Search Results (16,421)

This study investigated the effects of bio-organic fertilizer (BF) containing plant growth-promoting bacterium Bacillus velezensis SS-20 on soil properties, microbial community structure, and C/N cycle functional genes. The results showed that compared with chemical fertilizer (CF) and deactivated bio-organic fertilizer (BFD) treatments, BF significantly improved soil physicochemical properties. Soil pH, organic matter, total nitrogen, total potassium, and total phosphorus content under BF treatment were increased by 14.8%, 56.5%, 48.2%, 38.8%, and 58.4%, respectively, compared to the control; soil urease and sucrase activities increased by 3.5 and 2.4 times those of CF treatment, respectively. Meanwhile, BF increased pakchoi yield by 11.2% (vs. CF). BF treatment enhanced the relative abundance of beneficial bacteria Actinomycetota by 28.4% compared with the BFD treatment and raised that of fungi Ascomycota to 1.9 times that of the control. At the genus level, BF significantly enriched biocontrol-relevant genus Pseudogymnoascus, whose abundance reached three times that of CF treatment, while the abundance of potentially harmful genus Penicillium decreased by 82%. BF also led to a high degree of synergy in carbon and nitrogen cycles. Functional gene analysis indicated that BF down-regulated multiple carbon-degrading genes, increased organic nitrogen metabolism genes by 5.3%, and reduced denitrification genes by 13.3%. Overall, bio-organic fertilizer optimized the soil microenvironment, regulated the microbial community structure, and improved C/N use efficiency and plant growth by introducing functional microorganisms and organic matter. Full article

Extrusion processing can induce gel-like network formation in plant proteins, enabling the advancement of structured meat alternatives with tailored textural properties. In this study, extrusion-induced gelation behavior of isolated mung bean protein (IMBP) was systematically investigated during the manufacture of low-moisture meat analogs (LMMA). The effects of key processing variables, rotational speed of the screw, moisture level, and processing temperature on gel network development, hydration behavior, and textural responses were evaluated using response surface methodology as an analytical framework. Increasing moisture content promoted protein hydration and facilitated the formation of continuous gel-like interactions, resulting in enhanced pore development and water-holding capacity. Variations in screw speed and processing temperature further modulated the extent of protein denaturation and network consolidation, influencing nitrogen solubility and mechanical properties. While the integrity index remained relatively insensitive to processing conditions, structural and functional responses exhibited clear dependencies on extrusion-induced gelation dynamics. The extrusion conditions of 39% moisture, 216 rpm, and 159 °C promoted the development of a well-defined protein network, leading to improved functional properties. These findings provide mechanistic insight into extrusion-driven gelation of IMBP and highlight its potential as a protein matrix for gel-based meat analog applications. Full article

TiO₂ nanoparticles were synthesized by a simple sol–gel route followed by high-temperature calcination at 800 °C, aiming to obtain an anatase-dominant reference photocatalyst with enhanced structural stability after severe thermal treatment. Raman spectroscopy and X-ray diffraction confirmed that anatase is the major crystalline phase, with only a minor rutile contribution after calcination at 800 °C. Nitrogen adsorption–desorption measurements revealed a narrow mesoporous contribution arising from interparticle voids and a relatively high specific surface area (108 m² g⁻¹) despite the severe thermal treatment, while electron microscopy showed nanometric primary particles assembled into compact agglomerates. Surface hydroxyl groups were identified by Fourier-transform infrared spectroscopy, consistent with sol–gel-derived TiO₂ systems. Diffuse reflectance UV–Vis spectroscopy combined with Kubelka–Munk and Tauc analysis yielded an optical band gap of 3.12 eV, typical of anatase TiO₂. Methylene blue (MB) was used as a probe molecule to evaluate photocatalytic activity under ultraviolet and visible light irradiation. Under UV illumination, degradation kinetics were governed by band-gap excitation and reactive oxygen species generation, whereas a slower but reproducible reference behavior under visible light was predominantly associated with surface-related effects and dye sensitization rather than intrinsic visible-light absorption. Overall, the results establish this anatase-dominant TiO₂ as a reliable high-temperature reference photocatalyst, retaining measurable activity after calcination at 800 °C and exhibiting UV-driven behavior as the dominant contribution. Full article

Soil salinization leads to soil nutrient loss and decreased crop yield. This research aims to determine the optimal reduction rate of diammonium phosphate (DAP) and suitable microbial inoculant for alfalfa cultivation and nitrogen-level improvement in saline-alkali land. The experiment consisted of a factorial arrangement of three DAP fertilizer levels (X1, 60%; X2, 70%; and X3, 80%) and four microbial inoculants (Y1, rhizobial inoculant; Y2, phosphate-solubilizing microbial inoculant; Y3, composite microbial inoculant; and Y4, control) in a split-plot design. The results indicated that DAP fertilizer, microbial inoculant, and their interaction significantly affected (p < 0.05) forage yield, crude protein, available nitrogen (N), and enzyme activities. Under 80% DAP fertilizer combined with the composite microbial inoculant, forage yield, plant height, soil urease (S-UE), and ammonium nitrogen (NH₄⁺-N) reached maximum values of 17.1 t ha⁻¹, 65.7 cm, 292.3 μg d⁻¹ g⁻¹, and 3.1 mg kg⁻¹, respectively. However, the soil total nitrogen (TN) significantly increased at the 60% DAP fertilizer application rate (p < 0.05). Overall, this study demonstrates that co-application of DAP fertilizer with compound microbial inoculant delivers a green, science-based fertilization approach for improving nitrogen levels and alfalfa cultivation in saline-alkali soils. Full article

Integrated water and nitrogen management plays a crucial role in the sustainable intensification of rapeseed production, particularly in water-limited regions. This two-year field study (2022–2024) evaluated the interactive effects of three irrigation lower limits—W₁ (90% of field capacity, [FC]), W₂ (70% FC), and W₃ (50% FC)—and four nitrogen rates (0, 80, 160, and 240 kg N ha⁻¹; representing N₀, N₁, N₂, N₃, and N₄) on winter rapeseed growth, yield, resource use efficiency, and economic performance under semi-arid conditions. Both irrigation and nitrogen significantly influenced plant growth, photosynthetic performance, biomass accumulation, and yield formation, with pronounced interactive effects observed across most measured parameters. The W₁N₂ treatment achieved optimal performance, producing seed yields of 5131 and 3220 kg ha⁻¹ with superior nitrogen use efficiency. Overall, N₁, N₂, and N₃ increased yield by 38.12%, 79.26%, and 84.85%, respectively, relative to N₀. Compared with W₃N₀, W₁N₂ improved yield by 178%, water use efficiency by 131%, and irrigation water use efficiency by 110%. Relative to W₁N₃, W₁N₂ increased nitrogen agronomic efficiency, physiological efficiency, recovery efficiency, and partial factor productivity by 40.5%, 7.4%, 30.4%, and 45.2%, respectively, while reducing nitrate nitrogen residue by 12%. Entropy-TOPSIS analysis identified W₁N₂ as the top-ranked treatment, indicating that optimized irrigation and nitrogen management offer a sustainable strategy to maximize rapeseed productivity, enhance resource-use efficiency, and improve economic returns under water-limited conditions. For practical application in semi-arid environments, the W₁N₂ treatment is recommended as the optimal management strategy for sustainable winter rapeseed intensification. Full article

Moulds of the Rhizopus oryzae species exhibit high biotechnological potential due to their significant metabolic activity, which is influenced by cultivation conditions. The study aimed to evaluate the ability of R. oryzae DSM 2199 to synthesize extracellular lipolytic and proteolytic enzymes in solid-state fermentation (SSF) using rapeseed cake as a substrate. The effectiveness of the SSF method in stimulating the synthesis of hydrolytic enzymes by R. oryzae was confirmed. The effect of an additional carbon and nitrogen source with three different dilution variants of the solid substrate on lipase and protease activity was analyzed. No significant correlation was found between enzyme activity and the applied diluents. The extracellular enzyme solution obtained from R. oryzae in SSF was lyophilized. The freeze-dried raw preparation exhibited high lipolytic activity (111.59 U/g) compared to its low proteolytic activity (0.013 U/g). Demonstrated hydrolytic activity made the biocatalyst useful for the hydrolysis and esterification reactions. Full article

Saline soil represents an important reserve of cultivated land in China, yet poor soil conditions and low-nitrogen use efficiency constrain crop production. Biochar has been widely applied to improve soil properties; however, its interactive effects with nitrogen fertilization in saline soils remain unclear. A pot experiment using coastal saline soil collected from the northern Jiangsu province was conducted to evaluate the combined effects of biochar (0%, 4%, and 8% w·w⁻¹) and nitrogen fertilizer (0, 150, and 200 mg·kg⁻¹) on the growth performance, photosynthetic indices, yield, quality, and nitrogen use efficiency of water spinach (Ipomoea aquatica Forssk.). Moderate biochar application significantly improved vegetative growth of water spinach, as indicated by higher plant height, stem diameter, leaf area index, and SPAD values. In addition, biochar substantially enhanced photosynthetic performance, dry matter accumulation, and yield, whereas excessive biochar or nitrogen application generally inhibited plant performance. The combined application of 4% biochar with 150 mg·kg⁻¹ nitrogen consistently produced the highest yield and nitrogen partial factor productivity, while simultaneously increasing soluble protein, soluble sugar, and vitamin C contents and reducing nitrite accumulation. These research results demonstrated a clear synergistic interaction between biochar and nitrogen fertilization. In coastal saline soils, reducing the usage of nitrogen fertilizer moderately and adding approximately 4% of biochar is an effective strategy. Full article

Microplastics (MPs) can serve as bearers of microorganisms and additional contaminants. However, the functional composition and assembly processes of plastisphere bacteria in co-contaminated soil–plant systems are not yet well understood. Using a pot experiment, we examined the effects of both individual and combined cadmium (Cd) and polypropylene (PP) MP contamination on the development of the bioenergy plant sorghum. The bacterial community, co-occurrence networks, and assembly processes in the rhizosphere soil and PP plastisphere were investigated using high-throughput sequencing. Compared with contamination by a single compound, combined contamination with Cd and PP had a more potent inhibitory effect on the development of sorghum. PCoA and diversity indices indicate that the bacterial community on PP plastics is structurally simpler than that in rhizosphere soil. The PP plastisphere could recruit bacteria from the genera Sphingomonas, Rhizobium, and Bacillus. The bacterial communities in the soil and the PP plastisphere were mostly formed by stochastic processes, with diffusion limitation playing a greater role in the bacterial community in the PP plastisphere. Co-occurrence network analysis revealed differences between the bacterial communities in the soil and in the PP plastisphere, with the network in the PP plastisphere showing lower complexity and connectivity. Functional prediction revealed that the prevalence of nitrogen cycling genes was greater in the PP plastisphere than in the dirt and that the PP plastisphere presented greater metabolic activity. The relative prevalence of metabolic pathways associated with human diseases was markedly elevated in the PP plastisphere, which may be correlated with the dissemination of pathogenic microorganisms. These findings indicate that the PP plastisphere, as a distinct microbial niche, might attract certain bacteria, consequently affecting the functional characteristics of cocontaminated soil–plant systems. Full article

Public health impacts of non-optimal temperatures and air pollution have received insufficient attention in Southeast Europe, one of the most air-polluted regions in Europe, simultaneously pressured by climate change. This study employed a multimodal approach to characterize the microclimate and air quality and conduct a health impact assessment in the three biggest cities in Bulgaria. Simulation of atmospheric thermo-hydrodynamics and assessment of urban microclimate relied on the Weather Research and Forecasting model. Concentrations of fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) were calculated with a land-use regression model. Ischemic heart disease (IHD) hospital admissions were linked to daily measurements at background air quality stations. The results showed declining trends in PM_2.5 but persistent levels of NO₂, especially in Sofia and Plovdiv. Distributed lag nonlinear models revealed that, in Sofia and Plovdiv, PM_2.5 was associated with IHD hospitalizations, with a fifth of cases in Sofia attributable to PM_2.5. For NO₂, an increased risk was observed only in Sofia. In Sofia, the risk of IHD was increased at cold temperatures, while both high and low temperatures were associated with IHD in Plovdiv and Varna. Short-term effects were observed in response to heat, while the effects of cold weather took up to several weeks to become apparent. These findings highlight the complexity of exposure–health interactions and emphasize the need for integrated policies addressing traffic emissions, urban design, and disease burden. Full article

Liquid digestate, a by-product of excess sludge in wastewater treatment plants (WWTPs), contains high concentrations of organic matter and essential nutrients that could promote plant growth. However, it also contains a significant number of pathogenic and opportunistic pathogenic microorganisms, which present major challenges in terms of its safe application. A sample taken from WWTP “Kubratovo” was treated using plasma devices. The aim was to evaluate the effect of treatment by two types of plasma sources on the content of pathogenic bacteria as well as the chemical composition of the liquid digestate. The Surfaguide plasma source demonstrated a higher disinfection effectiveness (100% for E. coli, Clostridium sp.; over 99% for fecal and total coliforms; 98% for Salmonella sp.). The β-device effectively removed (100%) the following groups: E. coli and Clostridium sp. However, its effectiveness was significantly lower for the other groups. The obtained results show that plasma treatment induces the transformation of nitrogen and phosphorus compounds, resulting in increased nitrite and phosphate concentrations. The application of cold atmospheric plasma disinfection significantly improved the sanitary and compositional characteristics of the liquid digestate. The Surfaguide achieved significantly better results than the β-device, confirming its suitability for sustainable resource recovery and safe agricultural use. Full article

Surface mulching and nitrogen (N) application are widely used to enhance crop yield and water productivity (WP). However, their combined effects remain unclear. Here, a three-year field experiment was conducted to comprehensively assess the effects of surface mulching (no mulching, B; straw mulching, S; and plastic film mulching, F) and N fertilization (no N application, N0; split application of urea, N1; 1:2 mixture of controlled-release urea and urea, N2) on maize growth, yield, and WP on the Loess Plateau. Application of nitrogen (N) significantly increased evapotranspiration (ET), grain yield, and WP by 4.58%, 176% (from 5215.43 kg ha⁻¹ in N0 to 14,548.21 kg ha⁻¹ in N2), and 166% (from 11.36 kg ha⁻¹ mm⁻¹ in N0 to 30.63 kg ha⁻¹ mm⁻¹ in N2), respectively. Compared with B and S, F increased ET during the pre-silking stage by 16.75% and 23.99%, respectively, and shortened the vegetative period of maize by 3–9 days but extended the duration from the milky stage (R3) to physiological maturity (R6) in the reproductive period by 5–13 days. F significantly increased yield and WP by 9.18% and 8.26% compared with S. Under F combined with N application, deep soil water (100–200 cm) consumption during R1–R3 increased by 15.75 mm and 13.15 mm compared with B and S, respectively. The combination of F and N2 achieved the highest yield (15,648.28 kg ha⁻¹) and WP (32.44 kg ha⁻¹ mm⁻¹) without causing detectable depletion of soil water within the 0–200 cm profile during the study period, providing an effective strategy for enhancing crop yield and improving water–fertilizer use efficiency in semi-arid regions. Full article

Anaerobic digestate (AD) has the potential to partially replace inorganic fertiliser, containing readily available nitrogen and other macro- and micronutrients. However, these properties vary with the feedstock. The objectives of this study were to analyse the chemical composition of AD materials and measure their effects on plant growth and greenhouse gas emissions. Anaerobic digestate came from a conventional reactor using vegetable waste and maize as feedstock (‘food AD’) and from a biogas system on a smallholder dairy farm using manure feedstock (‘manure AD’). Undigested cattle slurry (‘manure slurry’) and a complete mineral fertiliser were used as controls. These were applied to wheat plants grown in a glasshouse. Wheat grown with the food AD had a higher yield than the complete mineral fertiliser control, even when applied at a lower rate of nitrogen. Wheat grown with both the food AD and manure AD had macronutrient concentrations equal to or higher than the complete mineral fertiliser treatment. Furthermore, the wheat P concentration was significantly greater with the manure AD treatment, which was unrelated to a biomass dilution effect. However, food AD caused high ammonia emissions, and residual methane was emitted with manure AD, indicating incomplete digestion in the latter. Optimal yields and reduced greenhouse emissions were obtained with mixtures of AD and mineral fertiliser in a 1:1 ratio, indicating the potential to greatly reduce the costs and environmental impact of fertiliser application. Full article

The effect of afforestation in infertile mountainous areas is closely related to the soil ecological environment. Soil enzyme activities and the structure and functions of microbial communities are core indicators reflecting soil quality. Clarifying the response patterns of the two to Cyclobalanopsis gilva afforestation in infertile mountainous areas can provide a key scientific basis for targeted improvement of the cultivation efficiency of C. gilva plantations under different site conditions in the eastern subtropical region of China. In this study, 7-year-old C. gilva young forests in infertile mountainous areas and control woodland areas were selected in Shouchang Forest Farm, Jiande, Zhejiang Province, located in the subtropical region of China. Soil enzyme activities and microbial biomass in different soil layers, as well as metagenomes of rhizosphere and bulk soils, were determined to explore the effects and internal correlations of site conditions on soil enzyme activities and microbial community characteristics of C. gilva forests. The results showed that the activities of urease and catalase, as well as the content of microbial biomass nitrogen in the surface soil of infertile mountainous areas, were significantly lower than those in control woodland areas. The shared dominant phyla in the two types of sites included Proteobacteria and Acidobacteria, and the shared dominant genera included Bradyrhizobium. In addition, the relative abundances of three unclassified populations of Proteobacteria and functional genes related to cofactor and vitamin metabolism in the rhizosphere soil of infertile mountainous areas were significantly higher than those in control woodland areas. Meanwhile, the dominant microbial phyla in the rhizosphere soil of infertile mountainous areas had a closer correlation with soil enzyme activities and microbial biomass. This study clarified the ecological strategy of C. gilva young forests adapting to infertile mountainous areas: by increasing the relative abundances of functional genes related to cofactor and vitamin metabolism in rhizosphere microorganisms, promoting the enrichment of microorganisms associated with soil nitrogen cycling, and enhancing the correlations between dominant microbial phyla and soil enzyme activities and microbial biomass, the nitrogen resource limitation on soil microbial activity in infertile mountainous areas is balanced. This finding provides direct guidance for optimizing the afforestation and management techniques of C. gilva in infertile mountainous areas and has important practical value for promoting forest ecological restoration. Full article

Soil salinization remains a critical constraint on global land sustainability, severely limiting agricultural output and ecosystem resilience. To address this issue, a field trial was implemented to investigate the interactive benefits of vermicompost (VC) and a novel soil conditioner derived from coal gasification slag-based soil conditioner (CGSS) in mitigating saline–alkali stress. The perennial forage grass Leymus chinensis, valued for its ecological robustness and economic potential under adverse soil conditions, served as the test species. Five treatments were established: CK (unamended), T1 (CGSS alone), T2 (VC alone), T3 (CGSS:VC = 1:1), T4 (CGSS:VC = 1:2), and T5 (CGSS:VC = 2:1). Study results indicate that the combined application of CGSS and VC outperformed individual amendments, with the T4 treatment demonstrating the most effective results. Compared to CK, T4 reduced soil electrical conductivity (EC) by 12.00% and pH by 5.17% (p < 0.05), while markedly enhancing key fertility indicators—including soil organic matter and the availability of nitrogen, phosphorus, and potassium. Thus, these improvements translated into superior growth of L. chinensis, reflected in significantly greater dry biomass, expanded leaf area, and increased plant height. Additionally, the T4 treatment increased soil microbial richness (Chao1 index) by 21.5% and elevated the relative abundance of the Acidobacteria functional group by 16.9% (p < 0.05). Hence, T4 treatment (CGSS: 15,000 kg·ha⁻¹; VC: 30,000 kg·ha⁻¹) was identified as the optimal remediation strategy through a fuzzy comprehensive evaluation that integrated multiple soil and plant indicators. From an economic perspective, the T4 treatment (corresponding to a VC-CGSS application ratio of 2: 1) exhibits a lower cost compared to other similar soil conditioners and organic fertilizer combinations for saline–alkali soil remediation. This study not only offers a practical and economically viable approach for reclaiming degraded saline–alkali soils but also advances the circular utilization of coal-based solid waste. Furthermore, it deepens our understanding of how integrated soil amendments modulate the soil–microbe–plant nexus under abiotic stress. Full article

Polyethylene film (PE) mulching produces substantial “white pollution,” prompting the use of biodegradable film (BF) alternatives, yet their performance in rice systems on Northeast black soils is still uncertain. We compared three BFs with different induction periods (45 d, BF₄₅; 60 d, BF₆₀; 80 d, BF₈₀), PE and a no-film control (CK) to quantify their effects on soil hydrothermal conditions, rice growth, yield, grain quality, irrigation water use efficiency (IWUE) and soil C, N. Results showed that mulching increased soil temperature and soil moisture. Across the growing season, the mean soil temperature at the 0–5 cm depth under PE was 5.5% and 2.2–5.5% higher than that under CK and BFs, respectively. Specifically, compared with CK, PE increased grain yield by 31–77% and IWUE by 75–123%, while BFs improved yield by 25–73% and IWUE by 48–101%. PE only slightly outperformed BF₈₀ in yield (by 2.3% in 2023 and 2.1% in 2024) but achieved higher IWUE (11.0–11.7%). Grain chalkiness and sensory scores under BFs were comparable to PE and better than CK. At 0–20 cm, PE increased SOC (2.3–6.8%) and the C/N ratio (0–0.8%) but reduced total nitrogen (TN) (2.7–3.9%) and total carbon (TC) (2.5–3.1%), whereas BFs increased Org-N by 0.4–4.2%, SOC by 2.9–7.1%, and TN by 0.2–0.7%, with BF₈₀ showing the greatest stimulatory effect. Overall, BFs—particularly BF₈₀—are promising substitutes for PE in black soil rice systems, supporting sustainable rice production with strong application potential. Full article