Search Results (11,852)

This study aimed to characterize the spatiotemporal dynamics of soil respiration (CO₂ efflux), soil moisture, and soil temperature across different land-use systems in a semi-arid environment through in situ monthly monitoring and to evaluate the potential of UAV-based imagery combined with Random Forest modeling to spatialize these variables within the agroforestry system. The variables were monitored monthly using an Infrared Gas Analyzer (IRGA) over 9 months, and UAV imagery was acquired at two distinct time points. The 11-month experimental campaign enabled evaluation of seasonal and spatial variability and of soil physical and hydraulic properties. Soil CO₂ efflux ranged from 1.0 to 6.7 μmol m⁻² s⁻¹, with higher values observed during the rainy period, closely following soil moisture dynamics. Soil moisture and temperature exhibited clear seasonal patterns driven by rainfall variability. The pasture system showed higher CO₂ efflux in most months, while AFS2 presented more stable fluxes over time. In contrast, AFS1 exhibited lower CO₂ efflux, likely associated with its soil characteristics. Despite these patterns, no significant differences were observed among land-use systems for most soil physical properties. UAV-derived data combined with machine learning techniques proved effective for modeling soil CO₂ efflux, soil temperature, and soil moisture, demonstrating their potential for monitoring soil processes in semi-arid environments. Overall, agroforestry systems did not significantly differ from other land uses in terms of CO₂ efflux, likely due to their early stage of development. These findings indicate that the effects of agroforestry systems on soil processes occur gradually and highlight the importance of long-term monitoring to fully capture system dynamics. Full article

The valorization of agricultural wastes such as pumpkin peel generated from the food processing industry through thermochemical conversion offers sustainable solutions for both waste management and carbon cycling. This study aims to evaluate the physicochemical properties and environmental impacts of charcoals produced from pumpkin peel waste (PPW), without the use of chemicals or pre-washing. In this context, pumpkin peel hydrochar (PPH) was produced by hydrothermal carbonization (HTC) and pumpkin peel biochar (PPB) by pyrolysis. The systems were modeled according to a pilot-scale scenario based on the processing of 100 kg of PPW, and the functional unit was defined as the processing of this amount. The properties of the products were determined by various physicochemical characterization techniques, and environmental impacts were analyzed using Life Cycle Assessment (LCA). The results showed that PPH has a higher specific surface area (16.35 m² g⁻¹) than PPB (9.80 m² g⁻¹), as well as a higher carbon content (76.18% for PPH and 66.07% for PPB). Furthermore, the environmental impact of PPH (16.42 kg CO₂-equivalent/FU) is lower than that of PPB (32.33 kg CO₂-equivalent/FU). Based on the obtained physicochemical properties, the potential of both materials as soil conditioners has been evaluated. The lower environmental impact values suggest that PPH may be a more advantageous alternative in terms of sustainability. However, this evaluation is not based on direct soil application experiments, and further applied studies are needed to confirm this potential. Full article

Planar microwave (MW) sensors offer high-resolution, non-invasive technology for monitoring critical soil properties, serving as a support for modern precision agriculture. While laboratory studies confirm their exceptional sensitivity, the widespread adoption of these sensors is severely impeded by critical translational challenges that constitute a defining “lab-to-field gap”. These barriers include high sensor-to-sensor variability, debilitating thermal cross-sensitivity, soil heterogeneity necessitating unique site-specific calibration, and the enduring tension between high-performance and cost-effective scaling. This review systematically synthesizes the current state of planar permittivity MW technology, moving beyond technical mechanisms to critically assess these operational limitations. We detail advanced architectural strategies designed to bridge this gap, focusing particularly on the transition toward more robust solutions. The key strategies analyzed include the adoption of differential sensor designs using microstrip patch antennas to mitigate common-mode environmental errors, the integration of ultra-compact metamaterial structures such as split-ring resonators (SRRs) and complementary split-ring resonators (CSRRs) for enhanced field robustness and deep soil sensing, and the necessity of multi-parameter sensing capabilities (moisture, pH, and salinity). By establishing a comprehensive roadmap that prioritizes field stability, cost efficiency, and seamless IoT integration, this review demonstrates that planar MW sensors are poised to become reliable and scalable tools. Addressing these critical translational hurdles will ensure optimal resource management, significantly enhance crop productivity, and enable sustainable practices within smart farming ecosystems. Full article

The occurrence and concentration of potentially toxic elements (PTE) in fertilizers are a concern in tropical regions, and soil properties affect their bioavailability for crops. Cadmium is the most easily bioavailable for plants and so the food chain, and it represents a stepping-stone toward safe food production. So, this study aimed to evaluate the ionomics, metabolism, and growth of potato, tobacco, and rice in response to liming and to monoammonium phosphates (MAP) from different geographic origins and PTE contents (MAP 1, MAP 2, MAP 3). For this, independent experiments were conducted with each crop using MAP fertilizers as a phosphorus source applied to a Red-Yellow Latosol, with and without liming. Our findings indicated that physiological changes were primarily influenced by liming rather than PTE. Most acidic soils negatively impacted plant growth and sugar content and induced metabolic adjustments related to proline. The higher level of Cd in MAP 3 reduced manganese and zinc and increased sugar in plant shoots. Rice also had a lower Cd bioaccumulation than potato and tobacco, followed by a higher tolerance to acidic soil. The concentrations of As, Cd, and Cr present in fertilizers did not impair the growth and life cycle of the evaluated plants; however, metabolic adjustments were observed. Full article

Particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) are two operationally defined fractions frequently used in studies related to soil organic carbon (SOC) dynamics. However, the changes and governing mechanisms of these fractions, particularly along a restoration chronosequence, remain poorly understood. Here, we investigated changes in SOC fractions, soil properties, and microbial communities across a restoration chronosequence (1, 5, 7, 13, and 20 years) of alpine meadows using a space-for-time substitution approach on the Qinghai–Tibet Plateau. We quantified the contributions of biotic and abiotic drivers using Spearman correlation analysis, linear regression and random forest analysis. The results revealed a unimodal pattern in SOC, POC, and MAOC contents, peaking at 7, 5, and 7 years, respectively, with no further increase thereafter. Restoration duration strongly shaped microbial community structure and observed species richness, but had no significant effect on Shannon index and Pielou index. Random forest analysis identified soil water content (SWC) and total nitrogen (TN) as the primary predictors of SOC. The microbial community composition dominated the variation in POC while enzyme activity was the key driver of MAOC. Our findings highlight that soil carbon accumulation during alpine meadow restoration is a nonlinear process with a temporal threshold, and POC and MAOC are regulated by distinct biotic and abiotic mechanisms. This study provides a theoretical basis for understanding carbon sequestration mechanisms during alpine meadow restoration and developing sustainable grassland management strategies. Full article

Almond (Prunus dulcis (Mill.) D.A. Webb) is one of the most economically important nut crops worldwide, valued for its nutritional properties and adaptability to diverse agroecological environments. This review summarizes current knowledge on almond domestication, genetic diversity, production trends, and improvement strategies, with a focus on drought tolerance under climate change. Archaeobotanical and molecular evidence indicate central Asia and the eastern Mediterranean as key centers of origin, where recurrent introgression from wild Prunus species contributed to the high genetic variability of cultivated almond. Global production trends reveal increasing challenges due to prolonged drought, climate variability, and rising water and energy costs, particularly affecting major producers such as the United States. Mediterranean regions are transitioning from traditional low-density orchards to intensive systems, where cultivar and rootstock choice are crucial for sustainability. Self-fertile and late-blooming cultivars improve yield stability, while interspecific hybrid rootstocks enhance water use efficiency and tolerance to drought and poor soils. Drought stress impacts almond physiology and yield, although moderate deficit irrigation can maintain productivity and improve kernel quality. Future improvement relies on germplasm conservation, marker-assisted selection, and genomic tools to develop climate-resilient cultivars integrated with sustainable water management strategies. Full article

Enhanced rock weathering (ERW) is a promising carbon dioxide removal strategy that accelerates silicate mineral dissolution to generate alkalinity and sequester carbon in soils and aquatic systems. The frequency and severity of fires are increasing globally, and fire-prone regions such as agricultural lands, forests, and grasslands overlap substantially with potential ERW deployment areas. However, fire–ERW interactions remain unexamined. This perspective synthesizes the literature on fire effects on soil properties to develop a conceptual framework for predicting fire impacts on ERW performance. An assessment of the available literature reveals that the effects of fire on soil pH and inorganic carbon are nonlinear with respect to severity, complicating both dissolution kinetics and carbon verification. Base cation pulses from ash are temporary and subject to rapid export. Fire-induced soil water repellency and erosion may dominate chemical effects in controlling ERW material fate, particularly during the first year post-fire. Pyrogenic carbon and thermally altered minerals create novel soil‒rock interactions with unknown consequences for weathering rates. The authors concluded that fire history must be incorporated as a covariate in ERW deployment planning and monitoring, reporting, and verification design. Full article

Intensive nitrogen (N) fertilization in greenhouse vegetable systems degrades soil structure and accelerates soil carbon (C) mineralization. Biochar application can alleviate these adverse effects by enhancing aggregate stability and mediating microbially driven nutrient cycling, yet its effects across aggregate fractions remain poorly understood. Here, we investigated how biochar (0, 20, 40 t ha⁻¹) and N interact to affect aggregate stability, C mineralization, nutrient status, and microbial properties in bulk soil and four aggregate classes (large macroaggregates: LMA, > 2000 μm; small macroaggregates: SMA, 250–2000 μm; microaggregates: MA, 53–250 μm; silt + clay: S + C, < 53 μm) in vegetable soil after a 60-day incubation. Results showed that biochar–N co-application increased mean weight diameter by 27.4–30.5% and elevated soil total organic C (TOC) in LMA by 9.11–12.0% and in MA by 8.77–20.2% relative to the N-only treatment. It also reduced β-glucosidase and oxidase activities, as well as fungal and G⁻-bacterial abundance. Biochar amendment suppressed TOC mineralization by 2.7–24.6% in bulk soil and aggregate fractions, while boosting potentially mineralizable C pools by 12.5–155.7%, and thereby increasing overall mineralization potential. Structural equation modeling revealed the size-dependent regulatory mechanisms underlying these observations. Aggregate stability directly inhibited CO₂ emissions in bulk soil and SMA, while the effects in MA and S + C fractions were mediated by shifts in nutrient stoichiometry and hydrolase activities. Our findings clarified the size-dependent mechanisms by which biochar–N co-application promoted soil C sequestration, providing a theoretical basis for the sustainable management of intensive vegetable systems. Full article

Coastal reclaimed areas are characterized by complex strata and high groundwater levels, and pile foundations in such areas often suffer from insufficient uplift resistance. Compared with conventional cast-in-place piles, squeezed branch piles exhibit superior uplift performance; however, studies on squeezed branch piles in reclaimed areas remain limited. To investigate the uplift bearing performance of squeezed branch piles in the complex strata of coastal reclaimed areas, in situ full-scale uplift tests were conducted in the Shenzhen Binhai Avenue (Headquarters Base Section) traffic reconstruction project. Based on the actual physical and mechanical properties of the soil strata, a three-dimensional numerical model was established and validated against the load–displacement curves obtained from the in situ full-scale uplift tests. On this basis, the uplift bearing performance of squeezed branch piles, the differences in uplift bearing performance between branch and plate structures, and their applicable strata were analyzed. The plate structure and different branch configurations of squeezed branch piles exhibit distinct symmetric configuration characteristics, and these configuration differences influence the overall uplift bearing performance. The results show that the load–displacement curves of the uplift piles are generally smooth, without obvious abrupt rises or drops, exhibiting a gradual variation pattern, and the maximum pile-head displacements are all less than 100 mm. The mobilization of the bearing capacity of the branch and plate structures exhibits a distinct temporal and sequential pattern, with the plate structures at shallower embedment depths mobilized earlier than those at greater depths. Compared with conventional cast-in-place pile foundations, the presence of branches and plates endows squeezed branch piles with better elastic mechanical behavior and higher rebound ratios during unloading. Under identical stratum and loading conditions, the uplift bearing performance of the plate is 133% higher than that of the six-radial-branch configuration, while that of the six-radial-branch configuration is 34% higher than that of the four-radial-branch configuration. It is recommended to adopt the six-radial-branch configuration in clayey sandy gravel strata and the plate configuration in gravelly clayey soil and completely weathered coarse-grained granite strata, whereas neither branches nor plates are recommended in soil-like strongly weathered coarse-grained granite strata. Full article

A long-term positioning experiment was conducted from 2014 to 2021 to determine the appropriate tillage method for rapidly improving soil quality in reclaimed land. Four tillage methods were arranged before winter wheat sowing: deep tillage (DT), shallow tillage (ST), DT-ST alternate rotation (DST) and no tillage (NT). The results showed that: (1) with increasing reclamation years, ST, DT and DST had lower soil bulk density (SBD) and higher soil total porosity (STP) and soil capillary porosity (SCP) compared to NT. In the early stage of reclamation, ST had the lowest SBD and the highest STP and soil non-capillary porosity (NCP) in 0–20 cm soil layer, DT had the highest SCP and lowest NCP. In the 20–40 cm soil layer, DT has the lowest SBD and highest STP and SCP, followed by DST. In the late stage, SBD of each soil layer was NT > ST > DT > DST, while STP and SCP were NT < ST < DT < DST. (2) Different tillage methods influenced soil organic carbon (SOC) accumulation by affecting carbon sequestration rate (CSR). As opposed to NT, DT rapidly increased SOC of 0–40 cm soil layer in the early stages of reclamation, whereas DST facilitates maintaining higher SOC in the later stages. As compared to DT and DST, ST contributed more to SOC accumulation in surface soil, but less to SOC accumulation in deep soil. (3) Different tillage methods had various influences on SOC stratification ratio (SR). During the initial reclamation stage, NT had the lowest SR. Nevertheless, NT and ST maintained their high SR in the subsequent stage, whereas the SR of DT and DST experienced a notable decline due to the increase in SOC in deep soil. (4) It was observed that ST, DT and DST had higher grain yields compared with NT. The correlation analysis showed that DT improved soil properties by promoting SOC accumulation, increasing SCP and reducing NCP, thus increasing grain yield in the early stage of reclamation, while in the later stage of reclamation, DST can maintain better soil quality by reducing SBD and maintaining higher STP, SCP and SOC, and balanced the reasonable distribution of soil nutrients between the upper and lower soil layers by reducing SR of SOC, which helps the crop to maintain higher grain yields over time. Full article

The accumulation of highly alkaline red mud poses serious environmental risks due to land occupation and potential soil/groundwater contamination. Recycling red mud as a secondary resource offers an eco-friendly solution, yet its influence on the performance of high-performance mortar (HPM) remains incompletely understood, particularly in aggressive environments. This study aims to systematically evaluate the effects of red mud on the fresh and hardened properties of HPM, including rheological parameters, setting time, mechanical strength, drying shrinkage, and sulfate dry–wet erosion resistance. The novelty lies in (1) quantifying the nonlinear relationships between red mud content and rheological/setting behaviors, (2) revealing the dual effect of red mud with curing age, and (3) using XRD/SEM-EDS to elucidate the micro-mechanisms related to hydration products and elemental changes (Al and Fe). The results show that increasing red mud content reduces slump flow (max 76.03%), plastic viscosity (46.7%), and yield stress (42.3%) while also shortening initial/final setting times (67.91% and 76.18% max reductions). At curing ages below 7 days, flexural and compressive strength increase (up to 64.53% and 33.35%, respectively), following cubic functions; however, at 7 and 28 days, both strength values decrease (max reductions of 13.43% and 12.98%). Red mud increases drying shrinkage and delays sulfate-induced degradation. Microstructural analysis reveals improved compactness of hydration products at early ages but reduced compactness at later ages, accompanied by increased Al/Fe content and enhanced SiO₂/calcium silicate hydrate crystals. These findings provide valuable insights for applying red mud HPM in marine environments. Full article

Common wheat (Triticum aestivum ssp. vulgare) is one of the three major cereal crops cultivated worldwide and plays a key role in ensuring food safety. Adequate nitrogen supply is a key factor affecting the yield and functional properties of the grain of common wheat. Improving the efficiency of soil nitrogen use can be achieved through the application of appropriate mineral fertilizers and proper variety selection. The aim of this study was to determine the effect of residual nitrogen (N_res) remaining after maize cultivation on the functional properties of winter and spring wheat grain. The results of the present study clearly indicate that appropriate selection of the maize hybrid (preceding crop) and nitrogen fertilization strategy (residual nitrogen, N_res) can significantly enhance the antioxidant potential of grain in both forms of wheat (winter and spring). At the same time, our results highlight the practical importance of agronomic practices in improving the functional value of grain, both in terms of nutritional quality and health-promoting potential. Total polyphenol content in grain was stable, while antioxidant activity (ABTS⁺, DPPH) depended on genotype × fertilization interaction, particularly in winter wheat. These changes likely result from differences in polyphenol profile and the proportion of other antioxidants. Appropriate cultivar selection and nitrogen fertilization can enhance the antioxidant potential of wheat. No significant effect of either the preceding crop (maize) or its cultivar, or the form of nitrogen fertilizer, was found on the amino acid and total polyphenol content in winter and spring wheat grain. Population growth and the need to ensure adequate food supply highlight the importance of improving nitrogen management efficiency in agriculture by accounting for the amount and quality of residual soil nitrogen after the preceding crop. Full article

The conversion of livestock manure, including poultry waste (PW), into biochar represents a sustainable strategy to recycle nutrients while reducing environmental risks. This study evaluated how pyrolysis temperature regulates physicochemical properties, carbon structure, and nutrient dynamics in biochars produced from PW. Raw PW and biochars generated at 300 and 600 °C were characterized through proximate and elemental analyses, Fourrier Transform Infrared spectroscopy (FTIR), soil nutrient assessment, and germination bioassays. A multivariate approach was used to analyze the experimental data sets. Increasing pyrolysis temperature significantly reduced biochar yield (83.62% to 64.36%), while promoting carbon condensation and mineral enrichment, as indicated by the decline in H/C ratio from 1.02 to 0.22 and the increase in ash content from 41.47% to 56.77%. FTIR analysis revealed a progressive attenuation of O–H and aliphatic C–H functional groups and a relative increase in aromatic structures with increasing temperature, indicating structural reorganization of the carbon matrix. Total concentrations of macro- and micronutrients generally increased with temperature; for example, total Cu increased from 78.62 to 114.17 mg kg⁻¹, while Zn increased from 557.03 to 819.66 mg kg⁻¹ between 300 and 600 °C. In contrast, the bioavailable fractions of Fe, Cu, and Zn determined using the chelating agent DTPA declined, although not significantly (p < 0.05), with increasing pyrolysis temperature. Principal component analysis clearly distinguished raw PW from pyrolyzed materials, confirming pyrolysis temperature as the main factor dictating biochar properties. PW exhibited severe phytotoxicity, which was partially mitigated with increasing pyrolysis temperature. Overall, pyrolysis enhanced carbon stabilization and micronutrient immobilization, highlighting PW-derived biochars as promising soil amendments for improving nutrient management and reducing the environmental risks associated with raw PW application. Full article

Maize biomass production and quality are influenced by numerous factors, including fertilization, soil characteristics, and climatic conditions. The aim of our study was to evaluate how different fertilization treatments ((1) Control, (2) farmyard manure (FYM), (3) FYM with added mineral nitrogen (FYM + N), and (4) FYM with added NPK mineral fertilizers (FYM + NPK)) affect the biomass yield and quality parameters (crude protein (CP), fiber content (FC), neutral detergent fiber (NDF), starch content (STR), organic matter digestibility (OMD), and neutral detergent fiber digestibility (DNDF)) of silage maize under various soil and climatic conditions in the Czech Republic (Caslav—degraded Chernozem, Ivanovice na Hané–Chernozem, Lukavec–Cambisol). The experiment was conducted from 2020 to 2023. Additionally, the study analyzed the effects of fertilization on soil chemical properties (pH, P, K, Ca, Mg, C, N). The highest average biomass yields were recorded in Ivanovice (23.8 t ha⁻¹, A), followed by Lukavec (19.7 t ha⁻¹, B) and Caslav (18.1 t ha⁻¹, B). Comparing fertilizer treatments, no significant differences were observed among FYM, FYM + N, and FYM + NPK; however, all three treatments significantly outperformed the Control at all sites. Conversely, fertilization did not affect the quality parameters. For silage maize, FYM represents the optimal fertilization strategy, providing yields and quality comparable to the combined application of mineral N, P, and K, which are more costly (in terms of purchase and application) and, under certain conditions, may negatively impact the environment. Nevertheless, the application of mineral fertilizers increased soil nutrient content, thereby improving conditions for subsequent crops. Full article

The poultry sector generates large amounts of feather waste every year, providing an abundant keratin-rich residue that is difficult to valorise due to its crosslinked and highly compacted crystalline structure. In the present work, with the aim of promoting its use in biodegradable plastic films, environmentally friendly processes, such as mechanical grinding (compactor grinder, CG), deep eutectic solvents (DES), and steam explosion process (SE) are being explored as alternatives to conventional chemical processes. Thus, biodegradable feather-based films were produced by compounding treated feathers in a torque rheometer at 40 wt.% with glycerol, ethylene glycol, and 1,2-propanediol (propylene glycol), followed by hot pressing. All formulations produced homogeneous and translucent films, which were characterized in terms of colorimetric properties and thermal and mechanical behaviour, as well as their degradation in soil conditions, revealing pronounced differences in properties as a function of the specific combination of feather treatment and plasticizer employed. Interestingly, soil disintegration tests revealed the fastest degradation of films of DES-treated feathers plasticized with glycerol. Overall, controlling feather treatment and plasticizer type enables tuning of mechanical performance and biodegradation, supporting keratin-based films as a viable route for feather waste valorisation. Full article