Search Results (694)

Hydrochar has emerged as a promising carbonaceous amendment to enhance soil quality, yet its short-term effects on soil carbon (C) and nitrogen (N) dynamics and microbial functioning remain poorly understood. Here, a 77-day greenhouse pot experiment was conducted using a Cambisol cultivated with sunflower (Helianthus annuus L.) under two irrigation regimes simulating well-irrigated (WI) and water-deficit (WD) scenarios. Two doses of chicken-manure-derived hydrochar (3.25 and 6.5 t ha⁻¹, corresponding to 2.35 and 4.69 g kg⁻¹ of dry soil, respectively) and mineral fertilizer (MF) treatments providing equivalent N inputs were evaluated. Hydrochar promoted microbial growth and enhanced enzymatic and respiratory activities despite its low apparent C and nutrient input. After 77 days under WI, the addition of 6.5 t ha⁻¹ hydrochar enhanced the activity of phenol oxidase (POA) and acid phosphomonesterase (AcPA). Concomitantly, the availability of soluble C and N increased, whereas total organic C (TOC) and N decreased relative to the initial values. These responses may suggest enhanced mineralization potentially related to early-stage priming processes. The increase in POA relative to β-glucosidase is in line with a functional shift from a predominant degradation of labile compounds towards an increased oxidation of more complex structures. This interpretation is supported by solid-state ¹³C NMR data, revealing a higher degradation index of the soil organic matter. Under WD, the overall effects of hydrochar were attenuated or suppressed, particularly those related to C and N dynamics, emphasizing the interactive influence of moisture and amendment dose. Overall, our results show that hydrochar can modulate short-term soil biochemical processes, partly through enhanced microbial responses. Full article

Hyperspectral airborne data combined with machine learning has proven effective for characterizing plant nutritional quality. However, terrain, viewing geometry, and illumination can distort spectral signatures, leading to biased models with limited generalizability for large-scale mapping across farms with a heterogeneous landscape. In this study, we developed a framework for mapping pasture quality using airborne hyperspectral imaging while explicitly accounting for in-field acquisition and environmental effects. Nitrogen content (N%) and metabolizable energy (ME) were used as reference indicators across four hill country farms in New Zealand with contrasting environmental and management conditions. Ground truth was obtained using standard laboratory wet chemistry methods and paired with AisaFENIX airborne hyperspectral data, resulting in 1610 spectral samples derived from 161 spatially independent ground plots. Gaussian Process Regression (GPR) and a one-dimensional convolutional neural network (1D-CNN) were trained and evaluated on an independent test dataset. Both models achieved strong predictive performance (R² > 0.8); however, GPR provided more reliable estimates through predictive uncertainty. Using a 95% confidence interval threshold to mask uncertain predictions increased overall performance (R² > 0.9) and consequently improved the reliability of the mapped outputs. This approach enables spatially explicit pasture nutrient assessment to support precision land management for carbon and nitrogen. Full article

Permeable pavements are increasingly integrated into urban environments as sustainable systems that enhance stormwater infiltration, mitigate runoff, and contribute to pollutant control. However, long-term accumulation of contaminants within their porous structure may impair hydraulic performance and environmental functionality, particularly regarding microplastics (MPs), an emerging pollutant of growing concern. This study investigates the five-year environmental performance of porous concrete pavement slabs operating under real urban conditions, focusing on infiltration capacity and retention of nutrients, suspended solids, and MPs. A dual methodology combining continuous on-site permeability monitoring with laboratory analyses of aged slabs was used to assess performance decline and recovery after maintenance. Results show a 48% reduction in infiltration over five years, while maintaining effective functionality, and a 42.5% recovery after pressure cleaning. Used slabs exhibited substantial pollutant accumulation relative to new slabs, including increases of +258% in COD, +123% in total phosphorus, +28% in total nitrogen, and +48% in suspended solids. MP abundance reached 10,272 ± 5829 MPs/m², 7.5 times higher than in new slabs, dominated by fibers (~70%) and polymers such as PE, PP, and PET. These findings highlight the pavement surface layer as both hydraulic infrastructure and contaminant sink supporting improved maintenance and sustainable urban stormwater management. Full article

Modern agriculture faces major challenges due to rapid population growth, climate change, and environmental constraints. Advanced polymeric systems for controlled-release fertilizers (CRFs) are essential to address these challenges. Urea is one of the most widely used nitrogen fertilizers; however, its agronomic efficiency is limited by volatilization and losses. In this study, we report a sustainable strategy to encapsulate urea using a matrix derived from industrial sulfur waste and vegetable oil, improving agronomic efficiency while valorizing industrial residues and renewable resources. Through inverse vulcanization, a sponge-like polymer (Bp-SF) was synthesized. Two urea-loaded bio-composites (Bp-SF25U and Bp-SF32U) were also prepared. FT-IR analysis confirmed urea encapsulation and the formation of polymeric structures from sunflower oil. SEM revealed a porous morphology, while contact angle measurements confirmed the hydrophobic nature of the polymer matrix. Release kinetics showed sustained nitrogen release for more than 77 days, reaching approximately 60% cumulative release, governed by diffusion, with a fraction of urea retained within the matrix, potentially enabling prolonged nutrient availability. Pot experiments with maize showed that a lower dose of encapsulated urea (79 mg) produced similar plant growth responses to a higher dose of free urea (92 mg), indicating improved nitrogen use efficiency. These sulfur cross-linked biopolymers represent a promising strategy to enhance urea efficiency while supporting greener fertilization strategies aligned with circular economy principles. Full article

This study evaluated the use of visible and near-infrared (Vis-NIR) spectroscopy combined with machine learning (ML) algorithms to predict soil fertility-related properties in two contrasting agroecological regions of Peru: the Highlands and the Rainforest. A total of 297 soil samples were analyzed using portable spectroradiometers covering a spectral range of 350–2500 nm, applying transformations such as Savitzky–Golay smoothing, first derivative, and band depth. Predictive models were developed using PLSR, Random Forest, Support Vector Machines, and neural networks. Results show variable predictive performance across soil properties and ecosystems. Organic matter in Highland soils and calcium in Rainforest soils achieved the strongest test-set accuracy (R² > 0.70), while pH and texture fractions showed moderate performance (R² = 0.42–0.67), and mobile nutrients including phosphorus, potassium, and sodium showed limited predictive accuracy due to their weak spectral expression. Spectral predictions were further integrated into a structured nutrient balance framework to assess agronomic reliability. Nitrogen fertilizer recommendations showed the strongest agreement between observed and predicted values across both ecosystems, whereas K₂O and CaO recommendations in Highland soils were substantially underestimated, demonstrating that property-level statistical performance does not guarantee agronomic reliability. These findings confirm that Vis-NIR spectroscopy combined with ML represents a fast, cost-effective, and sustainable alternative to conventional soil analysis, especially in rural areas with limited laboratory infrastructure. Expanding regional calibration datasets and exploring mid-infrared FTIR spectroscopy as a complementary technology are identified as priority directions for improving predictions of agronomically critical nutrients. Full article

Thismia species are non-photosynthetic plants entirely dependent on fungal partners for carbon and nutrients. While their arbuscular mycorrhizal associations are well-documented, bacterial symbiont roles remain unexplored. Using 16S rRNA gene amplicon sequencing, we investigated endophytic bacterial communities in T. gardneriana, T. javanica, and T. mirabilis from geographically distinct locations in Thailand. Despite geographic separation, Thismia spp. consistently harbored bacterial compositions taxonomically and functionally distinct from surrounding soil microbiomes. Root endospheres were significantly enriched in Pseudomonadota and Bacteroidota, particularly Puia, while showing reduced compositional dynamics of Acidobacteriota and Planctomycetota. Bacterial communities in Thismia roots were markedly distinct from surrounding soil, while root endosphere communities from geographically distinct habitats clustered together regardless of spatial separation. Mantel and partial Mantel tests confirmed that host species identity, not geographical location, was the primary predictor of root bacterial community structure. Functional prediction analyses suggested root-associated communities were enriched for nitrogen cycling pathways, particularly nitrogen fixation and nitrate reduction. The selective enrichment of Bacteroidota, known for nitrogen fixation and phosphate mobilization, suggests these bacteria provide critical nutritional support in nutrient-poor forest floor environments. Isolated root strains belonged exclusively to Bacillota, including Neobacillus with plant growth-promoting traits. Our findings highlight the importance of tripartite plant–fungal–bacterial interactions in Thismia nutritional ecology. Full article

The global wine industry generates approximately 20 million tonnes of organic residues annually, representing a significant environmental and management challenge. While phenolic compounds from winery by-products have been extensively studied, protein and peptide fractions remain underutilised. This review provides a systematic overview of proteins derived from major winery side streams, including grapevine leaves, stems, pomace, seeds, and wine lees, with emphasis on their characterisation and recovery. Conventional and emerging extraction strategies are evaluated, with particular attention to green technologies such as ultrasound-assisted extraction (UAE), pulsed electric fields (PEF), and natural deep eutectic solvents (NADES) in the context of sustainable and resource-efficient processing. Enzymatic hydrolysis is discussed as a key approach for converting complex proteins into bioactive peptides with antioxidant, antimicrobial, and antihypertensive properties. Potential applications in agriculture, plant protection, animal nutrition, and food systems are considered, together with the implications of the EU circular economy regulatory framework. Overall, winery by-products are highlighted as promising nitrogen-rich secondary resources, and the review outlines valorisation pathways supporting nutrient recycling, waste reduction, and the development of a more sustainable agricultural bioeconomy. Full article

Invasive alien species such as Lantana camara L. impact native species and soil properties, but context-specific effects in transfrontier conservation areas remain poorly understood. Understanding these effects is essential for biodiversity conservation and management. We assessed associations between L. camara presence and native woody species composition and structure, as well as soil nutrients, in protected and communal areas within the Kavango–Zambezi Transfrontier Conservation Area (KAZA TFCA), Zimbabwe. The study hypothesised that invasion effects on vegetation are stronger in communal areas due to higher disturbance, and that soil changes are influenced by land-use intensity. We used stratified random sampling to select 60 plots across invaded and uninvaded sites. Woody vegetation was assessed for species composition and richness, stem density, canopy cover %, height, and diameter at breast height. Soil samples were analysed for nitrogen, organic carbon, phosphorus, potassium, and pH. The presence of L. camara was negatively associated with native species richness, density, height, and canopy cover %, with stronger effects in communal plots. Invaded plots had lower pH (e.g., 6.1 in Park areas) and higher levels of some soil nutrients, particularly phosphorus and organic carbon, though patterns varied by land-use type. These results suggest that anthropogenic disturbance amplifies invasion impacts. We conclude that L. camara reduces native vegetation diversity and structure in this species-rich transfrontier area. Management should prioritise control at communal edges to support woody species resilience, ecosystem services, and biodiversity, with strategies adapted to local land-use conditions. Full article

Harmful algal blooms (HABs) caused by Karenia brevis (K. brevis) present a persistent ecological and public health challenge across coastal Florida. Reliable bloom forecasting is critical for protecting public health, supporting coastal economies, and enabling timely management responses. This study develops a regionally integrated machine learning framework to predict weekly K. brevis bloom occurrence using environmental data from both the Peace and Caloosahatchee Rivers, combined with coastal bloom records from Southwest Florida and Tampa Bay to enhance the spatial and temporal continuity of the response record. A Random Forest classifier was trained on a multi-decadal dataset incorporating river discharge, nutrient concentrations (total nitrogen and total phosphorus), wind forcing, sea surface temperature, salinity, and sea surface height anomalies as a proxy for Loop Current variability. The model achieved strong predictive performance on a chronologically withheld test set, with an overall accuracy of ~90%, balanced accuracy of 87.6%, and ROC–AUC of 0.972, indicating strong discrimination between bloom and non-bloom conditions with high precision and recall for bloom events. Bloom timing and persistence were captured with strong agreement during ongoing bloom periods, while non-bloom conditions were identified with low false-positive rates. Feature-response analyses indicated that bloom probability increased most sharply under moderate discharge and nutrient conditions, with diminished sensitivity at higher extremes. Learning curve analysis demonstrated robust training performance and stable generalization, with validation accuracy plateauing near 84%, suggesting a data-limited ceiling on forecast skill. By aggregating nutrient inputs across multiple watersheds and integrating spatially aligned bloom observations, this study demonstrates the utility of multi-source machine learning frameworks for regional-scale HAB prediction. The results support the development of early warning tools and provide a reproducible foundation for evaluating how combined watershed loading and physical forcing are associated with K. brevis bloom occurrence in complex estuary systems with watershed and coastal coupling. Full article

Ratoon rice is a unique cropping system that utilizes the regenerative capacity of rice tillers to achieve one sowing with two harvests in a single growing season, thus exhibiting great yield potential. However, the ratooning ability is often constrained by impaired root function after the first harvest. In this study, we established an integrated nutrient management (INM) strategy to enhance root growth and function, thereby improving nutrient use efficiency and yield. Compared with farmers’ conventional management (FCM), INM increased annual total yield by 7.8% and 13.9% and enhanced ratooning ability by 20.7% and 19.0% in 2024 and 2025, respectively. INM consistently maintained higher root biomass in both main and ratoon crops: by 26.9% and 54.0% in 2024, and by 44.8% and 26.0% in 2025. Root biomass was significantly and positively correlated with brown rice weight across both seasons, and was positively associated with ratooning ability. INM also promoted early root establishment after transplanting, increasing the white-root number by 105.7%, 175.0%, and 484.8% at 3, 5, and 14 days after transplanting (DAT), respectively. Meanwhile, the xylem sap exudation rate and root triphenyl tetrazolium chloride (TTC) reduction activity were increased by 37.4% and 64.5% relative to FCM. In the 2024 ratoon season, INM improved nutrient use efficiency, with partial factor productivity (PFP) of nitrogen (PFP_N), phosphorus (PFP_P), and potassium (PFP_K) increased by 371.0%, 59.3%, and 91.1%, respectively. Gene Set Enrichment Analysis (GSEA) revealed significant enrichment of gene sets involved in root growth, development, nutrient acquisition, and assimilation under INM, providing molecular evidence for root-mediated nutrient synergy. In summary, INM enhances root growth and function, promotes nutrient uptake and utilization, and consequently improves yield. These results offer a practical management strategy supported by physiological and transcriptomic evidence for boosting ratoon rice production via root-mediated nutrient synergies. Full article

Pea (Pisum sativum L.) is a multifunctional legume of growing importance in sustainable cropping systems. This study presents an integrative assessment of a forage pea variety across multiple agronomic functions under temperate continental conditions. Results from three environmentally comparable field trials were synthesized to evaluate (i) grain yield and protein traits, (ii) biomass production and nutrient accumulation in cover cropping systems, and (iii) effects on soil nitrate dynamics and maize (Zea mays L.) yield. Compared with vegetable- and dry-seed-type genotypes, the forage-type cultivar exhibited greater plant height and lodging tendency, moderate grain yield, and elevated protein content (28.8%), characterized by a legumin-dominated protein profile. As a winter cover crop grown in mixture with oat (Avena sativa L.), pea produced lower total biomass than rye (Secale cereale L.) but showed substantially higher nitrogen concentrations (2.93–3.01%), indicating enhanced nitrogen input potential. In crop rotation, pea-based treatments significantly affected soil nitrate distribution and maize productivity. Complementary resource use in pea-based systems enhanced biomass production, supporting forage and green manure functions while contributing to soil fertility and system stability. Its morphological and physiological adaptability enables integration into diverse production models, from intensive to regenerative systems. Overall, pea should be regarded not merely as a single crop, but as a strategic component of diversified farming systems aimed at increasing protein yield, optimizing inputs, improving soil quality, and strengthening the long-term sustainability of agroecosystems. Full article

Systematic comparisons of how plants with contrasting ecological strategies respond to extremely wide nutrient availability gradients remain limited. We investigated the physiological, photosynthetic, and growth adaptations of four plant species representing distinct ecological strategies: Triticum aestivum L. (C3 annual crop), Zea mays L. (C4 annual crop), Ipomoea aquatica Forssk. (C3 annual/perennial aquatic vegetable), and Canna glauca L. (C3 perennial wetland ornamental). Plants were grown hydroponically under nitrogen (N), phosphorus (P), and potassium (K) gradients ranging from 0% to 500% of standard Hoagland nutrient solution. The study results showed that all measured plant traits exhibited characteristic unimodal dose–response patterns. Optimal performance mostly occurred at 100–150% nutrient availability gradients. Severe inhibition or mortality occurred at extreme gradients. Simultaneously, different plant species displayed markedly varying response amplitudes and nutrient-specific sensitivities. Z. mays showed the highest nutrient use efficiency and broadest optimal ranges, particularly for N and K. C. glauca exhibited extraordinary N responsiveness (32-fold increase in photosynthetic rate) but narrow optimal ranges (e.g., 1.01 ± 0.15 μmol CO₂/(m²·s) at the 1% N treatment vs. 32.52 ± 3.33 μmol CO₂/(m²·s) at the 150% N treatment). I. aquatica showed pronounced P limitation with broad tolerance to supra-optimal N and K. T. aestivum displayed moderate responses with clear sensitivity to N limitation. Root–shoot ratios declined systematically with increasing nutrient availability across all plant species, following negative exponential functions. The results of data analyses revealed significant effects of N, P, and K availability on all the determined plant traits. Correlation analyses demonstrated tight coupling effects among physiological, photosynthetic, and growth traits, indicating integrated whole-plant responses to nutrient variations. These findings reveal that plant ecological strategy systematically modulates nutrient response patterns and provide a quantitative framework for species-specific nutrient management. This study provides a theoretical basis for precision fertilization of aquatic vegetables and wetland plants, and more broadly support species-specific nutrient management in controlled-environment agriculture. Full article

The integration of rapidly renewable biomass into insect production systems has been proposed as a strategy to improve resource-use efficiency in insect production. This study evaluated the graded inclusion levels of dried watermeal (Wolffia globosa) in diets of two-spotted crickets (Gryllus bimaculatus) and assessed voluntary nutrient regulation under free-choice feeding. Four fixed-inclusion diets (0%, 25%, 35%, and 45% watermeal) and one self-selection treatment were tested over 28 days. Growth performance, feed conversion ratio (FCR), survival rate (Surv), production index (PI), and whole-body composition were determined. Repeated-measures analysis using linear mixed-effects models indicated that treatment, week, and their interaction were statistically significant (p ≤ 0.024). However, partial R² analysis showed that the independent contributions of treatment and week were negligible, whereas the treatment × week interaction explained measurable variance, indicating that dietary effects were primarily expressed through time-dependent responses. Segmented regression identified a breakpoint at 35% watermeal inclusion (95% CI: 24.93–45.07), indicating that PI was the highest within a moderate supplementation range under the present fixed-diet conditions rather than at a precise single optimum. Inclusion levels beyond this threshold reduced performance. Under free-choice conditions, crickets progressively increased watermeal intake with age and maintained stable nitrogen-free extract (NFE):crude protein (CP) and gross energy (GE):CP intake ratios, selecting an average of 25–35% watermeal over the experimental period. This supplementation range improved feed efficiency and protein deposition while limiting lipid accumulation, suggesting improved energy–protein balance and nutrient partitioning. The self-selection result is interpreted as evidence of behavioral intake regulation under choice conditions and not as direct validation of the segmented-regression breakpoint. Collectively, these findings provide complementary statistical and behavioral evidence supporting a biologically relevant moderate inclusion range (approximately 30–35%) of dried watermeal. Full article

To improve nitrogen (N) fertilizer management in vineyards and support sustainable production, we conducted field experiments in 2021–2022 to evaluate the effects of reduced N fertilization combined with organic fertilizer (OF) on vine growth, fruit quality, soil fertility, and economic returns in Shine Muscat grapes. Six treatments were established: conventional fertilization (CF), four reduced-N treatments combined with OF (0.9N + OF to 0.6N + OF; i.e., 10–40% N reduction), and a blank control (CK). Yield was significantly increased under 0.8N + OF (18.2% in 2021; 96.0% in 2022) and 0.7N + OF (10.8% in 2021; 47.9% in 2022), with 0.8N + OF also delivering the highest economic returns. Fruit quality analysis showed that 0.8N + OF consistently increased total sugar and the sugar–acid ratio, and improved vitamin C content. Substitution ratios >40% led to a decline in economic benefits. Path analysis indicated that vertical diameter and single-berry weight exerted significant positive effects on total yield. OF substitution also improved fruit quality. Soil available nutrients (N, P, and K) and organic matter were primary factors influencing yield; potassium was the key factor regulating sugar accumulation, with the strongest effect on improving flavor coordination. Reducing N by 20–30% combined with OF (particularly the 0.8N + OF treatment) synergistically enhanced photosynthetic efficiency, N utilization, yield and quality, and soil fertility, representing the optimal fertilization strategy. Full article

Campylobacter jejuni is a major zoonotic pathogen that circulates among birds, livestock, humans, and environmental reservoirs, yet the genomic mechanisms that enable persistence and transmission across divergent hosts remain incompletely understood. Here, we sequenced 61 C. jejuni isolates recovered from multiple host-associated sources in Shenzhen, China, from 2016 to 2023, and analyzed them together with 312 dereplicated publicly available high-quality reference genomes. Phylogenomic analyses resolved three major clades, including one avian-restricted clade and two clades showing frequent cross-host occurrence. Human-associated isolates displayed lower coding density than mammal-associated isolates and significantly higher proteome-level carbon and nitrogen demands than avian-associated isolates. Comparative genomic analyses further revealed strong host-associated divergence in chromosome-encoded, plasmid-encoded, and horizontally acquired gene repertoires. In human-derived isolates, 11 dataset-specific human-unique KEGG genes and 48 human-unique virulence-associated genes were identified, and human-associated strains showed the strongest multidrug-resistance signal across both chromosome-encoded and mobile-gene compartments. Resistance-associated functions enriched in human-associated genomes included antibiotic inactivation, efflux-mediated resistance, target protection/replacement/alteration, reduced permeability, and nutrient-acquisition-associated resistance. By contrast, core host-interaction loci remained under strong purifying selection, indicating that major human-associated traits were linked more closely to mobile gene acquisition than to extensive mutation-driven diversification. Together, these findings support a proposed genome-partition framework of host adaptation in C. jejuni, in which relatively stable chromosomal backgrounds are complemented by rapid plasmid- and horizontal-transfer-mediated acquisition of high-impact accessory genes. Full article