Chemical and Biological Technologies in Agriculture最新文献

Liquid manure storage contributes substantially to environmental emissions within manure management systems. This study evaluated Yucca schidigera extract (YE) as a sustainable microbial modulator for mitigating ammonia (NH₃) and greenhouse gas emissions during 60-day storage of liquid chicken manure. Three treatments were established: no additive (control, CK), 0.1% biological deodorant (positive control, BF), and 0.5% YE. The results demonstrated that both YE and BF significantly reduced electrical conductivity (EC) (YE: 38.35%; BF: 34.51%) and ammonium nitrogen (NH₄⁺-N) content (YE: 14.15%; BF: 20.21%) relative to CK, while elevating the C/N ratio by 9.97% (YE) and 18.63% (BF). Total nitrogen decreased by 23.88% (YE) and 26.34% (BF) from initial levels. In addition, the cumulative NH₃ emissions of YE and BF decreased significantly by 20.18% and 20.12% compared to CK. However, YE increased CH₄ emissions by 17.43%, elevating global warming potential, whereas BF exhibited no significant effect on CH₄. Neither additive influenced CO₂ or N₂O emissions. Microbial analysis revealed YE enriched Firmicutes (e.g., Fermentimonas), while BF enhanced Actinobacteriota (e.g., Corynebacterium) and Proteobacteria. Both additives suppressed ammonia-producing bacteria (e.g., Proteiniphilum). Mantel tests analysis indicated NH₃ emissions correlated positively with EC and NH₄⁺-N (P < 0.01), while CH₄ emissions correlated with organic matter (OM) content (P < 0.05). These findings elucidate the microbial mechanisms of YE in mitigating the NH₃ emission during liquid manure storage, whereas YE may induce trade-offs in CH₄ emission. In the future, the formulation of compound plant-derived additives will be necessary for the synergetic abatement of carbon and nitrogen gases.

Graphical Abstract

Background

Soil acidification seriously threatens sustainable agriculture by promoting phytotoxic exchangeable aluminum ions (Al³⁺) accumulation and impairing crop growth. However, conventional soil amendments, such as lime and biochar, have known limitations, making the introduction of more sustainable soil amendments crucial for mitigating soil acidification. Furthermore, the biological and chemical mechanisms by which amendments alleviate acidification and enhance soil fertility remain unclear. This impedes the search for more cost-effective soil amendments to rehabilitate infertile acidic soils.

Methods

In this study, pot experiments, microbial sequencing, and molecular modeling calculations were employed to assess the response of soil fertility and maize yield to the combined application of sodium carboxymethylcellulose (CMC) and desulfurized phosphogypsum (DP) in strongly acidic soils, as well as the underlying biological and molecular dynamic mechanisms.

Results

The results indicated that CMC + DP significantly reduced soil exchangeable Al³⁺ by 78.68–79.60%, while enhancing the base ion concentration by 59.93–102.27% and acid buffering capacity by 46.47–49.55% compared to the control (CK) in strongly acidic soils. Additionally, CMC + DP-amended soil exhibited a 24.47–48.65% increase in photosynthetic rate and a 50.57–155.48% increase in the weight of 100 grains. CMC contributed to Al³⁺ immobilization and base ion release via competitive electrostatic attraction and complexation of Al³⁺ on the surface of –COOH and –OH functional groups. CMC + DP application promoted direct enrichment of microbial communities, increasing the abundance of functional microbial taxa, including Acidobacteriota, Gemmatimonadota, and Ascomycota, and soil enzymes related to organic matter decomposition and phosphorus metabolism.

Conclusions

These findings suggest that CMC + DP could be used as a promising strategy to mitigate soil acidification, enhance soil fertility and crop yield, and highlight the synergistic potential of biodegradable polymers and industrial by-products for acidic soil remediation. They enhance our understanding of the synergistic biological and molecular dynamic mechanisms of amendments, mitigating soil acidification and enhancing soil fertility. These findings may help identify more effective soil amendments and application strategies to ensure cropland health and promote sustainable agriculture.

Graphical Abstract

Background

During storage, fruits and vegetables are susceptible to the pathogens responsible for postharvest decay. Various tools are available to manage these issues, but not all are environmentally sustainable. Low-temperature plasma (LTP) has garnered significant attention among the most promising and eco-friendly solutions. LTP can be applied directly or indirectly, offering versatile applications. One notable indirect application is the utilization of plasma-activated water (PAW). In this study, we investigated the efficacy of an aerosol made by droplets of water nebulized by the effluent gases of a plasma discharge as a delivery method of PAW to substrates. We named this novel application, reported for the first time, plasma-activated fog (PAF). In this work, it was tested as a new alternative technology for fruit decontamination against postharvest fungal pathogens and pesticide residues.

Results

PAF was generated via volume dielectric barrier discharge (VDBD) in a jet-like configuration and was applied to evaluate the in vitro effects on the conidial germination of major fungal postharvest pathogens, such as Alternaria alternata, Aspergillus carbonarius, Botrytis cinerea, Cladosporium sp., Monilinia fructicola, Penicillium italicum, Penicillium expansum and Rhizopus sp. Differences in fungal sensitivity to PAF were recorded, with A. alternata showing the lowest sensitivity to treatments. For most species, complete spore inhibition was obtained after 3–5 min of exposure. The efficacy of PAF against fungal rot was assessed on table grapes and strawberries, revealing a reduction in the percentage of rotted fruits exposed to 10 min of treatment, ranging from 45 to 80% on table grapes and from 52 to 74% on strawberries. PAF treatments also reduced pesticide residues on grape bunches and strawberry fruits, with various results depending on the active ingredient, with reductions of up to 96% for abamectin among insecticides and acaricides, and up to 38% for the fungicide fenhexamid.

Conclusions

The results obtained in the present work have the potential to refine and optimize PAF treatment conditions for the antimicrobial decontamination of plant products.

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Industrial hemp (Cannabis sativa L. subsp. sativa) is a multipurpose crop widely cultivated for its fibers, seeds, and oils. Despite the common use of hemp stems for fiber production in textiles and construction, they are frequently discarded as agricultural waste. This study aimed to enhance the utilization of hemp stems through the optimization of ultrasound-assisted extraction (UAE) employing aqueous propylene glycol solvent system as the extraction solvent, guided by Box–Behnken design (BBD). The optimal extraction parameters—an extraction duration of 30 min, a solvent–solute ratio of 28.25 mL/g, and a PG concentration of 32.72%—resulted in a hemp stem extract (HUPG) enriched with bioactive constituents exhibiting significant antioxidant activity. Following analysis by LC–QTOF–MS/MS, a total of 18 phytochemicals were detected, including isofeuric acid, m-coumaric acid, and chelidonic acid. HUPG exhibited antibacterial activity against Staphylococcus aureus, Streptococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa, and anti-inflammatory effects through 5-lipoxygenase inhibition and NO radical scavenging (1.41 ± 0.38 mg GAE/g). In LPS-induced RAW 264.7 macrophages, HUPG demonstrated inhibitory effect on NO production. Moreover, it enhanced wound closure in HaCaT cells (51.92 ± 6.05% at 10 mg/mL). These findings highlight the promise of HUPG as a sustainable source of bioactive compounds with potential applications in cosmetic and pharmaceutical formulations.

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Background

The rational utilization of agricultural straw is crucial for improving soil fertility and reducing greenhouse gas emissions (GHGs). The purpose of this study was to investigate how rice (RB) and maize (MB) straw-derived biochar, produced at varying pyrolysis temperatures and application rates, regulated straw decomposition and GHGs by reshaping soil microbial communities and physicochemical properties.

Results

Through 90-day incubation experiments, it was found that biochar produced using low temperature (300 °C) at 2.5–5.0% application rates significantly accelerated straw decomposition by 14.94–36.04% and reduced CH₄ and N₂O emissions by up to 37.84–90.26% and 41.60–91.10%, respectively. Application of biochar produced using low-temperature method enhanced the soil organic matter (9.92–29.26%), pH (1.82–11.32%), and soil enzyme activities (cellulase: 7.84–22.90%, β-glucosidase: 49.92–75.32%), while altering microbial communities, especially increasing copiotrophic bacteria (e.g., Proteobacteria, Ascomycota) in rice grown soils linked to rapid decomposition and reducing Ascomycota dominance in maize soil with altering nutrient dynamics due to higher C/N ratios. Path analysis indicated strong biochar–enzyme–decomposition linkages (normalized coefficient: 0.92), emphasizing microbial community structure as a pivotal mediator. In contrast, biochar produced through high pyrolysis temperatures (mentioning the temperature) diminished effectiveness due to higher structural stability and potential limitations in microbial activity.

Conclusions

Our results indicate that application rates of 2.5–5.0% biochar produced through low temperature can effectively balance straw decomposition and GHGs reduction, offering a sustainable approach for straw management in rice and maize cultivation. These findings provide scientific support for optimizing biochar use in agriculture, contributing to improved soil health and climate change mitigation.

Graphical Abstract

Plant growth is intricately regulated by soil ecosystems, where dynamic interactions between plants and soil metabolites shape root development. As critical mediators of these interactions, soil metabolites not only reflect biogeochemical cycling but also directly modulate root morphogenesis by eliciting stimulatory or inhibitory responses. To decode the mechanisms driving peanut (Arachis hypogaea L.) root system development, utilizing UPLC-HRMS we profiled 702 soil specific metabolites across soil samples collected from five different regions. Further 118 differentially expressed metabolites were identified in collected soil samples, and 10 metabolites were selected to validate their function associated with peanut root length phenotype. Through systematic screening, four root promoting metabolites (nicotinamide, carbendazim, vanillic acid, and raffinose) and four phytotoxic compounds (phthalic acid, myristic acid, formononetin, and syringic acid) were identified. Our results showed that the seedlings treated with nicotinamide, carbendazim, vanillic acid, and raffinose promotes root elongation by up to 28.3% as compared to untreated seeds. Whereas, seedlings treated with phthalic acid, myristic acid, formononetin, and syringic acid, suppressed root growth by 56.6%, demonstrating a bimodal inhibition pattern. Dose response assays revealed hierarchical efficacy among these metabolites, with carbendazim and formononetin representing the most potent enhancer and suppressor, respectively. Current findings reveal a causal link between soil metabolite composition and peanut root development, providing a biochemical basis for harnessing soil specific metabolites in precision agriculture.

Graphical Abstract

Cordyceps sinensis is widely utilized in China as an edible and medicinal fungus for the treatment of immunodeficiency-related disorders. Evidence suggests that polysaccharides are the principal bioactive components responsible for its immunostimulatory effects. However, the physicochemical properties, bioactivities, and structure–function relationships of these polysaccharides remain inadequately elucidated. In this study, four distinct crude polysaccharides from wild Cordyceps sinensis (WCP) were isolated using stepwise ethanol precipitation at final concentrations of 20%, 40%, 60%, and 80% (v/v). These fractions were designated as WCP-20, WCP-40, WCP-60, and WCP-80, respectively. Results demonstrated that the molecular weight (MW) of WCP decreased as the ethanol concentration increased. High-MW fractions (WCP-20/-40) exhibited high glucose content, a partially triple-helical structure, levorotation (−), and greater thermal stability. In contrast, the low-MW fractions (WCP-60/-80) were enriched in galactose and mannose, exhibited a higher branching density, and dextrorotation ( +). Furthermore, this study revealed that WCPs activated macrophages by enhancing phagocytosis and stimulating the secretion of nitric oxide and interleukin-1 beta. These immunostimulatory effects were mediated through the MAPK/NF-κB signaling pathway. Specifically, WCP-20 triggered macrophage activation via the ERK/JNK/p65 pathway, with P38/ERK/JNK pathway for WCP-40, P38/ERK/JNK/p65 pathway for WCP-60, and JNK/p65 pathway for WCP-80. Correlation analysis revealed that the immunostimulatory effects of WCPs were closely linked to their monosaccharide composition and secondary structures. These findings established that the physicochemical properties of WCP were critical determinants of precise immune modulation. This study provided a foundational reference for developing precision polysaccharide-based immune-enhancing nutraceuticals.

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Background

Mineral-dissolving rhizobacteria are considered ecological friendly rhizonutrifying agents capable of promoting rhizospheric enzymatic activities, microbial biomass, and nutrient availability even under nutrient-deficient alkaline soil conditions. However, comprehensive studies on their effectiveness in calcareous soil are lacking. The current study hypothesized that beneficial rhizobacteria improve soil biochemical properties in calcareous soil through their impact on enzymatic activities, microbial biomass, and nutrient availability in the rhizosphere.

Methods

Rhizobacterial strains were isolated from wheat rhizosphere and characterized in vitro for their mineral solubilization potential, production of beneficial metabolites, and various enzymatic activities. A pot experiment was conducted to investigate the effect of sole and co-inoculation treatments on wheat growth, grain attributes, nutrient availability in soil and absorption in plants, soil enzymatic activities, and microbial biomass accumulation in wheat rhizosphere under calcareous soil conditions.

Results

The most effective mineral-dissolving rhizobacteria were identified as Bacillus altitudinis (strains SAM1, SAM7, SAM13, and SAM15) and Bacillus cereus (strain SAM9) through 16S rRNA partial gene sequencing. These strains demonstrated the dissolution of insoluble tricalcium phosphate, mica, zinc oxide, and manganese oxide, and promoted nutrient availability in the soil by producing organic acids. Inoculation enhanced wheat growth and grain development by promoting nutrient acquisition and stimulating rhizospheric microbial activity. Both sole and co-inoculation with rhizobacterial strains significantly increased soil enzymatic activities, microbial biomass carbon, nitrogen, and phosphorus, and nutrient availability in the wheat rhizosphere through organic matter decomposition. Among treatments, sole inoculation with B. cereus SAM9 and co-inoculation with B. cereus SAM9 + B. altitudinis SAM13 demonstrated the most dominant increase in wheat growth and grain attributes, nutrient availability in soil and absorption in plants, deposition of microbial biomass, and soil enzymatic activities.

Conclusions

The sole inoculation with B. cereus SAM9 and co-inoculation with B. cereus SAM9 + B. altitudinis SAM13 showed strong potential as bioinoculants for calcareous soils. These strains could be effectively integrated into commercial biofertilizer formulation as sustainable alternatives or supplements to chemical fertilizers, enhancing soil productivity and crop performance.

Graphical Abstract

Background

Soybean–maize rotation is an effective strategy for addressing the challenges associated with continuous soybean cropping. However, the effects of maize frequency in cropping sequences on soil fungal functions and their associations with soybean yields remain unclear. Through a 12-year field study comparing continuous soybean (CS), maize–soybean (MS), and maize–maize–soybean (MMS) systems, fungal community functions, system-specific taxa, and bacterial–fungal inter-kingdom co-occurrence patterns were analyzed.

Results

In contrast to conventional assumptions, CS enriched symbiotic fungi and suppressed pathogens, suggesting adaptive disease resilience. Integrating maize into soybean cropping systems increased the complexity of bacterial–fungal cross-kingdom co-occurrence networks. While the MS system increased the relative abundances of plant pathogens and saprotrophs, the MMS system stabilized fungal functions and inhibited plant pathogen accumulation. The system-specific taxa identified in the CS and MMS systems included potential plant growth-promoting microbes and were associated with the relative abundances of pathogens and saprotrophic fungi as well as soybean yield. This relationship may represent a critical link between fungal function and soybean production.

Conclusions

These findings indicate that integrating maize into soybean rotations, especially in the MMS system, can stabilize fungal functions and mitigate pathogen accumulation, ultimately increasing soybean yield. These results underscore the importance of tailored crop rotation practices to optimize soil microbial communities for sustainable agricultural production.

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