Search Results (1,244)

Data-driven approaches are increasingly required to optimize biofertilization strategies in forage systems. Machine learning (ML) provides an efficient tool for identifying functional drivers in complex plant–soil–microbe systems, offering important perspectives for precision data-driven agriculture. However, despite its potential, ML remains data-driven in studies involving diazotrophic inoculation using biochar as a pelletizing material, particularly in forage grasses. This study applied ML to predict the key drivers controlling Brachiaria brizantha performance and soil quality under biochar-pelletized diazotrophic bacteria (DB). Five isolates were inoculated with or without biochar, and plant traits and soil attributes, including pH, potassium, phosphorus, sodium, and urease activity were evaluated. These data were integrated into multivariate analyses and ML algorithms, including Linear Discriminant Analysis, Random Forest, and Support Vector Machine, to identify the functional drivers that best discriminate treatment performance and uncover mechanistic functional drivers. All isolates increased soil potassium content, with the highest values in the biochar amended treatments, and a 39% increase. Soil pH and urease activity were significantly modulated by isolate identity, while biomass allocation patterns differed among treatments. Overall, the results highlight that biochar pelletization can enhance the effectiveness of DB inoculants. ML revealed that dry foliar biomass, soil pH, and fresh root weight were the most predictive variables, highlighting consistent signatures explaining plant–soil responses to biochar-pelletized DB. These findings demonstrate that interpretable ML can disentangle complex plant–soil–microbe interactions, support precision biofertilization design, and serve as an efficient decision-support tool for sustainable pasture management. Beyond the present system, this study establishes a transferable and scalable analytical framework for precision biofertilization strategies in forage systems and other biochar-mediated agroecosystems, advancing predictive and data-driven approaches in sustainable agricultural engineering. Full article

Despite the essential role of soil microbial communities in driving nutrient cycling within alpine meadows, their distribution patterns along elevational gradients and their responses to environmental changes remain largely unexplored. To investigate this, soil samples were collected from five elevations (3300–4500 m) in the northeastern Qinghai–Tibet Plateau to analyze bacterial community composition and diversity, as well as their associations with soil physicochemical properties and enzyme activities. The results showed significant variation in bacterial community composition and diversity across elevations. Actinomycetota, Pseudomonadota, and Acidobacteriota were the dominant phyla at all sampling sites. Community diversity, measured by the Shannon index, generally increased with elevation, peaking at 4500 m and lowest at 3300 m. Pearson correlation analysis and redundancy analysis (RDA) indicated that soil bacterial community structure was significantly correlated with both soil nutrient factors and enzyme activities. Among these variables, total potassium, available phosphorus, catalase, and urease were strongly correlated with bacterial community differentiation. In addition, PERMANOVA results showed that elevation was the primary factor driving community variation, explaining a substantial proportion of the variation in community composition at a statistically significant level. Overall, this study highlights the distribution of bacterial communities in alpine meadow soils along an elevational gradient and their environmental associations, providing foundational data for understanding microbial community responses to environmental changes in alpine ecosystems. Full article

Soil nitrogen availability is a major constraint to crop productivity in rainfed arid and semi-arid regions. The influence of straw strip mulching on nitrogen availability and transformation across soil layers remains unclear. This study investigates the effect of straw strip mulching on soil nitrogen dynamics and crop-specific variation in wheat- and potato-cultivated soils under rainfed semi-arid conditions. This study consisted of five mulching treatments, including without mulching (Tck), black plastic film mulching (Tp), straw strip mulching (Tss), plant strip without mulch (Tps), and composite strip of straw strip mulching and plant strip without mulch (Tcs) applied in wheat and potato cultivation during 2019 and 2020, and soil nitrogen fractions were determined across different soil depths. Tss mulching showed the highest increase in urease activity (48%), nitrite reductase activity (48%), microbial biomass nitrogen (52%), NH₄ (11%), acid-hydrolyzed total nitrogen (10%), acid-soluble NH₄ (6%), acid-hydrolyzed amino sugar (16%) and acid-hydrolyzable unknown nitrogen (59%) relative to Tck without mulching. While total nitrogen (11%) and acid-hydrolyzed amino acid (9%) were highest in the Tps treatment compared to Tck treatment, the mulching treatment had no significant effect on soil organic nitrogen-derived functional traits. Across all treatments, the 0–20 cm soil layer consistently showed the highest concentrations of observed soil traits, which declined with increasing soil depth. Furthermore, potato-cultivated soils showed consistently higher concentrations of these traits than wheat-cultivated soils, and the concentrations of these traits in 2020 exceeded those observed in 2019. This study highlights that maize straw mulching in strips significantly promotes soil organic nitrogen fractions, particularly in the upper soil layers, and promotes higher nitrogen availability in potato than in wheat-cultivated soils, and is recommended as an effective soil management practice to improve soil nitrogen availability in rainfed semi-arid Loess Plateau conditions. Full article

Against the backdrop of increasingly scarce global arable land resources, the remediation and resource utilization of saline–alkali soils have become a critical issue in circular agriculture. This study proposes micro-nano bubble (MNB) irrigation technology as a green, low-carbon strategy for saline–alkali soil remediation, highlighting its multi-level driving mechanism through pot experiments at different aeration frequencies. Results indicated that MNB irrigation significantly enhanced salt leaching and acid-base neutralization by reducing the soil pH (11.75%) and electrical conductivity (53.41%). Meanwhile, soil organic matter, cation exchange capacity, and available nitrogen, phosphorus, and potassium increased to normal soil levels. MNBs also strongly activated native enzymes (urease and alkaline phosphatase), raising the total enzyme activity by 68.54%, which is linked to carbon, nitrogen, and phosphorus metabolism. These results were also validated by microbial analysis, which indicated that MNBs shifted the community structure from one dominated by salt-tolerant taxa (i.e., Pseudomonadota) to a more functionally beneficial composition (i.e., Bacillota). Through these changes, the microbial diversity and network connectivity were enhanced, with Qipengyuania and Psychrophilus identified as critical nodes. This study reveals the multi-level driving mechanism of MNB technology, providing new technical pathways and theoretical support for the remediation, resource recovery, and circular utilization of agricultural waste soils. Full article

As a response to aging of cultured urease-producing microorganisms, the blending method was examined to obtain the required carbonate production amount using the apparent viability (Rcv) based on previous research. As a result, a significantly higher carbonate content than the amount of CaCl₂ 2H₂O used was produced. Since this trend has been obtained in previous studies, it was judged that carbonate hydrate was formed. As a next step, a penetration test of soil–biocement–liquid (BCS) was conducted to investigate the properties and behavior of the BCS system, taking into account the microscopic properties of the BCS response. The depth distribution of carbonate content (C) was measured by the acid dissolution method of soil sampled from the specimen. It was assumed that the C-profile was formed by adsorption based on the diffuse double layer of microorganisms. It was shown that the amount of precursor-carbonate (precursor CPR), the optical density (OD) of viable bacteria, and the physical amount of soil adsorbed at that position can be estimated from C obtained at the various depths. In addition, the previously obtained formulas among CPR, viable OD, and Rcv shown are briefly explained in this paper. Full article

Background and Clinical Significance: Foreign body ingestion represents an endoscopic emergency, with a risk of organ perforation of up to 35%, where increased prevalence was noticed among people with mental disorders and institutionalized patients. Case Presentation: The patient—male, 23 years old, and institutionalized for sequelae of infantile encephalopathy—was admitted for epigastric pain and hyperemetic syndrome that began 10 days earlier. Endoscopically, 12 hard plastic foreign bodies with sharp edges and sizes of 6–7 cm were identified, followed by extraction that was successfully performed in two sessions using a polypectomy snare and a Foreign Body Hood Protector. Additionally, multiple sessile exulcerated polypoid lesions were observed, measuring around 1–3 cm each, occupying the entire antrum. Histological examination showed inflammatory/regenerative elements, with features of moderate-to-high-grade dysplasia, while a rapid urease test for Helicobacter pylori infection was positive. As a consequence, the patient was administered triple eradication therapy. In addition, the patient presented marked features of hypereosinophilia and splenomegaly. Upon endoscopic reevaluation after 3 years and 8 months, no polyps were present and the H. pylori test was negative, while a complete and spectacular remission of both the hypereosinophilia and splenomegaly was observed. Conclusions: This case illustrates that the development and progression of gastric polyposis may be caused by the coexistence of chronic mucosal irritation from foreign bodies and H. pylori infection, which is a rare association. H. pylori eradication and endoscopic removal of the foreign bodies resulted in significant mucosal improvement. Full article

This study investigated the effects of different application rates of spent mushroom substrate (SMS) from Morchella sextelata on soil properties and microbial communities in a moso bamboo (Phyllostachys edulis) plantation. Three SMS rates (2.4, 4.7, and 9.4 kg·m⁻²) were applied, and soil samples were collected at 6 and 12 months from two depths (0–20 cm and 20–40 cm). One year after application, topsoil total phosphorus (TP) increased 12–20 fold, while available phosphorus (AP) and potassium (AK) were significantly elevated. Soil pH initially decreased but partially recovered, whereas electrical conductivity (EC) continued to rise, indicating salt accumulation. Urease (UA) and sucrase (SA) activities increased 10–17 fold and 3–5 fold, respectively, while catalase (CAT) and acid phosphatase (ACP) were temporarily suppressed. SMS application significantly altered microbial community composition, with Acidobacteriota and Basidiomycota becoming more abundant. Correlation analysis identified pH, organic matter, AP, and UA as key factors linked to microbial changes. The medium application rate (4.7 kg·m⁻²) provided the best balance between soil improvement and environmental risk. These findings demonstrate that M. sextelata SMS can effectively enhance soil fertility while modulating microbial communities, but salt accumulation and short-term acidification warrant attention. Full article

Background/Objectives: This study provides the first comprehensive evaluation of the antioxidant, antimicrobial, and enzyme inhibitory activities of Onosma alboroseum subsp. alboroseum var. alboroseum, including a novel nanoformulation-based comparative assessment of its most active extract. The study further aimed to investigate whether nanoparticles modulate the biological performance of the extract. Methods: Antioxidant activity was assessed using DPPH, FRAP, and CUPRAC assays, and total phenolic content was determined by the Folin–Ciocalteu method. Antimicrobial activity was evaluated using agar well diffusion and microdilution assays, while enzyme inhibitory activities were assessed through anticholinesterase and anti-urease assays. The most biologically active extract was subjected to LC–QTOF–MS-based tentative metabolite profiling and subsequently formulated into nanoparticles for comparative biological evaluation. Results: Among the extracts studied, the methanol extract had the highest total phenolic content and demonstrated superior antioxidant, antimicrobial, and enzyme inhibitor activities. LC–QTOF–MS profiling indicated a phenolic-rich composition, with rosmarinic acid as the predominant compound based on relative peak area. The methanol extract was encapsulated within alginate nanoparticles for subsequent comparative biological assessment. While the crude extract showed superior activity in antioxidant assays, nanoparticles enhanced cholinesterase and urease inhibition (28.03% and 12.11%, respectively) and improved antibacterial efficacy in microdilution assays (MIC range: 3.13–12.5 µg/mL), although no inhibition was observed in agar diffusion tests. Conclusions: These findings indicate the first time that the methanol extract of Onosma alboroseum subsp. alboroseum var. alboroseum represents a phenolic-rich source of bioactive constituents and a nanoparticle formulation that can modulate specific biological activities depending on the assay system, highlighting the relevance of formulation strategy in phytochemical-based pharmaceutical applications. Full article

Long-term excessive chemical fertilization threatens the sustainability of wheat–maize rotation systems in the North China Plain. Organic substitution is a promising alternative to sustain crop productivity and soil health, yet its underlying mechanisms require clarification. This study investigated the effects of six fertilization treatments (unfertilized [CK], chemical nitrogen [N] alone at 180 kg N ha⁻¹ season⁻¹ [NPK], chemical N 25% substituted by chicken manure per season [NPKM], full manure substitution per season [CM], chemical N 25% substituted by straw return under no tillage per season [NT] and chemical N 25% substituted by straw return under rotary tillage per season [ST]) on soil fertility and crop productivity in a long-term wheat–maize rotation field experiment initiated in 2007. All treatments followed a randomized complete block design with three replicates per treatment. Wheat and maize plants were randomly collected from each plot at the harvest stage of each season, and weighed and measured for yield and N uptake, while soil samples were randomly collected from each plot at maize harvest stage for chemical and enzyme activity analyses. Compared to NPK, organic substitution maintained grain yields while significantly enhancing key soil fertility indicators: soil organic carbon (C) (up to 53.8%), and labile C and N pools including readily oxidizable C (by 120.0%), ammonium N (by 23%) and microbial biomass C (up to 164.5%). It also strongly stimulated the activities of C-acquiring (e.g., β-glucosidase and cellobiohydrolase) and N-cycling (e.g., β-N-acetylglucosaminidase and urease) enzymes by up to 278.7% and 256.3%, respectively. Multivariate analyses identified these enzymes as primary drivers of soil C and N dynamics, with direct positive links to crop yield. In conclusion, long-term organic substitution, particularly full manure substitution, improved yield stability and soil fertility predominantly through an enzymatic-driven stimulation of nutrient cycling and organic matter accumulation, offering a viable strategy to reduce chemical fertilizer inputs and enhance crop production sustainability. Full article

Fruit quality and yield of citrus orchards are co-regulated by complex interactions among soil properties, microbial communities, and plant physiological processes. However, systematic studies that integrate the soil–microbe–plant–fruit continuum remain limited. This study selected four representative ponkan orchards based on yield and fruit quality performance, and systematically determined and correlated key indicators in the soil–plant–fruit continuum. The results showed that the orchards with higher comprehensive performance exhibited more suitable soil pH, higher contents of soil organic matter and available nutrients, as well as higher activities of soil enzymes including urease and acid phosphatase. Compared with the orchards with lower comprehensive performance, soil bacterial and fungal Chao1, Shannon, and Simpson indices were higher in the orchards with higher comprehensive performance. Among the dominant phyla, the relative abundance of Proteobacteria was significantly higher, while that of Actinobacteria was significantly lower. Leaf photosynthetic indexes (chlorophyll content, net photosynthetic rate, Rubisco activity) of the higher-performing orchards were also significantly higher. Correlation analysis showed that soil microbial diversity and Proteobacteria were significantly positively correlated with soil nutrients, enzyme activities, leaf photosynthesis, fruit quality and yield, while Actinobacteria showed the opposite trend. These results provide a theoretical basis for soil management and high-quality cultivation of ponkan orchards. Full article

Potato (Solanum tuberosum L.), the world’s fourth most significant food crop, faces a critical sustainability challenge: meeting escalating global demand while mitigating the substantial environmental footprint of its production. Potato exhibits high nitrogen requirements, which makes conventional fertilization significantly inefficient, with nitrogen use efficiency (NUE) being below 40%, contributing to severe environmental losses, including nitrate leaching and nitrous oxide emissions. In this comprehensive review, global research is examined regarding enhanced-efficiency nitrogen fertilizers, such as nitrification inhibitors (NIs), urease inhibitors (UIs), and slow-released fertilizers, which promote a pivotal strategy for sustainable potato cultivation. An extensive analysis is provided exploring the biochemical mechanisms of these inhibitors, their complex interactions with potato physiology, and also their impact on tuber yield, quality, and environmental footprint. These insights are combined with sustainable strategies to optimize nitrogen fertilization in potato cropping systems. Lastly, essential knowledge gaps, such as ongoing soil-health impacts and climate-change interactions, are underlined, and future directions of research are proposed to advance inhibitor utilization on potato production. Full article

The individual contributions of arbuscular mycorrhizal (AM) fungi and earthworms to soil nitrogen (N) cycling are well-established; however, their combined effects on N sequestration through glomalin-related soil proteins (GRSPs) are not elucidated. This study evaluated their individual and interactive impacts on plant–soil N dynamics, with an emphasis on GRSP-mediated mechanisms. Trifoliate orange (Poncirus trifoliata) plants were treated with an AM fungus (Funneliformis mosseae), earthworms (Pheretima guillelmi), and their co-inoculation. Measurements were conducted on plant biomass and N content, soil N fractions, GRSP levels, GRSP-sequestered N (N_GRSP), contribution of N_GRSP to soil total N, and N-metabolizing enzymes. Co-inoculation of F. mosseae and P. guillelmi demonstrated synergistic effects, significantly increasing leaf and root N by 26% and 77%, respectively, compared to individual treatments (14–21% increases). All inoculations significantly elevated levels of total N (by 102–405%), nitrate-N (by 24–62%), soluble organic N (by 35–73%), and total dissolved N (by 31–53%), while ammonium-N decreased only with F. mosseae, with the most pronounced effect in the co-inoculation. Individual and combined inoculations significantly increased difficultly extractable (DEG) and total GRSP (TG) levels and their sequestered N content, with co-inoculation showing superior efficacy (N_DEG and N_TG increased by 53% and 42%). Adding F. mosseae alone and co-inoculation enhanced all N_GRSP contributions to soil total N (by 17–56%), whereas P. guillelmi alone only increased N_DEG and N_TG contributions (by 13–17%), with co-inoculation revealing greater effects on N_EEG contribution to soil total N than individual inoculations. All inoculations elevated nitrate reductase (by 72–101%) and urease (by 29–80%) activity while diminishing catalase (by 42–58%) activity, with synergistic enhancement of urease and catalase activity under co-inoculation. The synergistic interaction between earthworms and AM fungi facilitates N sequestration within the rhizosphere and promotes plant uptake. Full article

Red soils suffer from nutrient imbalances and low-phosphorus availability. Rational intercropping plays an important role for increasing crop yield and improving nutrient use efficiency, while its long-term effects on biogeochemical cycles and ecological stoichiometric stability are poorly understood. Based on a 7-year continuous field experiment in low-phosphorus red soil, the soil enzyme activity, soil carbon (C), nitrogen (N), phosphorus (P) and C:N:P content, soil microbial biomass (MBC, MBN, MBP), and their ecological stoichiometric characteristics in maize monoculture (MM) and maize//soybean intercropping (MI) under four phosphate fertilization gradients (0, 60, 90, 120 kg P₂O₅ hm⁻²) were investigated. The impacts of continuous MI on soil CNP ecological stoichiometric stability in red soil were studied. The results showed that intercropping significantly elevated the content of soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), and microbial biomass (MBC, MBN, MBP). Compared to maize monoculture, the contents of SOC, TN, and TP in intercropping soils increased by an average of 26.01%, 12.08%, and 7.58%, respectively, and soil MBC, MBN, and MBP increased by an average of 40.87%, 29.50%, and 38.34%, respectively, across different phosphate application gradients. Intercropping also significantly enhanced the activities of key C-, N-, and P-cycling enzymes (β-glucosidase, urease, acid phosphatase), increased by an average of 33.47%, 14.69%, and 60.15%, respectively. Most importantly, intercropping substantially improved the stoichiometric homeostasis of the microbial biomass and decreased the homeostasis index 1/H of MBC, MBN, MBP. Continuous intercropping shifted MBN from a sensitive to a strongly homeostatic state, MBP to homeostatic and the MBC/MBP ratio from weakly to strongly homeostatic in red soil. In conclusion, continuous MI in low-P red soil demonstrably increases soil nutrient content, enhances soil enzyme activity, and promotes ecological stoichiometric stability. This system represents one of the optimized cropping models for the synergistic enhancing of soil ecological stability in red soil regions. Full article

Populus euphratica (P. euphratica) is a dominant tree species in the arid and semi-arid regions along the main stem of the Tarim River. This study aims to explore the response of microbial communities in the rhizosphere soil of P. euphratica to varying groundwater depths (GWD) and to elucidate the ecological functions of key microbial groups in drought resistance. We established three groundwater depth levels (3.8 m, 5.4 m, and 7.35 m) and employed metagenomic sequencing technology to systematically analyze the topological characteristics of functional microbial community networks, as well as the types and quantities of key microbial groups in the rhizosphere soil of P. euphratica under different GWD conditions. The results indicate that compared to GWDs of 3.8 m and 7.35 m, the average degree and graph density of microbial communities in the rhizosphere soil of P. euphratica at a depth of 5.4 m are the highest. This suggests that at a GWD of 5.4 m, the connectivity and stability of the microbial network structure in the rhizosphere soil of P. euphratica are significantly enhanced. Analysis of the Zi-Pi values within the microbial network structure reveals that, compared to GWDs of 3.8 m and 7.35 m, a depth of 5.4 m supports the greatest variety and quantity of key microbial species in the rhizosphere soil of P. euphratica. The four connecting nodes identified are Actinophytocola, Haladaptatus, Devosia and Pseudonocardia. Spearman correlation analysis demonstrates that the relative abundance of the key bacterial genus Mesorhizobium in the rhizosphere soil of P. euphratica at different GWD is significantly positively correlated with soil catalase (CAT) and urease (UE) activity. Furthermore, the relative abundance of the key bacterial genus Pseudonocardia shows a significant positive correlation with soil total nitrogen (TN) and ammonium nitrogen (NH₄⁺-N) (p < 0.05). The relative abundance of the key bacterial genus Devosia exhibits a highly significant positive correlation with soil water content (SWC) (p < 0.01) and a significant negative correlation with soil NH₄⁺-N (p < 0.05). Additionally, the relative abundance of Devosia is significantly positively correlated with soil CAT (p < 0.05). This study provides a theoretical foundation for the conservation of desert poplar forests in arid regions and for the identification and cultivation of specific key microbial communities in the rhizosphere soil of P. euphratica. Full article

In this research, the effects of organic amendments and planting methods on the grain yields, enzyme activity, soil quality, and the structures of fungal populations in the rhizosphere of rice were evaluated. In comparison to the control group with direct seeding, the transplanting method resulted in a 23.5% higher grain yield. Furthermore, rice straw addition significantly improved fungal diversity indices (i.e., Chao1, ACE, Shannon, and Simpson). Dissimilarity distances and principal coordinate analysis revealed substantial variations in the compositions of root-associated fungal communities across the experimental groups with different planting methods. When the transplanting method was used, the Ascomycota, Basidiomycota, Chytridiomycota, Olpidiomycota, Aphelidiomycota, Monoblepharomycota, and Calcarisporiellomycota phyla became dominant. Biochar and rice straw applications caused substantial increases in the abundance of the Ascomycota, Basidiomycota, Chytridiomycota, Rozellomycota, Mucoromycota, Olpidiomycota, Aphelidiomycota, and Gammaproteobacteria phyla. Changes in enzyme activity and the physicochemical properties of the soil were also observed across the treatment groups with different planting methods and organic amendments. Direct seeding enhanced cellulase activity, microbial biomass carbon and nitrogen, available nitrogen, available potassium, nitrate nitrogen, and ammonium nitrogen, whereas transplanting boosted the activity of sucrase and urease enzymes. Rice straw application enhanced cellulase activity and the concentrations of available nitrogen, available phosphorus, nitrate nitrogen, and ammonium nitrogen in the soil. Biochar addition resulted in increased urease activity, microbial biomass carbon and nitrogen, soil pH, and available potassium. The Ascomycota abundance and grain yield exhibited a positive connection, while unclassified_Fungi exhibited negative correlations with the soil pH, organic carbon, available phosphorus, grain yield, and activity of sucrase and urease. Mortierellomycota was positively correlated with microbial biomass nitrogen and nitrate nitrogen. Overall, both the organic additives and planting methods influenced the soil properties, enzyme activity, rhizosphere fungal populations, and grain yield. These results provide new insights and a theoretical basis for studying the changes in soil fungal diversity and richness with different planting methods and organic amendments in Northeastern China. Full article