Search Results (4,499)

Optimizing organic fertilizer substitution is essential for enhancing the sustainability of agriculture and achieving a balance between crop productivity, nutritional quality, and environmental safety. Here, we conducted an 11-year field experiment to evaluate the effects of substituting 50% of mineral fertilizers with pig manure (PM) or cattle manure (CM) on the nutritional quality of wheat grain, heavy metal (HM) accumulation, and associated human health risks. The yield and protein content were highest in the mineral fertilizer (MF) treatment, and grain micronutrients (Fe, Mn, Cu, Zn) were 6.7–13.8% higher under organic substitution (PM/CM) than in the MF treatment. The Ni, Pb, and As contents were 35.4–43.0% higher in the PM treatment than in the MF treatment, which stems from the higher HM content in pig manure. Health risk assessments indicated that the Hazard Index (HI) for children exceeded 1 in the PM treatment, primarily due to As, which accounted for 69.6% of the HI. All treatments remained within safe thresholds, although As and Pb posed detectable carcinogenic health risks. The higher levels of Ni and As in pig manure likewise led to a significant increase in the health risk associated with the PM treatment compared to the MF treatment. We developed a novel Grain Quality Index (GQI) that combined nutrient and HM data, which indicated that the nutritional quality of wheat grain was similar in the CM and MF treatments. The GQI was 9.1% lower in the PM treatment than in the MF treatment. These findings suggest that the substitution of mineral fertilizer with cow manure can help achieve a balance between yield, nutrition, and safety, and more stringent regulation of HMs is required for the use of pig manure. Our findings provide actionable insights with implications for sustainable wheat production policies. Full article

The composting of organic waste is a sustainable strategy for waste management and soil fertility improvement. However, the composting process is often associated with greenhouse gas (GHG) emissions, having a negative impact on the environment. This study investigated the effects of BC pyrolysis temperature (300 °C, 600 °C) and application rate (5% and 10%) on GHG emissions during the thermophilic phase and compost quality. The experimental treatments were a control and four BC treatments varying in pyrolysis temperature (300 °C, 600 °C) and application rate (5%, 10%). As a result, BC pyrolyzed at 600 °C and added at 10% (T2R2) resulted in the highest thermophilic temperature (63.5 ± 0.5 °C). This treatment significantly achieved substantial reductions in NH₃, N₂O, CH₄, and CO₂ emissions by 55 ± 2.7%, 50 ± 2.7%, 88 ± 4.2%, and 23 ± 2.3%, respectively, relative to the control. Compost quality was enhanced notably, with dry matter increasing to 46.4 ± 0.11% (T2R1), organic matter reaching 30.9 ± 0.05% in T2R1, and total nitrogen peaking at 0.8 ± 0.001% (T1R2). The C:N ratio decreased from 27:1 in the control to 21:1 in the treatment of T1R2, indicating an accelerated composting process. The NH₄-N levels were the highest in T1R2 and T2R2 (659 ± 0.1 and 416 ± 0.2 mg kg⁻¹), while EC increased to 9.5 ± 0.006 ms/cm (T2R1), and bulk density decreased to 410 ± 0.08 kg/m³ (T1R1). These results demonstrate that high-temperature biochar, especially at a rate of 10%, is effective in reducing emissions and improving compost quality. Future research should explore long-term effects and microbial mechanisms to optimize biochar use in composting systems. Full article

As an important technology to enhance nutrient use efficiency and reduce agricultural non-point source pollution, controlled-release fertilizers (CRFs) have been widely applied in modern agriculture. However, during packaging, transportation, and field application, CRF particles are prone to mechanical impacts, which can lead to particle fragmentation and damage to the controlled-release coating. This compromises the release kinetics, increases nutrient loss risk, and ultimately exacerbates environmental issues such as eutrophication. Currently, studies on the impact-induced fragmentation behavior of CRF particles remain limited, and there is an urgent need to investigate their fragmentation susceptibility mechanisms from the perspective of internal stress evolution. In this study, the mechanical properties of CRF particles were first experimentally determined to obtain essential parameters. A two-layer finite element model representing the coating and core structure of the particles was then constructed, and a fragmentation susceptibility index was proposed as the key evaluation criterion. The index, defined as the ratio of fractured volume to peak impact energy, reflects the efficiency of energy conversion at the critical moment of particle rupture (1–5). An explicit dynamic simulation framework incorporating multiple influencing factors—equivalent diameter, sphericity, impact material, velocity, and angle—was developed to analyze fragmentation behavior from the perspective of energy transformation. Based on the observed effects of these variables on fragmentation susceptibility, three regression models were developed using response surface methodology to quantitatively predict fragmentation susceptibility. Comparative analysis between the simulation and experimental results showed a fragmentation rate error range of 0–11.47%. The findings reveal the relationships between particle fragmentation modes and energy responses under various impact conditions. This research provides theoretical insights and technical guidance for optimizing the mechanical stability of CRFs and developing environmentally friendly fertilization strategies. Full article

This study examined the application of rhyolite filler in agroecological farming systems in the Fourth Colony of Italian Immigration (Quarta Colônia de Imigração Italiana), Rio Grande do Sul, Brazil. The aim was to explore sustainable alternatives to synthetic fertilizers in line with organic agriculture principles. The region’s designation as the Quarta Colônia UNESCO Global Geopark reinforces the relevance of this initiative. The research involved petrographic characterization, incubation experiments, and chemical analyses of rhyolite samples. Incubation tests with pigeon pea and elephant grass assessed combinations of rock filler and poultry litter. The results showed that rhyolite filler supported plant growth, especially with poultry litter, which supplies nitrogen and microorganisms that accelerate mineral weathering. Petrographic observations indicated that elephant grass promoted stronger mineral alteration, likely due to its dense fibrous roots and substrate interaction. Chemical analyses confirmed the rhyolite’s quartz content and trace elements remain within safety limits defined by Brazilian legislation on soil remineralizers. The K₂O content and the base sum (CaO, MgO, and K₂O) also complied with minimum legal requirements. Beyond mineralogical and chemical aspects, the study emphasized the economic feasibility of using locally sourced rock fillers, offering lower costs than synthetic fertilizers and supporting sustainable, resilient agroecological systems. Full article

Balancing soil nitrogen leaching with production benefits remains a critical challenge in sustainable greenhouse tomato cultivation. This study evaluated the effects of reduced water-soluble nitrogen fertilizer (N) application rates on soil environmental parameters and production outcomes to optimize nitrogen management strategies. Four treatments were implemented across two growing seasons: control (CK), high-N (H), medium-N (M), and low-N (L) nitrogen fertilizer applications in soil solution (SS) and autumn–winter (AW) systems. Results demonstrated that reduced nitrogen inputs significantly decreased soil electrical conductivity and soil nitrogen retention by 88% and 83% in SS and AW, respectively, while reducing soil residual nitrate nitrogen. The tomato yield decreased by 14–26% under low fertilizer treatment, while fruit quality was substantially enhanced, with soluble solid content increasing by 56% in SS and 217% in AW for the L treatment compared to the CK. Nitrogen-use efficiency improved by 54.7% and 34.78% in SS and AW, respectively, demonstrating superior resource utilization under reduced fertilizer applications. Principal component analysis revealed that fruit quality was primarily influenced by soluble solid content, organic acid, total soluble solids, and sugar–acid ratio. Gray relational analysis identified the L treatment (361.62 kg ha⁻¹ in SS and 182.6 kg ha⁻¹ in AW) as optimal for comprehensive performance evaluation. The findings demonstrate that strategic nitrogen reduction effectively balances production benefits with environmental sustainability, providing a practical framework for sustainable nitrogen management in controlled environment agriculture. Full article

Tree endotherapy has risen to prominence in the field of precision agriculture as an innovative and sustainable method of tree care, being respectful of both environmental protection and consumer health needs. A comprehensive review of the state of the art of research in this field has made it possible to spotlight the main advantages of tree infusion, which has undergone significant progress in step with technological innovation and an increased understanding of tree anatomy and physiology. The major criticalities associated with this technique, as well as the biological and technical–operational obstacles that still hinder its wider use, are also highlighted. What emerges is an innovative and rapidly expanding technique in tree care, in both the cultivation and phytosanitary management of fruit and ornamental trees. Some of the strengths of the endotherapy technique, such as the next-to-no water consumption, the strong reduction in the use of fertilizers and pesticides, the possibility of using biological control agents (BCAs) or other products of natural origin, the precision administration of the product inside the xylem of the tree, and the efficacy (20–90%) and persistence (1–2 years) of treatments, make it one of the cornerstones of sustainable tree protection at present. With a very low consumption of the “active ingredient”, endotherapy has a negligible impact on the external environment, minimizing the drift and dispersal of the active ingredient and thus limiting the exposure of non-target organisms such as beneficial insects, birds, and wildlife. The large-scale application of the technique would therefore also help to achieve an important goal in “climate-smart agriculture”, the saving of water resources, significantly contributing to climate change mitigation, especially in those areas of the planet where water is a precious resource. Full article

Population growth drives increasing energy demands, agricultural production, and organic waste generation. The organic waste contributes to greenhouse gas emissions and increasing landfill burdens, highlighting the need for novel closed-loop technologies that integrate water, energy, and food resources. Within the context of the Water–energy–food Nexus (WEF), wastewater can be recycled for food production and food waste can be converted into clean energy, both contributing to environmental impact reduction and resource sustainability. A novel household-scale, closed-loop WEF system was designed, installed and operated to manage organic waste while retrieving water for irrigation, nutrients for plant growth, and biogas for energy generation. The system included a biodigester for energy production, a sand filter system to regulate nutrient levels in the effluent, and a hydroponic setup for growing food crops using the nutrient-rich effluent. These components are operated with a daily batch feeder coupled with automated sensors to monitor effluent flow from the biodigester, sand filter system, and the feeder to the hydroponic system. This novel system was operated continuously for two months using typical household waste composition. Controlled experimental tests were conducted weekly to measure the nutrient content of the effluent at four locations and to analyze the composition of biogas. Gas chromatography was used to analyze biogas composition, while test strips and In-Situ Aqua Troll Multi-Parameter Water Quality Sonde were employed for water quality measurements during the experimental study. Experimental results showed that the system consistently produced biogas with 76.7% (±5.2%) methane, while effluent analysis confirmed its potential as a nutrient source with average concentrations of phosphate (20 mg/L), nitrate (26 mg/L), and nitrite (5 mg/L). These nutrient values indicate suitability for hydroponic crop growth and reduced reliance on synthetic fertilizers. This novel system represents a significant step toward integrating waste management, energy production, and food cultivation at the source, in this case, the household. Full article

This article examines the growing potential of low-emission hydrogen as an innovative solution supporting the decarbonization of the agricultural sector. It discusses its potential applications on farms, including as an energy source for powering agricultural machinery, producing fertilizers, and storing energy from renewable sources. Within the European context, it considers actions arising from the European Green Deal and the “Fit for 55” strategy, which promote the development of hydrogen infrastructure and support research into low-emission technologies. The article also discusses global initiatives and trends in the development of the hydrogen economy, pointing to international cooperation, investment, and the need for technology standardization. It highlights the challenges related to cost, infrastructure, and scalability, as well as the opportunities hydrogen offers for a sustainable and energy-efficient agriculture of the future. Full article

The dairy sector produces considerable amounts of nutrient-rich effluents, which are frequently undervalued as simple by-products or waste. In particular, Second Cheese Whey (SCW), also known as scotta, exhausted whey, or deproteinized whey, represents the liquid fraction from ricotta cheese production. Despite its abundance and high organic and saline content, SCW is often improperly discharged into terrestrial and aquatic ecosystems, causing both environmental impact and resource waste. The available purification methods are expensive for dairy companies, and, at best, SCW is reused as feed or fertilizer. In recent years, increasing awareness of sustainability and circular economy principles has increased interest in the valorization of SCW. Biological treatment of SCW using microalgae represents an attractive strategy, as it simultaneously reduces the organic load and converts waste into algal biomass. This biomass can be further valorized as a source of proteins, pigments, and bioactive compounds with industrial relevance, supporting applications in food, nutraceuticals, biofuels, and cosmetics. This review, starting from analyzing the characteristics, production volumes, and environmental issues associated with SCW, focused on the potential of microalgae application for their valorization. In addition, the broader regulatory and sustainability aspects related to biomass utilization and treated SCW are considered, highlighting both the promises and limitations of microalgae-based strategies by integrating technological prospects with policy considerations. Full article

Soybean inoculation with nitrogen (N) fixing bacteria can be highly promising for enhancing biological nitrogen fixation (BNF) and improving crop productivity. It helps to reduce dependency on chemical fertilizers, promotes sustainable agricultural practices, and minimizes environmental impacts. Therefore, understanding the specific aspects and conditions is essential for establishing the BNF process in particular environments. In this study, we investigated whether soybean inoculation is an effective strategy in cool-climate regions beyond their typical northern distribution, and which soybean varieties and microbial strains are the most effective for optimizing soybean productivity and performance in relatively cool environments. To address these questions, a natural abundance nitrogen stable isotope ratio analysis was conducted on two soybean varieties of different maturity groups, which were inoculated with three Bradyrhizobium japonicum strains, along with organic fertilizer and new promising endophyte treatments. This approach aimed to determine the differences in biological and chemical parameters of soybean, as well as the origin of N sources, its uptake, and the isotopic distribution within the plants. It was demonstrated that inoculation with Bradyrhizobium japonicum was more effective than fertilization, as the strains had a significant effect on nitrogen derived from the atmosphere (Ndfa), produced stable nitrogen isotope ratios close to 0‰, and substantially increased nitrogen content, particularly in beans. Soybean varieties Laulema and Merlin, representing different maturity groups, exhibited distinct nitrogen uptake patterns. Bradyrhizobium japonicum strain AGF78 consistently produced the greatest effect on biological parameters in both varieties, particularly in seed yield and grain weight, with the later-maturing Merlin achieving the highest average yield of 3066.89 kg ha⁻¹. Notably, the Merlin inoculated with AGF78 resulted in the highest nitrogen fixation in beans, with 66.8%NDFA and 134.0 kg/ha of fixed nitrogen. Similarly, Laulema inoculated with AGF78 resulted in 88.2%NDFA and 123.2 kg/ha of fixed nitrogen. Inoculation with selected bacterial strains significantly increased protein content from 30% to 41%, with the effects being both strain- and variety-specific. Our study showed that establishing effective soybean–microbe interactions by choosing soybean variety and microbial strain is crucial for optimizing agricultural practices and improving crop performance, especially in sustainable and environmentally conscious farming systems under cool climatic conditions of Europe. Full article

This study evaluated the effects of applying a biofertilizer, alone and in combination with nanoparticles (NPs), under controlled greenhouse conditions to improve soil quality and wheat performance (soil from the region of General Cepeda, Coahuila, Mexico, was used). The integration of the biofertilizer with Fe_xO_x NPs proved particularly effective in enhancing soil physical and biological parameters as well as promoting superior crop growth compared with individual treatments. The incorporation of NPs markedly improved the biofertilizer’s biocompatibility and stability, reinforcing its potential for optimizing plant nutrition, nutrient use efficiency, and overall agricultural sustainability. In addition, the combined treatments enhanced the utilization of native microbial diversity, thereby contributing to increased soil fertility and the quality and yield of crops in the study region. The best yield obtained in previous harvests (8.3 Mg ha⁻¹) was improved to 8.48 Mg ha⁻¹ with application of the biofertilizer with Fe_xO_x NPs. Moreover, shoot length increased significantly with the combination of the biofertilizer and ZnO NPs as well as with Fe_xO_x NPs separately, whereas root length was maximized with the addition of the biofertilizer alone. These findings underscore the synergistic effects of combining biofertilizers with metal-based nanoparticles to sustainably enhance wheat growth and productivity. Full article

Plant growth-promoting bacteria (PGPBs) offer a sustainable alternative for enhancing crop productivity in low-fertility tropical soils. In this study, 30 bacterial isolates were screened in vitro for multiple PGP traits, including phosphate solubilization (from aluminum phosphate—AlPO₄ and thermophosphate), potassium release from phonolite rock, siderophore production, indole-3-acetic acid (IAA) synthesis, ACC deaminase activity, and antagonism against Fusarium spp. Statistical analysis revealed significant differences (p < 0.05) among the isolates. The most efficient isolates demonstrated a solubilization capacity ranging from 24.0 to 45.2 mg L⁻¹ for thermophosphate and 21.7 to 23.5 mg L⁻¹ for potassium from phonolite. Among them, Pseudomonas azotoformans K22 showed the highest AlPO₄ solubilization (16.6 mg L⁻¹). IAA production among the isolates varied widely, from 1.34 to 9.65 µg mL⁻¹. Furthermore, 17 isolates produced carboxylate-type siderophores, and only Pseudomonas aeruginosa SS183 exhibited ACC deaminase activity, coupled with strong antifungal activity (91% inhibition). A composite performance index identified P. azotoformans K22, E. hormaechei SS150, S. sciuri SS120, and B. cereus SS18 and SS17 as the most promising isolates. This study provides a valuable foundation for characterizing plant growth-promoting traits and identifies key candidates for future validation and the development of microbial consortia. Full article

The excessive use of irrigation water and fertilizers in agriculture raises serious environmental concerns, emphasizing the need for more sustainable practices. Screening genotypes with reduced nutrient and water requirements, combined with favorable responses to plant growth-promoting rhizobacteria (PGPR), offers a promising strategy for developing more sustainable farming systems. Seven sweet pepper genotypes (Capsicum annuum L.) were evaluated under six treatments, involving two fertilization levels (100% and 50% standard dose), two irrigation regimes (100% and 75% full irrigation), and PGPR inoculation applied under reduced fertilization. Yield, fruit weight, rhizosphere enzymatic activities, and soluble sugars in green and red fruits were evaluated. The genotype effect contributed significantly to all traits. Combined reductions in fertilizer and irrigation decreased average yield by 21.7%, while PGPR did not fully compensate for these losses. Alkaline phosphomonoesterase activity increased by 22.9% under low fertilization, whereas averaged catalase and dehydrogenase remained relatively stable regardless of PGPR. In green fruits, PGPR inoculation under combined stress conditions increased glucose and fructose concentrations by 11.6% and 13.9%, respectively, compared to uninoculated stressed plants, although sucrose decreased. At fully ripe stage, sugar composition was less responsive to treatments. These findings underscore the importance of genotype evaluation and the exploitation of genotype × treatment interactions in peppers breeding for sustainable farming. Full article

Organic manure and grass mulching are widely recognized as modifiers of soil microbial communities and nutrient dynamics; however, the combined effects of these practices on nitrogen fractionation and microbial functionality in orchard ecosystems remain poorly understood. This study conducted a comprehensive evaluation of soil nitrogen fractions, enzymatic activity, microbial diversity and functional traits in walnut orchards under three management practices: organic manure (OM), grass mulching combined with manure (GM), and chemical fertilization (CF) in China’s Loess Plateau. The results revealed that OM and GM significantly enhanced soil nutrient pools, with GM elevating total nitrogen by 1.96-fold, soil organic carbon by 97.79%, ammonium nitrogen by 128%, and nitrate nitrogen by 54.56% relative to CF. Furthermore, the OM significantly increased the contents of total hydrolysable nitrogen, amino sugar nitrogen, amino acid nitrogen, ammonia nitrogen, hydrolysable unidentified nitrogen, non-acid-hydrolyzable nitrogen compared to the CF and GM treatments. Meanwhile, ASN and AN had significant effects on mineral and total nitrogen. The OM and GM had higher activities of leucine aminopeptidase enzymes (LAP), α-glucosidase enzyme, β-glucosidase enzyme (βG), and N-acetyl-β-D-glucosidase enzyme (NAG). Microbial community analysis revealed distinct responses to different treatments: OM and GM enhanced bacterial Shannon index, while suppressing fungal diversity, promoting the relative abundance of copiotrophic bacterial phyla such as Proteobacteria and Chloroflexi. Moreover, GM favored the enrichment of lignocellulose-degrading Ascomycota fungi. Functional annotation indicated that Chemoheterotrophy (43.54%) and Aerobic chemoheterotrophy (42.09%) were the dominant bacterial metabolic pathways. The OM significantly enhanced the abundance of fermentation-related genes. Additionally, fungal communities under the OM and GM showed an increased relative abundance of saprotrophic taxa, and a decrease in the relative abundances of potential animal and plant pathogenic taxa. The Random forest model further confirmed that βG, LAP, and NAG, as well as Basidiomycota, Mortierellomycota, and Ascomycota served as pivotal mediators of soil organic nitrogen fraction. Our findings demonstrated that combined organic amendments and grass mulching can enhance soil N retention capacity, microbial functional redundancy, and ecosystem stability in semi-arid orchards. These insights support the implementation of integrated organic management as a sustainable approach to enhance nutrient cycling and minimize environmental trade-offs in perennial fruit production systems. Full article

Iodine deficiency remains a significant nutritional problem, which stimulates the search for sustainable approaches to biofortification of vegetable crops. The aim of the work was to develop a “smart” bio-iodine fertilizer based on the organoiodide complex 1-carboxy-2-phenylethan-1-aminium iodide 2-azaniumyl-3-phenylpropanoate (PPI) and highly porous biochar from agro-waste, assessing its efficiency on the parsley model. PPI was synthesized and characterized (IR/UV spectroscopy, thermal analysis), and biochar was obtained by KOH activation and studied by low-temperature nitrogen adsorption (S_BET) methods, as well as standard physico-chemical characterization. The granulated composition PPI + biochar (BIOF) was tested in pot experiments in comparison with KI and control. The biomass of leaves and roots, iodine and organic nitrogen content, and antioxidant indices (ascorbic acid, total polyphenols, antioxidant activity) were assessed. BIOF provided a significant increase in yield and nutrition: leaf mass reached 86.55 g/plant versus 77.72 g/plant with KI and 65.04 g/plant in the control; root mass—up to 8.25 g/plant (p < 0.05). Iodine content in leaves and roots increased to 11.86 and 13.23 mg/kg (d.w.), respectively, while organic nitrogen levels increased simultaneously (57.37 and 36.63 mg/kg). A significant increase in the antioxidant status was noted (ascorbic acid 36.46 mg/100 g dry weight; antioxidant activity 44.48 mg GA/g; polyphenols 23.79 mg GA/g). The presented data show that the combination of PPI with activated biochar forms an effective platform for controlled supply of iodine to plants, increasing the yield and functional qualities of products; the prospects for implementation are associated with field trials and dosage optimization. Full article