Tea tree germplasm resource soil fertility quality evaluation method

Abstract

The invention relates to the field of soil evaluation methods, in particular to a tea tree germplasm resource soil fertility quality evaluation method. The invention provides a tea tree germplasm resource soil fertility quality evaluation method with operability. The representative soil in a certain area is detected (the representative soil can be selected according to own needs and experience) to obtain the pH value, organic matters, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, total nitrogen, total phosphorus and total potassium values, then the final IFI index is obtained according to the scheme provided by the invention, and whether the soil is suitable for planting the tea trees or not can be known according to the IFI index. According to the method, a fuzzy mathematical theory is introduced, and quantitative analysis is carried out on soil nutrient indexes by constructing a membership function model.

Description

Technical Field

[0001] The present invention relates to the field of soil evaluation methods, and in particular to a method for evaluating the soil fertility quality of tea germplasm resources. Background Art

[0002] Tea trees are perennial plants of the genus Camellia. Yunnan's unique low-latitude plateau climate and geographical conditions have nurtured a rich supply of tea germplasm resources. Yunnan has the largest variety, largest number, and widest distribution of tea plants in China, and is also one of the origin centers of tea in the world.

[0003] At the same time, soil is the foundation for tea tree growth. Its nutrient content is a key indicator of soil fertility in tea gardens, directly affecting tea tree growth, tea yield, and quality. Tea trees prefer acidic soils, and a suitable soil pH is essential for root growth. Studies have shown significant differences in soil nutrient status between ancient and modern tea gardens, and these differences play a significant role in the formation of tea quality. Therefore, in-depth research on the tea germplasm resources and soil characteristics of Tujie Town, Nanhua County, will not only help to discover excellent tea resources but also provide a theoretical basis for the selection and breeding of improved tea varieties, standardized planting management, and the improvement of tea quality. Summary of the Invention

[0004] The present invention aims to provide a method for evaluating the soil fertility quality of tea germplasm resources. The specific scheme is as follows:

[0005] A method for evaluating soil fertility quality of tea germplasm resources comprises the following steps:

[0006] (1) Determination of membership functions: Function 1 is the membership function of the nutrient index pH value, and function 2 is the membership function of the nutrient index organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen, total phosphorus, and total potassium values;

[0007] Function 1: Where x is the measured value of the nutrient index, and x1, x2, x3 and x4 are the turning point values ​​of the membership curve;

[0008] Function 2: Where x is the measured value of the nutrient index, and x1, x2, x3 and x4 are the turning point values ​​of the membership curve;

[0009] The following table shows the values ​​of x1, x2, x3 and x4 for different nutrient indicators

[0010]

[0011] (2) Determination of indicator weights: The indicator weights are as follows:

[0012]

[0013] (3) Calculation of soil fertility index membership value: The soil fertility index membership value IFI is obtained based on the index weight and membership function.

[0014] The IFI index is divided into four levels: an IFI index greater than 0.75 is an extremely high level, an IFI index between 0.5-0.75 is a higher level, an IFI index between 0.25-0.55 is a medium level, and an IFI index less than 0.25 is a low level.

[0015] The present invention provides a practical method for evaluating the soil fertility quality of tea germplasm resources. In practice, it is only necessary to test representative soils in a certain area (this part can be selected based on individual needs and experience) to obtain the pH value, organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen, total phosphorus, and total potassium values. After that, the final IFI index is obtained according to the scheme of the present application. Based on the IFI index, it can be determined whether the soil is suitable for tea cultivation. The present invention introduces fuzzy mathematics theory and constructs a membership function model to quantitatively analyze soil nutrient indicators. DETAILED DESCRIPTION

[0016] 1. Determination of membership function

[0017] The present invention adopts soil pH value, organic matter (OM), alkaline nitrogen (AN), available phosphorus (AP), and available potassium

[0018] Eight conventional soil nutrient indicators, namely, total nitrogen (AK), total phosphorus (TP), and total potassium (TK), are used to comprehensively evaluate the overall soil fertility quality. The present invention introduces fuzzy mathematics theory and constructs a membership function model to quantitatively analyze soil nutrient indicators. The membership function of pH value is set as a parabola (function 1), while the membership functions of the remaining seven indicators use an S-shaped curve (function 2).

[0019] Parabolic function (function 1):

[0020]

[0021] S-type function (function 2):

[0022]

[0023] Where x represents the measured value of the nutrient index, and x1, x2, x3 and x4 are the turning points of the membership curve.

[0024] The test methods for various components in soil can refer to the following methods:

[0025] Soil nutrient determination method

[0026]

[0027] 2. Determination of the turning point value of the membership curve

[0028] In the present invention, the turning point value of the membership curve is determined according to the actual situation. Specific numerical information is detailed in Table 2-8. The membership value range of each indicator is set between 0.1 and 1.0, where 1.0 represents that the indicator reaches the optimal state for tea tree growth. In actual agricultural production, some components in the soil cannot be completely zero. Therefore, the minimum value of the membership is set to 0.1 to more realistically reflect the actual production and avoid deviations in the soil fertility assessment results due to missing indicators. The specific table is as follows:

[0029]

[0030] 3. Determination of weight of individual soil fertility indicators

[0031] The formation of soil fertility is a complex ecological process in which various environmental factors interact with each other and jointly influence soil productivity.

[0032] This study uses fuzzy mathematics and the coefficient of variation method to calculate the membership and weight coefficients of individual soil fertility quality indicators. The weight coefficients of various soil nutrient indicators across tea germplasm resources vary significantly. As shown in the table below, AP has the highest weight coefficient (0.349), while pH has the lowest (0.022). The weight coefficients for OM, AN, AK, TN, TP, and TK range from 0.088 to 0.126, indicating that soil fertility maintenance across the 135 tea germplasm resources is primarily dependent on phosphorus in the soil, while pH has little impact on soil fertility.

[0033]

[0034] 4. Calculation of soil fertility index membership value

[0035] The addition rule is used to combine the related and cross-related indicators of the same type to calculate the IFI value, a comprehensive indicator of soil fertility.

[0036] The calculation formula is as follows: Where Wi and Ni represent the weight coefficient corresponding to the i-th fertility index and its fertility index membership value (i.e., the data calculated by the membership function), respectively. The higher the IFI value, the better the soil fertility quality.

[0037] Application Description:

[0038] The table below shows the specific numerical ranges for the Integrated Soil Fertility Index (IFI) of 135 tea germplasm resources. The IFI values ​​range from 0.201 to 0.990, reflecting the minimum and maximum possible values ​​of the comprehensive index of soil fertility quality. The mean of the index is 0.537, and the coefficient of variation of 36.50% reveals the degree of variation between samples, with larger values ​​indicating greater dispersion between samples. Across the different levels of soil fertility standards, 23 samples reached the very high level, accounting for 36.50% of the total number of samples; 51 samples reached the high level; 52 samples reached the medium level; and 9 samples reached the low level.

[0039]

[0040] The following table shows the maximum, minimum and average values ​​of eight nutrient indicators in the soil of 125 tea tree planting resources:

[0041] Nutrient indicators Minimum Maximum mean pH 4.20 5.80 5.03 Organic matter OM (g / kg) 13.84 138.63 61.44 Alkaline hydrolyzable nitrogen AN (mg / kg) 28.00 203.00 90.91 Available phosphorus AP (mg / kg) 1.39 116.84 20.17 Fast-acting potassium AK (mg / kg) 108.56 512.80 273.63 Total nitrogen TN (g / kg) 0.51 5.20 2.79 Total phosphorus TP (g / kg) 0.36 1.48 0.76 Total potassium TK (g / kg) 7.99 36.11 21.15

[0042] After analyzing 135 samples, we believe that our evaluation standards meet market demand.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for evaluating soil fertility quality of tea germplasm resources, characterized in that: The steps include: (1) Determination of membership functions: Function 1 is the membership function of the nutrient index pH value, and function 2 is the membership function of the nutrient index organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen, total phosphorus, and total potassium values; Function 1: ; Where x is the measured value of the nutrient index, and x1, x2, x3 and x4 are the turning point values ​​of the membership curve; Function 2: ; Where x is the measured value of the nutrient index, and x1, x2, x3 and x4 are the turning point values ​​of the membership curve; The following table shows the values ​​of x1, x2, x3 and x4 for different nutrient indicators ； (2) Determination of indicator weights: The indicator weights are as follows: ； (3) Calculation of soil fertility index membership value: The soil fertility index membership value IFI is obtained based on the index weight and membership function.

2. The method for evaluating soil fertility quality of tea germplasm resources according to claim 1, wherein: The IFI index is divided into four levels: an IFI index greater than 0.75 is an extremely high level, an IFI index between 0.5-0.75 is a higher level, an IFI index between 0.25-0.55 is a medium level, and an IFI index less than 0.25 is a low level.

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