Keystone node species declined progressively from frozen to thawed stages, indicating substantial yet continuous community reorganization. Furthermore, total carbon, organic carbon, available nitrogen, and phospholipid fatty acids peaked in freeze–thaw alternating soil. Active fungal biomass and species richness were most strongly correlated with soil carbon, temperature, and moisture. Overall, the influence of nutrients on soil fungi was limited across different freeze–thaw stages, while temperature emerged as the primary driver reshaping fungal community structure during freeze–thaw dynamics. Full article

Global climate change poses increasing challenges to agricultural production and global food security by intensifying temperature and precipitation variability and increasing the frequency of extreme weather events. While several studies have examined farmers’ perceptions of climate change in the United States, limited empirical evidence exists for the Delaware, Maryland, and Virginia (Delmarva) Peninsula. This study assessed farmers’ perceptions of climate change in the Delmarva region and identified key factors influencing these perceptions, as well as adaptation strategies employed to address climate-related risks. Primary data were collected through a structured survey administered to farmers across the Delmarva Peninsula, while secondary data consisted of historical temperature and precipitation records obtained from meteorological stations in the region. Descriptive statistics were used to summarize farmer perceptions and adaptation practices, and a logit regression model was applied to examine socioeconomic and experiential factors influencing perceptions of climate change. Analysis of climate data revealed notable variability in temperature and rainfall patterns, with the warmest temperatures occurring during June, July, and August and peak rainfall generally observed between May and September. Survey results showed that a large majority of respondents (88.2%) perceived that climate change is occurring. Logit model results indicated that farmers’ age, education level, acceptance of climate change adaptation practices, and observed changes in climate over the past 5–10 years positively influenced perceptions of climate change. Adaptation strategies included selective crop choices, avoiding cultivation in flood-prone areas, adoption of soil conservation practices, and the use of crop insurance. Full article

Modern agriculture has to alleviate extremes in water demand and/or water waste. In this regard, this work showcases how soil moisture instruments can be combined with low-end microcontrollers, energy-efficient communication protocols, single-board computers, flow and pressure sensors, and purpose-built actuators to form a synergistic platform able to generate and study realistic irrigation scenarios. These scenarios, potentially emulating anomalies such as clogged emitters or pipe leaks with a satisfactory time granularity of a few minutes, provide valuable data that pave the way for the creation of intelligent models intercepting water misuse events and/or irrigation failures. The proposed system utilizes widely available, well-documented, low-cost components to form a functioning whole which is optimized for outdoor, low-power, low-maintenance and long-term operation and is accessible remotely via typical end-user devices. Two drip irrigation points were set up, each having a TEROS 12 and a TEROS 10 instrument placed at different depths, while a prototype water flow/pressure control and report system was developed. All modules sent data in real time, via LoRa, to a central node implemented using a Raspberry Pi for further processing and to make them widely available via common network infrastructures, also provisioning for remote scenario invocation. The system does not claim to achieve specific irrigation water savings, but it contributes to maintaining/increasing the benefits of modern irrigation practices (such as drip irrigation). This goal is served by emulating a wide variety of irrigation events and by gathering and studying the corresponding data. These multimodal data are collected at a frequency of a few minutes, reflecting key irrigation-specific parameters with an accuracy better than or equal to 3%. The exact steps for specific hardware and software component interoperation are clearly explained, allowing other teams of researchers and/or university educators worldwide to be inspired and benefit from platform replication. Full article

Against the backdrop of increasingly scarce global arable land resources, the remediation and resource utilization of saline–alkali soils have become a critical issue in circular agriculture. This study proposes micro-nano bubble (MNB) irrigation technology as a green, low-carbon strategy for saline–alkali soil remediation, highlighting its multi-level driving mechanism through pot experiments at different aeration frequencies. Results indicated that MNB irrigation significantly enhanced salt leaching and acid-base neutralization by reducing the soil pH (11.75%) and electrical conductivity (53.41%). Meanwhile, soil organic matter, cation exchange capacity, and available nitrogen, phosphorus, and potassium increased to normal soil levels. MNBs also strongly activated native enzymes (urease and alkaline phosphatase), raising the total enzyme activity by 68.54%, which is linked to carbon, nitrogen, and phosphorus metabolism. These results were also validated by microbial analysis, which indicated that MNBs shifted the community structure from one dominated by salt-tolerant taxa (i.e., Pseudomonadota) to a more functionally beneficial composition (i.e., Bacillota). Through these changes, the microbial diversity and network connectivity were enhanced, with Qipengyuania and Psychrophilus identified as critical nodes. This study reveals the multi-level driving mechanism of MNB technology, providing new technical pathways and theoretical support for the remediation, resource recovery, and circular utilization of agricultural waste soils. Full article

Tropical cyclones kill thousands and inflict vast destruction annually. While ocean temperatures and atmospheric conditions dominate their formation and behaviour, forests’ potential influence has received little systematic attention. This review examines whether and how forests may affect tropical cyclone frequency, intensity, and behaviour. Support varies by mechanism and stage. Post-landfall effects have the strongest support: forests slow storms, moderate wind speeds and curb flooding through enhanced soil infiltration. Forests also influence storm tracks, though magnitudes are uncertain. Pre-landfall effects are less certain. These include processes that modify offshore humidity, temperature, and aerosols. The Biotic Pump theory proposes that forest cover creates pressure gradients drawing moisture inland, reducing its availability for ocean storms. Forest influences are likely to be most evident near thresholds for storm formation or intensification, where small perturbations in conditions can alter outcomes. This context-dependency reconciles divergent findings and aids the integration of forests into climate risk assessments. Forest conservation provides clear post-landfall protection; pre-landfall effects, while uncertain, further strengthen the case for protection and highlight research priorities. Full article

Micro- and nanoplastics (MNPs) are being found, with growing frequency, in agroecosystems, where soils function as major sinks and direct interfaces with food crops. This review shows an integrated soil–plant–food analytical framework and synthesizes evidence on MNPs behavior in soils (dispersion, aging, aggregation), plant uptake pathways (root vs. foliar, including atmospheric deposition), tissue translocation, and plant physiological responses. Across crop species and exposure conditions, convergent patterns included oxidative stress, disruption of nutrient homeostasis, impaired photosynthesis, and growth penalties, with magnitude modulated by particle size, polymer type, and surface chemistry within specific soil–plant contexts. Occurrence of MNPs in edible tissues of leafy, root, and fruit vegetables is critically appraised, as well as its implications for food safety and potential dietary exposure. Key uncertainties persist, including heterogeneous analytical methods, scarce long-term field datasets, and limited alignment between laboratory doses and environmental concentrations. These constraints translate into priorities for exposure assessment and risk governance, including the need for standardized metrics, harmonized quality criteria, and field-scale monitoring aligned with agronomic practices. By re-centering the analysis on crops and food systems while acknowledging human exposure implications, the review provides a decision-oriented basis for research and mitigation. Full article

In this study, representative soil profiles developed on clastic rock parent materials in Yunnan Province were investigated to elucidate the formation mechanisms of soil magnetic properties under weakly magnetic parent material conditions and to evaluate the response of magnetic enhancement to chemical weathering and pedogenic differentiation. A combination of environmental magnetic measurements, bulk geochemical analyses, weathering index calculations, and ternary diagram discrimination was applied to characterize soil magnetic behavior, magnetic grain size distribution, and chemical weathering processes. The results show that the clastic rock parent materials exhibit overall low magnetic intensities, with low-frequency magnetic susceptibility (χ_lf) ranging from 2.543 × 10⁻⁸ m³/kg to 595.652 × 10⁻⁸ m³/kg. Under this weakly magnetic background, soils in the study area display pronounced pedogenic magnetic enhancement, with magnetic parameters showing clear and systematic vertical differentiation along soil profiles, indicating that soil magnetic signals are primarily controlled by pedogenesis. The frequency-dependent susceptibility (χ_fd%) generally falls within the range of 5.403%–17.574%, with a mean value of 12.898%, suggesting a substantial contribution from fine-grained magnetic particles. Magnetic grain size diagnostics further indicate that newly formed superparamagnetic (SP) and stable single-domain (SSD) particles generated during pedogenesis dominate the magnetic enhancement signal. The results of the Chemical Index of Alteration (CIA) indicate that approximately 78% of the profiles reach the strong weathering category (CIA > 85), while only 22% fall into the moderate weathering category (CIA: 65–85). Correlation analyses further reveal that grain-size-sensitive magnetic ratios (e.g., χ_fd%, χ_ARM/SIRM) exhibit a strong correspondence with chemical weathering intensity indicators. These findings suggest that, under weakly magnetic parent material conditions, pedogenically induced magnetic enhancement can be more readily identified and quantitatively assessed. The integration of environmental magnetism and geochemical approaches, therefore, provides a robust framework for investigating pedogenic differentiation and supports high-resolution paleoenvironmental reconstruction in regions dominated by weakly magnetic parent materials. Full article

Optimizing public investment in urban green infrastructure under water scarcity is a core challenge in resource economics. Against the backdrop of global climate change—characterized by rising temperatures, increased frequency and intensity of droughts, and altered precipitation patterns—this study addresses the critical knowledge gap in quantifying the economic returns on the physiological adaptations of urban trees, which are central to their value as natural capital. We integrated dual-water isotope (δ²H, δ¹⁸O) and leaf carbon isotope (δ¹³C) analyses to mechanistically decode the water use strategy of Machilus yunnanensis (M. yunnanensis) in drought-prone Kunming, China. The results show strategic seasonal plasticity: a shift from shallow soil water (10–50 cm) in the wet season to deeper soil sources (50–90 cm) and stem reserves in the dry season, coupled with a dynamic, diurnally variable water use efficiency (WUE_13C). We then constructed a transparent economic valuation model translating these traits into three quantifiable benefit streams: (1) operational cost savings (EV₁) from reduced irrigation demand; (2) enhanced marginal productivity of water (EV₂) in ecosystem service generation; and (3) climate resilience value (EV₃) via mitigated mortality risk. Our “Water–Carbon–Economy” nexus framework provides a generalizable methodology for assessing the cost-effectiveness and risk-adjusted returns of urban forest species, demonstrating that tree selection based on such eco-efficient traits is not merely an ecological choice but a sound economic investment, offering direct implications for budget-constrained municipalities seeking to maximize green infrastructure benefits under climate uncertainty. Full article

Shaking table testing has become a fundamental experimental approach in geotechnical earthquake engineering for investigating seismic soil–structure interaction. Although numerous studies have examined the dynamic behavior of reinforced retaining walls and soil slopes, the existing body of literature remains fragmented, with significant variations in scaling approaches, boundary conditions, input motions, and instrumentation methods. To date, no comprehensive review has critically synthesized these studies to identify consistent behavioral trends and methodological limitations. This paper presents a systematic and critical review of shaking table investigations of geosynthetic-reinforced retaining walls and clayey soil slopes. The review consolidates global experimental findings to evaluate how key parameters—including excitation characteristics, soil density, surcharge loading, reinforcement configuration, and boundary conditions—influence displacement patterns and acceleration amplification. Recurring response mechanisms are identified, such as elevation-dependent amplification, nonlinear frequency effects, and the confinement benefits of reinforcement and surcharge. The review further examines discrepancies among studies and between experimental and numerical results, highlighting challenges related to similitude requirements, boundary effects, and signal fidelity By synthesizing dispersed experimental evidence and critically evaluating methodological variations, this review provides a clearer understanding of seismic response mechanisms and offers guidance for improving experimental consistency and promoting future standardization in shaking table testing. Full article