Search Results (3,110)

Nutrient losses through leaching and low nutrient use efficiency are major challenges limiting crop productivity and causing environmental pollution. Biochar has been widely studied as a soil amendment to improve nutrient retention; however, the combined effects of pyrolysis temperature and post-production oxidation on soil nutrient dynamics and plant performance remain unclear. In this study, wheat straw and wood residue biochars were produced at two pyrolysis temperatures (350 and 450 °C) and subsequently modified by hydrogen peroxide (H₂O₂) oxidation to enhance surface functionality. A pot experiment with fava bean (Vicia faba L.) was conducted to evaluate the effects of pristine and oxidized biochars on soil chemical properties, nutrient leaching, and plant nutrient uptake. Results showed that pristine biochars increased soil pH from 6.82 (control) to 8.73–9.12 and EC from 2.15 to 3.06–4.71 dS m⁻¹, with wheat straw biochars having stronger alkalizing effects. In contrast, oxidized biochars decreased soil pH to 5.62–5.93 due to the introduction of oxygen-containing functional groups. All biochars reduced NO₃⁻-N, NH₄⁺-N, and PO₄³⁻-P leaching, with the most pronounced reductions observed in oxidized wheat straw biochar produced at 450 °C (O-BWS₄₅₀). Improved nutrient retention translated into higher plant nutrient uptake: fava bean plants grown in O-BWS₄₅₀-amended soil achieved the greatest N (6.71%) and P (3.89%) uptake, significantly higher than the control. These findings highlight the potential of oxidation-modified biochars, particularly wheat straw biochar produced at moderate pyrolysis temperature, to improve soil nutrient conservation and enhance crop nutrition simultaneously. Such modifications represent a promising approach for developing biochar-based soil amendments that promote sustainable nutrient management. Full article

Optimizing nutrient formulations is essential to improving the biomass yield and C-phycocyanin (C-PC) productivity of Spirulina sp., a cyanobacterium with wide-ranging applications in food, pharmaceutical, and biotechnological industries. This study evaluated the effects of macronutrient modifications on growth and pigment biosynthesis using a two-level full factorial design across eight Zarrouk-based formulations compared to the standard medium. Cultivation experiments were conducted in triplicate, and growth was evaluated using linear growth rate, maximum optical density (OD₆₈₀), and dry biomass, while C-PC was quantified in crude extracts (PCL), dried biomass (PCD), and the purity index (PI). Among the tested formulations, F2 (16 g/L NaHCO₃, 5 g/L NaNO₃, 0.25 g/L K₂HPO₄) achieved the highest biomass productivity, yielding a 37.6% increase in dry weight and a 38.1% improvement in daily productivity compared to the control. In contrast, F3 (16 g/L NaHCO₃, 5 g/L NaNO₃, 1 g/L K₂HPO₄) yielded the highest C-PC content, nearly doubling both PCL and PCD values and enhancing pigment purity by 40.2%. ANOVA and interaction analyses confirmed that carbon and nitrogen synergistically promoted biomass formation, while phosphorus had a strong effect on pigment biosynthesis through C:N:P interactions. These findings demonstrate that Spirulina sp. requires distinct nutrient balances for optimal growth and pigment formation. Formulation F2 is ideal for maximizing biomass productivity, whereas F3 is optimal for high-value C-PC production. The results provide a rational framework for designing nutrient-efficient cultivation systems to advance sustainable Spirulina-based biomanufacturing. Full article

This study presents a green and sustainable approach for synthesizing zinc oxide nanoparticles (ZnO-NPs) using Melia azedarach leaf extract as a reducing and stabilizing agent, with zinc acetate as the precursor. The synthesized nanoparticles were thoroughly characterized to assess their structural, morphological, and physicochemical properties, revealing nanoscale dimensions, enhanced crystallinity, and improved stability compared to commercial ZnO. Controlled release experiments under plant-relevant pH conditions demonstrated a gradual and sustained release of Zn²⁺ ions, accompanied by buffering effects and re-precipitation of Zn(OH)₂, highlighting their potential for long-term nutrient availability in soil systems. Unlike conventional studies that focus mainly on synthesis or characterization, this work emphasizes the functional performance of ZnO-NPs as nanofertilizers, combining eco-friendly production with practical agricultural applications. The plant-mediated synthesis yielded nanoparticles with uniform size distribution, enhanced dispersion, and stability, which are critical for efficient nutrient delivery and persistence in soil. Overall, this study provides a cost-effective, scalable, and environmentally benign strategy for producing ZnO nanoparticles and offers valuable insights into the development of sustainable nanofertilizers aimed at improving crop nutrition, soil fertility, and agricultural productivity. Full article

The escalating challenges of climate change, soil degradation, and the need to ensure global food security are driving the transition towards more sustainable agricultural practices. Biostimulants, a diverse category of substances and microorganisms, have emerged as promising tools to enhance crop resilience, improve nutrient use efficiency (NUE), and support sustainable intensification. However, their widespread adoption is hampered by significant variability in efficacy and a lack of consensus on their optimal use. This comprehensive review synthesizes current scientific knowledge to critically evaluate the performance of biostimulants within sustainable agricultural systems. It aims to move beyond isolated case studies to provide a holistic analysis of their modes of action, efficacy under stress, and interactions with the environment. The analysis confirms that biostimulant efficacy is inherently context-dependent, governed by a complex interplay of biological, environmental, and management factors. Performance variability is explained by four core principles: the Limiting Factor Principle, the Biological Competition Axiom, the Stress Gradient Hypothesis, and the Formulation and Viability Imperative. A significant disconnect exists between promising controlled-environment studies and variable field results, highlighting the danger of extrapolating data without accounting for real-world agroecosystem complexity. Biostimulants are not universal solutions but are sophisticated tools whose value is realized through context-specific application. Their successful integration requires a precision-based approach aligned with specific agronomic challenges. We recommend that growers adopt diagnostic tools and on-farm trials, while producers must provide transparent multi-location field data and invest in advanced formulations. Future research must prioritize field validation, mechanistic studies using omics tools, and the development of crop-specific protocols and industry-wide standards to fully unlock the potential of biostimulants for building resilient and productive agricultural systems. Full article

Facility agriculture is essential for modernizing the production of horticultural plants, while long-standing over-fertilization and improper tillage in some vegetable facilities in northern China have resulted in reduced soil quality, increased greenhouse gas (GHG) emissions, and diminished vegetable yields and quality. This study systematically analyzed the deteriorating health of typical cucumber facility soils in Hebei Province, China, induced by long-term over-fertilization. Based on field surveys, we explored dynamic changes in soil physicochemical properties across different durations of over-fertilization. Subsequently, a series of field trials were conducted to assess whether reducing nitrogen application, either alone or when combined with microbial agents, could ameliorate soil properties, reduce greenhouse gas emissions, and enhance cucumber productivity. The initial field assessment revealed severe topsoil salt and nutrient accumulation, with water-soluble salt content in 5-year-old greenhouses from Yongqing soaring to 3.82 g·kg⁻¹, nearly eight times the level found in 1-year-old plots. Field experiments demonstrated that a 20% reduction in nitrogen application from the conventional rate of 900 kg·hm⁻² effectively mitigated salt accumulation, improved the structure of the microbial community, and maintained cucumber yield at 66,914 kg·hm⁻², an output comparable to conventional practices. More notably, integrating this 20% nitrogen reduction with an inoculation of Bacillus megaterium reduced the overall global warming potential by 26.7% and simultaneously increased cucumber yield to 72,747 kg·hm⁻². The most comprehensive strategy combined deep tillage, soybean straw incorporation, and B. megaterium application under reduced nitrogen, which boosted nitrogen use efficiency by 13.7% and achieved the highest yield among all treatments. In conclusion, our findings demonstrate that a combined approach of nitrogen reduction, microbial amendment, and straw application offers an effective strategy to restore soil health, enhance crop productivity, and mitigate environmental impacts in protective vegetable production systems. Full article

Although pastures cover nearly half of Brazil’s agricultural land and form the backbone of national livestock production, they have historically received limited attention regarding management and fertilization, resulting in widespread degradation. Sustainable intensification of these pasture-based systems is therefore essential to meet growing global demand for animal products while minimizing environmental impacts. This review highlights recent technological innovations in pasture fertilization in Brazil, with a particular focus on alternative phosphorus sources such as natural reactive phosphates, which offer slow-release nutrients at lower costs compared to conventional fertilizers. Efforts to enhance nitrogen use efficiency through nitrification and urease inhibitors show promise in reducing nutrient losses and greenhouse gas emissions, despite current cost constraints limiting adoption. The integration of grass-legume intercropping, especially with Arachis pintoi, has been shown to enhance forage quality and system persistence when appropriately managed. Moreover, plant growth-promoting microorganisms emerge as sustainable biotechnological tools for restoring degraded pastures and boosting forage productivity without adverse environmental consequences. Properly treated agro-industrial residues also present a viable nutrient source for pastures, provided environmental regulations are strictly followed to prevent pollution. Together, these innovations offer a comprehensive framework for enhancing the productivity and sustainability of Brazilian livestock systems, highlighting the pressing need for continued research and the adoption of advanced fertilization strategies. Full article

Eutrophication of freshwater bodies is primarily caused by excessive nitrogen and phosphorus, resulting in significant environmental challenges, including harmful algal blooms and hypoxia. This review examines the potential for natural and modified zeolites to act as adsorbents and regulate nutrient concentrations in eutrophic freshwater ecosystems, excluding applications for wastewater or industrial water effluents. Natural zeolites are effective adsorbents of ammonium, whereas modified zeolites (with aluminum, iron, calcium, and many others) have been noted to have enhanced phosphate adsorption and a higher overall nutrient removal efficiency. The application of modified zeolites for controlling eutrophication in freshwater bodies has proven to have high efficiency in adsorbing nitrogen and phosphorus, resulting in reduced nutrient release from sediments and improved water quality in shallow lakes and reservoirs. This review describes the adsorption mechanisms and modification methods, with an appreciation for the multifunctional role of zeolites in nutrient immobilization and capping sediments. Finally, it presents the potential to use zeolite-based materials in eutrophic freshwater restoration through sustainable circular economy approaches. Zeolite materials present ample environmental applications for cost-effective and targeted mitigation approaches to freshwater eutrophication. Full article

Feed and water scarcity are major challenges for the sustainability of livestock production, particularly in semi-arid regions with structural limitations in resource availability. In this context, the valorization of agro-industrial by-products contributes to circular agriculture, reduces waste, and promotes more efficient resource use, in line with the United Nations Sustainable Development Goals. This study evaluated the inclusion of partial mixed tomato residue (PMR) silage in sheep diets and its effects on productive performance, total water intake, and meat quality. Eighteen ewe lambs were assigned to two groups: control (concentrate and deferred pasture) and PMR (tomato residue silage and deferred pasture). The PMR silage had a pH of 3.97 and was mainly characterized by lactic and acetic acids, with minor amounts of propionic and butyric acids. The butyric acid concentration (8.9 g kg⁻¹ DM) slightly exceeded the recommended threshold (0.5% DM), suggesting some clostridial activity but remaining below levels associated with severe deterioration. Animals fed PMR silage showed a 36% higher dry matter intake (p = 0.001), with greater intake of total digestible nutrients and fiber. This translated into a 54% higher average daily gain (p = 0.02) and an 11% greater final body weight compared with the control group (p = 0.02). Dietary water intake was also higher in the PMR group, reducing direct water consumption from drinkers by 38% (p < 0.001). Meat quality parameters were unaffected by the diet. Pesticide residue screening by LC-MS/MS revealed no detectable levels of abamectin, cymoxanil, chlorothalonil, difenoconazole, or mancozeb in silage. In meat samples, only chlorothalonil was tested and it was not detected. However, the use of PMR silage increased direct energy demand due to transport and compaction, while feeding costs per unit of weight gain were reduced. Overall, PMR silage proved to be a safe, fermentatively stable, and effective feeding alternative that enhances performance, reduces direct water intake, and maintains meat quality, representing a viable strategy for small ruminant production in water-limited regions. Full article

Soil organic carbon (SOC) is a critical component of soil health, influencing soil structure, soil water retention capacity, and nutrient cycling while playing a key role in the global carbon cycle. Accurate SOC estimation over croplands is essential for sustainable land management and climate change mitigation. This study explores a novel approach to SOC estimation using multi-frequency synthetic aperture radar (SAR) data, specifically Sentinel-1 and ALOS-2/PALSAR-2 imagery, combined with advanced machine learning techniques for cropland SOC estimation. Diverse agricultural practices, with major crop types such as rice (Oryza sativa), finger millet (Eleusine coracana), Niger (Guizotia abyssinica), maize (Zea mays), and vegetable cultivation, characterize the study region. By integrating C-band (Sentinel-1) and L-band (ALOS-2/PALSAR-2) SAR data with key polarimetric features such as the C2 matrix, entropy, and degree of polarization, this study enhances SOC estimation. These parameters help distinguish variations in soil moisture, texture, and mineral composition, reducing their confounding effects on SOC estimation. An ensemble model incorporating Random Forest (RF) and neural networks (NNs) was developed to capture the complex relationships between SAR data and SOC. The NN component effectively models complex non-linear relationships, while the RF model helps prevent overfitting. The proposed model achieved a correlation coefficient (r) of 0.64 and a root mean square error (RMSE) of 0.18, demonstrating its predictive capability. In summary, our results offer an efficient approach for enhanced SOC mapping in diverse agricultural landscapes, with ongoing work targeting challenges in data availability to facilitate large-scale SOC mapping. Full article

The efficacy of coated fertilizers in enhancing nutrient use efficiency and reducing environmental impacts depends on their coating properties. This study developed three biodegradable, waterborne polyacrylate latexes (A, B, and C) as eco-friendly coatings for controlled-release fertilizers (CRFs) using the Wurster fluidized bed process. The latexes were synthesized with varying hard-to-soft monomer ratios and cross-linked with 2 wt% aziridine to investigate how monomer composition affects coating properties and nutrient release. The results showed that coating B, which had an intermediate hard-to-soft monomer ratio, demonstrated optimal properties. It exhibited the lowest swelling capacity (2.54% at 60 °C), a suitable glass transition temperature (15.34 °C), and the slowest nutrient release, with cumulative nitrogen release remaining below 60% after 11 days in water at 40 °C. In field trials, the fertilizer coated with material B produced the highest rice yield among tested domestic CRF brands. It also achieved a significant 19.1% yield increase compared to a single basal application of conventional compound fertilizer. These findings confirm that this modified latex provides an effective and environmentally friendly solvent-free coating strategy for high-performance CRFs. Full article

Nutrient stoichiometry and dissolved organic matter (DOM) govern essential ecosystem processes; however, their coupling in tea garden soils remains obscure, and cultivar-specific effects on this linkage remain virtually unknown. In this study, soil carbon (C), nitrogen (N), and phosphorus (P) contents and their C/N/P stoichiometry were measured in two contrasting tea cultivars, Rougui and Shuixian. DOM composition and sources were resolved using UV–visible spectroscopy, three-dimensional fluorescence spectroscopy, and parallel factor analysis. The tea garden soils exhibited low C/N/P ratios but high nutrient availability. DOM was dominated by fulvic- and tyrosine-like components, indicating low humification and high biodegradability. Soil organic matter and C/N/P stoichiometry jointly controlled the quantity and quality of DOM. In Rougui soils, protein-like DOM accounted for 61.92% ± 7.27% of total fluorescence and was primarily regulated by the N/P ratio. In Shuixian soils, humic-like DOM increased to 53.13% ± 8.58% of total fluorescence and was positively driven by the C/P ratio. These findings demonstrate that tea cultivars modulate the coupling between DOM and C/N/P stoichiometry, providing a basis for cultivar-specific fertilization strategies, efficient regulation of soil nutrient cycling, and sustainable tea garden management. Full article

Donkey milk is highly regarded for its nutritional, immunological and hypoallergenic properties. In this context, the global demand is increasing, and the challenges of low production and milk hygiene need to be addressed. This study evaluated the effects of dietary and phytogenic supplementation on milk yield, nutrient digestibility, and milk quality in lactating jennies (Equus asinus). All donkeys had unrestricted access to natural pasture during the study. In addition to grazing, animals were divided into three groups (n = 10 per group) that differed only in the type of supplemental feed. The control group (CG) received pasture grass with a corn-based supplement; Group 1 (G1) received the same basal feed enriched with sunflower meal and a phytogenic blend of medicinal plants; and Group 2 (G2) received the same compound feed as G1 but without the phytogenic additives. Over an eight-week period, milk production, apparent digestibility coefficients (dry matter, protein, fibre, and ether extract), and microbiological quality were assessed. G1 demonstrated the highest milk yield (p < 0.001), improved nutrient digestibility (e.g., crude protein digestibility: 57.89 ± 4.21%), and a significant reduction in total viable counts (TVC) from 2.848 ± 0.265 to 1.898 ± 0.404 log₁₀ CFU/mL (p < 0.001), compared to CG and G2. The latter maintained relatively stable TVC values (2.930 ± 0.260 → 2.838 ± 0.196; p = 0.356641), accompanied by reduced interindividual variability, whereas CG exhibited a slight increase (2.922 ± 0.253 → 2.949 ± 0.323; p = 0.792259) and greater variability, suggesting a negative trend. Crude protein digestibility was 55.86 ± 6.66% in G2 and 45.26 ± 9.85% in CG, further supporting the superior nutrient utilization efficiency observed in G1. The phytogenic supplement stabilized milk chemical composition, suggesting potential galactagogues, immunomodulatory, and antimicrobial effects. These findings support the use of functional feed additives as a promising strategy to enhance productive performance and milk hygiene in sustainable donkey farming systems. Full article

Straw return is crucial for sustainable agriculture, but its efficiency is limited by low temperatures in cold regions, especially in saline-alkali soils. This study investigates the degradation process of maize straw and the response of soil properties and microbial communities during the winter low-temperature period in the alkaline farmland of Anda, China. A two-year field experiment with straw return (SR) and no return (NR) treatments was conducted. Straw degradation rates and structural changes (as observed via scanning electron microscope, SEM) were monitored. Soil physicochemical properties and enzyme activities were analyzed. Microbial community composition was characterized using 16S rRNA and ITS sequencing. The cumulative straw degradation rate over two years reached 94.81%, with 18.33% occurring in the first winter freeze–thaw period. Freeze–thaw cycles significantly damaged the straw structure, facilitating microbial colonization. Straw return significantly improved soil properties after winter, increasing field water capacity (3.45%), content of large aggregates (6.57%), available nutrients (P 38.17 mg/kg, K 191.93 mg/kg), and organic carbon fractions compared to NR. Microbial analysis revealed that low temperatures filtered the community, enriching cold-tolerant taxa like Pseudogymnoascus, Penicillium, and Pedobacter, which are crucial for lignocellulose decomposition under cold conditions. The winter period plays a significant role in initiating straw degradation in cold regions. Straw return mitigates the adverse effects of winter freezing on soil quality and promotes the development of a cold-adapted microbial consortium, thereby enhancing the sustainability of alkaline farmland ecosystems in Northeast China. Full article

Urea is one of the most widely used sources of non-protein nitrogen (NPN) in ruminant diets due to its low cost and high availability. However, its rapid solubilization in the rumen can result in abrupt ammonia release, leading to toxicity risks and low nitrogen utilization efficiency. In this context, slow-release technologies, particularly microencapsulation, have been developed to synchronize NPN release with fermentable carbohydrate availability, thereby enhancing microbial protein synthesis, improving animal performance, and reducing environmental impacts. This review compiles recent advances in urea microencapsulation, emphasizing different wall materials such as waxes, lipids, polysaccharides, and fatty acids, as well as drying techniques and formulation strategies. Slow-release urea (SRU) addition in small ruminants’ diet may increase nutrient intake and digestibility, improve N balance, and reduce urinary excretion losses. Regarding performance, positive responses are observed when nitrogen release is properly synchronized with energy availability, although the results may vary depending on the encapsulant type, forage-to-concentrate ratio, and ruminal passage rate. Additionally, effects on meat quality and environmental parameters indicate that this technology holds not only zootechnical but also socio-environmental potential. It is concluded that urea microencapsulation can represent a promising alternative to optimize NPN use efficiency in ruminant production systems, though greater methodological standardization, long-term evaluations, and comparative economic analyses are required to encourage its broader adoption. Full article

Nitrogen fertilization is a critical factor in maize (Zea mays L.) production, as nitrogen is often the primary limiting nutrient. The use of microbial biostimulants has emerged as a promising strategy to enhance nitrogen use efficiency. This study assessed the field performance of an industrially produced inoculant (Nodusoja™), formulated with Azospirillum brasilense strains Ab-V5 and Ab-V6, under contrasting soil and climatic conditions. The aim of this study is to assess the grain yield of maize cultivated in different edaphoclimatic conditions using the biostimulant, together with lower doses of topdressing fertilization. Field experiments were conducted across double cropping seasons in Sete Lagoas, Minas Gerais (19°28′ S; 44°15′ W), and Palmas, Tocantins (10°8′ S; 48°19′ W), Brazil, during the 2018, 2019, and 2021 harvests. Evaluated parameters included grain yield, shoot dry mass, and nitrogen content. The most pronounced effects were observed on productivity, with maximum grain yields of 8.76 and 9.05 t·ha⁻¹ recorded in the 2019 season, under inoculation without topdressed N and inoculation with 50% of the recommended N dose, respectively. By contrast, uninoculated treatments with 20, 60, and 120 kg N·ha⁻¹ yielded 6.41, 7.13, and 7.49 t·ha⁻¹, respectively. Statistical analyses demonstrated that inoculation with strains Ab-V5 and Ab-V6 increased maize grain yield by up to 40% when combined with 50% of the recommended nitrogen fertilization. These findings highlight the potential of Azospirillum-based inoculants to improve N use efficiency and reduce dependence on synthetic fertilizers in maize cultivation. Full article