Method for increasing sugar, color and fragrance and reducing acid of kuerle fragrant pear

Abstract

The application discloses a method for increasing sugar, color, fragrance and reducing acid of Korla fragrant pear. The method is characterized in that organic water-soluble fertilizer is applied to young fruit expansion period of the fragrant pear, and high-nitrogen type, balanced type and high-potassium type water-soluble fertilizer containing humic acid are applied to fruit expansion period in batches, and the application is accurate through drip irrigation. The method adopts biomass biochemical cracking engineering technology, and through the synergistic effect of improving soil structure, enhancing photosynthesis and improving fertilizer utilization rate and the like, the fruit quality is significantly improved, the soluble sugar content is increased by 1.65% to 13.48%, the titratable acid content is reduced by 1.87% to 29.36%, the fruit skin redness value is increased by 96.68% to 105.53%, the number of aroma components is increased by 11.76% to 22.06%, the relative content of alcohol and olefin substances is obviously increased, the relative content of aldehyde substances is reduced, and the fruit and flower fragrance is more fragrant. The method is simple in operation, environment-friendly, can completely replace chemical fertilizer and meets the green food production standard.

Description

Technical Field

[0001] This application relates to the field of fruit tree cultivation technology, and in particular to a method for increasing the sugar content, color, aroma, and acidity of Korla fragrant pears. Background Technology

[0002] Korla fragrant pears, a distinctive geographical indication product of Xinjiang, are renowned for their vibrant appearance, rich aroma, thin skin, delicate flesh, and juicy, sweet taste. In recent years, however, due to factors such as climate change and improper cultivation management, the problems of "weak aroma and declining quality" have become prominent. Specifically, this manifests as poor peel coloring, increased flesh firmness, decreased soluble sugar content, increased titratable acid content, increased stone cells, and a less pronounced aroma. These issues directly impact their commercial economic value, market reputation, and competitiveness. Therefore, improving the quality and aroma of fragrant pears is one of the important challenges facing production and research.

[0003] Currently, research and applications on improving the quality and aroma of Korla pears mainly focus on tree shape control, soil management optimization, organic and inorganic fertilizer application, and the use of plant growth regulators. However, there is little research on the role of liquid organic water-soluble fertilizers in improving the quality and aroma of Korla pears, especially research and production practices on improving the aroma content of Korla pears before harvest through cultivation measures are rarely reported. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, this application proposes a new method for increasing the sugar content, color, aroma, and acidity of Korla fragrant pears.

[0005] This invention proposes the use of highly efficient, highly active organic water-soluble fertilizers and humic acid-containing water-soluble fertilizers, applied at different key growth stages of Korla pears, to enhance the sensory quality and aroma content of the fruit, increase its commercial value and economic benefits, and improve its market reputation. The organic water-soluble fertilizers and humic acid-containing water-soluble fertilizers used in this solution contain both mineral nutrients and organic nutrients such as amino acids, auxins, and fulvic acid, exhibiting high activity, rapid absorption, and high utilization rates. This invention innovatively applies biomass biochemical pyrolysis engineering technology to Korla pear cultivation. Through the synergistic effects of multiple pathways—improving soil aggregate structure, regulating pH balance, promoting plant growth, enhancing photosynthesis, and increasing fertilizer utilization—it significantly improves fruit quality and enhances aroma. This solution is technically simple to operate, environmentally friendly, and can completely replace chemical fertilizers to reduce their impact on soil and the ecosystem, providing a replicable and easily scalable new paradigm for improving the quality of geographical indication agricultural products.

[0006] To achieve the above objectives, the present invention employs the following technical strategies: (a) During the fruit enlargement period (10-15 days after flowering, around May 10), apply 50-150 kg of diluted organic water-soluble fertilizer per mu to the roots of the fragrant pear trees by drip irrigation.

[0007] (II) During the fruit enlargement period (45-120 days after flowering, mid-June to late August), apply 105 kg of diluted humic acid-containing water-soluble fertilizer per mu (approximately 0.067 hectares) to the roots of the fragrant pear trees in two separate applications. Specifically, in the early stage of fruit enlargement (around June 15th), apply 35 kg of diluted humic acid-containing water-soluble fertilizer (high nitrogen type) per mu to the roots of the fragrant pear trees. In the rapid fruit enlargement period (around July 15th), apply 35 kg of diluted humic acid-containing water-soluble fertilizer (balanced type) per mu to the roots of the fragrant pear trees. In the late stage of rapid fruit enlargement (August 10th and August 25th), apply 35 kg of diluted humic acid-containing water-soluble fertilizer (high potassium type) per mu to the roots of the fragrant pear trees, divided into two applications, each at 17.5 kg / mu.

[0008] (iii) The organic water-soluble fertilizer contains organic matter ≥150g / L, humic acid ≥150g / L, N+P2O5+K2O ≥60g / L (ratio 20:20:20), and pH 5.0-7.0.

[0009] (iv) The humic acid-containing water-soluble fertilizer contains humic acid ≥30g / L, fulvic acid ≥120g / L, high nitrogen type N+P2O5+K2O=120:45:40g / L, balanced type N+P2O5+K2O=70:70:70g / L, high potassium type N+P2O5+K2O=40:40:120g / L, and pH 6.0-8.5.

[0010] (v) The drip irrigation location is on both sides of the tree row, from the drip line of the canopy to 1 / 2 of the base of the trunk.

[0011] (vi) The organic water-soluble fertilizer is diluted 25-75 times, and the humic acid-containing water-soluble fertilizer is diluted 50-150 times to ensure that the solution penetrates evenly into the root distribution layer (30-40cm soil layer).

[0012] Specifically, this application provides the following technical solutions: This invention provides a method for increasing the sugar content, color, aroma, and acidity of Korla fragrant pears, such as... Figure 1 As shown, it includes the following steps: S1. Fertilization during the fruit enlargement period: 10-15 days after flowering, dilute the organic water-soluble fertilizer and drip irrigate the roots of the fragrant pear tree to ensure that the solution penetrates evenly into the root system's concentrated distribution layer. S2. First fertilization during the fruit enlargement period: 45-50 days after flowering, dilute the high-nitrogen water-soluble fertilizer containing humic acid and drip irrigate the roots of the fragrant pear tree to ensure that the solution penetrates evenly into the root system's concentrated distribution layer. S3. Second fertilization during the fruit enlargement period: 75-80 days after flowering, dilute the balanced humic acid-containing water-soluble fertilizer and drip irrigate the roots of the fragrant pear tree to ensure that the solution penetrates evenly into the root system's concentrated distribution layer. S4. The third and fourth fertilizations during the fruit enlargement period: 100-105 days after flowering and 115-120 days after flowering, respectively, dilute the high-potassium humic acid-containing water-soluble fertilizer and drip irrigate the roots of the fragrant pear trees to ensure that the solution penetrates evenly into the root system's concentrated distribution layer.

[0013] Furthermore, in the method of the present invention, the application rate of the organic water-soluble fertilizer in step S1 is 50-150 kg / mu, and the dilution ratio is 25-75 times.

[0014] Furthermore, in the method of the present invention, the organic water-soluble fertilizer in step S1 contains organic matter ≥150g / L, fulvic acid ≥150g / L, N+P2O5+K2O ≥60 g / L, and pH 5.0-7.0.

[0015] Furthermore, in the method of the present invention, the mass ratio of N:P2O5:K2O in the organic water-soluble fertilizer is 20:20:20.

[0016] Furthermore, in the method of the present invention, the application rate of the high-nitrogen humic acid-containing water-soluble fertilizer in step S2 is 35 kg / mu, and the dilution ratio is 50-150 times; The application rate of the balanced humic acid-containing water-soluble fertilizer mentioned in step S3 is 35 kg / mu, and the dilution ratio is 50-150 times. The total application rate of the high-potassium humic acid-containing water-soluble fertilizer mentioned in step S4 is 35 kg / mu, applied in two applications, with each application being 17.5 kg / mu and a dilution ratio of 50-150 times.

[0017] Furthermore, in the method of the present invention, the high-nitrogen, balanced, and high-potassium humic acid-containing water-soluble fertilizers contain humic acid ≥30g / L, fulvic acid ≥120g / L, and pH 6.0-8.5.

[0018] Furthermore, in the method of the present invention, the N:P2O5:K2O mass ratio of the high-nitrogen humic acid-containing water-soluble fertilizer is 120:45:40 g / L; the N:P2O5:K2O mass ratio of the balanced humic acid-containing water-soluble fertilizer is 70:70:70 g / L; and the N:P2O5:K2O mass ratio of the high-potassium humic acid-containing water-soluble fertilizer is 40:40:120 g / L.

[0019] Furthermore, in the method of the present invention, the drip irrigation location is located on both sides of the tree row at a distance of 1 / 2 from the drip line of the tree canopy to the base of the trunk.

[0020] Furthermore, in the method of the present invention, the root system concentrated distribution layer is a soil layer of 30–40 cm.

[0021] In summary, this invention significantly improves the overall quality of Korla fragrant pears through improved cultivation methods. Regarding internal quality, the soluble sugar content of the fruit increases by 1.65%-13.48%, while the titratable acid content decreases by 1.87%-29.36%, resulting in a significantly improved sugar-acid ratio. In terms of appearance quality, the peel redness value (a* value) increases by 96.68%-105.53%, significantly enhancing the coloring effect. Regarding aroma quality, this invention significantly increases the total amount of aroma compounds in the fragrant pear fruit, with the number of major aroma components increasing by 11.76%-22.06%. Specifically, the relative content of alcohols increases by 13.82%-66.72%, the relative content of olefins increases by 28.41%-74.58%, while the relative content of aldehydes decreases by 6.10%-52.59%, resulting in a more harmonious proportion of aroma components and a richer fruit and floral aroma.

[0022] In addition, this technology is easy to operate and environmentally friendly. It can completely replace chemical fertilizers, effectively reducing the negative impact of chemical fertilizers on soil and the ecological environment, and meets the standards for green food production.

[0023] Other features and advantages of this application will be set forth in detail in the following description, or will become apparent through the implementation of the relevant technical solutions of this application. The objectives and other advantages of this application can be achieved through the technical features and means explicitly pointed out in the description, claims, and drawings, and will be obtained through the implementation of these technical contents. Attached Figure Description

[0024] To more clearly illustrate the technical solution of this application, the accompanying drawings involved in the description of this invention will be briefly introduced below. It should be noted that the drawings only show some embodiments of the invention. For those skilled in the art, other related drawings can be derived from these drawings without creative effort.

[0025] Figure 1 The flowchart illustrates the implementation process of the method for increasing the sugar content, color, aroma, and acidity of Korla fragrant pears according to the present invention.

[0026] Figure 2 This is a schematic diagram showing the relative content of aroma components in pears treated with different methods in this invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of this application, and this application can also be implemented or applied through other different specific implementation methods. The details in this specification can also be modified or changed based on different viewpoints and applications.

[0028] At the same time, it should be understood that the scope of protection of this application is not limited to the specific implementation schemes described below; it should also be understood that the terminology used in the embodiments of this application is for describing specific implementation schemes, and not for limiting the scope of protection of this application.

[0029] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this application, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical terms used in this application have the same meaning as commonly understood by those skilled in the art. In addition to the specific methods, equipment, and materials used in the embodiments, based on the knowledge of those skilled in the art and the description in this application, any prior art methods, equipment, and materials similar to or equivalent to those described, used, and materials in the embodiments of this application may be used to implement this application. In this application, unless otherwise specified, all parts and percentages are in units of weight, and unless otherwise specified, all instruments and reagents are commercially available or commonly used in the industry. Unless otherwise specified, the experimental methods and operations in the following embodiments are conventional experimental methods and operations in the art.

[0030] Example: A method for increasing the sugar content, color, aroma, and acidity of Korla fragrant pears. (I) Materials and Methods 1.1 Materials In May 2025, the technical solution of this invention was implemented in the 29th Regiment of Tiemenguan City, Xinjiang. The experimental orchard had fragrant pear trees with a spacing of 1 meter × 5 meters, the orchard was neat and uniform, and the soil, fertilizer and water management were consistent.

[0031] 1.2 Experimental Design The experiment included three treatments (T1, T2, T3) and one control (CK). The control group was 2 mu (approximately 0.33 hectares), and the treatment groups were 6 mu (approximately 0.33 hectares) each (2 mu for each treatment).

[0032] Group T1: On May 10, 2025, apply 50 kg of organic water-soluble fertilizer diluted 50 times per mu (0.067 hectares) to the roots of the fragrant pear trees via drip irrigation. On June 15, apply 35 kg of humic acid-containing water-soluble fertilizer (high nitrogen type) per mu; on July 15, apply 35 kg of humic acid-containing water-soluble fertilizer (balanced type) per mu; on August 10, apply 17.5 kg of humic acid-containing water-soluble fertilizer (high potassium type) per mu; and on August 25, apply 17.5 kg of humic acid-containing water-soluble fertilizer (high potassium type) per mu diluted 100 times to the roots of the fragrant pear trees via drip irrigation.

[0033] Group T2: On May 10, 2025, apply 100 kg of organic water-soluble fertilizer per mu (667 square meters) diluted 50 times and drip-irrigate the roots of the fragrant pear trees. On June 15, apply 35 kg of humic acid-containing water-soluble fertilizer (high nitrogen type) per mu; on July 15, apply 35 kg of humic acid-containing water-soluble fertilizer (balanced type) per mu; on August 10, apply 17.5 kg of humic acid-containing water-soluble fertilizer (high potassium type) per mu; and on August 25, apply 17.5 kg of humic acid-containing water-soluble fertilizer (high potassium type) per mu diluted 100 times and drip-irrigate the roots of the fragrant pear trees.

[0034] Group T3: On May 10, 2025, apply 150 kg of organic water-soluble fertilizer per mu (667 square meters) diluted 50 times and drip-irrigate the roots of the fragrant pear trees. On June 15, apply 35 kg of humic acid-containing water-soluble fertilizer (high nitrogen type) per mu; on July 15, apply 35 kg of humic acid-containing water-soluble fertilizer (balanced type) per mu; on August 10, apply 17.5 kg of humic acid-containing water-soluble fertilizer (high potassium type) per mu; and on August 25, apply 17.5 kg of humic acid-containing water-soluble fertilizer (high potassium type) per mu diluted 100 times and drip-irrigate the roots of the fragrant pear trees.

[0035] Group CK: Conventional management and fertilization methods were adopted. On May 10, 2025, 50 kg of diammonium phosphate per mu was applied. On June 15, 30 kg of quick-acting compound fertilizer with nitrogen and phosphorus as the main components was applied per mu. On July 15, 2025, 20 kg of bio-fertilizer was applied per mu. On August 10, 25 kg of potassium sulfate per mu was applied per mu. On August 25, 2025, 25 kg of potassium sulfate per mu was applied per mu. The application method was trench application, followed by irrigation.

[0036] 1.3 Measurement Indicators and Methods At the fruit ripening period (September 20, 2025), 30 fruits from the upper and middle parts of the canopy and the sun-facing side of each treatment group and control group were randomly collected and brought back to the laboratory to determine the relevant quality indicators of the fruits.

[0037] The weight of a single fruit was measured using an electronic balance, the firmness of the flesh was determined using a GY-1 hardness tester, the soluble solids content was determined using a refractometer, and the peel color (brightness L, red-green deviation a*, blue-yellow deviation b*) was determined using a WN700S spectrophotometer. Each treatment was repeated 15 times, and the average value was taken.

[0038] Soluble sugar content was determined using the method specified in GB / T 10782-2021 "General Rules for Quality of Preserved Fruit". Titratable acid content was determined using the method specified in GB 12456-2021 "National Food Safety Standard - Determination of Total Acid in Food". Vitamin C content was determined using high performance liquid chromatography. Each treatment was repeated three times, and the average value was taken.

[0039] The volatile components of the fruit were determined using headspace-solid phase microextraction and gas chromatography-mass spectrometry. Five fruits were randomly selected from each treatment, with three replicates. The pulp was quartered and homogenized. 8 ml of the homogenate was placed in a 15 ml sample vial, and 2.5 g of NaCl and a rotor were added. The vial was sealed with a rubber septum and equilibrated in a 40°C water bath for 10 min. Extraction was then performed at 40°C for 30 min, followed by desorption for 5 min.

[0040] Gas chromatography-mass spectrometry (GC-MS) conditions: HP-5MS column (30m × 0.25mm, 0.25μm); temperature program: 40℃ for 2 min, ramp to 140℃ at 2℃ / min, hold for 2 min, ramp to 250℃ at 10℃ / min, hold for 2 min; injection port temperature 250℃; carrier gas: helium (>99.999%); full scan; mass scan range: 35–500 u. Chromatograms of unknown compounds were searched by computer and matched against the NIST14 standard library (compounds with reported matching greater than 80%), and qualitatively analyzed using manual chromatographic interpretation. The relative content of each volatile substance was calculated using the peak area normalization method. Each treatment was repeated three times, and the average value was taken.

[0041] (II) Results and Analysis The effects of different treatments on the main quality indicators of Korla pear fruit are shown in Table 1. As shown in Table 1, compared with the control (CK), the weight of individual Korla pear fruits gradually increased with the increase in the amount of organic water-soluble fertilizer applied. Treatments T1, T2, and T3 increased by 1.79%, 16.27%, and 20.72% respectively compared to the control, with treatments T2 and T3 showing highly significant differences from the control. All treatments reduced flesh firmness, with treatment T3 showing a significant reduction of 8.32% compared to the control. Soluble solids content and soluble sugar content increased to varying degrees compared to the control. The soluble solids content of treatments T1, T2, and T3 increased by 4.72%, 4.96%, and 4.57% respectively compared to the control, all showing significant differences. The soluble sugar content increased by 1.65%, 13.48%, and 12.88% respectively, with treatments T2 and T3 showing highly significant differences from the control. The titratable acid content decreased in all treatments, with T1, T2, and T3 treatments showing reductions of 1.87%, 16.51%, and 29.36% respectively compared to the control, exhibiting significant or highly significant differences. The vitamin C content was higher in all treatments than in the control, with the T2 treatment showing a significant difference from the control.

[0042] Table 1. Effects of different treatments on the main quality indicators of fragrant pear fruit

[0043] The effects of different treatments on the color of the pear peel are shown in Table 2. Table 2 shows that there were no significant differences in the brightness and yellowness values ​​of the pear peel among the different treatments, but all treatments increased the redness value of the peel. T1, T2, and T3 showed increases of 96.68%, 105.53%, and 102.65% compared to the control, respectively, with all differences reaching a highly significant level. This indicates that each treatment significantly promoted the synthesis and accumulation of red pigments such as anthocyanins in the peel, resulting in a more vibrant red peel. Combined with the changes in the main quality indicators, a synergistic optimization of both internal and external quality was achieved.

[0044] Table 2 Effects of different treatments on the peel color of fragrant pear

[0045] The contents of each aroma component in fruits treated with different methods are shown in Table 3. Figure 2 Table 3 shows that a total of 121 compounds in 11 categories were detected in the aroma components of the treated and control pears, covering 46 esters, 19 alcohols, 11 aldehydes, 13 alkanes, 10 alkenes, 4 ketones, 3 phenols, 2 amides, 4 acids, 2 aromatics, and 7 other compounds. Specifically, the control group (CK) contained 68 compounds in 9 categories, group T1 contained 78 compounds in 10 categories, group T2 contained 76 compounds in 9 categories, and group T3 contained 83 compounds in 11 categories. Compared with the control group (CK), the number of aroma components in groups T1, T2, and T3 increased by 14.71%, 11.76%, and 22.06%, respectively.

[0046] Table 3. Relative content (%) of each aroma component in fruits under different treatments

[0047] Note: - indicates not detected.

[0048] Depend on Figure 2Table 3 shows that the aroma components of fragrant pear fruit are mainly esters, alcohols, and aldehydes, accounting for 88.63%-93.95% of the total aroma components. Among them, esters account for 34.44%-48.40%, mainly composed of hexyl acetate, butyl acetate, ethyl hexanoate, and (Z)-2-hexen-1-ol acetate, which give the fruit a fruity aroma. Alcohols account for 14.15%-23.59%, mainly composed of n-hexanol, n-octanol, and (E)-2-hexen-1-ol, which give the fruit a green aroma. Aldehydes account for 19.04%-40.16%, represented by n-hexanal, 2-hexenal, (E)-2-hexenal, and n-nonanal, which also give the fruit a green aroma. In addition, olefins, which give the fruit a floral aroma, also play a certain role in the aroma composition, accounting for 5.05%-8.81%, mainly composed of α-farnesene. These components work together to create the unique sweetness, floral aroma, and fruity fragrance of the fragrant pear.

[0049] The control group had a higher relative content of aldehydes (40.16%) in the fruit aroma components, resulting in a more intense green aroma. Compared to the control, the T3 treatment significantly increased the relative content of esters, by 22.06%. All treatments significantly increased the relative content of alcohols and decreased the relative content of aldehydes. The relative contents of alcohols in the T1, T2, and T3 treatments increased by 13.82%, 43.40%, and 66.72% respectively compared to the control, while the relative contents of aldehydes decreased by 19.19%, 6.10%, and 52.59% respectively. The treatments altered the relative proportions of different aroma components, with the T3 treatment significantly increasing the relative contents of ethyl hexanoate and hexyl acetate. They also increased the number of different aroma components, such as ethyl acetate, ethyl valerate, ethyl tetroxide, and ethyl 2-methyl-2-butenoate. These substances have lower aroma thresholds and contribute significantly to the fruit aroma, resulting in a more intense fruit flavor. All treatments significantly increased the relative content of olefins with floral aromas in the fruit, with treatment T1 reaching the highest level (8.81%), exhibiting the most prominent floral aroma. Treatment T3 further reduced the proportion of aldehydes, making the sweet aroma dominated by esters more prominent, and achieving the best overall harmony of fruit aroma. Compared with the control, all treatments significantly enhanced the layers of floral aroma, making the fruit and floral aromas more prominent.

[0050] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to obtain equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the content of the technical solution of this application should be included within the scope of protection of the claims of this application.

Claims

1. A method for increasing the sugar content, color, aroma, and reducing the acidity of Korla fragrant pears, characterized in that... Includes the following steps: S1. Fertilization during the fruit enlargement period: 10-15 days after flowering, dilute the organic water-soluble fertilizer and drip it onto the roots of the fragrant pear tree to ensure that the solution penetrates evenly into the root system's concentrated distribution layer. S2. First fertilization during the fruit enlargement period: 45-50 days after flowering, dilute the high-nitrogen water-soluble fertilizer containing humic acid and drip irrigate the roots of the fragrant pear tree to ensure that the solution penetrates evenly into the root system's concentrated distribution layer. S3. Second fertilization during the fruit enlargement period: 75-80 days after flowering, dilute the balanced humic acid-containing water-soluble fertilizer and drip irrigate the roots of the fragrant pear tree to ensure that the solution penetrates evenly into the root system's concentrated distribution layer. S4. The third and fourth fertilizations during the fruit enlargement period: 100-105 days after flowering and 115-120 days after flowering, respectively, dilute the high-potassium humic acid-containing water-soluble fertilizer and drip irrigate the roots of the fragrant pear trees to ensure that the solution penetrates evenly into the root system's concentrated distribution layer.

2. The method according to claim 1, characterized in that, The application rate of the organic water-soluble fertilizer mentioned in step S1 is 50-150 kg / mu, and the dilution ratio is 25-75 times.

3. The method according to claim 1, characterized in that, The organic water-soluble fertilizer described in step S1 contains organic matter ≥150g / L, fulvic acid ≥150g / L, N+P2O5+K2O ≥60 g / L, and pH 5.0-7.

0.

4. The method according to claim 3, characterized in that, The mass ratio of N:P2O5:K2O in the organic water-soluble fertilizer is 20:20:

20.

5. The method according to claim 1, characterized in that, The application rate of the high-nitrogen humic acid-containing water-soluble fertilizer mentioned in step S2 is 35 kg / mu, and the dilution ratio is 50-150 times; The application rate of the balanced humic acid-containing water-soluble fertilizer mentioned in step S3 is 35 kg / mu, and the dilution ratio is 50-150 times. The total application rate of the high-potassium humic acid-containing water-soluble fertilizer mentioned in step S4 is 35 kg / mu, applied in two applications, with each application being 17.5 kg / mu and a dilution ratio of 50-150 times.

6. The method according to claim 1, characterized in that, The high-nitrogen, balanced, and high-potassium humic acid water-soluble fertilizers contain humic acid ≥30g / L, fulvic acid ≥120g / L, and pH 6.0-8.

5.

7. The method according to claim 1, characterized in that, The high-nitrogen humic acid-containing water-soluble fertilizer has an N:P2O5:K2O mass ratio of 120:45:40 g / L; the balanced humic acid-containing water-soluble fertilizer has an N:P2O5:K2O mass ratio of 70:70:70 g / L; and the high-potassium humic acid-containing water-soluble fertilizer has an N:P2O5:K2O mass ratio of 40:40:120 g / L.

8. The method according to claim 1, characterized in that, The drip irrigation location is on both sides of the tree row, from the drip line of the canopy to half the distance from the base of the trunk.

9. The method according to claim 1, characterized in that, The root system is concentrated in a 30–40 cm soil layer.

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