Search Results (459)

Agricultural soils play a dual role in the climate system, acting both as carbon sinks and natural sources of greenhouse gas emissions, which may be intensified under unsustainable management. However, the comparative effectiveness of different soil management strategies, particularly organic amendments derived from agro-industrial residues, remains insufficiently clarified. This review aims to critically synthesize current scientific evidence on soil stewardship practices for mitigating greenhouse gas emissions and enhancing soil carbon sequestration. The analysis is based on a structured review of peer-reviewed literature published over the last decade, including field experiments, long-term trials, and LCA studies. Comparative insights are provided across conventional mineral fertilization, organic amendments, and circular fertilization approaches based on agro-industrial by-products. The results indicate that organic amendments such as compost, digestate, and vermicompost generally increase soil organic carbon stocks (up to +40% in long-term systems) and can reduce greenhouse gas emissions and carbon footprint compared with mineral fertilization, although responses vary depending on soil, climate, and management conditions. The review evaluates the effects of different management practices on soil organic carbon dynamics, greenhouse gas fluxes, nutrient use efficiency, and soil biological functioning. Special emphasis is placed on the role of waste-derived fertilizers—such as composts, digestates, and vermicompost—in promoting soil carbon stabilization while reducing the environmental burden associated with synthetic inputs. Evidence consistently indicates that soil stewardship strategies grounded in circular economy principles can lower net carbon footprints, improve soil resilience, and mitigate trade-offs between productivity and climate mitigation. By framing soil management within the context of global warming mitigation, this review highlights the multifunctional role of soils as climate regulators and underscores the potential of agro-industrial waste valorization as a scalable pathway toward climate-smart and low-emission agricultural systems. Full article

The growing global food demand has increased the use of chemical fertilizers, causing environmental issues. Previous studies have often assessed waste-derived fertilizers separately in terms of soil improvement or environmental impact, with limited integration of these aspects across different recycling processes. This study evaluated the effects on soil quality and the environmental impact of fertilizers produced with different percentages of food wastes and different recycling processes. The fertilizers investigated include vermicompost (VC, 70% wood sawdust + 30% food wastes), Compost 1 (C1, 50% wood sawdust + 50% food wastes), Compost 2 (C2, 10% straw + 90% food wastes), and sulfur–bentonite (SBC, 90% SB + 10% food wastes). Six months post-fertilization, vermicompost significantly improved soil properties, increasing soil organic matter from 3.01% to 4.70% (+56%) and total nitrogen from 0.15% to 0.22%, along with an increase in microbial biomass compared to the unfertilized control. Compost treatments also improved soil quality, although to a lesser extent. A Life Cycle Assessment (LCA) was performed across the entire life cycle of the fertilizers. Vermicompost showed the lowest environmental impact, with a global warming potential of 45 kg CO₂ eq ton⁻¹, compared to 93 and 100 kg CO₂ eq ton⁻¹ for C1 and C2, respectively, and 167 kg CO₂ eq ton⁻¹ for SBC. The results evidenced that vermicompost improved soil quality by increasing soil organic matter, total nitrogen, microbial biomass, and biological activity and that it emitted less CO₂ eq, SO₂ eq and PO₄³⁻ during the vermicomposting process, emphasizing its environmental sustainability. The two composts improved soil quality with a moderate environmental impact. SBC positively affected soil properties but with a strong negative environmental impact. From the benefit–cost perspective, the sustainable fertilizer ranking was VC > C2 > C1 > SBC. These findings underscore that these waste management processes represent a possible transition to sustainable fertilizers derived from waste materials to mitigate the environmental degradation associated with the production and use of conventional fertilizers. By adopting these practices, the agricultural sector can boost productivity while maintaining environmental sustainability standards. Full article

Soil contamination in Sub-Saharan Africa (SSA) is increasingly driven by rapid industrialization, intensive agriculture, mining activities, and urban expansion, posing significant risks to food safety, ecosystem services, and human livelihoods. Despite the growing scale of the problem, low-cost, locally adaptable remediation technologies are widely available and technically feasible within the region. Organic waste and waste-derived products—such as compost, manure, biochar, vermicompost, digestate, and agro-industrial residues—have emerged as sustainable and cost-effective amendments for the remediation of contaminated soils. These materials can immobilize heavy metals, enhance the microbial degradation of organic pollutants, and improve soil health, making them especially suitable for resource-constrained settings. This review synthesizes the current knowledge on the use of organic waste-based remediation approaches in SSA, highlighting technologies already applied at the laboratory, pilot, and field scales, as well as their effectiveness across different contaminant types. However, despite their demonstrated potential, their widespread adoption remains limited. The primary challenge is not the absence of affordable solutions, but rather the systemic constraints characteristic of many SSA countries, including limited technical capacity, weak policy and regulatory frameworks, low stakeholder awareness, and insufficient financial and institutional support for large-scale implementation. To enable broader uptake, there is a need to strengthen waste segregation and treatment systems, standardize composting and pyrolysis processes, and develop robust regulatory guidelines and certification schemes. Investments in monitoring infrastructure, practitioner training, and knowledge transfer mechanisms will also be critical to translating scientific advances into scalable, field-ready solutions for sustainable soil remediation in SSA. Full article

Tomato (Solanum lycopersicum L.) is a globally important vegetable, prized for its nutritional value and antioxidant content. Given the increasing demand for foods with health-promoting properties and the need for sustainable production practices, this study evaluated the impact of different growth substrates combined with plant growth-promoting rhizobacteria (PGPR) inoculation on the yield and nutraceutical quality of greenhouse tomatoes grown in a semi-hydroponic system. ‘Nereida’ variety saladette tomato plants were either inoculated with a single PGPR consortium (1 × 10⁸ CFU mL⁻¹) or uninoculated. Three substrates were used: a chemical fertilization control and a sand-vermicompost mixture with two inherent levels of phosphorus (253 and 442 ppm). The chemically fertilized substrate without inoculation served as the control treatment. The results indicated that the chemically fertilized substrate presented a significantly higher yield per square meter (p < 0.05), reaching values of 5.20 ± 0.70 kg m⁻² and 4.83 ± 0.35 kg m⁻² in the control treatment. However, fruits grown in the vermicompost-based substrate with higher phosphorus content (442 ppm) and PGPR inoculation exhibited significantly greater antioxidant capacity (54.16 µmol TE g⁻¹ FW) and higher concentrations of vitamin C (14.03 mg·100 g⁻¹ FW), lycopene (47.68 mg·100 g⁻¹ FW), flavonoids, carotenoids, and glutathione. This represented an increase of 28–45% in bioactive compounds including lycopene, vitamin C, flavonoids, carotenoids, and glutathione compared to the chemical control. While the interaction between substrate and inoculation was significant only for soluble solids, both factors independently and additively contributed to the enhancement of nutraceutical parameters. These findings suggest that the use of vermicompost-based substrates, particularly those with higher phosphorus content, in combination with PGPR inoculation, is a promising strategy to enhance the accumulation of health-promoting bioactive compounds in tomato fruits, despite a trade-off in total yield. Full article

Integrated waste management through vermicomposting combined with biochar amendments represents an innovative approach for sustainable resource recovery. This study evaluated the effects of sugarcane bagasse biochar (SBB) at 0%, 5%, and 10% application rates on Eisenia fetida performance and vermicompost quality during preincubation-vermicomposting of sewage sludge and press-mud mixtures. The 10% SBB treatment significantly (p < 0.05) enhanced earthworm biomass (72.3% increase) and cocoon production (24.8 ± 1.8 per earthworm vs. 12.3 ± 1.2 in control). Lignocellulosic degradation improved substantially, achieving 22.6%, 10.7%, and 38.8% degradation for cellulose, hemicellulose, and lignin, respectively. Macronutrient concentrations increased significantly: TN by 38.4%, TP by 15%, and TK by 21.4% compared to initial mixtures. Moreover, total heavy metal concentrations decreased significantly during vermicomposting, with reductions of 8.1–8.7% for Pb, 5.3–7.6% for Cd, and 3.0–4.8% for Cr, with reduced bioavailability factors indicating enhanced metal stabilization. The final vermicompost exhibited optimal maturity indices, including a C:N ratio of 15.4 ± 0.2 and improved electrical conductivity. Results demonstrate that 10% sugarcane bagasse biochar amendment facilitates efficient concurrent management of sewage sludge and sugarcane industrial wastes while producing high-quality organic fertilizer with enhanced nutrient content, reduced heavy metal bioavailability, and accelerated stabilization for sustainable agricultural/horticultural applications. Full article

Accurate prediction of compost maturity is vital for ensuring quality, safety, minimum substrate weight loss and agronomic performance of compost products. In this study, eight supervised machine learning (ML) classification models including Random Forest, Logistic Regression, Decision Tree, Gaussian and Multinomial Naive Bayes, K-Nearest Neighbors, Support Vector Machine, and AdaBoost were systematically evaluated for their ability to predict compost maturity using three key indicators: cation exchange capacity (CEC), carbon to nitrogen ratio (C/N), and humic acid (HA) content. A dataset comprising 756 samples (4 composting/vermicomposting systems × 7 treatments × 9 time points × 3 replicates) was generated. To reduce replicate-induced variability and ensure robust machine learning analysis, triplicates were averaged at each time point, resulting in 252 effective observations used for model development. Pearson correlation and heatmap analysis indicated strong interdependencies among CEC, HA, total nitrogen (TN) and organic matter (OM) content, confirming their collective utility in compost maturity classification. Model performance was assessed based on classification metrics (accuracy, precision, recall, F₁-score) and regression-based error indicators, including mean absolute error (MAE), mean squared error (MSE), root mean squared error (RMSE), and coefficient of determination (R²). Ensemble models, particularly RF and AdaBoost, showed the highest predictive accuracy (up to 0.98) and lowest error rates (e.g., MAE < 0.05, RMSE < 0.1, R² > 0.95) when predicting CEC and C/N-based maturity classes. HA-based predictions showed slightly lower precision and higher variance across models. Full article

Dragon fruit (Hylocereus spp.) is an emerging crop in the tropics and subtropics, but its production is increasingly threatened by diseases that reduce yield and profitability. Early diagnosis of these diseases is crucial for timely intervention, yet visual symptoms often appear only after significant infection has occurred. The study aims to evaluate how optical spectral reflectance can detect dragon fruit diseases and identify the most responsive spectral regions. In this study, six major dragon fruit stem diseases: Neoscytalidium stem canker, stem sunburn, anthracnose, Botryosphaeria stem canker, Bipolaris stem rot, and bacterial soft rot were characterized by the goal of identifying unique spectral signatures for early detection and differentiation of each disease. Seventy-two potted dragon fruit plants of three distinct species were grown under four organic vermicompost treatments (0, 5, 10, 20 tons/acre) in both open-field and high-tunnel conditions together, in a randomized complete block design. A handheld spectroradiometer (350–2500 nm) was used to collect reflectance from the diseased and healthy cladodes (stem segment). Various spectral vegetative indices were computed to identify disease-specific features. The results revealed distinct spectral features for each disease. Infected cladodes consistently exhibited higher reflectance especially in the visible region (400–700 nm) and the near-infrared region (900–2500 nm) of the spectrum than healthy cladodes. The Normalized Difference Vegetative Index (NDVI), Green Normalized Difference Vegetative Index (GNDVI), and Spectral Ratio (SR) spectral indices were significantly higher in healthy plants than in diseased ones, reflecting higher chlorophyll concentration and plant biomass. Conversely, the 1110/810 ratio was lower in healthy plants than in diseased plants, suggesting a more compact internal plant structure. Statistical analysis revealed highly significant differences (p < 0.00001) between healthy and diseased spectra in the Red, Green and NIR regions. Linear Discriminant Analysis(LDA) achieved the highest classification accuracy (OA = 0.642, κ = 0.488), though performance was limited for minority classes. These findings demonstrate that targeted spectral sensing can identify dragon fruit diseases before obvious symptoms emerge. By pinpointing disease-specific spectral indices, our study paves the way for early-warning tools such as targeted multispectral sensors or drone-based imaging that would enable growers to intervene sooner and limit losses. These results highlight the potential for development of UAV-based or portable spectral sensors for large-scale, near real-time disease monitoring in dragon fruit production. Full article

Soil-dwelling predatory mites (Acari: Mesostigmata) are key components of decomposer-based soil food webs and contribute to the regulation of soil microarthropods, including agricultural pests. Despite their ecological and applied importance, the predatory mite fauna of Slovenia has remained poorly documented. This study provides the first systematic inventory of soil-dwelling mesostigmatid mites in Slovenia, based on standardized sampling conducted between July and October 2024 and between June and September 2025. Samples were collected from a range of organic substrates, including stable manure, compost, vermicompost, decomposing plant material and forest litter, and mites were extracted using a modified Berlese–Tullgren method. In total, 31 predatory mite taxa belonging to nine families were recorded, with all species except Macrocheles glaber being reported for the first time in Slovenia. Diversity analyses, based on species richness, Shannon index and minimum confirmed abundance, revealed clear differences in community structure among substrate types. Manure- and compost-based substrates showed the highest species richness and abundance, whereas forest litter supported lower diversity but more even communities. Several recorded genera include species with documented or potential relevance for the suppression of soil-dwelling pests such as Rhizoglyphus spp. These findings provide baseline data for future faunistic, ecological and applied research and improve our understanding of predatory mite communities in organically enriched agroecosystems. Full article

Arsenic (As) contamination of soils is a critical environmental and geochemical concern, with its mobility and bioavailability largely controlled by molecular-scale interactions with soil minerals. This study investigates the adsorption behavior of arsenate [As(V)] and arsenious acid [As(III)] on major clay minerals to elucidate fundamental controls on As retention in soil and sediment systems. Molecular modeling approaches were employed to investigate these interactions. Density functional theory (DFT) calculations were performed on cluster models of illite, chlorite, montmorillonite, and kaolinite to evaluate adsorption configurations and binding energies of arsenate and arsenious acid. In addition, semiempirical (PM6) and classical force-field (UFF) methods were used to examine the influence of vermicompost-derived organic matter on arsenate-mineral interactions. Multiple adsorption configurations, including atop atom, bridge, three-fold filled, and three-fold hollow sites, were evaluated, and binding energies were calculated with correction for basis set superposition error. The results indicate that three-fold hollow sites are the most favorable, with As(V) binding energies of 60–65 kcal mol⁻¹ on illite, chlorite, and montmorillonite, reaching 75 kcal mol⁻¹ on kaolinite at a surface distance of 2.7 Å. In contrast, As(III) shows weaker and energetically flatter adsorption, with binding energies of 28–54 kcal mol⁻¹ and larger equilibrium distances of 3.2–4.0 Å. Modeling of vermicompost addition suggests a substantial reduction in arsenate binding on most clay minerals, except illite, indicating competitive or disruptive interactions at mineral surfaces. These findings provide quantitative, atomistic insight into mineral- and amendment-specific controls on As stabilization and mobility in soil and sediment systems. Full article

Liquid vermicompost fertilizer (LVF) represents a valuable organic resource in the promotion of sustainable crop production. This study assessed how LVF at four different dilution rates (0, 0.5:1000, 1:1000, and 1.5:1000, v/v) impacted the growth, yield, and quality parameters of Thai basil (Ocimum basilicum L.) grown in greenhouse conditions. The study was carried out from September 2023 to January 2024 at Ton Duc Thang University, Vietnam. Measurements and statistical analyses were conducted on growth and yield traits, which included plant height, leaf area (LA), leaf number, and fresh biomass. Additionally, quality parameters such as total phenolic content, total flavonoid content, and antioxidant activity were also assessed. The application of LVF had a notable impact on all of the assessed parameters (p < 0.05). The highest LVF rate (1.5:1000) led to the most substantial increases in plant height, LA, leaf number, and fresh weight, while also significantly boosting phenolic and flavonoid content in comparison to the control. The antioxidant activity demonstrated a distinct upward trend as the concentration of LVF was increased. Full article

This study evaluated the effects of thermocomposting followed by vermicomposting on the physicochemical properties of insect frass and its suitability as a germination and growth substrate for kale, tomato, and bell pepper. Vermicomposting improved frass stability by reducing pH, electrical conductivity, carbon content, and the C/N ratio, while increasing total nitrogen, cation exchange capacity, and calcium and magnesium availability, indicating enhanced maturity and nutrient retention. Peat–frass mixtures (20–100%), increased pH from acidic conditions in the control to near neutral in 100% frass and raised electrical conductivity from 0.67 dS m⁻¹ to the highest values in the pure frass treatment. Tomato seedlings exhibited strong tolerance and enhanced growth at all frass proportions, with seedling heights exceeding 33 cm compared with the control. Kale showed optimal growth at 20–60% frass, while 80–100% reduced early development. In bell pepper, emergence declined at high frass proportions, although seedlings grown with ≥40% frass reached heights of approximately 8.3–8.6 cm. Vermicomposted frass also influenced plant metabolism, increasing flavonoid accumulation and modifying antioxidant activity. These findings demonstrate that stabilized frass can serve as a sustainable substrate component, contributing to organic waste valorization and improved seedling production when applied at crop-specific proportions. Full article

Papaya (Carica papaya L.) is a highly cross-pollinated crop that exhibits considerable genetic variability when propagated through seeds, resulting in non-true-to-type progeny. Therefore, the development of an efficient in vitro regeneration system is essential for large-scale clonal propagation of elite cultivars. In the present study, a highly efficient and reproducible somatic embryogenesis protocol was developed for C. papaya var. TNAU Papaya CO 8 using immature zygotic embryos as explants. This study provides the first comprehensive comparative evaluation of three basal media, viz., Murashige and Skoog Medium, N6 Medium, and Woody Plant Medium, for somatic embryogenesis and plant regeneration in this variety, along with the optimization of polyamine-enriched media for enhanced plantlet recovery. The embryogenic potential of explants was assessed across different stages, including callus induction, somatic embryo development, plant regeneration, shoot elongation, rooting, and acclimatization. Maximum callus induction (81.96%) was observed on half-strength MS medium supplemented with 2,4-Dichlorophenoxyacetic acid under dark conditions, followed by ½ N6 (63.00%) and ½ WPM (58.02%). Somatic embryo initiation was highest on ½ MS medium containing 2.0 mgL⁻¹ 2,4-D (77.82%). Somatic embryos developed through distinct globular, heart, torpedo, and cotyledonary stages. Embryo maturation was significantly enhanced on MS medium supplemented with abscisic acid, polyethylene glycol, benzylaminopurine, and proline. The highest plantlet regeneration (85.02%) was achieved on MS medium enriched with putrescine, whereas comparatively lower regeneration was recorded on N6 (75.99%) and WPM (57.97%). Shoot elongation was significantly improved by supplementation with gibberellic acid (1.0 mgL⁻¹). Root induction was optimal on half-strength MS medium containing Indole-3-butyric acid, 1-Naphthaleneacetic acid, phloroglucinol, and activated charcoal, resulting in well-developed roots. Regenerated plantlets were successfully acclimatized in a cocopeat–vermicompost substrate with a survival rate of 74.01%. The optimized protocol provides a reliable and efficient system for large-scale clonal propagation and offers promising applications in genetic transformation and commercial production of papaya var. TNAU papaya CO 8. Full article

This study evaluated the effects of fly ash (F) and effective microorganisms (EM) on nutrient dynamics and heavy metal transformations during vermicomposting of camel manure (CM). Four treatments (CM, CM + F, CM + EM, and CM + F + EM) were arranged in a completely randomized design and monitored over 12 weeks. Significant (p < 0.05) treatment and time interactions were observed for pH, NH₄-N, Mn, Pb, and Mo. The addition of EM resulted in a greater decline in pH compared to other treatments. After 12 weeks, Olsen P increased from 300.62 to 398.71 mg/kg in CM + EM, while NH₄-N increased markedly from 22.74 to 86.62 mg/kg. In contrast, NO₃/NO₂-N declined in EM-amended treatments but increased in the control and CM + F. Trace metal concentrations generally increased due to mass reduction during vermicomposting yet remained within internationally acceptable limits. Germination index (GI) values varied significantly among crops and treatments, ranging from phytotoxic to non-phytotoxic responses. Although CM + EM produced superior nutrient enrichment, several vegetables exhibited GI values below 50%, indicating potential phytotoxicity for sensitive crops. In case of established crops for which nutrient supply outweighs early phytotoxic concerns, CM + EM represents the most agronomically beneficial option. Future studies should explore blending CM + EM and CM + F with stabilizing amendments such as biochar to optimize nutrient availability while minimizing salinity and phytotoxic risks. Full article

Drought reduces soil moisture and impairs root function, posing a significant threat to rice production in arid regions. The influence of soil amendments on early rice root development under semi-dry cultivation remains insufficiently characterized, especially when assessed using non-destructive rhizotron techniques. This study employed a scanner-based rhizotron system to evaluate early root responses of rice seedlings to six amendments under semi-dry irrigation: vermicompost and peat moss, spirulina powder, gypsum, rice husk biochar, zeolite, and an unamended control. The vermicompost plus peat moss (VC+PM) treatment demonstrated the highest water-holding capacity (26%), root projected area (9.60 cm² plant⁻¹), and root surface area (84.79 cm² plant⁻¹). VC+PM also promoted extensive lateral branching (233 secondary and 1709 tertiary roots) and the greatest total lateral root length (363.09 cm plant⁻¹), resulting in superior biomass (shoot: 140.00 mg plant⁻¹; root: 56.70 mg plant⁻¹) and the lowest root-to-shoot ratio (0.90). These improvements are attributed to the enhanced moisture retention of peat moss and the nutrient and phytohormone contributions of vermicompost. In contrast, rice husk biochar exhibited the lowest water-holding capacity (14%), while other amendments produced moderate or limited effects. The results establish a direct relationship between improved soil water retention and early-stage drought-avoidant root development. The combination of VC and PM emerges as a promising approach to enhance root plasticity and seedling establishment in water-saving rice systems. As this study was conducted under controlled rhizotron conditions and limited to the seedling stage (20 days after sowing), future research should prioritize multi-season field trials to assess yield translation and economic feasibility assessments to support farmer adoption. Full article

The undegradable characteristics of heavy metals on environmental quality have become a serious human health concern. A study was conducted in a potato field to investigate the impact of soil amended with animal manure or biochar on the transport of toxic heavy metals and nitrates to runoff and seepage water. The soil in 18 field plots was separated, and each of 3 plots was mixed with biochar, chicken manure, vermicompost, sewage sludge, or cow manure, with 3 plots used as the control. Following a natural rainfall event, the impact of soil treatments on the runoff and infiltration water volume was monitored. Runoff water from the soil amended with biochar exhibited 10.6 L plot⁻¹, whereas cow manure exhibited 4.1 L plot⁻¹, indicating about 61% reduction in runoff water volume. The vermicompost-amended soil increased the seepage water volume from 1.6 L plot⁻¹ in the control treatment to 4.4 L plot⁻¹, indicating a 175% increase in percolating water, a desirable attribute to direct rainfall water towards the plant roots. The concentrations of Pb, Cd, Ni, Mn, Cr, Mg, Cu, and K in infiltration water were greater in runoff sediments, highlighting the need for runoff sediment remediation technology. Full article