Search Results (15,180)

To address the severe challenge of soil salinization, effective soil amelioration methods are urgently needed; however, current research on the microbial mechanisms of the combined application of multiple amendments is insufficient. Therefore, this study aims to investigate the impacts of biochar combined with humic acid (HA) on the physicochemical properties and microbial community structure of saline–alkali soils by a field experiment. The results showed that the co-application treatments significantly improved soil physicochemical properties and increased bacterial community richness; specific effects depended on the biochar feedstock. Notably, the H-MBC treatment was the most effective in reducing soil electrical conductivity (EC) by 44.1%, while the H-SBC treatment most significantly increased soil water content by 80.3%. Stochastic processes influenced the assembly of microbial communities, particularly the co-application group, forming a more complex and stable microbial network. Furthermore, Spearman correlation and random forest analyses revealed EC, nitrate nitrogen, and available phosphorus as the primary variables affecting microbial communities. These findings support the potential of the combined application of biochar and HA for saline–alkali soil amelioration, as this strategy mitigates salt stress and increases nutrient availability, thereby reshaping microbial communities toward states conducive to ecological restoration. Full article

The efficient and non-destructive inspection of the chlorophyll content of grey jujube leaf is of great significance for its growth surveillance and nutritional diagnosis. Near-infrared spectroscopy combined with chemometric methods provides an effective approach to achieve this goal. This study took grey jujube leaves as the research object, systematically collected near-infrared spectral data in the range of 4000–10,000 cm⁻¹, and simultaneously measured their soil and plant analyzer development (SPAD) value as a reference index for chlorophyll content. Through various pretreatment and their combination methods on the original spectrum—smooth, standard normal variable transformation (SNV), first derivative (FD), second derivative (SD), smooth + first derivative (Smooth + FD), smooth + second derivative (Smooth + SD), standard normal variable transformation + first derivative (SNV + FD), standard normal variable transformation + second derivative (SNV + SD)—the effects of different methods on the quality of the spectrum and its correlation with SPAD value were compared. The competitive adaptive reweighted sampling algorithm (CARS) was adopted to extract the characteristic wavelength, aiming to reduce data dimensionality and optimize model input. Both BP neural network and RBF neural network prediction models were established, and the model performance under different training functions was compared. The results indicate that after Smooth + FD pretreatment, followed by CARS screening of the characteristic wavelength, the BP neural network model trained using the LBFGS algorithm demonstrated the best performance, with its coefficient of determination (R²) of 0.87 (training set) and 0.85 (validation set), root mean square error (RMSE) of 1.36 (training set) and 1.35 (validation set), and residual prediction deviation (RPD) of 2.81 (training set) and 2.56 (validation set) showing good prediction accuracy and robustness. Research indicates that by combining near-infrared spectroscopy with feature extraction and machine learning methods, the rapid and non-destructive inspection of the grey jujube leaf SPAD value can be achieved, providing reliable technical support for the real-time monitoring of the nutritional status of jujube trees. Full article

Soil organic matter (SOM) is a key component of nutrient cycling and soil fertility in terrestrial ecosystems. SOM is of great significance to the stability of terrestrial ecosystems and the improvement of soil productivity; to further exert its role, it is first necessary to clarify its actual distribution and occurrence status in specific regions. Under the combined impacts of intensive agriculture, unreasonable farming practices, and climate change, the SOM content in the Songnen Plain is showing a degradation trend, posing multiple stresses on its soil ecosystem functions. This study aims to systematically track the dynamic changes of SOM in the Songnen Plain, assess its spatiotemporal evolution characteristics, and reveal its driving mechanisms. A total of 113 representative soil profiles were selected in 2023; standardized excavation and sampling procedures were employed in the Songnen Plain. Soil pH, SOM, total nitrogen (TN), total phosphorus (TP), total potassium (TK), particle size (PSD), texture, and Munsell soil colors of samples were determined. Temporal variation characteristics, as well as horizontal and vertical spatial distribution patterns, in SOM content in the Songnen Plain were assayed. Structural equation modeling (SEM), together with freeze–thaw of soil and soil color mechanism analyses, was applied to reveal the spatiotemporal dynamics and driving mechanisms of SOM. The result indicated that the distribution pattern of SOM content in horizontal space shows higher levels in the northeastern region and lower levels in the southwestern region, and decreased with increasing soil depth. SEM analysis indicated that TN and PSD were the main positive factors, whereas bulk density exerted a dominant negative effect. The ranking of contribution rates is TN > TK > TP > PSD > annual average temperature > annual precipitation > bulk density. Mechanistic analysis revealed a significant negative correlation between SOM content and R, G, B values, with soil color intensity serving as a visual indicator of SOM content. Freeze–thaw thickness of soil was positively correlated with SOM content. These findings provide a scientific basis for soil fertility management and ecological conservation in cold regions. Full article

Bio-based fertilisers (BBFs) are gaining attention as sustainable alternatives to mineral fertilisers due to their potential for nutrient recovery, reduced environmental emissions, and improved soil health. However, their broader adoption is hindered by regulatory uncertainty, quality inconsistencies, and methodological variability in assessing their environmental impacts. This study can reveal about the body of research on bio-based fertilisers (BBFs), using a hybrid methodology that combines bibliometric and content analysis. A total of 247 publications from 2001 to 2024 were reviewed to identify research trends, environmental concerns, and assessment approaches. Results show a sharp increase in BBF-related publications after 2016, driven primarily by European and North American research, with growing focus on life cycle assessment (LCA) and nutrient recovery. The in-depth analysis of the ten most cited LCA and non-LCA studies highlights key methodological differences: non-LCA studies frequently rely on empirical fieldwork and generate primary data, whereas LCA studies typically synthesise secondary data to provide broader system-level insights. Despite this complementarity, the lack of methodological harmonisation poses a barrier to consistent comparison and interpretation. The findings highlight the need for a unified, standardised assessment framework to reliably evaluate the environmental performance of BBFs and support their effective implementation within circular and sustainable agricultural systems. Full article

Efficient water and nitrogen management is essential for maintaining soil fertility and achieving sustainable agricultural production, especially in arid oasis regions where soil degradation and nutrient loss are common challenges. However, the interactions between irrigation regimes, nitrogen application, and soil biological processes in such environments remain insufficiently understood. This study investigated the effects of water and nitrogen management on the sustainability of sandy soil nutrients within the context of the sustainable development goals during silage maize cultivation in the oasis irrigation area of the Hexi Corridor, Northwest China. Four irrigation regimes and five nitrogen management regimes were tested. The results indicate that ammonium nitrogen (NH₄⁺-N) varied significantly during the jointing stage (W4 treatment), ranging from 3.52 to 16.38 mg/kg (p < 0.05). Nitrate nitrogen (NO₃⁻-N) exhibited significant differences during the tasseling stage (W1 treatment), with a range of 6.16–21.58 mg/kg (p < 0.05). Soil total phosphorus (STP) gradually declined from early to late growth stages, ranging from 0.20 to 0.97 g/kg. Regarding enzyme activity, alkaline phosphatase (ALP) increased progressively throughout the growth period, with a range of 0.02–0.14 mg/g/d, while urease (URE) showed a declining trend, ranging from 0.25 to 0.66 mg/g/d. Water management exerted a significant negative effect on soil enzyme activity (p < 0.05), while nitrogen fertilization had a minimal impact on soil microbial communities (p > 0.05). Growth stage and irrigation regime are key regulators of the soil–microbe–enzyme activity system. The crop’s nutrient demand cycles and microbially mediated nutrient transformations exhibited strong dependence on growth stage. Enzyme activity is notably and positively affected by nitrogen inputs and plant developmental stages, while microbial biomass is mainly regulated by soil C, N, and P contents and enzyme activities. These findings provide a scientific basis for implementing water-saving irrigation and high-efficiency fertilization strategies in oasis agricultural systems. Full article

This study investigated the mechanisms of soil water–salt and nitrogen transport and optimal strategies under freeze–thaw (F-T) cycles in the salinized farmlands of the Hetao Irrigation District. A combined approach of field monitoring and laboratory simulation, utilizing both undisturbed and repacked soil columns subjected to 0–15 F-T cycles and five irrigation treatments, was employed to analyze the spatiotemporal dynamics in Gleyic Solonchaks. The results demonstrated that freeze–thaw processes play an important role in salt migration in surface soil layers, driving salt redistribution through phase changes of soil moisture. Increased freeze–thaw cycles reduced surface soil moisture content while promoting upward salt accumulation, salt dynamics exhibited pronounced spatial heterogeneity and irrigation source dependency, and the surface layer exhibited lower salinity levels after irrigation compared to pre-irrigation levels. These cycles also enhanced short-term soil nitrogen transformation and facilitated inorganic nitrogen accumulation. Different irrigation regimes exhibited a significant impact on the dynamics of water–salt and nitrogen in soil, with low-salinity treatment (S2) and moderate-nitrogen irrigation (N2) effectively reducing surface salt accumulation while improving nitrogen utilization efficiency (moderate-nitrogen irrigation exhibited higher mineralization rates, which facilitated the release of inorganic nitrogen from soil). This study reveals the synergistic transport mechanisms of water–salt and nitrogen under freeze–thaw driving forces and provides a scientific basis and practical pathway for sustainable agricultural management in cold arid irrigation districts. Full article

Phosphorus (P) is an essential element for plant growth, yet it is only available to plants in the form of orthophosphate. In most soils, P occurs predominantly in insoluble forms, such as calcium phosphates in alkaline soils and aluminum/iron phosphates in acidic soils, limiting plant uptake. Fertilization is commonly used to overcome this limitation; however, large fractions of applied P rapidly become unavailable. Phosphorus-solubilizing bacteria (PSB) are a sustainable alternative to enhance P availability. This study evaluated the P-solubilization capacity of bacterial strains belonging to different genera isolated from different host plants, soil types, and climates (mainland Portugal, Cape Verde, and Angola). Following initial screening, the most efficient strains were tested under greenhouse conditions in soils with pH 7 and 8. Strains exhibited diverse solubilization capacities, with highly efficient PSB (phosphate solubilization index ≥ 2) accounting for 5% of the total isolates, predominantly originating from the Namib Desert (Angola) and Southern Portugal, and mainly belonging to the genera Pseudomonas, Flavobacterium, Enterobacter, Chryseobacterium and Pantoea. At pH 7, most PSB promoted maize growth, with strain C11 increasing plant P content around 2-fold compared to the control. At pH 8, fewer strains were effective, but strains F and C11 enhanced shoot weight and M shoot length by 28%, 27%, and 10%, respectively. These findings highlight the potential of selected PSB strains as next-generation bioinoculants for sustainable agriculture. However, strain selection must consider geography, crop type, and management practices to ensure consistent efficacy, thereby supporting the broader application of PSB as a precision tool for improving food security. Full article

This study assessed the combined application of poultry manure (Pm), biochar (B), and coenzyme A (CoA) into soils to enhance Moringa oleifera Lam. growth, biomass yield, and nutritional and phytochemical composition. This approach allowed us to cover the gap of knowledge on sustainable, low-cost agronomic management alternatives suitable for smallholder systems. To achieve this objective a field experiment was conducted using three treatments (control (no amendment), Pm + B, and Pm + B + CoA) and four consecutive harvests were monitored. Morphological traits (height, stem diameter, number of branches, and leaf yield) were recorded, and phytochemical analyses of glucosinolates and (poly)phenols were performed via HPLC-DAD-ESI/MSn. Mineral and trace elements were quantified by ICP-OES. The main results retrieved allowed describing the capacity of the combined use of Pm + B + CoA to enhance plant growth and productivity, thus increasing the moringa trees’ height of 226.3 by 39.5%, on average, relative to control plants. ILeaf yield and branch number augmented up to 7.0-fold and 2.5-fold, respectively, under amendment treatments. Petiole girth also increased significantly by >50% (p < 0.01). Phytochemically, Pm + B + CoA significantly elevated total phenolics, vicenin-2, and quercetin acetyl-hexoside in leaves by 2.8-fold, on average, relative to control. The glucosinolate content also augmented as a result of the soil amendments assayed by 51.0%, on average, in stems and petioles, under Pm + B + CoA, compared to control samples. From these results, it can be concluded that the combined use of poultry manure, biochar, and CoA significantly improved M. oleifera growth, biomass yield, and nutritional quality, with a particular efficiency concerning (poly)phenolic accumulation. This low-cost, sustainable amendment strategy provides a viable agronomic solution in regions suffering socioeconomic constraints that hinder access to high-cost agronomic management options. Therefore, this approach effectively links ecological soil management with improved productivity, nutritional value, and potential for food industries. Full article

Eleutherococcus sessiliflorus is a medicinal shrub widely used in East Asian traditional medicine, yet field-based studies on environmental influences remain limited. In this study, branches from 26 cultivation sites across South Korea were analyzed for relationships among growth traits, soil and climatic conditions, and two major compounds, chlorogenic acid (CGA) and eleutheroside E (EleuE). Growth traits varied widely, with plant height ranging from 1.06 to 4.20 m. CGA content was relatively stable across sites (0.292–0.708 mg/g), while EleuE showed greater variability (0.038–0.264 mg/g). The combined content of CGA and EleuE showed a weak positive correlation with thorn density (r = 0.236, p = 0.037). Plant height and basal diameter were positively correlated with temperature indices (annual average temperature r = 0.410, p < 0.001; annual maximum temperature r = 0.341, p = 0.002), whereas thorn density decreased with soil electrical conductivity, potassium, and magnesium but increased with sand and precipitation. Principal component analysis and correlation networks highlighted distinct clusters separating growth traits from EleuE–environment associations. These findings demonstrate that growth performance in E. sessiliflorus is strongly influenced by thermal regimes, while EleuE accumulation responds to soil texture and light availability, providing an empirical foundation for site-specific cultivation strategies and standardized quality management. Full article

On acid soils, aluminum (Al³⁺) is typically toxic to plants, though certain species like Pogostemon cablin (patchouli) show growth stimulation. This study reveals that Al functions as a root development stimulant in patchouli under acidic conditions. Treatment with 1.0 mM AlCl₃ for 34 days significantly enhanced root architecture, increasing total root length by 172.12% and root dry weight by 161.75%, without affecting shoot biomass. Structural analysis showed Al accumulation in root tip meristems and lateral root primordia, triggering a 103.77% increase in meristem activity and a 111.9% promotion of cell elongation. Physiological assays showed that Al treatment reduced H₂O₂ and malondialdehyde (MDA) levels by 49.2% and 67.6%, respectively, while boosting glutathione (GSH) content by 187.5%, thereby mitigating oxidative membrane damage mainly through the non-enzymatic antioxidant system. Moreover, Al deprivation impaired lateral root elongation, highlighting its functional importance. Gene expression profiling further indicated that Al regulated pathways related to cell proliferation, cell wall remodeling, and lateral root development. Taken together, our findings uncover a novel mechanism by which Al, traditionally regarded as toxic, acts as a stimulator of root development in patchouli, providing new insights into the molecular networks underlying plant abiotic stress responses. Full article

Despite its high inulin content, Jerusalem artichoke (Helianthus tuberosus L.) remains an underutilized vegetable for human consumption. Organic field trials of two biotypes adapted to Northern Patagonia, Argentina, were conducted. Since no cultivars are formally registered in the country, two biotypes, “elongated” (E) and “rounded” (R), defined according to tuber morphology, were planted and characterized. Agronomic performance was evaluated through soil analysis and crop yield. Tubers were analyzed for horticultural quality (e.g., respiration rate, inulin, firmness) and microstructure. A nutritional profile was determined, including protein, fat, dietary fiber, sugars, organic acids, minerals, phenolic content, and antioxidant capacity. Sensory evaluation (overall liking, free association, and penalty–reward analysis) was performed with 128 consumers, most of them unfamiliar with the tuber. The biotype R exhibited twice the yield and higher consumer preference, whereas E showed a higher respiration rate, a better nutritional profile, a harder texture, and lower overall liking. Initially, 76% of participants expressed willingness to incorporate it into their diet, which increased to 96.6% after they were informed of its health benefits. This multidimensional study, support the revalorization of Jerusalem artichoke and its inclusion in human diets as a fresh vegetable for biotype R or functional ingredient for biotype E. Full article

Agricultural land management is a major determinant of terrestrial carbon (C) fluxes and has substantial implications for greenhouse gas (GHG) mitigation strategies. This study evaluated the net ecosystem carbon balance (NECB) of an agricultural field in an organic integrated crop–livestock system (ICLS) with a ley-arable rotation in northern Germany over two years (2021–2023). Carbon dioxide (CO₂) fluxes were measured using the eddy covariance (EC) method to derive net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (RECO). This approach facilitated an assessment of the temporal dynamics of CO₂ exchange, alongside detailed monitoring of field-based C imports, exports, and management activities, of a crop sequence including grass-clover (GC) ley, spring wheat (SW), and a cover crop (CC). The GC ley acted as a consistent C sink (NECB: −1386 kg C ha⁻¹), driven by prolonged photosynthetic activity and moderate biomass removal. In contrast, the SW, despite high GPP, became a net source of C (NECB: 120 kg C ha⁻¹) due to substantial export via harvest. The CC contributed to C uptake during the winter period. However, cumulatively, it acted as a net CO₂ source, likely due to drought conditions following soil cultivation and CC sowing. Soil cultivation events contributed to short-term CO₂ pulses, with their magnitude modulated by soil water content (SWC) and soil temperature (TS). Overall, the site functioned as a net C sink, with an average NECB of −702 kg C ha⁻¹ yr⁻¹. This underscores the climate mitigation potential of management practices such as GC ley systems under moderate grazing, spring soil cultivation, and the application of organic fertilizers. To optimize CC benefits, their use should be combined with reduced soil disturbance during sowing or establishment as an understory. Additionally, C exports via harvests could be offset by retaining greater amounts of harvest residues onsite. Full article

Chemical fertilizers are commonly used to supply phosphorus and other nutrients to crops, but due to high affinity of soils for P fixation, over-application of P fertilizer is common, which may result in groundwater and surface water pollution. To increase P use efficiency, different strategies, including different fertilizer formulations and types, have been developed. Two struvite-based fertilizers, Crystal Green^® (CG) and Crystal Green Pearl^® (CGP), are touted as environmentally safe, because they are insoluble in water but soluble in organic acids exuded from crop roots. The objective of this study was to assess fate and transport of P from diammonium phosphate (DAP), CG, and CGP through two loam soils with a significant difference in their initial P content. Two loamy soils, one collected from an experimental field receiving fertilizer continuously since 1985 and one from an adjacent area receiving no fertilizer, and a pure sand control were packed in 5 cm diameter and 5 cm long columns. Several grains equivalent to approximately 80 mg P from each fertilizer were imbedded at the bottom of the column. Distilled water was passed through the soil columns from the bottom at a relatively constant rate, and the outflow was collected every two hours using a fraction collector. Outflow samples from each treatment combination were analyzed for P by the colorimetric method, and the amount of P retained by the soils along the column at the end of the water application was determined by the nitric acid digestion method. Approximately 91% of P in DAP, 34% in CG, and only 3.8% in CGP was transported through the sand column. In contrast, the amounts of P transported were approximately 42.2% for DAP, 6.4% for CG, and 0.4% for CGP through the high-P soil and 22.4% for DAP, 0.6% for CG, and almost zero for CGP through the low-P soil. Overall, the results show a high solubility and transport for DAP, very low transport for CGP, and somewhat low to medium transport for CG fertilizers. In addition, the results show that even the high-P soil that has received fertilizer for about 40 years has the capacity to fix significant amounts of P. Full article

Nitrogen (N) fertilization is known to influence soil microbial communities and crop yield, but how N affects the bacterial community and the link to crop yield across different soil types remains poorly understood. Here, we conducted three 5-year stationary field experiments to explore the effect of N fertilization (0, 180, 240, and 300 kg ha⁻¹; termed N0, N1, N2, and N3, respectively) with different soil types (fluvo-aquic soil, FS; sandy soil, SS; lime concretion black soil, BS) on bacterial communities and the relationships among soil, microbes, and N-cycling functional genes to further investigate the effects on wheat yield. The results showed that the N2 treatment (240 kg ha⁻¹) achieved the highest wheat yield, with significantly lower yields in SS than those in FS and BS. N fertilization significantly altered soil physicochemical properties, with a notable decrease in pH, particularly in SS, and an increase in NO₃⁻-N content. Bacterial α-diversity significantly decreased with N application in SS but not in FS and BS, and NO₃⁻-N played a primary role in shaping beta diversity in FS and BS. There were 43, 62, and 11 bacterial species that changed significantly from phylum to genus in the FS, SS, and BS, respectively. The abundance of nitrification genes increased with N fertilization in FS and SS, and N-cycling genes were significantly associated with soil properties. Partial Least Squares Path Modeling (PLS-PM) revealed that N fertilizer affected soil properties, which in turn regulated bacterial communities, and ultimately influenced wheat yield, explaining 67.4% of the yield variation. This study highlights the soil-specific responses to N application, providing a basis for optimizing N management and enhancing agricultural sustainability. Full article

Snow cover, as a critical component of the global climate system, strongly influences ecological processes in cold and temperate regions. However, how different ecosystem components—plants, soils, and microbes—respond to snow cover change remains poorly understood, especially in terms of their coordination. Here, we conducted a global meta-analysis of 1986 single and 1047 paired observations from snow manipulation experiments across diverse terrestrial ecosystems. Our results showed that snow removal generally reduced SWC and microbial diversity, whereas snow addition exerted smaller or more variable influences across ecosystem components. Among all variables, the effect of snow cover change on soil water content was most pronounced, whereas its impacts on other factors were generally weak. Notably, the direction and magnitude of responses often differed among ecosystem components exposed to the same treatments. Pairwise comparisons revealed frequent mismatches between plant and soil organism responses, indicating substantial ecosystem-level decoupling across biomes. These findings support the ecosystem asynchrony hypothesis and highlight the need for integrated approaches that link aboveground and belowground processes. Our study improves the understanding of ecosystem stability under changing snow regimes and provides insights for predicting future terrestrial responses to global climate change. Full article