Search Results (1,696)

Corn stover biochar amendment significantly influences nitrogen (N) and phosphorus (P) transformations, microbial community composition, and enzyme activities in continuous cropping soils. This study aimed to identify the optimal biochar application rate for enhancing N and P nutrient availability in Solanum lycopersicum L. continuous cropping systems, providing theoretical and technical foundations for mitigating continuous cropping obstacles. A soil experiment under rain-out shelters employed four treatments: 1% biochar (BA1), 3% biochar (BA3), 5% biochar (BA5), and a non-amended control (BA0). The results indicated that biochar amendment significantly elevated available phosphorus content in the soil while effectively suppressing its vertical migration; nitrate N content increased under BA1 treatment but decreased in the BA3 and BA5 groups; and the strength of the inhibition effect of biochar treatment on the vertical migration of nitrate N was BA1 > BA5 > BA0 > BA3. The addition of biochar treatment had no significant effect on the content of ammonium N but could inhibit the vertical migration of ammonium N. The addition of biochar treatment could increase the soil’s ammonium N content. The addition of biochar treatment increased soil catalase and urease and sucrase activities, decreased alkaline phosphatase activity, led to the promotion of nitrate reductase activity at low doses and its inhibition at high doses, and resulted in BA1 treatment having the largest soil enzyme index (SEI), which was the most favorable to increase the overall level of soil enzyme activities. Biochar significantly increased the relative abundance of Patescibacteria and Ciliophora while reducing Gemmatimonadota, Acidobacteriota, Nitrospirota, Ascomycota, and Chlorophyta. Comprehensive evaluation using gray relational analysis (GRA) demonstrated that the addition of 5% biochar resulted in the optimal overall performance, enhancing nitrogen and phosphorus transformation, improving microbial community structure, and harmonizing enzyme activities, thereby exhibiting considerable potential for alleviating the nutrient limitations of nitrogen and phosphorus in continuous cropping soils. Full article

Zebra mussel invasion of North American lakes during the last century may play an important role in the occurrence of toxic cyanobacterial blooms. However, empirical evidence quantifying their influence on cyanobacterial community dynamics at broad spatial scales remains limited. Here, we analyzed data from the U.S. EPA National Lakes Assessment (>1000 lakes) to examine potential linkages among zebra mussels, cyanobacterial community composition, and cyanotoxin levels. The analysis results showed significant differences in cyanobacterial communities between lakes located in areas with and without established zebra mussel populations. The lakes with established zebra mussels exhibited significantly higher microcystin levels and cyanobacterial abundance, but lower phosphorus concentrations. Structural equation modeling was used to confirm and estimate the effect of zebra mussels on microcystin concentrations via different pathways. The results suggest three potential pathways whereby zebra mussels influence microcystin production: (1) altering phosphorus concentration; (2) increasing cyanobacterial abundance; and (3) shifting cyanobacteria community structure. The total effect of zebra mussel establishment resulted in an overall 1.40-fold net increase in microcystin level, which presumably resulted from three contributing factors: (1) a 1.06-fold increase through an increased cyanobacterial abundance; (2) a 1.53-fold increase through a selective force, resulting in increased cyanobacteria toxicity; and (3) a 0.86-fold decrease in microcystin level through total phosphorus decrease. The study highlights the potential role of zebra mussel invasion in altering cyanobacterial composition and influencing microcystin levels in U.S. lakes. Full article

Urbanization is a driving force of landscape transformation. One of the ecosystems most vulnerable to urban expansion processes is montane forests located in high altitude mountainous regions. Despite their significance for biodiversity, regulation of the hydrological cycle, stability, prevention of soil erosion, and potential for organic carbon storage, these forest ecosystems show high vulnerability and risk due to the global urbanization process. We analyzed the potential variations produced by land cover change in some attributes related to soil organic matter in transitional forest fragments due to the expansion of a predominantly urban matrix landscape. We identified and characterized a fragment of a high montane evergreen forest in the Western Cordillera of the Northern Andes located in the urban limits of Quito. Then, we comparatively analyzed the variations in the attributes associated with soil organic carbon: soil organic matter, density, texture, nitrogen, phosphorus, and pH. We also considered the following soil coverages: forest, eucalyptus plantations, and grassland. We viewed the latter two as hinge coverages between forests and urban expansion. Finally, we estimated variations in soil organic carbon stock in the three analyzed coverages. For the montane forest fragment, we identified 253 individuals distributed among 18 species, corresponding to 10 families and 14 genera. We found significant variations in soil attributes associated with organic matter and an estimated 66% reduction in the carbon storage capacity of montane soils when they lose their natural cover and are replaced by Eucalyptus globulus plantations. Urban planning strategies should consider the conservation and restoration of natural and degraded peri-urban areas, ensuring sustainability and utilizing nature-based solutions for global climate change adaptation and mitigation. Peri-urban agroforestry systems represent an opportunity to replace and restore conventional forestry or crop plantation systems in peri-urban areas that affect the structure and function of ecosystems and, therefore, the goods and services derived from them. Full article

Lake eutrophication is governed by persistent anthropogenic nutrient inputs, primarily nitrogen (N), phosphorus (P) and cryptic internal nutrient cycling processes that sustain bioavailable nutrient pools. While the impact of external nutrient loads on lake eutrophication has been extensively studied, the role of internal nutrient cycling in lake ecosystems remains underexplored. In this study, the hierarchical bootstrap generalized linear model (HBGLM) to long-term summer water quality data (1999–2020) from Lake Dianchi, China, to explore the relative importance of nitrogen (N), phosphorus (P), as well as the limitations of N and P on the growth of phytoplankton. The results revealed that from 1999 to 2020, the Chla and TP concentrations decreased by 49% and 78%, respectively, and that internal nutrient cycling significantly influenced changes in nutrient concentrations, reflecting the relationships among N, P, and chlorophyll a (Chla). Particularly in 2007, 2013, and 2017, the long-term trends of the TN:TP ratio, an indicator of potential nutrient limitation in the lake, were consistent with changes in the distributions of the average slopes of TN and TP across different periods, indicating that these years primarily exhibited patterns of colimitation by N and P or P limitation, indirectly confirming that Lake Dianchi will transition from N and P colimitation to being limited primarily by P. This study reveals that N is typically the primary limiting element, while P is a key element promoting water eutrophication. To further validate improvements to existing eutrophication mitigation models, conducting carefully de-signed experiments at different scales is recommended. Full article

The environmental problems brought about by factory-based aquaculture have become increasingly prominent. Reducing nitrogen and phosphorus concentrations in tailwater has become the key to tailwater management. In order to assess the potential of microalgae in removing nitrogen and phosphorus ions from aquaculture wastewater, four microalgae species, i.e., Chlorella sp., Dicrateria zhanjiangensis, Nitzschia closterium minutissima, and Platymonas subcordiformis, were used in this study, and their growth and nitrogen and phosphorus removal rates in four nutrient concentrations of simulated aquaculture wastewater were systematically evaluated. After 15 days of cultivation, the cell counts of all four types of microalgae increased. Three species, i.e., Chlorella sp., N. closterium minutissima, and P. subcordiformis, grew best in high PO₄³⁻ and low NH₄⁺ medium, whereas D. zhanjiangensis possessed best growth in low PO₄³⁻ and high NH₄⁺ medium. The removal rate of PO₄³⁻, NH₄⁺, NO₃⁻, and NO₂⁻ by four microalgae species exceeded 82.64%, 89.06%, 59.27%, and 42.15%, respectively, even though the four microalgae had different performance in the removal of nitrogen and phosphorus. All microalgae in the low-phosphorus groups removed PO₄³⁻ at significantly lower rates than those in the high–phosphorus groups, while high NH₄⁺ removal rates were observed in all four microalgae groups. Moreover, in phosphorus-limited conditions, four microalgae exhibit lower removal rates of NO₃⁻ when nitrogen content was high. The chlorophyll a contents of microalgae in four culture media strictly corresponded to their final cell densities. P. subcordiformis exhibited the highest intracellular polysaccharide accumulation in high PO₄³⁻ and low NH₄⁺ type medium, whereas D. zhanjiangensis demonstrated the strongest protein synthesis capacity in high PO₄³⁻ and low NH₄⁺ medium. The activities of acid phosphatase in all microalgae were higher under phosphorus–deficient conditions than phosphorus-sufficient conditions. Our results might provide useful references for microalgae selection in the treatment of different aquaculture wastewater conditions. Full article

This study presents a comprehensive assessment of long-term nutrient dynamics in the northern South China Sea (NSCS), a region that hosts the world’s largest marine ranching cluster and serves as a cornerstone of China’s “Blue Granary” initiative. By integrating multi-sensor satellite remote sensing data (Landsat and Sentinel-2, 2002–2024) with in situ observations, we developed robust retrieval algorithms for total nitrogen (TN) and total phosphorus (TP), achieving high accuracy (TN: R² = 0.82, RMSE = 0.09 mg/L; TP: R² = 0.94, RMSE = 0.0071 mg/L; n = 63). Results showed that TP concentrations increased significantly faster than TN, leading to a decline in the TN:TP ratio (NP) from 19.2 to 13.2 since 2013. This shift indicates a transition from phosphorus (P) limitation to nitrogen (N) limitation, driven by warming sea surface temperatures (SST) (about 1.16 °C increase) and increased anthropogenic phosphorus inputs (about 27.84% increase). The satellite-based framework offers a scalable, cost-effective solution for monitoring aquaculture water quality. When integrated with artificial intelligence (AI) technologies, these near-real-time nutrient anomaly data can support early warning of harmful algal blooms (HABs), offering key insights for ecosystem-based management and climate adaptation. Overall, our findings highlight the utility of remote sensing in advancing sustainable marine resource governance amid environmental change. Full article

Organic amendments, such as straw, biochar, and animal manure, have been demonstrated to enhance soil phosphorus (P) availability effectively; however, the long-term impacts and underlying mechanisms require further study. Based on a long-term field experiment, this research systematically analyzed the effects of biochar (BIO), biochar-based fertilizer (BF), straw-returning (CS), and pig manure compost (PMC) on soil phosphorus transformation and crop phosphorus uptake. Results showed that biochar significantly boosted soil available phosphorus (AP) by releasing soluble phosphorus, raising soil pH, reducing phosphorus fixation by iron and aluminum oxides, and enhancing soil cation exchange capacity (CEC) to promote phosphorus dissolution and transformation. Notably, biochar increased the proportion of NaOH-P, facilitating phosphorus accumulation in peanut grains and improving the phosphorus harvest index and utilization efficiency. Straw-returning primarily elevated soil AP by promoting organic phosphorus mineralization and inorganic phosphorus release; however, its acidification of the soil impaired phosphorus translocation to grains, resulting in lower phosphorus-use efficiency compared to biochar. Pig manure compost reduced soil phosphorus fixation and increased soil total organic carbon (TOC), thereby boosting phosphorus transformation. Despite enhancing phosphorus dry-matter production in plants, most phosphorus remained in stems and leaves, with limited translocation to grains, leading to lower phosphorus-use efficiency than biochar. In conclusion, biochar was most effective in enhancing soil phosphorus availability and crop phosphorus-use efficiency, highlighting its potential in sustainable soil fertility management and optimized crop production. Full article

Cake fertilizers are phosphorus-rich organic fertilizers that are commonly used in horticulture. Soil plays a crucial role in determining the effectiveness of phosphorus fertilizer. Comparative data on the relative phosphorus efficiency (rPE) of cake fertilizers across contrasting soils are scarce in the international literature. Information on the mechanisms that control phosphorus supply is also limited. This study examined the rPE of rapeseed and soybean cakes in three soils using ryegrass growth experiments and investigated the main factors affecting their phosphorus efficiency. The results showed that the rPE of rapeseed cake did not differ significantly among the three soils, with an average value of 71%. In contrast, the rPE of soybean cake showed a clear soil-dependent pattern, with the highest rPE in red soil (67%), followed by fluvo-aquic soil (47%), and the lowest in yellow-brown soil (32%). In red soil, there was no significant difference in rPE between the two cakes. Water-soluble phosphorus content of cake fertilizers and soil phosphatase activity are key factors affecting rPE. Owing to its low water-soluble phosphorus content, the phosphorus supplied by soybean cake is predominantly mobilized through soil phosphatase–mediated mineralization of organic phosphorus. In phosphorus fertilization practices, both cake water-soluble phosphorus content and soil phosphatase activity should be considered. In soils with low phosphatase activity, cake fertilizers with a higher water-soluble phosphorus content should be prioritized. Full article

Rapid on-site detection of chemical warfare agents (CWAs) is vital for security and environmental monitoring. In this work, copper(I) oxide (Cu₂O) nanowire (NW) chemiresistors were investigated as gas sensors for low-concentration organophosphorus chemical warfare agent (CWA) simulants. The NWs were hydrothermally synthesized and deposited onto microheater platforms, enabling them to operate at elevated working temperatures. Their sensing performance was tested against a range of vapor-phase simulants, including dimethyl methylphosphonate (DMMP), triethyl phosphate (TEP), diethyl ethylphosphonate (DEEP), diphenyl phosphoryl chloride (DPPCl), parathion, diethyl phosphite (DEP), diethyl adipate (DEA), and cyanogen chloride (ClCN). Fully oxidized P(V) simulants (DMMP, DEEP, TEP) produced modest, predominantly reversible responses (~3–6% RR). On the contrary, DPPCl and DEP induced the strongest relative responses (RR −94.67% and >200%, respectively), accompanied by irreversible surface modification as revealed by SEM and EDS. ClCN produced a substantial but reversible negative response (RR −9.5%), consistent with transient oxidative interactions. Surface poisoning was confirmed after exposure to DEP and DPPCl, which left phosphorus or chlorine residues on the Cu₂O surface. These results highlight both the promise and limitations of Cu₂O NW chemiresistors for selective CWA detection. Full article

Phosphorus deficiency significantly limits soybean production across 74% of China’s arable land. This study investigated the molecular mechanisms enabling soybean to access insoluble phosphorus through transcriptome sequencing of the Heinong 48 variety across four developmental stages (Trefoil, Flower, Podding, and Post-podding). RNA-Seq analysis identified 2755 differentially expressed genes (DEGs), with 2506 up-regulated and 249 down-regulated genes. Notably, early developmental stages showed the most substantial transcriptional reprogramming, with 3825 DEGs in the Trefoil stage and 10,660 DEGs in the Flower stage, compared to only 523 and 393 DEGs in the Podding and Post-podding stages, respectively. Functional enrichment analysis revealed 44 significantly enriched GO terms in the Trefoil stage and 137 in the Flower stage, with 13 GO terms shared between both stages. KEGG pathway analysis identified 8 significantly enriched pathways in the Trefoil stage and 21 in the Flower stage, including key pathways related to isoflavonoid biosynthesis, alpha-linolenic acid metabolism, and photosynthesis. Among 87 differentially expressed transcription factors from 31 families, bHLH (8.08%), bZIP (7.18%), and WRKY (5.94%) were most prevalent. These findings provide genetic targets for developing soybean varieties with improved phosphorus acquisition capacity, potentially reducing fertilizer requirements and supporting more sustainable agricultural practices. Full article

This paper aims to assess the water quality of the Ismailia Canal, Egypt, in accordance with Article 49 of Law 92/2013. QUAL2K and Convolutional Neural Networks and Long Short-Term Memory (CNN-LSTM) are utilized to simulate the water quality parameters of dissolved oxygen (DO), pH, biological oxygen demand (BOD), chemical oxygen demand (COD), total phosphorus (TP), nitrate nitrogen (NO₃-N), and ammonium (NH₃-N) in winter and summer 2023. The parameters of the QUAL2K and CNN-LSTM models were calibrated and validated in both winter and summer through trial and error, until the simulated results agreed well with the observed data. Additionally, the model’s performance was measured using different statistical criteria such as mean absolute error (MAE), root mean square (RMS), and relative error (RE). The results showed that the simulated values were in good agreement with the observed values. The results show that all parameter concentrations follow and did not exceed the limit of Article 49 of Law 92/2013 in winter and summer, except for dissolved oxygen concentration (8.73–4.53 mg/L) in winter and summer, respectively, which exceeds the limit of 6 mg/L, and in June, biological oxygen demand exceeds the limit of 6 mg/L due to increased organic matter. It is imperative to compare QUAL2K and CNN-LSTM models because QUAL2K provides a physics-based simulation of water quality processes, whereas CNN-LSTM employs deep learning in modeling complex temporal patterns. The two models enhance prediction accuracy and credibility towards enabling enhanced decision-making for Ismailia Canal water management. This research can be part of a decision support system regarding maximizing the benefits of the Ismailia Canal. Full article

This review supports formulation engineers in designing compatible and regulation-compliant additive systems. The integration of functional additives into polymer matrices plays a pivotal role in tailoring material properties to meet the demanding performance, safety, and sustainability criteria of the automotive industry. Key findings highlight that (1) optimal additive loadings are critical for balancing performance and mechanical integrity; (2) HALS and benzotriazole-based UV stabilizers extend service life by up to 3000 h in accelerated weathering without modulus loss; (3) bio-based plasticizers such as ESO and ATBC reduce migration rates by 30–40% compared to conventional phthalates; (4) phosphorus-based flame retardants and zinc borate synergistically achieve UL-94 V-0 ratings with minimal smoke release. This work introduces an integrative mapping of additive–polymer interactions under real-world conditions, coupled with synthesis tables that provide multi-criteria evaluations of performance, limitations, and sustainability—tools not present in prior literature. In contrast to previous reviews, this work introduces an integrative mapping of additive–polymer interactions under real-world automotive stressors, explicitly linking performance, compatibility, regulatory compliance, and sustainability. In addition, a series of synthesis consolidate multi-criteria evaluations—covering functional performance, technical limitations, regulatory risks, and sustainability potential—which provide practitioners with a decision-support tool not found in prior literature. These features constitute the primary methodological and practical contributions of this review. This review uniquely integrates an “evidence strength” assessment into synthesis tables and develops an integrative mapping of polymer–additive systems, offering actionable guidelines that go beyond prior literature reviews. Full article

Indonesia has 13.43 million hectares of tropical peatlands, the largest in Southeast Asia, which are crucial for carbon sequestration. This function is influenced by vegetation nutrient content, particularly carbon (C), nitrogen (N), phosphorus (P), and potassium (K), which regulate biogeochemical cycles and peat formation. This study analyzed stoichiometric profiles of tree species in South Sumatra peatlands based on (1) C:N ratios across roots, stems, twigs, and leaves, and identified species with traits associated with high carbon sequestration potential, and (2) leaf N:P:K stoichiometry to infer nutrient limitations. Research was conducted in a 1-hectare primary peatland plot within the PT. Tri Pupa Jaya conservation area. C, N, P, and K contents were measured using Kjeldahl distillation, spectrophotometry, flame photometry, and the Walkley–Black method following acid digestion. Stoichiometric distribution was visualized with violin-box plots and species grouped through hierarchical clustering. Among 153 identified species, stems showed the highest mean C:N ratio (314.9 ± 210.8), while leaves had the lowest (29.7 ± 13.0). Species were grouped into three clusters by C:N ratios across four organs, with six in clusters 1 and 2 showing high carbon sequestration potential. Leaf N:P:K stoichiometry suggested nitrogen, phosphorus, or combined N + P limitations. Full article

The content and stoichiometric ratios of plant biogenic elements are key indicators for understanding plants’ ecological traits and their responses to environmental changes. However, it remains unclear how wetland herbaceous plants allocate these biogenic elements and how they relate to soil conditions. This study examines the variations in carbon (C), nitrogen (N), and phosphorus (P) stoichiometry across different organs and life forms, and their response to soil factors in Yellow River Delta wetlands. We analyzed the stoichiometric characteristics of 44 herbaceous species (17 annuals and 27 perennials) and their organs (leaves and stems). The results showed that annual plants show higher N and P but lower C content compared to perennials, indicating distinct life history strategies. In plant organs, leaves exhibited higher C, N, and P concentrations than stems, reflecting functional adaptation. Notably, random forest analysis identified stem C content as a key indicator for life history strategy differentiation. Furthermore, soil factors directly influenced organ-level stoichiometry but showed limited effects across life forms. The plants demonstrated P limitation with high sensitivity to soil P availability. This study provides new insights into organ-specific nutrient allocation strategies in wetland plants and offers valuable guidance for coastal wetland conservation. Full article

Background: The overall incidence of malignancy in patients with end-stage kidney disease (ESKD) is reportedly higher compared to the general population. Cancer remains one of the dominant causes of death in these patients, due in part to uremia-induced impairment of tumor immune surveillance. Malignancy is one of the major limitations in the evaluation of potential kidney transplantation. This study aimed to assess the prevalence of cancer in hemodialysis population, particularly in relation to the waiting list. Materials and Methods: From the population of 5879 prevalent hemodialysis patients (60% men), 757 of them had a history of malignancy. In this population, 449 patients were actively waitlisted, and 4619 were not considered for potential kidney transplantation. Only 54 patients had unclear status in relation to active waiting list (during evaluation/disqualification). We assessed demographic data, basal biochemical data, and comorbidities, including malignancy, in relation to age, sex, presence of metastasis, and being actively waitlisted. Results: Malignancy was reported in 13% of hemodialysis patients, 6% of which had metastatic disease. Patients with malignancy were older (p < 0.001). More cases of cancer were observed in males (p = 0.02), who also had higher Charlson Comorbidity Index scores. Moreover, in patients with cancer, cardiovascular diseases were more common. They were also more malnourished (lower albumin, hemoglobin, lean mass) and more inflamed (higher ferritin, lower phosphorus). Only 27 patients with cancer were actively waitlisted, representing only 3.8% of this population. Patients with prior cancer on the active waiting list constituted 6% of all the waitlisted patients. Patients with a history of malignancy on the active waiting list were significantly younger, healthier, with significantly lower Charlson Comorbidity Index score, significantly lower ferritin, lower prevalence of diabetes, and higher blood pressure when compared to patients with malignancy who not listed for kidney transplantation. Conclusions: As malignancy became a more common comorbidity in dialysis patients, the elderly in particular, standardized cancer screening protocols should be promoted in dialysis units. Modern oncology has made huge progress, enabling the treatment of previously incurable cancers, as malignancy after kidney transplantation is considerably increased either due to de novo cancers or the recurrence of previous malignancy. Therefore, the evaluation of potential kidney transplant recipients, with tailored cancer screening and multidisciplinary evaluation, is strongly recommended. Besides a history of malignancy, the cardiovascular status also determines the eligibility for transplantation in dialysis patients. It is of paramount importance as the main cause of death in transplant recipients is cardiovascular death followed by malignancy. Full article