Next Article in Journal
Exploring Natural Infection in Alternative Hosts of Corn Stunt Spiroplasma and Tracking the Temporal Dynamics of Corn Stunt Disease in the Brazilian Cerrado Biome
Previous Article in Journal
Use of Beauveria bassiana and Bacillus amyloliquefaciens Strains as Gossypium hirsutum Seed Coatings: Evaluation of the Bioinsecticidal and Biostimulant Effects in Semi-Field Conditions
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Agronomy
Volume 14
Issue 10
10.3390/agronomy14102339
agronomy-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Biochar, Organic Fertilizer, and Bio-Organic Fertilizer Improve Soil Fertility and Tea Quality

by
Rongxiu Yin
,
Lulu Li
,
Huifang Liu
,
Jianmei Yao
,
Chiyu Ma
,
Lulu Pu
and
Zhiwei Lei
*
Tea Research Institute, Guizhou Provincial Academy of Agricultural Sciences, Guiyang 550006, China
*
Author to whom correspondence should be addressed.
Agronomy 2024, 14(10), 2339; https://doi.org/10.3390/agronomy14102339
Submission received: 11 September 2024 / Revised: 7 October 2024 / Accepted: 9 October 2024 / Published: 11 October 2024
(This article belongs to the Section Soil and Plant Nutrition)
Browse Figures
Versions Notes

Abstract

:
Tea, the world’s second most traded commodity, significantly impacts the economies of producing countries. However, prolonged cultivation leads to soil degradation, particularly through acidification and the depletion of essential nutrients, which adversely affects tea quality. This study investigates the effects of biomass materials—biochar, organic fertilizer, and bio-organic fertilizer—on both tea quality and soil properties. The results revealed that all biomass treatments improved the catechin quality index (CQI) of tea, with bio-organic fertilizer (BOF) yielding the highest CQI at 629.41, followed closely by biochar (624.16) and organic fertilizer (581.34). Soil analysis indicated that biochar increased soil pH from 4.53 to 5.54, total carbon by 194.6% (from 12.61 g kg−1 to 24.42 g kg−1), and nitrogen levels by 11.7% (from 14.91 mg kg−1 to 16.17 mg kg−1), while reducing soluble salts significantly. Furthermore, biomass treatments enhanced enzyme activities, with urease and acid phosphatase increasing by up to 136.6% and 149.5%, respectively. Correlation analysis revealed significant positive relationships, with tea amino acid content correlating with soil total nitrogen (r = 0.62, p < 0.05) and tea polyphenols positively correlating with available potassium (r = 0.60, p < 0.05). This study demonstrates that integrating biomass materials into tea cultivation not only enhances tea quality but also contributes to soil health, supporting sustainable tea garden management practices.

1. Introduction

Green tea is a popular beverage worldwide, renowned for its distinctive taste, aroma, and color. The sensory characteristics of green tea are primarily influenced by active compounds such as polyphenols, amino acids, and catechins [1]. Among these, polyphenols are particularly significant, as they greatly contribute to the taste and color of green tea [2,3]. Studies have demonstrated a notable relationship between amino acids and the infusion color, taste, and aroma of green tea [4]. Moreover, the levels of catechins, caffeine, theanine, and free amino acids in green tea can vary depending on brewing conditions, further influencing its quality [5]. The composition and interaction of these active substances are crucial for evaluating and enhancing the quality of green tea products.
Assessing tea quality is a complex and multifaceted process involving both chemical composition and sensory attributes. Due to the inherently subjective nature of sensory analysis, the catechin quality index (CQI) serves as a valuable reference for tea evaluation [6,7,8]. Key quality indicators include tea polyphenols, caffeine, catechins, and amino acids [9]. Among these, catechins, a type of flavonoid, are particularly important for their antioxidant properties. Catechins offer various health benefits, including the prevention of oxidative stress and inflammation, and they may even have anti-cancer potential [10,11]. Therefore, enhancing the catechin content in tea could significantly improve its health-promoting properties.
The growth quality of tea is closely related to the physical and chemical properties of soil. Planting tea trees can lead to several changes in soil properties. One significant alteration is soil acidification, which occurs when tea plants absorb ammonia nitrogen and release protons, resulting in increased soil acidity [12,13]. Additionally, organic matter content may decrease due to the removal of biomass and insufficient replenishment, leading to diminished soil fertility. To increase yield, large amounts of chemical fertilizers are often applied. However, the use of chemical fertilizers can result in nutrient imbalances, particularly concerning nitrogen (N), phosphorus (P), and potassium (K) levels, potentially impacting soil health and tea quality [14]. Research shows that N enhances leaf development and chlorophyll production, which improves photosynthesis [15]. This process is crucial for accumulating essential compounds in tea leaves, including amino acids and polyphenols, ultimately affecting flavor and health benefits [16,17]. K regulates water uptake and enzyme activation, maintaining plant turgor and stress resistance [18]. It also promotes the synthesis of flavonoids and catechins, which are critical for the taste and antioxidant properties of tea [19]. Consequently, there is an urgent need to identify effective soil amendments that can replace chemical fertilizers.
Biomass materials derived from waste present a sustainable and environmentally friendly alternative for soil improvement. The use of biomass materials such as biochar, organic fertilizers, and bio-organic fertilizers has shown promising results in enhancing soil quality, nutrient availability, and plant growth in tea gardens [20,21,22]. Biochar improves soil structure, increases nutrient and water retention, and provides long-term benefits by enhancing soil pH and carbon sequestration [23,24]. Organic fertilizers, such as compost and manure, boost soil fertility by supplying essential nutrients, enhancing soil structure, and promoting microbial activity [25]. Bio-organic fertilizers combine organic matter with beneficial microorganisms to improve nutrient availability and plant health while supporting soil microbial activity [26,27]. Given these advantages, biomass materials are emerging as one of the most promising solutions for ameliorating tea garden soils and promoting sustainable agricultural practices.
This study focuses on Wuniu early tea (Camellia sinensis), a prominent green tea variety originating from Wuniu Town in Yongjia County, Zhejiang Province, China [28]. The primary objectives of this study are to (i) evaluate the effects of biochar, organic fertilizer, and bio-organic fertilizer on the nutritional quality of tea; (ii) examine how these three biomass materials alter the physical and chemical properties of the soil; and (iii) assess how soil properties, including pH, carbon (C), nitrogen, phosphorus, and soil enzyme activity, affect tea quality. The findings will provide valuable insights into the use of biomass materials in tea gardens and contribute to the sustainable development of tea garden ecosystems.

2. Materials and Methods

2.1. Experimental Site Description and Sampling

From July 2023 to July 2024, a field experiment was conducted at Hongfengshan Yunchachang (26°55′60″ N, 106°47′07″ E) in Qingzhen City, Guizhou Province, China. Before the experiment, the tea plants had been growing for 16 years, with the tea garden remaining unfertilized for the last three years. The experiment was designed with individual treatment plots, each covering an area of 36 m2 (4 m × 9 m), with 108 tea plants planted in each plot. There is a 1 m small partition between adjacent tea rows in the plot. The region experiences a subtropical humid monsoon climate, and according to the Food and Agriculture Organization of the United Nations (FAO) soil classification, the soil in the area is classified as laterite. The soil characteristics were as follows: pH 4.85, organic carbon (OC) 34.82 g kg−1, total nitrogen (TN) 3.62 g kg−1, total phosphorus (TP) 1.86 g kg−1, total potassium (TK) 13.87 g kg−1, available phosphorus (AP) 142.57 mg kg−1, available potassium (AK) 548.31 mg kg−1, ammonia nitrogen (AN) 41.05 mg kg−1, and nitrate nitrogen (NN) 45.08 mg kg−1.
The experiment comprised four treatments: control (CK, no fertilization), biochar (B), organic fertilizer (OF), and bio-organic fertilizer (BOF). A randomized block design with three replicates for each treatment. Wuniu early tea (Camellia sinensis), a representative green tea in Guizhou, was the focus of this study. All biomass materials were applied as base fertilizers, sprayed on the soil surface, and then incorporated into the soil to a depth of 0–20 cm. Pest control, weeding, and water management measures are the same. The recommended application rate for biochar, organic fertilizer, and bio-organic fertilizer by local farmers was 150 kg ha−1. The biomass materials used in the experiment were tobacco biochar, organic fertilizer, and bio-organic fertilizer. Biochar (garland) was sourced from Guizhou Shike Jinnian Biotechnology Co., Ltd. (Guiyang, China) with a composition of organic carbon ≥ 50%, ash ≥ 20%, moisture ≤ 15%, and a pH of 10. The organic fertilizer was purchased from Guizhou Wulian Fertilizer Co., Ltd. (Guiyang, China). The bio-organic fertilizer was obtained from Chongqing Jiakang Technology Co., Ltd. (Chongqing, China), containing effective strains of Bacillus subtilis and Bacillus mucilaginosus, with a viable bacterial count of 500 million g−1. The nutrients of the three biomass materials are shown in Table 1.
After the tea was harvested in June 2024, soil samples (0–20 cm depth) were randomly collected from five points in each plot using a soil auger. The soil from each plot was thoroughly mixed to create a composite sample for subsequent analysis. The composite samples were then divided into two portions: one portion was air-dried for soil chemical property analysis, while the other was used for soil enzyme activity analysis. Simultaneously, tea plant samples were collected during the harvest to measure various nutritional quality parameters.

2.2. Soil Physical and Chemical Properties

Soil pH was measured using a pH meter (SevenCompact, S220) after shaking a mixture of soil and distilled water at a ratio of 1:5 for 30 min. Soil organic carbon (OC) was quantified using the K2Cr2O7-H2SO4 oxidation method, as described by Nelson and Sommers [29]. Soil ammonia nitrogen and nitrate nitrogen were determined according to the method described by Zhong et al. [30]. TC and TN contents were measured using an elemental analyzer (Vario EL Cube, Elementar, Hanau, Germany). TP content was determined using an H2SO4-HClO4 digestion followed by molybdenum–antimony colorimetry [31]. Soil available phosphorus was measured using molybdenum–antimony spectrophotometry, as detailed by Zhang and Gong [32]. AK was measured using 1 M NH4OAc extracts and analyzed by flame atomic absorption spectrophotometry. Soluble total nitrogen was determined using the sulfate digestion method as described by Hood-Nowotny et al. [33]. Soluble salts (SS) were measured according to the method outlined by Bado et al. [34]. Fresh soil samples were weighed, dried at 105 °C for 12 h, and weighed again to determine soil moisture content (SMC). Soil enzyme activities, including invertase (INV), acid phosphatase (ACP), and urease (URE), were measured following the methods described by Hou et al. [35].

2.3. Nutrient and Quality Analysis of Tea

The pretreatment of tea samples, including drying, grinding, and screening, and the analysis of dry matter weight (DMW) were performed according to the national standard (GB/T 8303). The water extract was determined using the standard method (ISO 1572-80). Total ash (TA) content was measured following the standard method (ISO 1572-87). The contents of tea polyphenols, gallic acid (GA), catechin (C), epigallocatechin (EGC), epicatechin (EC), epigallocatechin gallate (EGCG), epicatechin gallate (ECG), total catechin (total C), and caffeine were determined using HPLC by the national standard (GB/T 8313-2018). The total amount of free amino acids was also determined by HPLC, as specified by the national standard (GB/T 23193-2017). Additionally, theobromine and theacrine in tea were quantified using HPLC according to the national standard (NY/T 3631-2020).

2.4. Catechin Quality Index Calculation

CQI is a parameter used to assess the quality of tea [7,36]. A higher CQI indicates better tenderness and quality of fresh leaves, leading to higher-quality green tea. Conversely, as the grade of green tea and the quality of fresh leaves decrease, the CQI also decreases [37]. The calculation formula for the CQI is as follows:
C Q I = E G C G + E C G × 100 / E G C .

2.5. Statistical Analysis

All data were analyzed using the Excel plug-in XLSTAT (version 2019.2.2) for variance analysis (ANOVA) with a Least Significant Difference (LSD) test and correlation analyses to evaluate soil physical and chemical properties, enzyme activity, and tea nutritional quality. Data are presented as mean ± standard deviation. Post-analysis data were plotted using Origin software (version 2022), and Cytoscape (version 3.10.1) was used to create the correlation network diagram.

3. Results

3.1. Effects of Different Biomass Materials on Quality of Tea

The effects of different biomass materials on the nutritional quality of tea (Figure 1a–j). In terms of water-soluble matter, B, OF, and BOF were lower than CK, which had a water-soluble matter content of 45.70% (Figure 1a). There was no significant difference in total ash content among the four treatments (p < 0.05), and the total ash contents of CK, B, BF, and BOF were 4.94 (%), 4.89 (%), 4.89 (%), and 4.96 (%), respectively (Figure 1b). Generally, the results for dry matter content and moisture content show an inverse relationship (Figure 1c,d). Specifically, OF exhibited the highest dry matter content (95.29%) but the lowest moisture content (4.71%). Tea polyphenols exhibited the highest content, ranging from 17% to 18% (Figure 1e). However, compared to CK, which had a polyphenol content of 17.97%, the levels in the other three treatments were slightly lower. Additionally, amino acids and caffeine contents were relatively high, ranging from 3% to 5%, with the highest levels observed in B treatment (Figure 1f,g). OF had the highest gallic acid (0.07%) and theacrine (0.02%) contents among the treatments (Figure 1i,j).
The results for catechins are presented in Figure 2. There was no significant difference in the total amount of catechins among the four treatments (p < 0.05). The total catechin content was highest in CK at 10.49%, followed by B at 10.35%, OF at 10.13%, and BOF at 9.80%. Specifically, the contents of EGC, C, EC, and EGCG in B, OF, and BOF were lower compared to CK. However, the content of EGC was higher in B (2.68%), OF (2.54%), and BOF (2.63%) compared to CK (2.49%). The catechin quality index was calculated, showing values of 545.58 for CK, 624.16 for B, 581.34 for OF, and 629.41 for BOF. All treatments had higher catechin quality index values than CK. Thus, from the perspective of catechin quality, the application of biochar, organic fertilizer, and bio-organic fertilizer enhanced the nutritional quality of tea.

3.2. Effects of Biomass Materials on Soil Physical and Chemical Properties

Soil properties, including SWC, SS, pH, carbon-related indicators, nitrogen-related indicators, phosphorus-related indicators, and potassium-related indicators, are shown in Table 2. The application of B, OF, and BOF reduced SWC compared to CK. However, SS content was significantly increased in all three treatments (p < 0.05), with increases of 112.1%, 670.1%, and 297.3% for B, OF, and BOF, respectively. Additionally, the input of biomass materials raised pH by 22.4%, 6.5%, and 9.6%, respectively. Phosphorus-related results indicated that compared to CK, the treatments with B, OF, and BOF reduced TP but significantly increased AP content (p < 0.05). Among them, BOF had the most pronounced effect, reducing TP by 42.7% and increasing AP by 85.4%. In contrast, the addition of the three materials increased TK, but AK decreased. The results for B showed that TC in B, OF, and BOF increased significantly by 194.6%, 130.1%, and 79.49%, respectively, compared to CK (p < 0.05). DOC and TC followed the same trend. However, B significantly increased OC by 8.4%, while OF and BOF significantly reduced OC by 8.9% and 42.2%, respectively (p < 0.05). Nitrogen-related results indicated that compared to CK, TN in B, OF, and BOF increased by 11.7%, 8.2%, and 0.9%, respectively (p < 0.05). Notably, compared to CK, B, and OF significantly reduced AN content, while BOF significantly increased AN (p < 0.05). B and BOF decreased NN, whereas OF increased NN. Additionally, DTN content in B, OF, and BOF soils increased by 552.3%, 624.3%, and 939.4%, respectively.

3.3. Effect of Biomass Materials on Soil Enzyme Activity

After adding biomass materials, the activities of soil invertase, acid phosphatase, and urease were generally significantly increased (with the invertase activity of BOF being nearly the same as CK) (p < 0.05) (Figure 3). Specifically, compared to CK, invertase activity increased by 55.5% for B and 27.4% for OF. Acid phosphatase activity increased by 41.8%, 144.1%, and 149.5% for B, OF, and BOF, respectively. Urease activity increased by 90.8%, 133.1%, and 136.6% for B, OF, and BOF, respectively.

3.4. Correlation between Tea Nutritional Quality and Soil Variables

Figure 4 shows the correlation analysis within the soil–tea nutrient quality system under different biomass materials, as depicted in Figure 4. Tea amino acid content was significantly positively correlated with TN (r = 0.62, p < 0.05). Tea polyphenol content was significantly positively correlated with AK (r = 0.60) and significantly negatively correlated with AP, SS, URE, ACP, and DNT, with correlation coefficients of −0.59, −0.59, −0.67, −0.66, and −0.60, respectively (p < 0.05). Caffeine was significantly negatively correlated with TN (r = −0.62, p < 0.05). ECG was significantly positively correlated with TN (p < 0.05). Theophylline was negatively correlated with TN (r = −0.68). No significant correlation (positive or negative) was observed between theacrine, GA, C, EC, EGCG, Total C, CQI, and soil parameters. Water extractables were positively correlated with theobromine and EGC.
In addition, there are notable links between tea nutritional quality parameters. Specifically, DMW was positively correlated with theacrine and C, with correlation coefficients of 0.64 and 0.72, respectively. Water extractables and tea polyphenols showed a significant positive relationship with theobromine and EGC, with correlation coefficients of 0.64 and 0.61, respectively (p < 0.05). Amino acid content was negatively correlated with caffeine and theobromine.

4. Discussion

Compared to CK, the application of B and BOF increased the contents of WC, amino acids, and GA. The CQI values of B, OF, and BOF were significantly higher than those of CK (p < 0.05), with B and BOF showing more pronounced effects. Our results indicated that B and BOF increased soil attributes such as SS, pH, AP, TK, DOC, TC, TN, and DTN while decreasing SWC, TP, and AK. Additionally, we observed that B, OF, and BOF increased soil URE and ACP, but for invertase, BOF and the other treatments exhibited a declining trend.
Biochar, organic fertilizer, and bio-organic fertilizer can influence the solubility of compounds in tea, potentially altering their extraction efficiency. A general inverse relationship was observed between dry matter content and water content (Figure 1). Typically, higher dry matter content correlates with a greater concentration of solid components, which can impact tea density and overall quality [38]. Conversely, lower moisture content might affect the storage stability and processing characteristics of tea [39]. Kaneko et al. [40] reported that approximately 70% of the umami intensity in green tea is attributed to amino acids. Additionally, caffeine influences both the flavor and the irritating properties of tea [41]. Biochar has been shown to enhance amino acids and caffeine in tea, thereby improving its overall quality. Yang et al. [42] found that the addition of biochar increased amino acids and caffeine by 28.2% and 16.7%, respectively (compared to CK). Furthermore, gallic acid and theophylline play crucial roles in determining tea flavor. Our results indicate that organic fertilizers can elevate these beneficial compounds, potentially enhancing tea quality. Catechins, important bioactive compounds in tea, offer various health benefits [43]. The catechin quality index revealed that biochar, organic fertilizer, and bio-organic fertilizer improved overall catechin quality, consistent with previous findings [44,45,46].
Our results suggest that the application of biochar, organic fertilizer, and bio-organic fertilizer can significantly affect the physical and chemical properties of soil. They can lead to a decrease in SWC, likely due to changes in soil structure and water retention characteristics. DeLuca et al. [47] observed that biochar increased soil pH and reduced soil bulk density, thereby enhancing soil fertility and structure. Bio-organic fertilizer not only promotes the formation of aggregate structures but also reduces soil bulk density, increases soil porosity, and improves hydraulic conductivity [48]. The decrease in TP and increase in AP suggest that biomass materials improved phosphorus utilization in tea plants [49], contributing to better plant nutrition and growth. The application of biochar, organic fertilizer, and bio-organic fertilizer led to increases in TC and DOC, reflecting higher carbon content and potential benefits for soil fertility [42,46]. Biochar, which contains a large amount of ash, can directly increase the content of TC and DOC [50]. Bio-organic fertilizer, containing substantial organic matter, decomposes in the soil with microorganisms to form stable organic carbon [51]. Liu, Cui, Wu, Qi, Chen, Ye, Ma and Liu [22] reported that OF boosted both DOC and TN content. Similarly, Ansari and Mahmood [52] found that BOF enhanced soil water holding capacity and nutrient utilization. The application of these materials in tea gardens improved soil physical properties and nutrient content, consistent with previous findings. However, the differing effects on AN and NN suggest that the type of biomass material influences nitrogen dynamics in the soil. Appropriate management is crucial for optimizing nitrogen use and avoiding potential imbalances.
This study also revealed that biomass materials improve the nutritional quality of tea by affecting soil enzyme activity. Enzymes such as sucrase, acid phosphatase, and urease are essential for soil fertility and nutrient cycling, impacting various soil processes critical to ecosystem function [53,54]. The general increase in soil enzyme activity suggests that biomass materials positively affect soil biological processes. Azeem et al. [55] found that co-inoculation of B. cereus with biochar significantly increased urease and phosphatase activities, improving microbial biomass and crop growth. Similarly, Wang et al. [56] investigated the effects of wheat straw and biochar application on soil carbon content, enzyme activity, and nutrients in tobacco fields, finding that straw return improved soil fertility by increasing active organic carbon content, stimulating enzyme activity, and releasing more effective nutrients.
Correlation analysis between the soil physical and chemical and tea nutrition quality system revealed that tea amino acid content was positively correlated with soil TN (r = 0.62, p < 0.05) (Figure 4). An appropriate application of nitrogen fertilizer can promote the growth of tea plants and indirectly affect the synthesis of amino acids. Studies have shown that nitrogen can synthesize amino acids through transaminases [57]. TN is crucial for protein synthesis and can enhance amino acid accumulation in tea plants [58]. Thus, soil nitrogen availability may directly influence tea’s nutritional quality. The negative correlation with AP, SS, URE, ACP, and DNT indicates that higher levels of these factors might be associated with lower polyphenol content. Previous studies showed that excessive AP may inhibit the absorption of nitrogen, which in turn affects the synthesis of tea polyphenols [22,59]. What is not difficult to find is that high soil salinity can induce osmotic stress in plants, typically altering metabolic pathways and leading to reduced polyphenol synthesis [60]. As a strong reducing agent, tea polyphenols may inhibit the active site of urease, thereby reducing the catalytic efficiency of urease. This inhibitory effect may be one of the important reasons for the negative correlation between tea polyphenols and urease [61,62]. ACP plays a key role in the phosphorus cycle in soil. Elevated ACP activity may suggest that plants prioritize phosphorus assimilation over the synthesis of secondary metabolites, such as polyphenols [63]. High levels of available phosphorus in soil can promote rapid plant growth and nutritional development, potentially leading to a “dilution effect” that reduces the concentration of secondary metabolites, such as polyphenols in tea [19,64].
ECG was positively correlated with TN, suggesting that higher nitrogen utilization can promote ECG synthesis in tea, potentially enhancing its antioxidant properties [65]. Nitrogen positively affects the polyphenol pathway, resulting in increased production of catechins, including ECG. Increased nitrogen availability can up-regulate enzymes such as phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS) in the catechin biosynthesis pathway, converting phenylalanine into flavonoid compounds and ultimately synthesizing more catechins [17,66]. The positive correlation indicates that higher DMW is associated with increased levels of theacrine and catechins, implying that tea plants with more dry matter may accumulate greater amounts of these beneficial compounds. Ji et al. [67] found a positive correlation between water extractables and both theobromine and catechins, reinforcing our findings on the relationship between biomass materials and tea quality. Furthermore, the positive correlation between EGC and water extract, polyphenols, and theobromine arises because these compounds are part of the same metabolic network in tea plants. Factors that promote the synthesis of EGC also tend to enhance the overall levels of soluble solids (water extract), total polyphenols, and theobromine, leading to the observed correlations.

5. Conclusions

Biochar, organic fertilizer, and bio-organic fertilizer positively influenced tea quality by enhancing amino acids, caffeine, and catechin quality. Compared to CK, biochar notably increased amino acid and caffeine levels (increase 4.1% and 2.2%), while OF boosted gallic acid and theacrine contents (increase 30.8% and 20%). The catechin quality index was improved across all treatments. Among them, the CQI of BOF increased the most, reaching 629.41. Correlation analysis indicated that higher soil TN was associated with increased tea amino acid content, while excessive phosphorus and salinity negatively affected polyphenol levels. The network analysis highlighted that biochar had the most extensive influence on both tea quality and soil properties, with organic and bio-organic fertilizers also showing beneficial but varied effects. Overall, the study underscores the potential of biomass materials to enhance tea quality and soil health, emphasizing the need for tailored application strategies to optimize their benefits. However, our research has limitations. The amount and usage of materials are equally important to the quality of tea. However, our research has limitations; the quantity and application methods of these materials are equally crucial to tea quality. Therefore, further investigation is needed to determine the optimal amounts and application strategies for each biomass type.

Author Contributions

Methodology, Z.L.; Formal analysis, R.Y.; Investigation, H.L. and J.Y.; Data curation, R.Y., L.L. and Z.L.; Writing—original draft, R.Y., L.L. and Z.L.; Writing—review and editing, R.Y., L.L., H.L., J.Y., C.M., L.P. and Z.L.; Supervision, J.Y., C.M. and L.P. All authors have read and agreed to the published version of the manuscript.

Funding

This research was supported by the Guizhou Provincial Key Technology R&D Program ([2023]036), the Guizhou Provincial Basic Research Program (Natural Science No. Qiankehe foundation [2022]224), the Guizhou Academy of Agricultural Sciences JBGS [2024]05.

Data Availability Statement

The data are contained within the article; further inquiries may be directed to the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Yu, P.; Yeo, A.S.-L.; Low, M.-Y.; Zhou, W. Identifying key non-volatile compounds in ready-to-drink green tea and their impact on taste profile. Food Chem. 2014, 155, 9–16. [Google Scholar] [CrossRef]
  2. Jiang, H.; Xu, W.; Chen, Q. Determination of tea polyphenols in green tea by homemade color sensitive sensor combined with multivariate analysis. Food Chem. 2020, 319, 126584. [Google Scholar] [CrossRef] [PubMed]
  3. Jiang, Z.; Han, Z.; Zhu, M.; Wan, X.; Zhang, L. Effects of thermal processing on transformation of polyphenols and flavor quality. Curr. Opin. Food Sci. 2023, 51, 101014. [Google Scholar] [CrossRef]
  4. Liang, Y.; Ye, Q.; Jin, J.; Liang, H.; Lu, J.; Du, Y.; Dong, J. Chemical and instrumental assessment of green tea sensory preference. Int. J. Food Prop. 2008, 11, 258–272. [Google Scholar] [CrossRef]
  5. Zhang, H.; Li, Y.; Lv, Y.; Jiang, Y.; Pan, J.; Duan, Y.; Zhu, Y.; Zhang, S. Influence of brewing conditions on taste components in Fuding white tea infusions. J. Sci. Food Agric. 2017, 97, 2826–2833. [Google Scholar] [CrossRef]
  6. An, T.; Li, Y.; Tian, X.; Fan, S.; Duan, D.; Zhao, C.; Huang, W.; Dong, C. Evaluation of aroma quality using multidimensional olfactory information during black tea fermentation. Sens. Actuators B Chem. 2022, 371, 132518. [Google Scholar] [CrossRef]
  7. Yao, L.; Caffin, N.; D’arcy, B.; Jiang, Y.; Shi, J.; Singanusong, R.; Liu, X.; Datta, N.; Kakuda, Y.; Xu, Y. Seasonal variations of phenolic compounds in Australia-grown tea (Camellia sinensis). J. Agric. Food Chem. 2005, 53, 6477–6483. [Google Scholar] [CrossRef]
  8. Jin, J.-Q.; Ma, J.-Q.; Ma, C.-L.; Yao, M.-Z.; Chen, L. Determination of catechin content in representative Chinese tea germplasms. J. Agric. Food Chem. 2014, 62, 9436–9441. [Google Scholar] [CrossRef]
  9. Zhang, Q.; Zhang, Y.; Xie, J.; Ye, J.; Pang, X.; Jia, X. Differences in the analysis of the quality indexes and characteristic amino acids of the different grades of Wuyi Shuixian (Camellia sinensis) tea. Food Sci. Technol. 2022, 42, e66122. [Google Scholar] [CrossRef]
  10. Cheng, Z.; Zhang, Z.; Han, Y.; Wang, J.; Wang, Y.; Chen, X.; Shao, Y.; Cheng, Y.; Zhou, W.; Lu, X. A review on anti-cancer effect of green tea catechins. J. Funct. Foods 2020, 74, 104172. [Google Scholar] [CrossRef]
  11. Fan, F.-Y.; Sang, L.-X.; Jiang, M. Catechins and their therapeutic benefits to inflammatory bowel disease. Molecules 2017, 22, 484. [Google Scholar] [CrossRef] [PubMed]
  12. Wan, Q.; Xu, R.-K.; Li, X.-H. Proton release from tea plant (Camellia sinensis L.) roots induced by Al (III) under hydroponic conditions. Soil Res. 2012, 50, 482–488. [Google Scholar] [CrossRef]
  13. Lin, S.; Liu, Z.; Wang, Y.; Li, J.; Wang, G.; Zhang, W.; Wang, H.; He, H. Soil acidification associated with changes in inorganic forms of N reduces the yield of tea (Camellia sinensis). Arch. Agron. Soil Sci. 2023, 69, 1660–1673. [Google Scholar] [CrossRef]
  14. Peñuelas, J.; Sardans, J. The global nitrogen-phosphorus imbalance. Science 2022, 375, 266–267. [Google Scholar] [CrossRef] [PubMed]
  15. Mu, X.; Chen, Y. The physiological response of photosynthesis to nitrogen deficiency. Plant Physiol. Biochem. 2021, 158, 76–82. [Google Scholar] [CrossRef]
  16. Zhou, B.; Chen, Y.; Zeng, L.; Cui, Y.; Li, J.; Tang, H.; Liu, J.; Tang, J. Soil nutrient deficiency decreases the postharvest quality-related metabolite contents of tea (Camellia sinensis (L.) Kuntze) leaves. Food Chem. 2022, 377, 132003. [Google Scholar] [CrossRef]
  17. Huang, H.; Yao, Q.; Xia, E.; Gao, L. Metabolomics and transcriptomics analyses reveal nitrogen influences on the accumulation of flavonoids and amino acids in young shoots of tea plant (Camellia sinensis L.) associated with tea flavor. J. Agric. Food Chem. 2018, 66, 9828–9838. [Google Scholar] [CrossRef] [PubMed]
  18. Johnson, R.; Vishwakarma, K.; Hossen, M.S.; Kumar, V.; Shackira, A.; Puthur, J.T.; Abdi, G.; Sarraf, M.; Hasanuzzaman, M. Potassium in plants: Growth regulation, signaling, and environmental stress tolerance. Plant Physiol. Biochem. 2022, 172, 56–69. [Google Scholar] [CrossRef]
  19. Wei, K.; Liu, M.; Shi, Y.; Zhang, H.; Ruan, J.; Zhang, Q.; Cao, M. Metabolomics reveal that the high application of phosphorus and potassium in tea plantation inhibited amino-acid accumulation but promoted metabolism of flavonoid. Agronomy 2022, 12, 1086. [Google Scholar] [CrossRef]
  20. Wang, H.; Hu, T.; Wang, M.; Liang, Y.; Shen, C.; Xu, H.; Zhou, Y.; Liu, Z. Biochar addition to tea garden soils: Effects on tea fluoride uptake and accumulation. Biochar 2023, 5, 37. [Google Scholar] [CrossRef]
  21. Gu, S.; Hu, Q.; Cheng, Y.; Bai, L.; Liu, Z.; Xiao, W.; Gong, Z.; Wu, Y.; Feng, K.; Deng, Y. Application of organic fertilizer improves microbial community diversity and alters microbial network structure in tea (Camellia sinensis) plantation soils. Soil Tillage Res. 2019, 195, 104356. [Google Scholar] [CrossRef]
  22. Liu, W.; Cui, S.; Wu, L.; Qi, W.; Chen, J.; Ye, Z.; Ma, J.; Liu, D. Effects of bio-organic fertilizer on soil fertility, yield, and quality of tea. J. Soil Sci. Plant Nutr. 2023, 23, 5109–5121. [Google Scholar] [CrossRef]
  23. Rahman, G.M.; Rahman, M.M.; Alam, M.S.; Kamal, M.Z.; Mashuk, H.; Datta, R.; Meena, R.S. Biochar and organic amendments for sustainable soil carbon and soil health. In Carbon and Nitrogen Cycling in Soil; Springer: Singapore, 2020; pp. 45–85. [Google Scholar] [CrossRef]
  24. Tan, M. Conversion of agricultural biomass into valuable biochar and their competence on soil fertility enrichment. Environ. Res. 2023, 234, 116596. [Google Scholar] [CrossRef] [PubMed]
  25. Ho, T.T.K.; Le, T.H.; Tran, C.-S.; Nguyen, P.-T.; Thai, V.-N.; Bui, X.-T. Compost to improve sustainable soil cultivation and crop productivity. Case Stud. Chem. Environ. Eng. 2022, 6, 100211. [Google Scholar] [CrossRef]
  26. Ye, L.; Zhao, X.; Bao, E.; Li, J.; Zou, Z.; Cao, K. Bio-organic fertilizer with reduced rates of chemical fertilization improves soil fertility and enhances tomato yield and quality. Sci. Rep. 2020, 10, 177. [Google Scholar] [CrossRef]
  27. Hafez, M.; Popov, A.I.; Rashad, M. Integrated use of bio-organic fertilizers for enhancing soil fertility–plant nutrition, germination status and initial growth of corn (Zea mays L.). Environ. Technol. Innov. 2021, 21, 101329. [Google Scholar] [CrossRef]
  28. Xu, R.; Xu, Z.; Lin, G.; Hu, L.; Wang, X.; Ma, J. Effect of Repeated Wuniu Early Tea Administration on the CYP450 Activity Using a Cocktail Method. Indian J. Pharm. Sci. 2013, 75, 94–98. [Google Scholar] [CrossRef]
  29. Nelson, D.W.; Sommers, L.E. Total carbon, organic carbon, and organic matter. In Methods of Soil Analysis: Part 3 Chemical Methods; American Society of Agronomy, Inc.: Madison, WI, USA, 1996; Volume 5, pp. 961–1010. [Google Scholar] [CrossRef]
  30. Zhong, X.; Zhou, X.; Luo, G.; Huang, Y.; Wu, Y.; Cao, R.; Tian, C.; Peng, J. Soil mineral nitrogen, soil urease activity, nitrogen losses and nitrogen footprint under machine-planted rice with side-deep fertilization. Plant Soil 2024, 494, 185–202. [Google Scholar] [CrossRef]
  31. Vaz, S. Chemical Analyses for Agriculture. In Sustainable Agrochemistry: A Compendium of Technologies; Vaz, S., Jr., Ed.; Springer International Publishing: Cham, Switzerland, 2019; pp. 147–182. [Google Scholar] [CrossRef]
  32. Zhang, G.; Gong, Z. Soil Survey Laboratory Methods; Science Press: Beijing, China, 2012; Volume 38, pp. 47–49. [Google Scholar]
  33. Hood-Nowotny, R.; Umana, N.H.-N.; Inselbacher, E.; Oswald-Lachouani, P.; Wanek, W. Alternative Methods for Measuring Inorganic, Organic, and Total Dissolved Nitrogen in Soil. Soil Sci. Soc. Am. J. 2010, 74, 1018–1027. [Google Scholar] [CrossRef]
  34. Bado, S.; Forster, B.P.; Ghanim, A.M.; Jankowicz-Cieslak, J.; Berthold, G.; Luxiang, L.; Bado, S.; Forster, B.P.; Ghanim, A.M.; Jankowicz-Cieslak, J. Protocol for measuring soil salinity. In Protocols for Pre-Field Screening of Mutants for Salt Tolerance in Rice, Wheat and Barley; Springer: Cham, Switzerland, 2016; pp. 13–19. [Google Scholar] [CrossRef]
  35. Hou, W.; Wang, J.; Nan, Z.; Christensen, M.J.; Xia, C.; Chen, T.; Zhang, Z.; Niu, X. Epichloë gansuensis endophyte-infection alters soil enzymes activity and soil nutrients at different growth stages of Achnatherum inebrians. Plant Soil 2020, 455, 227–240. [Google Scholar] [CrossRef]
  36. Jin, J.-Q.; Liu, Y.-F.; Ma, C.-L.; Ma, J.-Q.; Hao, W.-J.; Xu, Y.-X.; Yao, M.-Z.; Chen, L. A novel F3′ 5′ H allele with 14 bp deletion is associated with high catechin index trait of wild tea plants and has potential use in enhancing tea quality. J. Agric. Food Chem. 2018, 66, 10470–10478. [Google Scholar] [CrossRef]
  37. Kilel, E.; Faraj, A.; Wanyoko, J.; Wachira, F.; Mwingirwa, V. Green tea from purple leaf coloured tea clones in Kenya-their quality characteristics. Food Chem. 2013, 141, 769–775. [Google Scholar] [CrossRef] [PubMed]
  38. Aroyeun, S.O. Crude fibre, water extracts, total ash, caffeine and moisture contents as diagnostic factors in evaluating green tea quality. In World Sustainable Development Outlook 2012; World Association For Sustainable Development: Brighton, UK, 2012. [Google Scholar]
  39. Ocieczek, A.; Pukszta, T.; Żyłka, K.; Kirieieva, N. The influence of storage conditions on the stability of selected health-promoting properties of tea. LWT 2023, 184, 115029. [Google Scholar] [CrossRef]
  40. Kaneko, S.; Kumazawa, K.; Masuda, H.; Henze, A.; Hofmann, T. Molecular and sensory studies on the umami taste of Japanese green tea. J. Agric. Food Chem. 2006, 54, 2688–2694. [Google Scholar] [CrossRef] [PubMed]
  41. Keast, R.S. Modification of the bitterness of caffeine. Food Qual. Prefer. 2008, 19, 465–472. [Google Scholar] [CrossRef]
  42. Yang, W.; Li, C.; Wang, S.; Zhou, B.; Mao, Y.; Rensing, C.; Xing, S. Influence of biochar and biochar-based fertilizer on yield, quality of tea and microbial community in an acid tea orchard soil. Appl. Soil Ecol. 2021, 166, 104005. [Google Scholar] [CrossRef]
  43. Musial, C.; Kuban-Jankowska, A.; Gorska-Ponikowska, M. Beneficial properties of green tea catechins. Int. J. Mol. Sci. 2020, 21, 1744. [Google Scholar] [CrossRef]
  44. Zhang, N.; Reguyal, F.; Praneeth, S.; Sarmah, A.K. A green approach of biochar-supported magnetic nanocomposites from white tea waste: Production, characterization and plausible synthesis mechanisms. Sci. Total Environ. 2023, 886, 163923. [Google Scholar] [CrossRef]
  45. Raza, A.; Chaoqun, C.; Luo, L.; Asghar, M.A.; Li, L.; Shoaib, N.; Yin, C. Combined application of organic and chemical fertilizers improved the catechins and flavonoids biosynthesis involved in tea quality. Sci. Hortic. 2024, 337, 113518. [Google Scholar] [CrossRef]
  46. Hu, Z.; Ji, L.; Wan, Q.; Li, H.; Li, R.; Yang, Y. Short-term effects of bio-organic fertilizer on soil fertility and bacterial community composition in tea plantation soils. Agronomy 2022, 12, 2168. [Google Scholar] [CrossRef]
  47. DeLuca, T.H.; Gundale, M.J.; MacKenzie, M.D.; Jones, D.L. Biochar effects on soil nutrient transformations. In Biochar for Environmental Management; Routledge: Abingdon, UK, 2015; pp. 421–454. [Google Scholar]
  48. Meng, Q.; Ma, X.; Zhang, J.; Yu, Z. The long-term effects of cattle manure application to agricultural soils as a natural-based solution to combat salinization. Catena 2019, 175, 193–202. [Google Scholar] [CrossRef]
  49. Manzoor; Ma, L.; Ni, K.; Ruan, J. Effect of integrated use of rapeseed cake, biochar and chemical fertilizers on root growth, nutrients use efficiency and productivity of tea. Agronomy 2022, 12, 1823. [Google Scholar] [CrossRef]
  50. Liu, C.-H.; Chu, W.; Li, H.; Boyd, S.A.; Teppen, B.J.; Mao, J.; Lehmann, J.; Zhang, W. Quantification and characterization of dissolved organic carbon from biochars. Geoderma 2019, 335, 161–169. [Google Scholar] [CrossRef]
  51. Duan, C.; Li, J.; Zhang, B.; Wu, S.; Fan, J.; Feng, H.; He, J.; Siddique, K.H. Effect of bio-organic fertilizer derived from agricultural waste resources on soil properties and winter wheat (Triticum aestivum L.) yield in semi-humid drought-prone regions. Agric. Water Manag. 2023, 289, 108539. [Google Scholar] [CrossRef]
  52. Ansari, R.A.; Mahmood, I. Optimization of organic and bio-organic fertilizers on soil properties and growth of pigeon pea. Sci. Hortic. 2017, 226, 1–9. [Google Scholar] [CrossRef]
  53. Neemisha; Sharma, S. Soil enzymes and their role in nutrient cycling. In Structure and Functions of Pedosphere; Springer: Singapore, 2022; pp. 173–188. [Google Scholar] [CrossRef]
  54. Kooch, Y.; Noghre, N. Nutrient cycling and soil-related processes under different land covers of semi-arid rangeland ecosystems in northern Iran. Catena 2020, 193, 104621. [Google Scholar] [CrossRef]
  55. Azeem, M.; Hassan, T.U.; Tahir, M.I.; Ali, A.; Jeyasundar, P.G.S.A.; Hussain, Q.; Bashir, S.; Mehmood, S.; Zhang, Z. Tea leaves biochar as a carrier of Bacillus cereus improves the soil function and crop productivity. Appl. Soil Ecol. 2021, 157, 103732. [Google Scholar] [CrossRef]
  56. Wang, Y.; Dong, J.; Zheng, X.; Zhang, J.; Zhou, P.; Song, X.; Song, W.; Wang, S. Wheat straw and biochar effect on soil carbon fractions, enzyme activities, and nutrients in a tobacco field. Can. J. Soil Sci. 2021, 101, 353–364. [Google Scholar] [CrossRef]
  57. Chen, Y.; Wang, F.; Wu, Z.; Jiang, F.; Yu, W.; Yang, J.; Chen, J.; Jian, G.; You, Z.; Zeng, L. Effects of long-term nitrogen fertilization on the formation of metabolites related to tea quality in subtropical China. Metabolites 2021, 11, 146. [Google Scholar] [CrossRef]
  58. Yang, T.; Li, H.; Tai, Y.; Dong, C.; Cheng, X.; Xia, E.; Chen, Z.; Li, F.; Wan, X.; Zhang, Z. Transcriptional regulation of amino acid metabolism in response to nitrogen deficiency and nitrogen forms in tea plant root (Camellia sinensis L.). Sci. Rep. 2020, 10, 6868. [Google Scholar] [CrossRef]
  59. Tang, S.; Pan, W.; Tang, R.; Ma, Q.; Zhou, J.; Zheng, N.; Wang, J.; Sun, T.; Wu, L. Effects of balanced and unbalanced fertilisation on tea quality, yield, and soil bacterial community. Appl. Soil Ecol. 2022, 175, 104442. [Google Scholar] [CrossRef]
  60. Arif, Y.; Singh, P.; Siddiqui, H.; Bajguz, A.; Hayat, S. Salinity induced physiological and biochemical changes in plants: An omic approach towards salt stress tolerance. Plant Physiol. Biochem. 2020, 156, 64–77. [Google Scholar] [CrossRef] [PubMed]
  61. Sivapalan, K.; Fernando, V.; Thenabadu, M.W. N-mineralization in polyphenol-rich plant residues and their effect on nitrification of applied ammonium sulphate. Soil Biol. Biochem. 1985, 17, 547–551. [Google Scholar] [CrossRef]
  62. Lin, S.; Liu, Z.; Wang, Y.; Li, J.; Wang, G.; Ye, J.; Wang, H.; He, H. Soil metagenomic analysis on changes of functional genes and microorganisms involved in nitrogen-cycle processes of acidified tea soils. Front. Plant Sci. 2022, 13, 998178. [Google Scholar] [CrossRef] [PubMed]
  63. Al-Khayri, J.M.; Rashmi, R.; Toppo, V.; Chole, P.B.; Banadka, A.; Sudheer, W.N.; Nagella, P.; Shehata, W.F.; Al-Mssallem, M.Q.; Alessa, F.M. Plant secondary metabolites: The weapons for biotic stress management. Metabolites 2023, 13, 716. [Google Scholar] [CrossRef] [PubMed]
  64. Zhang, H.; Li, C.; Wei, K.; Liu, M.; Shi, Y.; Yang, X.; Fang, L.; Ruan, J.; Zhang, Q. The reduction of tea quality caused by irrational phosphate application is associated with anthocyanin metabolism. Beverage Plant Res. 2023, 3, 10. [Google Scholar] [CrossRef]
  65. Piyasena, K.N.P.; Hettiarachchi, L. Comparison of tea quality parameters of conventionally and organically grown tea, and effects of fertilizer on tea quality: A mini-review. Food Chem. Adv. 2023, 3, 100399. [Google Scholar] [CrossRef]
  66. Wang, Y.; Wang, Y.-M.; Lu, Y.-T.; Qiu, Q.-L.; Fan, D.-M.; Wang, X.-C.; Zheng, X.-Q. Influence of different nitrogen sources on carbon and nitrogen metabolism and gene expression in tea plants (Camellia sinensis L.). Plant Physiol. Biochem. 2021, 167, 561–566. [Google Scholar] [CrossRef]
  67. Ji, L.; Ni, K.; Wu, Z.; Zhang, J.; Yi, X.; Yang, X.; Ling, N.; You, Z.; Guo, S.; Ruan, J. Effect of organic substitution rates on soil quality and fungal community composition in a tea plantation with long-term fertilization. Biol. Fertil. Soils 2020, 56, 633–646. [Google Scholar] [CrossRef]
Agronomy 14 02339 g001
Figure 1. Effects of different biomass materials on (a) water soluble matter, (b) total ash, (c) moisture content, (d) dry matter weight, (e) tea polyphenols, (f) caffeine, (g) amino acid, (h) theophylline, (i) gallic acid, and (j) theacrine of tea. Different lowercase letters represent significant differences between different treatments at p < 0.05.
Figure 1. Effects of different biomass materials on (a) water soluble matter, (b) total ash, (c) moisture content, (d) dry matter weight, (e) tea polyphenols, (f) caffeine, (g) amino acid, (h) theophylline, (i) gallic acid, and (j) theacrine of tea. Different lowercase letters represent significant differences between different treatments at p < 0.05.
Agronomy 14 02339 g001
Agronomy 14 02339 g002
Figure 2. Effects of different biomass materials on (a) total catechin, (b) content of catechins, and (c) catechin quality index of tea. EGC, epigallocatechin; C, catechin; EGCG, epigallocatechin gallate; ECG, epicatechin gallate; EC, epicatechin. Different lowercase letters represent significant differences between different treatments at p < 0.05.
Figure 2. Effects of different biomass materials on (a) total catechin, (b) content of catechins, and (c) catechin quality index of tea. EGC, epigallocatechin; C, catechin; EGCG, epigallocatechin gallate; ECG, epicatechin gallate; EC, epicatechin. Different lowercase letters represent significant differences between different treatments at p < 0.05.
Agronomy 14 02339 g002
Agronomy 14 02339 g003
Figure 3. Effects of different biomass materials on (a) invertase, (b) acid phosphatase, and (c) urease activities. Different lowercase letters indicate significant differences between treatments at p < 0.05.
Figure 3. Effects of different biomass materials on (a) invertase, (b) acid phosphatase, and (c) urease activities. Different lowercase letters indicate significant differences between treatments at p < 0.05.
Agronomy 14 02339 g003
Agronomy 14 02339 g004
Figure 4. Correlation heat map analysis of tea nutritional quality and soil physical and chemical properties. SS, soluble salt; TP, total phosphorus; AP, available phosphorus; TK, total potassium; AK, available potassium; OC, organic carbon; DOC, dissolved organic carbon; TC, total carbon; TN, total nitrogen; AN, ammoniacal nitrogen; NN, nitrate nitrogen; DTN, dissolved total nitrogen; SMC, soil moisture content; DMW, dry matter weight; EGC, epigallocatechin; C, catechin; EGCG, epigallocatechin gallate; ECG, epicatechin gallate; EC, epicatechin; Total C, total catechin; TA, total ash; CQI, catechin quality index; URE, urease; INV, invertase; ACP, acid phosphatase. *, and ** show the correlations significant at the 0.05 and 0.01 levels.
Figure 4. Correlation heat map analysis of tea nutritional quality and soil physical and chemical properties. SS, soluble salt; TP, total phosphorus; AP, available phosphorus; TK, total potassium; AK, available potassium; OC, organic carbon; DOC, dissolved organic carbon; TC, total carbon; TN, total nitrogen; AN, ammoniacal nitrogen; NN, nitrate nitrogen; DTN, dissolved total nitrogen; SMC, soil moisture content; DMW, dry matter weight; EGC, epigallocatechin; C, catechin; EGCG, epigallocatechin gallate; ECG, epicatechin gallate; EC, epicatechin; Total C, total catechin; TA, total ash; CQI, catechin quality index; URE, urease; INV, invertase; ACP, acid phosphatase. *, and ** show the correlations significant at the 0.05 and 0.01 levels.
Agronomy 14 02339 g004
Table 1. Nutrient content of biomass materials.
Table 1. Nutrient content of biomass materials.
Biomass MaterialpHOrganic Matter (g kg−1)Total N (g kg−1)Total P (g kg−1)Total K (g kg−1)
Biochar9.21299.2813.252.6418.62
Organic fertilizer6.92250.329.5310.2418.15
Bio-organic fertilizer7.21250.7510.3810.4517.15
Table 2. Soil properties response to different biomass materials.
Table 2. Soil properties response to different biomass materials.
TreatmentSWC (%)SS (mg g−1)pHPKCN
TP
(g kg−1)		AP
(mg kg−1)		TK
(g kg−1)		AK
(mg kg−1)		OC
(g kg−1)		DOC
(mg kg−1)		TC
(g kg−1)		TN
(g kg−1)		AN
(mg kg−1)		NN
(mg kg−1)		DTN
(mg kg−1)
CK25.47 ± 1.61 a0.02 ± 0 c4.53 ± 0.22 b1.19 ± 0.22 a15.95 ± 2.86 c12.61 ± 0.31 a404.36 ± 7.49 a14.91 ± 1.6 ab58.69 ± 6.26 c7.57 ± 2.79 c1.16 ± 0.4 a13.73 ± 1.87 ab13.05 ± 2.49 ab22.12 ± 0.7 d
B23.84 ± 0.74 a0.04 ± 0.01 c5.54 ± 0.4 a0.75 ± 0.19 b18.2 ± 0.69 c14.7 ± 1.22 a276.69 ± 8.25 b16.17 ± 0.84 a142.42 ± 6.07 a22.3 ± 2.14 a1.3 ± 0.32 a6.01 ± 0.68 c9.33 ± 1.31 b144.28 ± 4.98 c
BOF24.78 ± 0.63 a0.13 ± 0.01 a4.82 ± 0.13 b0.68 ± 0.08 b29.57 ± 2.28 a13.22 ± 0.85 a267.72 ± 5.77 b8.62 ± 0.29 c69.33 ± 2.72 c13.58 ± 2.3 b1.17 ± 0.12 a15.92 ± 1.53 a8.76 ± 1.78 b160.22 ± 2.11 b
OF23.33 ± 2.2 a0.07 ± 0.02 b4.96 ± 0.19 b0.74 ± 0.17 b23.38 ± 1.74 b13.91 ± 2.32 a234.95 ± 9.87 c13.58 ± 1.85 b102.23 ± 0.25 b17.42 ± 1.87 b1.25 ± 0.13 a13.06 ± 0.96 b14.24 ± 1.88 a229.91 ± 3.18 a
Note: The values in the table are presented as mean ± SE (n = 3); the same letter in a column indicates no significant difference at p < 0.05 according to the least-significant difference (LSD). SWC, soil water content; SS, soluble salt; TP, total phosphorus; AP, available phosphorus; TK, total potassium; AK, available potassium; OC, organic carbon; DOC, dissolved organic carbon; TC, total carbon; TN, total nitrogen; AN, ammoniacal nitrogen; NN, nitrate nitrogen; DTN, dissolved total nitrogen.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Yin, R.; Li, L.; Liu, H.; Yao, J.; Ma, C.; Pu, L.; Lei, Z. Biochar, Organic Fertilizer, and Bio-Organic Fertilizer Improve Soil Fertility and Tea Quality. Agronomy 2024, 14, 2339. https://doi.org/10.3390/agronomy14102339

AMA Style

Yin R, Li L, Liu H, Yao J, Ma C, Pu L, Lei Z. Biochar, Organic Fertilizer, and Bio-Organic Fertilizer Improve Soil Fertility and Tea Quality. Agronomy. 2024; 14(10):2339. https://doi.org/10.3390/agronomy14102339

Chicago/Turabian Style

Yin, Rongxiu, Lulu Li, Huifang Liu, Jianmei Yao, Chiyu Ma, Lulu Pu, and Zhiwei Lei. 2024. "Biochar, Organic Fertilizer, and Bio-Organic Fertilizer Improve Soil Fertility and Tea Quality" Agronomy 14, no. 10: 2339. https://doi.org/10.3390/agronomy14102339

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Article metric data becomes available approximately 24 hours after publication online.
Back to TopTop