Search Results (441)

This study demonstrated that application of the particular plant growth-promoting rhizobacteria (PGPR) strains Erwinia sp. and Serratia sp. (named C15 and C20, respectively) significantly enhanced tea plant resilience in Zn (zinc)-, Pb (lead)-, and Zn + Pb-contaminated soils by the improving survival rates (over 60%) and chlorophyll content of tea plants, and by reducing the accumulation of these metals in tea plants’ tissues (by 19–37%). The PGPRs elevated key soil nutrients organic carbon (OC), total nitrogen (TH), hydrolysable nitrogen (HN), and available potassium (APO) and phosphorus (APH) contents. Compared to non-PGPR controls, both strains consistently increased microbial α-diversity (Chao1 index: +28–42% in Zn/Pb soils; Shannon index: +19–33%) across all contamination regimes. PCoA/UniFrac analyses confirmed distinct clustering of PGPR-treated communities, with strain-specific enrichment of metal-adapted taxa, including Pseudomonas (LDA = 6) and Bacillus (LDA = 4) under Zn stress; Rhodanobacter (LDA = 4) under Pb stress; and Lysobacter (LDA = 5) in Zn + Pb co-contamination. Fungal restructuring featured elevated Mortierella (LDA = 6) in Zn soils and stress-tolerant Ascomycota dominance in co-contaminated soils. Multivariate correlations revealed that the PGPR-produced auxin was positively correlated with soil carbon dynamics and Mortierellomycota abundance (r = 0.729), while the chlorophyll content in leaves was closely associated with Cyanobacteria and reduced by Pb accumulation. These findings highlighted that PGPR could mediate and improve in tea plant physiology, soil fertility, and stress-adapted microbiome recruitment under heavy metal contaminated soil and stress. Full article

Biochar is an amendment that can enhance both soil fertility and sequester carbon. However, its historical applications continue to be underexplored. In this overview, we investigate the formiguer method of burning woody biomass to create agricultural biochar for use as fertilizer in Catalonia, Spain, within the context of historical biochar use. A literature review targeted searches of scholarly databases to compare the formiguer method to Amazonian terra preta and other traditional biochar use. We identified sources covering biochar properties, soil impacts, and historical agricultural practices within the Iberian Peninsula and briefly described the main methods or treatments used during this process. Past research demonstrates that the formiguer method, which involves pyrolytic combustion of biomass within soil mounds, improves microbial activity, increases soil phosphorus and potassium availability from soil structure, and leads to long-term carbon stabilization, even though it can result in short-term decreases in soil organic carbon and nitrogen losses. Despite being abandoned in Europe with the rise of chemical fertilizers, the use of formiguers exemplifies a decentralized approach to nutrient and agroecosystem management. The literature highlights the relevance that these traditional biochar practices can have in informing modern soil management and sustainable agricultural strategies. Understanding the formiguer can offer critical insights to optimize contemporary biochar applications and historical techniques into future sustainability frameworks. Full article

The primary aim of this study was to explore the influence of abiotic factors on weed development in maize fields, with the goal of informing more effective weed management practices. We focused on identifying key environmental, edaphic, and agricultural variables that contribute to weed infestations, particularly before the application of spring herbicide treatments. Field investigations were conducted from 2018 to 2021 across selected maize-growing regions in Hungary. Over the four-year period, a total of 51 weed species were recorded, with Echinochloa crus-galli, Chenopodium album, Portulaca oleracea, and Hibiscus trionum emerging as the most prevalent taxa. Collectively, these four species accounted for more than half (52%) of the total weed cover. Altogether, the 20 most dominant species contributed 95% of the overall weed coverage. The analysis revealed that weed cover, species richness, and weed diversity were significantly affected by soil properties, nutrient levels, geographic location, and tillage systems. The results confirm that the composition of weed species was influenced by several environmental and management-related factors, including soil parameters, geographical location, annual precipitation, tillage method, and fertilizer application. Environmental factors collectively explained a slightly higher proportion of the variance (13.37%) than farming factors (12.66%) at a 90% significance level. Seasonal dynamics and crop rotation history also played a notable role in species distribution. Nutrient inputs, particularly nitrogen, phosphorus, and potassium, influenced both species diversity and floristic composition. Deep tillage practices favored the proliferation of perennial species, whereas shallow cultivation tended to promote annual weeds. Overall, the composition of weed vegetation proved to be a valuable indicator of site-specific soil conditions and agricultural practices. These findings underscore the need to tailor weed management strategies to local environmental and soil contexts for sustainable crop production. Full article

Nitrogen (N) availability often limits primary productivity in terrestrial ecosystems, and arbuscular mycorrhizal fungi (AMF) can enhance plant N acquisition. This study investigated the interactive effects of N fertilization and AMF inoculation on N uptake, plant performance and phenolic acid content in Hyssopus officinalis L., with the aim of promoting sustainable N management in H. officinalis cultivation. A factorial randomized complete block design was employed to evaluate four AMF inoculation strategies (no inoculation, root inoculation, soil inoculation and combined root–soil inoculation) across three N application rates (0, 0.5 and 1,1 g N pot⁻¹ (7 L)) in a controlled greenhouse environment. Combined root and soil AMF inoculation alongside moderate N fertilization (0.5 mg N pot⁻¹) optimized N use efficiency, maximizing plant biomass and bioactive compound production. Compared to non-inoculated controls, this treatment combination increased N uptake by 30%, phosphorus uptake by 24% and potassium uptake by 22%. AMF colonization increased chlorophyll content and total phenolic compounds under moderate N supply. However, excessive N application (1 g N pot⁻¹) reduced AMF effectiveness and secondary metabolite accumulation. Notably, AMF inoculation without N fertilization yielded the highest levels of anthocyanin and salicylic acid, indicating differential N-dependent regulation of specific biosynthetic pathways. The interaction between AMF and N demonstrated that moderate N fertilization (0.5 g N pot⁻¹) combined with dual inoculation strategies can reduce total N input requirements by 50%, while maintaining optimal plant performance. These findings provide practical insights for developing N-efficient cultivation protocols in medicinal plant production systems, contributing to sustainable agricultural practices that minimize environmental N losses. Full article

To address the issue of excessive chemical fertilizer use in agricultural production, this study conducted a pot experiment with four treatments: CK (no fertilization), T1 (the application of potassium magnesium sulfate fertilizer), T2 (the application of slow-release fertilizer equal to T1), and T3 (the application of slow-release fertilizer with the same fertility as T1). The effects of these treatments on garlic seedling yield, growth quality, chlorophyll content, photosynthetic characteristics, and the soil environment were investigated to evaluate the feasibility of replacing conventional fertilizers with slow-release formulations. The results showed that compared with CK, all three fertilized treatments (T1, T2, and T3) significantly increased the plant heights and stem diameters of the garlic sprouts (p < 0.05). Plant height increased by 14.85%, 17.81%, and 27.75%, while stem diameter increased by 9.36%, 8.83%, and 13.96%, respectively. Additionally, the chlorophyll content increased by 4.34%, 7.22%, and 8.05% across T1, T2, and T3, respectively. Among the treatments, T3 exhibited the best overall growth performance. Compared with those in the CK group, the contents of soluble sugars, soluble proteins, free amino acids, vitamin C, and allicin increased by 64.74%, 112.17%, 126.82%, 36.15%, and 45.43%, respectively. Furthermore, soil organic matter, available potassium, magnesium, and phosphorus increased by 109.02%, 886.25%, 91.65%, and 103.14%, respectively. The principal component analysis indicated that soil pH and exchangeable magnesium were representative indicators reflecting the differences in the soil’s chemical properties under different fertilization treatments. Compared with the CK group, the metal contents in the T1 group slightly increased, while those in T2 and T3 generally decreased, suggesting that the application of slow-release fertilizer exerts a certain remediation effect on soils contaminated with heavy metals. This may be attributed to the chemical precipitation and ion exchange capacities of phosphogypsum, as well as the high adsorption and cation exchange capacity of bentonite, which help reduce the leaching of soil metal ions. In summary, slow-release fertilizers not only promote garlic sprout growth but also enhance soil quality by regulating its chemical properties. Full article

The simplex strategies of fertilizer management and problems caused by simultaneous precipitation and high-temperature (SPH) climate were the main factors that led to yield loss and quality decline in the continuous cropping of tea chrysanthemum (Dendranthema morifolium ‘Jinsi Huang’). In this study, with sustainable biofertilizers being proposed as a potential solution. However, their effects under such constraints are underexplored. In this study, we compared different proportions of a sustainable dark tea biofertilizer, made with two commonly used fertilizers, by their contributions to the morphological, photosynthetic, and flowering traits of D. morifolium ‘Jinsi Huang’. The results showed that increasing the dark tea biofertilizer application to 4.5 kg·m⁻² significantly enhanced the soil alkali hydrolyzed nitrogen (596.53% increase), available phosphorus (64.11%), and rapidly available potassium (75.56%) compared to the levels in yellow soil. This nutrient enrichment in soil caused D. morifolium ‘Jinsi Huang’ to produce more leaves (272.84% increase) and flower buds (1041.67%), along with a strengthened photosynthetic capacity (higher Fv/Fm values and light saturation point). These improvements alleviated the photoinhibition caused by SPH climate conditions, ultimately leading to significantly higher contents of chlorogenic acid (38.23% increase) and total flavonoids (80.28%) in the harvested flowers compared to the control group. Thus, dark tea biofertilizer is a cost-effective and efficient additive for growing tea chrysanthemum in SPH regions due to improving soil quality and causing nutritional and functional components to accumulate in harvest flowers, which greatly promotes the commercial value of rural revitalization industries centered around tea chrysanthemum. Full article

(1) Background: The escalating issue of soil degradation caused by excessive chemical fertilizer application poses significant threats to the sustainable development of Chinese flowering cabbage (Brassica campestris L. ssp. chinensis (L.) var. utilis Tsen et Lee) production. This research aimed to identify the impacts of reduced chemical fertilizer application integrated with organic amendments on cabbage yield and rhizosphere soil microenvironment characteristics. (2) Methods: A biennial field experiment was conducted during the 2022–2023 growing seasons at Lijun Town, Yinchuan City, Ningxia Hui Autonomous Region. Five treatments were tested: (i) Control (CK, no fertilizer); (ii) Conventional chemical fertilization (CF1, chemical fertilizer only); (iii) Reduced chemical fertilization (CF2, 30% less chemical fertilizer); (iv) CF2 + Well-decomposed chicken manure (FCM, 30% less chemical fertilizer + rotted chicken manure); and (v) CF2 + Vermicompost (FEM, 30% less chemical fertilizer + vermicompost). (3) Results: In 2023, the FCM treatment reduced electrical conductivity (EC) by 24.80% and pH by 2.16%, while the FEM treatment decreased EC by 31.13% and pH by 3.84% compared to controls. The FEM treatment significantly enhanced total nitrogen content by 12.71% and 8.85% relative to CF1 and FCM treatments, respectively. Compared to CF1, FEM increased soil organic matter content by 10.49% in 2022 and 11.24% in 2023. Organic fertilizer amendments elevated available nitrogen, phosphorus, and potassium levels while enhancing sucrase activity: FCM and FEM treatments increased sucrase activity by 23.62% and 32.00%, respectively, in 2022. Organic fertilization improved bacterial diversity and richness, optimized microbial community structure, and increased the relative abundance of Bacillus. It also upregulated microbial metabolic pathways related to carbohydrate and amino acid metabolism. Soil nutrients and bacterial community structure showed positive correlations with yield, whereas soil enzyme activities exhibited negative correlations. Key factors influencing yield were identified as Proteobacteria, Chloroflexi, available potassium, organic matter, available nitrogen, Actinobacteria, Firmicutes, total nitrogen, pH, and sucrase activity. (4) Conclusions: Integrated analysis of yield and soil microenvironmental parameters demonstrates that the fertilization regimen combining 30% chemical fertilizer reduction with vermicompost amendment (FEM) constitutes a more efficient fertilization strategy for Chinese flowering cabbage, making it suitable for regional promotion in the Ningxia area. Full article

Ochroma lagopus, a fast-growing tropical tree species, faces fertilization challenges due to slope heterogeneity in plantations. This study examined 3-year-old Ochroma lagopus at upper and lower slope positions under five treatments: CK (no fertilizer), F1 (600 g/plant), F2 (800 g/plant), F3 (1000 g/plant), and F4 (1200 g/plant) of secondary macronutrient water-soluble fertilizer. Growth parameters and N-P-K stoichiometry were analyzed. Key results: (1) Height increased continuously with fertilizer dosage at both slopes, while DBH peaked and then declined. (2) At upper slopes (nutrient-poor soil), fertilization elevated leaf P but reduced branch N/K and increased root P/K. At lower slopes (nutrient-rich soil), late-stage leaf N increased significantly, with roots accumulating P/K via a “storage strategy”. Stoichiometric thresholds indicated N-K co-limitation (early-mid stage) shifting to P limitation (late stage) on upper slopes and persistent N-K co-limitation on lower slopes. (3) PCA identified F4 (1200 g/plant) and F1 (600 g/plant) as optimal for upper and lower slopes, respectively. This research provides a theoretical basis for precision fertilization in Ochroma lagopus plantations, emphasizing slope-specific nutrient status and element interactions for dosage optimization. Full article

Cost-effective methods for improving soil fertility and mitigating the negative impact of heavy metal contamination in agricultural soils are currently under investigation. This study aimed to evaluate the impact of soil lead (Pb) contamination and the application of secondary pulp and paper mill sludge on the relative growth rate (RGR) and its determinants, as well as the specific absorption rate (SAR) of nutrients of Lactuca sativa L. For the 46-day pot experiment, which was carried out in 2022 under controlled conditions at the Karelian Research Centre of RAS, sandy loam soil was used, to which Pb was added at rates of 0, 50, and 250 mg Pb(NO₃)₂ kg⁻¹. Secondary sludge was applied with each watering at concentrations of 0%, 20%, and 40%. RGR values varied significantly, primarily due to changes in net assimilation rate (NAR) rather than specific leaf area. Positive relationships were found between RGR and NAR, and RGR and SAR of nitrogen and phosphorus, but not potassium. Sludge applications can stimulate NAR at early stages of plant growth. For plants grown on soil with the highest Pb concentration studied, secondary sludge reduced root lead content by an average of 35%. Soil contamination with lead increased nutrient SAR by 79 and 39% when applied as 20 and 40% sludge, respectively, while 40% sludge increased nitrogen SAR by 51% but did not change phosphorus and potassium SAR. A sludge-mediated reduction in root Pb content and an increase in NAR suggest that secondary paper sludge may contribute to the remediation of Pb-contaminated soils and reduce the toxicity of heavy metals to plants. The results may help in finding new ways to manage soil fertility, especially for contaminated soils. Full article

Biochar and seaweed fertilizers could improve soil quality and promote plant growth. However, the key soil factors and microbial mechanisms that drive maize growth in coastal saline–alkali soils remain unclear. A soil culture experiment was designed with four treatments—no organic fertilizer (CK), single seaweed fertilizer (F), single biochar (B), and combined application of seaweed fertilizer and biochar (BF)—to investigate the effects of biochar and seaweed fertilizer on maize growth and its mechanism. The results showed that B and BF significantly increased maize aboveground biomass by 8.86% and 17.28% compared to CK, respectively. The soil organic carbon, total nitrogen, available nitrogen, available phosphorus, available potassium content, and pH of B and BF were significantly increased. Bacterial diversity increased under B and BF, while fungal richness decreased under BF. The changes in the fungal community were mainly affected by soil available nitrogen, but there was no significant correlation between bacterial communities and these indicators. Pearson correlation analysis suggested that the bacterial Chao1 index was significantly positively correlated with maize growth indicators, soil available phosphorus, and available potassium, as well as the bacterial PD whole tree index with leaf area and available phosphorus. The fungal Shannon index was significantly negatively correlated with maize plant height, leaf area, SPAD, aboveground biomass, and soil total nitrogen and available nutrients. Overall, biochar and seaweed fertilization could significantly promote maize growth by improving soil chemical properties and microbial communities in coastal saline–alkali soils. Full article

Accurate and timely wheat yield prediction is valuable globally for enhancing agricultural planning, optimizing resource use, and supporting trade strategies. Study addresses the need for precision in yield estimation by applying machine-learning (ML) regression models to high-resolution Unmanned Aerial Vehicle (UAV) multispectral (MS) and Red-Green-Blue (RGB) imagery. Research analyzes five European wheat cultivars across 400 experimental plots created by combining 20 nitrogen, phosphorus, and potassium (NPK) fertilizer treatments. Yield variations from 1.41 to 6.42 t/ha strengthen model robustness with diverse data. The ML approach is automated using PyCaret, which optimized and evaluated 25 regression models based on 65 vegetation indices and yield data, resulting in 66 feature variables across 400 observations. The dataset, split into training (70%) and testing sets (30%), was used to predict yields at three growth stages: 9 May, 20 May, and 6 June 2022. Key models achieved high accuracy, with the Support Vector Regression (SVR) model reaching R² = 0.95 on 9 May and R² = 0.91 on 6 June, and the Multi-Layer Perceptron (MLP) Regressor attaining R² = 0.94 on 20 May. The findings underscore the effectiveness of precisely measured MS indices and a rigorous experimental approach in achieving high-accuracy yield predictions. This study demonstrates how a precise experimental setup, large-scale field data, and AutoML can harness UAV and machine learning’s potential to enhance wheat yield predictions. The main limitations of this study lie in its focus on experimental fields under specific conditions; future research could explore adaptability to diverse environments and wheat varieties for broader applicability. Full article

Based on an integrated analysis, this study summarized the current status of soil quality in Yantai apple orchards, developed a multivariate regulation model for key soil physicochemical properties, and proposed optimized fertilization strategies to improve soil quality in the region. The study analyzed the physicochemical properties of the topsoil (0–30 cm) in 19 representative apple orchards across Yantai, including indicators like pH, organic matter (OM), major nutrient ions, and salinity indicators, using standardized measurements and multivariate statistical methods, including descriptive statistics analysis, frequency distribution analysis, canonical correlation analysis, stepwise regression equation analysis, and regression fit model analysis. The results demonstrated that in apple orchards across the Yantai region, reductions in pH were significantly mitigated under the combined increased OM and exchangeable calcium (Ca). Exchangeable potassium (EK) rose in response to the joint elevation of OM and available nitrogen (AN), and AN was also positively influenced by EK, while OM also exhibited a promotive effect on Olsen phosphorus (OP). Furthermore, Ca increased with higher pH. AN and EK jointly contributed to the increases in electrical conductivity (EC) and chloride ions (Cl), while elevated exchangeable sodium (Na) and soluble salts (SS) were primarily driven by EK. Accordingly, enhancing organic and calcium source fertilizers is recommended to boost OM and Ca levels, reduce acidification, and maintain EC within optimal limits. By primarily reducing potassium’s application, followed by nitrogen and phosphorus source fertilizers, the supply of macronutrients can be optimized, and the accumulation of Na, Cl, and SS can be controlled. Collectively, the combined analysis of soil quality status and the multivariate regulation model clarified the optimized fertilization strategies, thereby establishing a solid theoretical and practical foundation for recognizing the necessity of soil testing and formula fertilization, the urgency of improving soil quality, and the scientific rationale for nutrient input management in Yantai apple orchards. Full article

This study presents an integrated approach to sustainable soil and crop management by evaluating the individual and combined effects of cow manure (CM), rice husk biochar (RHB), and potassium humate (KH)—three underutilized, low-cost organic amendments derived from agricultural byproducts. Uniquely, it investigates how these amendments simultaneously affect soil physical and chemical properties, plant growth, and the accumulation of bioactive compounds in sunflower sprouts, thereby linking soil health to crop nutritional quality. The application of 2% w/w KH alone resulted in the greatest increases in macroaggregation (+0.51), soil pH (from 6.8 to 8.6), and electrical conductivity (+298%). The combination of 1% w/w CM and 2% KH led to the highest increases in soil organic carbon (OC, +62.9%) and soil respiration (+56.4%). Nitrate and available phosphorus (P) peaked with 3% w/w RHB + 2% KH (+120%) and 1% w/w CM + 0.5% KH (+35.5%), respectively. For plant traits, 0.5% w/w KH increased the total leaf area by 61.9%, while 1% w/w CM enhanced shoot and root biomass by 60.8% and 79.0%, respectively. In contrast, 2% w/w KH reduced chlorophyll content (−43.6%). Regarding bioactive compounds, the highest total phenolic content (TPC) was observed with 1% w/w KH (+21.9%), while the strongest DPPH antioxidant activity was found under 1% w/w CM + 1% w/w KH (+72.6%). A correlation analysis revealed that biomass production and secondary metabolite accumulation are shaped by trade-offs arising from resource allocation under stress or nutrient limitations. Potassium, P, soil microbial respiration, and OC emerged as key integrators connecting soil structure, fertility, and plant metabolic responses. Overall, the combination of 1% w/w CM with 0.5–1% w/w KH proved to be the most effective strategy under the tested conditions. Full article

Replacing partial chemical fertilizers with organic fertilizer can increase organic carbon input, change soil nutrient stoichiometry and microbial metabolism, and then affect soil organic carbon (SOC) storage. A 6-year field experiment was used to explore the mechanism of SOC storage under different ratios of manure substitution in northeast China, with treatments including chemical fertilizer application alone (nitrogen, phosphorus, and potassium, NPK) and replacing 1/4 (1/4M), 2/4 (2/4M), 3/4 (3/4M), and 4/4 (4/4M) of chemical fertilizer N with manure N. Soil nutrients, enzymatic activity, and SOC fractions were analyzed to evaluate the effect of different manure substitution ratios on SOC storage. A high ratio of manure substitution (>1/4) significantly increased soil total N, total P, total K, and available nutrients (NO₃⁻-N, available P, and available K), and the 4/4M greatly decreased the C/N ratio compared to the NPK. Manure incorporation increased microbial biomass carbon (MBC) by 18.3–53.0%. Treatments with 50%, 75%, and 100% manure substitution (2/4M, 3/4M, and 4/4M) enhanced bacterial necromass carbon (BNC), fungal necromass carbon (FNC), and total microbial necromass carbon (MNC) by 31.9–63.5%, 25.5–107.1%, and 27.4–94.2%, respectively, compared to the NPK treatment. Notably, the increase in FNC was greater than that of BNC as the manure substitution ratio increased. The increasing manure substitution significantly enhanced particulate organic C (POC) and total SOC but did not affect mineral-associated organic C (MAOC). High soil N and P supplies decreased leucine aminopeptidases (LAPs) and alkaline phosphatase activities but increased the activity ratio of β-glucosidase (BG)/(N-acetyl-glucosaminidase (NAG) + LAP). Treatments with 25% manure substitution (1/4M) maintained maize and soybean yield, but with increasing manure rate, the maize yield decreased gradually. Overall, the high ratio of manure substitution enhanced SOC storage via increasing POC and MNC, and decreasing the decomposition potential of manure C and soil C resulting from low N- and P-requiring enzyme activities under high nutrient supplies. This study provides empirical evidence that the rational substitution of chemical fertilizers with manure is an effective measure to improve the availability of nutrients, and its effect on increasing crop yields still needs to be continuously observed, which is still a beneficial choice for enhancing black soil fertility. Full article

Ancient tea plantations possess extremely important economic and cultivation value. In China, ancient tea plantations with trees over 100 years old have been preserved. However, the status of soil microorganisms, soil fertility, and soil heavy metal pollution in these ancient tea plantations remains unclear. This study took four Dancong ancient tea plantations in Fenghuang, Chaozhou City, and Guangdong Province as the research objects. Soil samples were collected from the surface layer (0–20 cm) and subsurface layer (20–40 cm) of the ancient tea trees. The rhizosphere soil microbial diversity and soil nutrients were determined. On this basis, the soil fertility was evaluated by referring to the soil environmental quality standards so as to conduct a comprehensive evaluation of the soil in the Dancong ancient tea plantations. This study found that Proteobacteria, Acidobacteriota, Chloroflexi, and Actinobacteria were the dominant bacteria in the rhizosphere soil of the Dancong ancient tree tea plantation. Ascomycota and Mortierellomycota are the dominant fungal phyla. Subgroup_2, AD3, Acidothermus, and Acidibacter were the dominant bacterial genera. Saitozyma, Mortierella, and Fusarium are the dominant fungal genera. The redundancy analysis (RDA) revealed that at the bacterial phylum level, Verrucomicrobia showed positive correlations with alkali-hydrolyzable nitrogen (AN), available potassium (AK), and total nitrogen (TN); Proteobacteria exhibited a positive correlation with available phosphorus (AP); and Gemmatimonadetes was positively correlated with total potassium (TK). At the fungal phylum level, Ascomycota demonstrated a positive correlation with TK. TN, AN, and TK were identified as key physicochemical indicators influencing soil bacterial diversity, while TN, AN, AP, and AK were the key physicochemical indicators affecting soil fungal diversity. This study revealed that the soil of Dancong ancient tea plantations has reached Level I fertility in terms of TN, TP, SOM, and AP. TK and AN show Level I or near-Level I fertility, but AK only meets Level III fertility for tea planting, serving as the main limiting factor for soil fertility quality. Considering the relatively abundant TK content in the tea plantations, potassium-solubilizing bacteria should be prioritized over blind potassium fertilizer application. Meanwhile, it is particularly noteworthy that AN and SOM are at extremely high levels. Sustained excess of AN and SOM may lead to over-proliferation of dominant microorganisms, inhibition of other functional microbial communities, and disruption of ecological balance. Therefore, optimizing nutrient input methods during fertilization is recommended. Full article