Abstract: Climate change driven by the accumulation of greenhouse gases (GHG) in the atmosphere is projected toincrease average global surface temperatures, influencing agricultural production and nutrient cycling. Phosphorus (P), a key nutrient for plant growth, can both contribute to and reduce the effects of climate change. Climate change and P management are interrelated, as climate change will influence optimal P management while P fertilizer can both help in ameliorating and adapting to climate change effects on agriculture and the environment and contribute to direct and indirect GHG emissions. Greenhouse gases are emitted during phosphate rock extraction, as well as during the production transport and application of P fertilizer. Emissions during production could be reduced by improving energy efficiency, using alternative, non-fossil energy sources, or possibly using emerging technologies for synthesis of the ammonia used in production. To reduce the amount of indirect greenhouse gas emissions linked to P manufacture, it is important to optimize the efficiency of P fertilizer as the less P that is mined, processed, transported and applied to the field per unit of agricultural production, the less risk there is of both GHG emissions and off-site transport. While production and transport of P fertilizer can contribute to climate change, efficient P management can reduce negative effects of climate change and may contribute to reductions in GHG emissions and to climate change adaptation. Optimal P management is needed to support carbon sequestration in soil, to allow plants to benefit from increasing CO2 concentrations, to reduce risk of indirect GHG emissions, to reduce P movement to water bodies and to enhance resiliency of crops to climate stress. Proper nutrient management, including P management, plays a key role in Climate Smart Agriculture, Low-Carbon Agriculture and Sustainable Intensification, that are different approaches to encouraging optimal crop productivity while minimizing the contribution of agriculture to climate change. Managing P fertilizer in a changing environment requires use of the 4R principles to select the rate, source, timing and placement combination best suited to the site-specific agronomic and environmental conditions.

Abstract: Soil, with 30,000 Gt SOC (Gigatonnes of Soil Organic Carbon), is the greatest global store of active carbon as well as being source and sink of most atmospheric CO2. Soil respiration/decay (~220 Gt C/yr) is twenty times Fossil Fuel (FF) emissions (~10 Gt C/yr). Soil supports >99.9% of species biodiversity (mainly microbes), provides ~99% of human food, and filters100% of our drinkable freshwater (via earthworm burrows). Soil is yet the most neglected biome as are its main monitors and mediators, the resident earthworms. These are silently dying, just as soil is being eroded and degraded at irreplaceable rates, to our, and all other species’, detriment. Land use changes (LUC) release carbon from deforestation and soil erosion/poisoning at rates about twice that of FF emissions, themselves twice the CO2 increase (5 Gt C/yr). Knowing all this provides a ready solution to Climate, to Food Security as well as the most pressing of issues: The rapid and irreversible species extinction. Based upon proper scientific context and urgent triage priority, the imperative is to redirect all our efforts and funding to restore topsoil. The simplest remedies, available to anyone, are to vermi-compost, to demand or support 100% organic food (thus protecting earthworms), and to reduce excess red-meat. In this way rich soil humus is revived, deforestation is reduced and toxic poisoning of our air, water, soil and food is resolved. Organic husbandry within broader Permaculture design principles allows practical and proven solutions to the ecologically interlinked problems.

Abstract: Urban and peri-urban agriculture (UA) plays an increasingly important role in pro-moting sustainable urban development, delivering socioeconomic, environmental, and educational benefits. However, UA is often associated with nutrient accumulation in soils, as vegetable-growing areas typically receive substantial inputs of organic and inorganic fertilizers. This study examines soil variability in two sections of an urban allotment garden subjected to long-term manure fertilisation for 12 or 16 years at ap-plication rates up to 10–12 kg m⁻² yr⁻¹. Surface soils were analysed for organic and in-organic carbon, total N, available P and K, pH, and elemental composition using port-able X-ray fluorescence (pXRF). Prolonged manure incorporation substantially in-creased soil fertility, evidenced by elevated soil organic carbon, total N, available K, and both total and available P. Marked shifts in mineral composition were also ob-served, including significant increases in total Ca, inorganic C (as calcium carbonate), Sr, and S. Despite the high manure inputs, no accumulation of potentially toxic ele-ments (PTEs) was detected. Nevertheless, pronounced heterogeneity was found among individual plots, reflecting differences in fertilisation intensity and management prac-tices. pXRF proved highly effective for identifying soil compositional changes and pre-dicting nutrient availability, highlighting its potential as a rapid diagnostic tool for precision agriculture management.

Abstract:

Modeling the water cycle requires a proper understanding of interactions within the critical zone compartments - soil, vegetation, and atmosphere. Among the key processes involved, soil water flow modeling using a mechanistic approach relies on accurately determining the hydrodynamic parameters that define the soil hydraulic conductivity and water retention curves. Various estimation methods exist, including pedotransfer functions (PTFs) based on soil properties derived from field samples, and inverse modeling approaches that adjust hydrodynamic parameters to minimize discrepancies between simulations and observations. While the PTF approach is widely used due to its simplicity and limited technical requirements, inverse modeling demands specific instrumentation and advanced numerical tools. This study, conducted on the experimental site of the Hydro-Geochemical Environmental Observatory - the Strengbach forested catchment - aimed to determine the optimal hydrodynamic parameters for two contrasting forest plots, one dominated by spruce and the other by beech. The results highlight the importance of accounting for soil stoniness to improve the efficiency of flow modelling, as well as the need to assess the robustness of the derived parameter set, given that selecting an optimal calibration period remains challenging and that the model should be able to represent hydrological variability.

Abstract: For the numerical simulation of rainwater infiltration in forest slope, information on the water retention curve (WRC), which shows spatial variability due to forest ecosystem and weathered granite in natural forest soils, is required. A scaling approach using three parameters of the LN model has been developed to simplify the spatial variability in the WRCs of forest slope of the soil under geomorphological process. This approach showed that we required spatial data set in scaling parameter, effective porosity, e, and each average value of remaining two parameters (the matric pressure head corresponding to the median pore radius, m, and the width of the pore-size distribution, ) which were defined as reference parameters. In this study, we estimated the minimum number of WRCs required to determine the reference parameters effectively. For this purpose, 77 WRCs of core samples were collected from whole 25 m forest slope, and we randomly sampled WRCs using a Monte Carlo simulation. The effect of scaling (EOS) increased with the sample size, and the increase became small at a sample size of approximately 20. We could explain 78% (EOS = 0.78) of spatial variability in the WRCs at the 95% confidence level by using the reference parameters derived from 8 samples. In addition, we performed stratified sampling to reduce the number of WRCs required. As a result, the sampling scheme, which considers the variability in only slope direction, was the most advantageous. This result indicated that the geomorphological process, which produces spatial variability in the reference parameters of forested slopes, is an important factor to effectively determine reference parameters. This paper concluded that scaling approach enables us to reduce the required number of samples for WRCs.

Abstract:

Biochar surface chemistry strongly influences the adsorption and partitioning of organic matter in soils, yet the sorption-mediated stabilization mechanisms of biochars derived from invasive plant biomass remain poorly constrained. In this study, Solanum rostratum biomass was pyrolyzed at 300–700 °C to generate biochars with distinct surface functionalities and structural characteristics. Multi-analytical characterization (FTIR, Raman, XPS, SEM) was used to quantify temperature-induced changes in aromaticity, oxygen-containing groups, and pore morphology, while soil incubation experiments assessed impacts on organic carbon fractions. High-temperature biochars showed reduced O-containing groups and enhanced aromatic condensation, indicating a shift from hydrogen bonding and electrostatic interactions to hydrophobic and π–π sorption mechanisms. These surface transformations were associated with increased stable carbon pools and reduced labile carbon in soil, consistent with stronger adsorption and protection of organic matter. Sequencing analysis revealed that biochar amendments significantly altered bacterial community composition and enhanced deterministic assembly processes, suggesting that microbial reorganization further reinforces sorption-driven carbon stabilization. These findings demonstrate that S. rostratum biochars possess strong sorptive properties that promote long-term carbon retention and modulate microbial ecological processes, supporting their potential use as sustainable adsorbents in soil carbon management.

Abstract: Cowpea production potential often falls short, despite the crop's efficiency as a legume. This underperformance is primarily attributed to widespread deficiencies of phosphorus (P), cobalt (Co), and molybdenum (Mo) in Brazilian soils, especially in the Cerrado region. This study aimed to determine the optimal doses of P, Co, and Mo to enhance cowpea nodulation, biological nitrogen fixation, and overall plant growth. Two greenhouse exper-iments were conducted using a randomized complete block design in a 2 × 5 factorial scheme (two soils and five doses of each nutrient, inoculated with strain BR 3262), with four replicates. In Trial I, P₂O₅ doses of 0, 100, 200, 300, and 400 mg pot⁻¹ were tested, while in Trial II, Co:Mo ratios (w:w) were evaluated: 0:0, 2:8, 3:16, 4:32, and 6:64 (mg pot⁻¹). The variables analyzed included phytotechnical parameters. The application of 200 mg pot⁻¹ of P₂O₅ (200 kg ha⁻¹) resulted in the highest nodulation, nitrogen accumulation, and increased cowpea biomass. Furthermore, medium-high micronutrient levels (Mo at 32 g ha-1 and Co at 4 g ha-1) provided superior nodulation, biomass, and nitrogen accumu-lation. Adequate P and micronutrient fertilization is essential for plant development, rein-forcing its pivotal role in maximizing cowpea productivity under Cerrado soil conditions.

Abstract: Drought stress profoundly impacts citrus growth and soil health, yet the role of rhizosphere microbial communities in plant drought tolerance remains poorly understood. This study investigated the rhizosphere microbial structure, soil enzymatic activities, and physicochemical properties of drought-tolerant (DR) and drought-sensitive (DS) citrus varieties under drought stress condition. High-throughput sequencing revealed that drought significantly altered microbial community composition, enriching for gram-negative, stress-tolerant, and potentially pathogenic bacteria, as well as plant pathogenic fungi, while reducing undefined saprotrophs. Notably, the DR variety exhibited more stable and complex bacterial network, higher enrichment of beneficial fungi like Penicillium and Trichoderma, and unique recruitment of mycorrhizal fungi, which were absent in DS. Furthermore, soil catalase and urease activities downregulated under drought, whereas acid phosphatase activity upregulated, particularly in drought tolerant cultivar. Correlation analyses indicated that these microbial shifts were closely linked to changes in soil nutrient availability. Our findings demonstrate that the drought-tolerant citrus variety modulates its rhizosphere microbiome towards a more cooperative and resilient state, highlighting the critical role of host-specific microbial recruitment enhances plant adaptation to drought stress for sustainable agriculture.

Abstract: Greenhouse gas (GHG) emissions from agricultural crops remain a critical challenge for climate change mitigation. This review synthesizes evidence on cropland management interventions and global N₂O mitigation potential. Agricultural practices such as cover cropping, agroforestry, reduced tillage, and diversification show promise in reducing CO₂, CH₄, and N₂O emissions, yet uncertainties in measurement, verification, and socio-economic adoption persist. Complementing this, global-scale analysis underscores the dominant role of optimized nitrogen fertilization in curbing N₂O emissions while sustaining yields. To bridge gaps between practice-level interventions and global emission dynamics, this paper introduces the ICEMF, a novel approach combining field-based management strategies with spatially explicit emission modelling. Only peer-reviewed articles published in English between 2014 and 2025 were selected to ensure recent and reliable findings. The review highlights knowledge gaps, evaluates policy and technical trade-offs, and proposes ICEMF as a pathway toward scalable and adaptive mitigation strategies in agriculture.

Abstract: Humic substances (HSs) are naturally occurring macromolecular organic acids derived from plant residues, with structural properties that vary depending on their origin and environmental conditions. These substances influence the solubility and toxicity of environmental pollutants, making their chemical characterization essential. Charge-transfer-type fluorochromes, which exhibit shifts in fluorescence intensity and emission wavelength in response to solvent polarity changes, have been widely employed to investigate solute–solvent interactions. In this study, we developed a rapid and straightforward method to characterize HS polarity using fluorescent solvatochromism. The fluorescence peak shifts of four dyes—8-anilino-1-naphthalenesulfonic acid (ANS), acridine orange (AO), methylene blue (MB), and Rhodamine B (RhB)—were evaluated in the presence of humic acids (HAs), a major component of HSs. To assess environmental variability, HAs from seven different sources were tested. Among these, AO and MB exhibited distinct spectral shifts without overlapping with the intrinsic fluorescence of HAs. Notably, MB displayed a consistent blue shift dependent on HA concentration, with the most stable response observed at 5 mg/L. The magnitude of this shift was significantly correlated with HA aromaticity, molecular weight, and polarity index. Additionally, the peak shifts were positively correlated with log KOM (anthracene) and negatively correlated with log KML (mercury), suggesting that the method reflects HA–pollutant interaction characteristics. Overall, this study demonstrates that fluorescent solvatochromic dyes can serve as polarity-sensitive probes for HS characterization, offering a practical tool for environmental monitoring and risk assessment.

Abstract: Accumulation of salts in irrigated soils can be detrimental not only to growing crops but also to groundwater quality. Soil salinity should be monitored reg-ularly and appropriate irrigation with the required leaching rate should be applied to avoid excessive salt accumulation in the root zone, thereby im-proving soil fertility and crop production. We combined two frequency domain electromagnetic induction (FD-EMI) mono-channel sensors (EM31 and EM38) and operated them at different heights and with different coil orientations to monitor the vertical distribution of soil salinity in a salt-affected irrigated area in Kairouan (central Tunisia). Multiple measurement heights and coil orientations were used to enhance depth sensitivity and thereby improve salinity predictions from this type of proximal sensors. The resulting mul-ti-configuration FD-EMI datasets were used to derive soil salinity information using inverse modeling based on a recently developed in-house laterally constrained inversion (LCI) approach. The collected apparent electrical con-ductivity (ECa) data were inverted to predict the spatial and temporal distri-bution of soil salinity. The results highlight several findings about the distri-bution of salinity in relation to different irrigation systems using brackish water, both in the short and long term. The expected transfer of salinity from the surface to deeper layers was systematically observed by our FD-EMI surveys. However, the intensity and spatial distribution of soil salinity varied between different crops, depending on the frequency and amount of drip or sprinkler irrigation. Furthermore, our results show that the vertical transfer of salinity is also influenced by the wet or dry season. The study provides in-sights into the effectiveness of combining two different FD-EMI sensors EM31 and EM38 for the monitoring of soil salinity in agricultural areas, contributing to the sustainability of irrigated agricultural production. The inversion ap-proach provides a more detailed representation of the of soil salinity distri-bution over spatial and temporal scales across different depths and irrigation systems compared to the classical method based on soil samples and labora-tory analysis which is a point-scale measurement. It provides a more extensive assessment of soil conditions at depths up to 4 m with different irrigation systems. For example, the influence of local drip irrigation was imaged and the history of a non-irrigated plot was evaluated, confirming the potential of this method.

Abstract: In flooded soils, the concentrations of exchangeable Mn2+ and, mainly, Fe2+ can be high and need to be considered in determining the cation exchange capacity (CEC) of the soil under flooded conditions. However, these reduced forms of Mn and Fe are oxidized and precipitated during the extraction process used by traditional methods for determining CEC. This procedure underestimates the exchangeable portion of these cations and, consequently, the CEC value of the flooded soil. The objective of this study is to propose an alternative to estimate the exchangeable Fe2+ and the effective CEC (ECEC) of flooded soils. To achieve this goal, 21 surface samples (0-20 cm) of soils from rice fields were collected, distributed in the cultivation regions of Southern Brazil. The soils were flooded for 50 days. The soil solution was collected on the first day and after 50 days of flooding. and, pH, Na, K, Ca, Mg, Fe and Mn were determined. In these samples, exchangeable cations (K, Na, Ca, Mg, Mn, Al and H+Al) were determined to calculate ECEC and CEC at pH 7 of unflooded soil and after 50 days of flooding. The results were used to develop models to predict ECEC and exchangeable Fe content after 50 days of flooding. The estimation of the ECEC after flooding by the gradient of pH increase before and after flooding generated values closer to CEC pH 7.0, correcting the possible underdetermination of the ECEC during flooding. The amount of exchangeable Fe estimated was higher than the exchangeable Fe determined, correcting the possible underestimation of these quantities determined during flooding. It is concluded that the estimatives of ECEC after flooding through the equation ECECafter=ECEC+pHsol.after- pHsol.before . (CECpH7- ECEC)(7- pHsol.before) and the exchangeable Fe2+ after flooding through the equation Feexc.after.estimated=ECECafter- Ca+Mg+K+Na+Mn corrected the problem of underestimating the values of these variables by analythical methods, demonstrating its viability for the use in flood prone soils.

Abstract: Coal mining leaves behind extensive tailings dumps that pose long-term ecological and soil degradation challenges. This study investigates the restoration potential of vegetation on coal mine tailings in the Jiu Valley, Romania, focusing on soil nutrient dynamics and heavy metal distribution. Field sampling was conducted across three vegetation types—unvegetated (UV), herbaceous (HV), and arboreal (AV, Robinia pseudoacacia)—at two intervals: three- and six-years post-plantation. Soil samples were analyzed for pH, organic carbon, macronutrients, micronutrients, and heavy metals using standardized spectrometric and titrimetric methods. Results showed that vegetated plots, particularly AV, exhibited significant improvements in total nitrogen, organic carbon, and base cation availability, alongside reductions in pH and certain heavy metals. HV plots demonstrated enhanced manganese and copper mobilization, while UV soils retained higher levels of total potassium and zinc, likely due to limited biological uptake. Heavy metal concentrations remained below European safety thresholds for lead and chromium, though nickel levels exceeded recommended limits across all variants. Vegetation type influenced nutrient cycling and metal stabilization, with arboreal cover showing the most consistent ameliorative effects. These findings underscore the role of targeted revegetation in improving soil quality and mitigating ecological risks in post-mining landscapes.

Abstract: This study collected 820 topsoil samples from cultivated lands across Ningxia, covering the Yellow River irrigation area, the central arid zone, and the southern mountainous region. The concentrations of Arsenic (As), mercury (Hg), cadmium (Cd), chromium (Cr), and lead (Pb) were analyzed to evaluate the pollution levels and spatial distribution patterns of heavy metals, which were interpolated using Kriging. Pollution status was assessed via the Nemerow composite index and the geoaccumulation index (Igeo). Source identification and contribution quantification were performed using Pearson correlation analysis, principal component analysis (PCA), and positive matrix factorization (PMF). Results indicated that the cultivated soils in Ningxia are generally clean, with isolated instances of warning and light pollution. Ecological risk assessment revealed differential risk levels among elements, with Hg and Cd presenting the highest ecological risks. Geospatially, regions with higher pollution probabilities for Cd, Cr, Pb, Hg, and As were concentrated in the northern and central parts of Ningxia, whereas the southern region exhibited lower pollution probabilities.pH significantly influences the accumulation and spatial distribution of heavy metals in soil. Source apportionment identified three primary contributors: transportation and natural parent materials (As, Pb, Cr), industrial activities (Hg), and agricultural practices (Cd). Hg and Cd were identified as the key risk elements requiring prioritized management.

Abstract: Soil organic carbon (SOC) plays a crucial role in climate change mitigation by regulating atmospheric CO2 and maintaining ecosystem balance; however, its stability is influenced by land use in anthropized areas such as the tropical Andes. This study aimed to develop a dynamic compartmental model based on ordinary differential equations to simulate carbon fluxes among litter, humus, and microbial biomass under four different land uses in the Las Piedras River basin (Popayán, Colombia): riparian forest (RF), ecological restoration (ER), natural regeneration (NR), and livestock (LS). The model was calibrated using field data on soil physicochemical and biological properties, as well as carbon inputs and outputs. The results showed clear differences in SOC dynamics between land uses: RF exhibited the highest SOC stocks (148.7 Mg ha⁻¹) and microbial biomass, while LS showed the lowest values and the largest deviation from the model due to compaction and low residue input. The humus fraction remained the most stable pool (K₂ ≈ 10⁻⁴ month⁻¹), confirming its recalcitrant nature. Overall, the model accurately reproduced SOC behavior (MAE = 0.01–0.30 Mg ha⁻¹) and provides a useful framework for understanding carbon stabilization mechanisms and guiding adaptive soil management to enhance carbon sequestration in mountain ecosystems.

Abstract: To test hydrochar from chicken manure (CM) produced with the hydrothermal carbonization (HTC) process as a potential soil amendment, the fertilization potential and phytotoxicity of the product was assessed to ensure both effectiveness and safety for crops. The hydrochar produced by heating the feedstock at 250 °C for 0.5 h showed low nutrient and organic carbon (Corg) recovery but a high relative abundance of aromatic and alkyl C. Its favorable available-to-recalcitrant nitrogen (N) ratio, and low heavy metal (HM) concentrations suggest low phytotoxicity and high short- to medium-term N fertilization potential of the amendment. Pot experiments with lettuce, sunflower, and tomato plants confirmed species- and dosage-dependent effects. A dosage equivalent to 3.25 t ha⁻¹ (2.7% w/w) improved lettuce and sunflower yields, whereas higher dosage (6.5 t ha⁻¹; 5.4% w/w) did not provide additional growth benefits. Tomato plants, however, exhibited phytotoxic sensitivity to the higher dosage, which was expressed in a negative impact on germination and yield. Overall, these results highlight the need for a thorough chemical characterization of HTC-derived hydrochar before its use as an organic fertilizer amendment, considering dosage, crop species, and their specific sensitivities when applying it.

Abstract: Tea (Camellia sinensis) cultivation is a major global industry that faces sustainability challenges due to soil degradation and greenhouse gas (GHG) emissions from intensive management. Biochar—charcoal designed and used as a soil amendment—has emerged as a potential tool to improve soil health, enhance carbon sequestration, and mitigate GHG fluxes in agroecosystems. However, field-scale evidence of its effects on GHG dynamics in woody crops like tea remains limited, particularly regarding methane (CH₄). Here, we present the first field assessment of biochar impacts on CO₂, CH₄, and H₂O vapour fluxes in a subtropical tea agroforestry system in northeastern Bangladesh. Using a closed dynamic chamber and real-time gas analysis, we found that biochar application (at 7.5 t ha⁻¹) significantly enhanced soil methane (CH₄) uptake by 84%, while soil respiration (CO₂ efflux) rose modestly (+18%) and water-vapour fluxes showed a marginal increase (+12%). Canopy conditions modulated these effects: biochar effects on CH₄ oxidation were more pronounced in open conditions, whereas biochar effects on water-vapour flux were detectable only in open conditions. Structural equation modeling suggests that CH₄ flux was chiefly governed by biochar-induced changes in soil pH, moisture, nutrient status and temperature, while CO₂ and H₂O fluxes were shaped by organic matter availability, temperature and phosphorus dynamics. These findings demonstrate that biochar can promote CH₄ oxidation and alter soil carbon-water interactions in tea plantation systems, and specifically support biochar use in combination with shade-tree agroforestry.

Abstract: Utilizing an asperity model, this research thoroughly simulates 3D seismic wave propagation to assess the 2016 Kumamoto earthquake. The research employs finite difference methods (FDM) to solve the 3D wave propagation equations incorporating realistic subsurface geological data and slip distributions from the Kumamoto active fault system. The simulation domain covers a 15 km × 12 km subsection of the fault plane, discretized into 250 m³ grid cells, resulting in a 48 × 60 mesh for numerical computation. The model utilized 800 iterative cycles to generate complete ground velocity time histories for an 8 second duration at numerous receiver locations. The results show that the x-direction component has the highest amplitude at station KMMH16, with seismic activity beginning around 3.5 seconds and rising around 5.9 seconds. The timing and intensity of the shaking differed greatly from one location to another primarily based on how far each site was from the fault and the direction in which it was located. This study advances our knowledge of earthquake source mechanics and helps to improve seismic hazard assessment and mitigation techniques by offering crucial insights into the intricacies of seismic wave propagation across heterogeneous media. The study clarifies the complex process of seismic waves propagating across various mediums which advances our knowledge of earthquake dynamics and enhances seismic risk assessment and mitigation strategies.

Abstract:

This study investigated the representative elementary volume (REV) for visible porosity in horticultural growing media (peat, commercial mixture, treated wood fibre/peat, pure wood fibre) using x-ray micro-computed tomography (µCT) with 2D and 3D image division, pore morphology, water retention curve (WRC), and saturated hydraulic conductivity (K_sat) via pore network modelling (PNM). Two sample sizes (10 x 10 cm, 3 x 3 cm, height x diameter) with resolutions of 46 and 15 µm were analysed. REV was assessed using deterministic (dREV) and statistical (sREV) criteria, evaluating porosity and coefficient of variation across subvolumes. Results showed 3D division of large samples achieved REV only for pure wood fibre (8000–10000 µm), while 2D division met both criteria for all media. For small samples, 3D division achieved REV only for wood fibre/peat mixture, but 2D division succeeded for all media above 3,000 µm. Pore analyses indicated pure wood fibre had the largest, most connected pores, enhancing drainage, while peat showed complex, retentive structures. WRCs aligned well with lab data (R2 > 0.88). PNM Ksat estimates from small images were more accurate, with discrepancies (21–172%) due to segmentation artefacts. Future studies should incorporate permeability or tortuosity and explore multiscale imaging for improved hydrophysical predictions. This study also highlights advantages unique to X-ray µCT compared to standard laboratory methods, e.g. direct three-dimensional quantification of pore structure parameters and an image-based determination of the REV.

Abstract: To investigate the response of soil microbial communities to reduce the chemical fertilization supplement with organic fertilizer in Acanthopanax senticosus cultivation, we analyzed the diversity, composition and structural of soil microbiota by using high-throughput sequencing technology. The results showed that reducing chemical fertilizer application significantly increased soil microbial richness (ACE and Chao1 indices), which was positively correlated with soil total nitrogen (TN) content. At the phylum level, the relative abundance of Cyanobacteria decreased at T2 (reduction of 20% fertilizer application) but increased at T4 (reduction of 60% fertilization application), exhibiting an opposite trend to Bacteroidetes. At the genus level, the relative abundance of Paucibacter was significantly higher in T4 than in other treatments, while Nitrospira reached its peak under T3 treatment. For fungal communities, the richness index showed a non-linear response, initially decreasing and then increasing, which was positively correlated with the soil available potassium (AK) content. At phylum level, reduced fertilizer application significantly reduced the relative abundance of Ascomycota compared to conventional fertilization. At genus level, the relative abundance of Fusarium was significantly lower in the T4 treatment than in the other treatments. Redundancy analysis (RDA) revealed that the total organic carbon (TOC), TN, AK as the key environmental factors affecting the soil microbial community. This study demonstrated that partial substitution of chemical fertilizers with organic amendments can improve soil physicochemical properties and enhance microbial diversity, providing a scientific basis for developing sustainable fertilization strategies for Acanthopanax senticosus cultivation.