Low-accumulation variety screening test method based on multiple indexes

Abstract

The invention provides a low-accumulation variety screening test method based on multiple indexes, and relates to the technical field of agricultural planting. The low-accumulation variety screening test method based on multiple indexes comprises test soil selection, test crop variety selection, test design, sample collection and analysis, index determination and analysis and low-accumulation variety screening. According to the invention, a multi-index comprehensive evaluation system (such as a heavy metal enrichment coefficient, a transport coefficient, bio-availability and the like) is established, and a soil-crop-environment interaction model is integrated; heavy metal accumulation trends in different planting periods can be predicted, and a scientific basis is provided for screening out low-accumulation varieties to promote planting and guarantee quality safety of local vegetables and soil environment safety of agricultural land.

Description

Technical Field

[0001] The present invention relates to the field of agricultural planting technology, and in particular to a low-accumulation variety screening test method based on multiple indicators. Background Art

[0002] With the development of industrialization and agricultural modernization, heavy metal contamination in soil is becoming increasingly serious. When crops are grown on contaminated soil, heavy metals are easily absorbed and accumulated by the crops, affecting not only their growth and yield but also entering the human body through the food chain, posing a threat to human health.

[0003] Currently, numerous methods are available to address soil heavy metal contamination, but screening for low-accumulation crop varieties is a cost-effective and effective approach to reducing heavy metal content in agricultural products. However, existing methods often suffer from single indicators and a less scientific and systematic testing process, resulting in inaccurate and unreliable results that are difficult to meet the needs of practical agricultural production. Therefore, developing a scientific and systematic method for screening low-accumulation varieties based on multiple indicators is of great practical significance. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In response to the shortcomings of the existing technology, the present invention provides a low-accumulation variety screening test method based on multiple indicators, which solves the problems raised by the above-mentioned background technology. By comprehensively considering multiple indicators, it accurately screens out crop varieties with low heavy metal accumulation and good growth characteristics in heavy metal contaminated soil, providing a scientific basis for safe and efficient agricultural production in contaminated soil areas.

[0006] (2) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a multi-index based low accumulation variety screening test method, comprising the following steps:

[0008] Step 1: Selection of test soil:

[0009] Select representative heavy metal contaminated soil areas as test sites and record basic information on soil type, texture, pH value, and heavy metal background content;

[0010] Step 2: Selection of test crop varieties:

[0011] Based on the results of the previous soil and agricultural product collaborative survey and sampling, sensitive crops were selected as research objects, and specific test varieties were determined in combination with local planting conditions;

[0012] Step 3: Experimental design:

[0013] Using the field trial method, the test crop varieties were randomly grouped and arranged, with multiple replicates for each variety. The plot area, planting method, and plant spacing were determined, and field management was carried out according to local models.

[0014] Step 4: Sample collection and analysis:

[0015] Before planting crops, soil samples were collected to test pH, chromium, and nickel content; after vegetables matured, samples of roots, stems, leaves, and edible parts of plants were collected to test chromium and nickel content;

[0016] Step 5: Index measurement and analysis:

[0017] Determine the heavy metal content in plant samples and calculate the enrichment coefficient and transfer coefficient of heavy metals for different crop varieties;

[0018] Step 6: Screening of low-accumulation varieties:

[0019] By comprehensively considering multiple indicators such as whether the heavy metal content in the edible part of crops exceeds the standard, the enrichment coefficient, the transfer coefficient, and the output of agricultural products, low-accumulation varieties are screened out.

[0020] Preferably, in the step 2, the test crop varieties include cabbage, green vegetables, radish and lettuce, wherein the cabbage varieties include Huangfei (BC-HF) and Yuhuang No. 2 (BC-YH2H), the green vegetable varieties include Chunxi Green Stem Green Vegetables (QC-CXLGQC) and Kuanye Green Vegetables (QC-KYQC), the radish varieties include Good Luck Seven Inch (LB-HYQC) and Full Body Red Radish (LB-MSHLB), and the lettuce varieties include Hongsunwang (KJ-HSW) and Bawangqing (KJ-BWQ).

[0021] Preferably, in step 3, each variety is repeated 3 times, and the area of the plot is about 10m 2 , it is planted by direct seeding. After the seedlings emerge, they are transplanted when they grow to about 5 cm. The spacing between rows and plants is 20 cm × 30 cm.

[0022] Preferably, in step 4, soil samples are collected by multi-point mixing, with each sample weighing no less than 1 kg. The detection method uses potentiometric method to determine the pH value and flame atomic absorption spectrophotometry to determine the chromium and nickel contents. The plant samples are rinsed with tap water and deionized water in turn, dried and crushed, and then the chromium and nickel contents are determined by inductively coupled plasma mass spectrometry.

[0023] Preferably, in step five, the enrichment coefficient is calculated as the ratio of the heavy metal content in a certain part of the crop to the heavy metal content in the soil, and the transfer coefficient is calculated as the ratio of the heavy metal content in the edible part of the crop to the heavy metal content in the root of the crop.

[0024] Preferably, in the screening of low-accumulation varieties, the heavy metal content in the edible part of the crop is compared with the relevant standards of the "National Food Safety Standard Limits of Contaminants in Food". When the economic benefits of the crop are not considered, varieties with heavy metal content in the edible part that does not exceed the standard, low enrichment coefficient and transfer coefficient, and relatively high yield are given priority.

[0025] Preferably, in the high-risk areas of heavy metal chromium and nickel in the ancient city's agricultural land, the low-accumulation varieties screened out include: cabbage varieties Seminis, Chunhuangfei and Chunxi Gaokangwang AC-2; green vegetable varieties glutenless flat-stem greens and Niuribe greens; radish varieties Biyu, Aomeixi and Yuchanghe white radish; lettuce varieties Dali red-tip leaf lettuce and Bawangqing.

[0026] (3) Beneficial effects

[0027] The present invention provides a low-accumulation variety screening test method based on multiple indicators, which has the following beneficial effects:

[0028] 1. The present invention comprehensively considers multiple indicators such as soil environmental quality, crop heavy metal content, enrichment coefficient, transfer coefficient and yield, and screens crop varieties comprehensively and systematically, avoiding the limitations of single indicator screening and improving the scientificity and accuracy of the screening results.

[0029] 2. The present invention establishes a multi-index comprehensive evaluation system (such as heavy metal enrichment coefficient, transport coefficient, bioavailability, etc.) and an integrated soil-crop-environment interaction model, which can predict the heavy metal accumulation trend in different planting cycles, screen out low-accumulation varieties for promotion and planting, and provide a scientific basis for ensuring the quality and safety of localized vegetables and the environmental safety of agricultural soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the method flow in Example 1 of the present invention;

[0031] Figure 2 This is a graph of enrichment transfer coefficients for different cabbage varieties in Example 2 of the present invention;

[0032] Figure 3 This is a graph of enrichment transfer coefficients for different green vegetable varieties in Example 2 of the present invention;

[0033] Figure 4 This is a graph of enrichment transfer coefficients for different radish varieties in Example 2 of the present invention;

[0034] Figure 5 This is a diagram of the enrichment transfer coefficients of different lettuce varieties in Example 2 of the present invention. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] Example 1:

[0037] like Figure 1 As shown, the embodiment of the present invention provides a low-accumulation variety screening test method based on multiple indicators, comprising the following steps:

[0038] Step 1: Selection of test soil:

[0039] Select representative areas of heavy metal-contaminated soil as test sites, such as specific test plots within the ancient city demonstration area. Conduct a detailed soil survey of the selected areas, recording basic information such as soil type, texture, pH, and background heavy metal content.

[0040] Step 2: Selection of Test Crop Varieties: Based on the results of the previous collaborative soil and agricultural product survey and sampling, sensitive crops were selected as research subjects. Common crops with a wide variety of planting and sales in the area, such as Chinese cabbage, green vegetables, radishes, and lettuce, were selected. Specific test varieties were determined based on the local villagers' planting practices. For example, the Chinese cabbage varieties tested included Huangfei (BC-HF) and Yuhuang No. 2 (BC-YH2H); the green vegetable varieties tested included Chunxi Green Stem Green Cabbage (QC-CXLGQC) and Broad Leaf Green Cabbage (QC-KYQC); the radish varieties tested included Good Luck Seven Inch (LB-HYQC) and Full Body Red Radish (LB-MSHLB); and the lettuce varieties tested included Hongsun King (KJ-HSW) and Bawangqing (KJ-BWQ).

[0041] Step 3: Experimental design:

[0042] (1) Test method: A field test method was used, and all test crop varieties were randomly grouped to ensure that each variety had three replicates to improve the reliability of the test results. A total of 120 plots were set up, each with an area of about 10m 2 , providing suitable space for crop growth;

[0043] (2) Planting method: Direct seeding is used according to the planting requirements of the selected crops. After the seedlings emerge, when the crops grow to about 5 cm, they are transplanted, leaving 1-2 seedlings per hole, and the spacing between rows and plants is set at 20 cm × 30 cm to ensure a reasonable growth density of the crops.

[0044] (3) Field management: During the crop growth process, refer to the local mature field management model. Weeding should be carried out in a timely manner to prevent weeds from competing with crops for nutrients, water and light; watering should be carried out according to the soil moisture conditions and crop growth needs to ensure that crops have sufficient water for growth; at the same time, pay close attention to the occurrence of crop diseases and insect pests, and adopt green, environmentally friendly and effective prevention and control measures to prevent and control diseases and insect pests to ensure the healthy growth of crops.

[0045] Step 4: Sample collection and analysis:

[0046] (1) Soil sample collection: Before planting crops, soil samples are collected from each plot using a multi-point mixing method, with each sample collection volume of no less than 1 kg. The collected soil samples are numbered, circulated, prepared, and tested and analyzed in accordance with relevant standards. The test indicators include pH value, chromium and nickel content, etc. The detection methods use the potentiometric method HJ962-2018 to determine pH value, and the flame atomic absorption spectrophotometry method HJ491-2019 to determine chromium and nickel content;

[0047] (2) Plant sample collection: After the vegetables mature, harvest the roots, stems, leaves and edible parts of the crops. Rinse each part with tap water and deionized water in turn, absorb the surface moisture with filter paper and weigh the fresh weight. Put it into an envelope, fix it in an oven at 105℃ for 15 minutes, and then dry it at a constant temperature of 80℃ to constant weight and weigh it. Use a grinder to crush the dried sample into powder for use. The biomass and heavy metal content are both expressed as fresh weight data. The heavy metal chromium and nickel content of plant samples were determined by inductively coupled plasma mass spectrometry (ICP-MS) GB5009.268-2016.

[0048] Step 5: Index measurement and analysis:

[0049] (1) Determination of heavy metal content: The heavy metal chromium and nickel content of the collected plant samples was determined to obtain the heavy metal content data of different parts of different crop varieties. Through statistical analysis of the data, the differences in heavy metal absorption and accumulation of different varieties were understood;

[0050] (2) Calculation of enrichment coefficient: Calculate the enrichment coefficient (BF) of different crop varieties for heavy metals. Enrichment coefficient = heavy metal content in a certain part of the crop / heavy metal content in the soil. The enrichment coefficient is used to analyze the enrichment capacity of different varieties for heavy metals. The lower the enrichment coefficient, the weaker the variety's ability to accumulate heavy metals, and the more suitable it is for planting in contaminated soil.

[0051] (3) Transfer coefficient calculation: Based on the heavy metal content data of the roots and edible parts of plant samples, the transfer coefficient (TF) is calculated as follows: transfer coefficient = heavy metal content in the edible part of the crop / heavy metal content in the root of the crop. The transfer coefficient reflects the ability of heavy metals to transfer from the root to the edible part of the crop. The lower the transfer coefficient, the less heavy metals transfer from the root to the edible part, and the safer the agricultural product.

[0052] Step 6: Screening of low-accumulation varieties:

[0053] Comprehensively consider multiple indicators such as whether the heavy metal content in the edible part of the crop exceeds the standard (refer to the relevant standards of the "National Food Safety Standard Limits of Contaminants in Food"), the heavy metal enrichment coefficient and transfer coefficient, and the yield of agricultural products. Without considering the economic benefits of the crop, varieties with no excessive heavy metal content in the edible part, low enrichment coefficient and transfer coefficient, and relatively high yield are preferred as low-accumulation varieties. For example, in the screening of cabbage varieties, Seminis, Chunhuangfei, and Chunxi Gaokangwang AC-2 performed relatively low in terms of enrichment coefficient; among green vegetable varieties, gluten-free flat-stem green vegetables and Niu Liba green vegetables had better comprehensive indicators; among radish varieties, Biyu, Aomeixi, and Yuchanghe white radishes were more advantageous; among lettuce varieties, Dali red-tipped leaf lettuce and Bawangqing were suitable for cultivation in areas with high risk of heavy metal chromium and nickel.

[0054] Example 2:

[0055] The embodiment of the present invention provides a low-accumulation variety screening test method based on multiple indicators, comprising the following steps:

[0056] 1. Test preparation stage

[0057] In the ancient city demonstration area, 120 experimental plots were determined based on factors such as topography and soil uniformity, with each plot covering an area of approximately 10m 2 Sampling and analyzing the soil in the test area, recording basic data such as soil pH, chromium and nickel content;

[0058] Prepare sufficient seeds for the selected test crop varieties. Contact a professional printing company to produce simple signage in different colors (green for green vegetables, red for cabbage, yellow for radish, and blue for lettuce) to distinguish between different crop varieties and plots.

[0059] 2. Experimental implementation phase

[0060] Soil tillage and film laying: The test plots were tilled using a small hand-held rotary tiller to a depth of 5-10 cm. Ridges were manually formed with a width of approximately 1.8 m. After ridge formation, black film was manually laid to prevent weeds and maintain heat and moisture retention.

[0061] Production and installation of plot signs: After determining the test crop varieties, the prepared signboards are accurately inserted into the corresponding areas according to the plot layout to ensure that each plot is clearly marked to facilitate subsequent test operations and data recording;

[0062] Soil sample collection: Before planting crops, soil samples are collected from each plot using a multi-point mixing method. Each sample should be no less than 1kg. After collection, they are numbered according to the name on the identification plate. The samples are then circulated, prepared, tested and analyzed according to relevant standards.

[0063] Crop Planting: After consulting with seed store sales staff and local vegetable growers, seed the test crops using direct seeding in the designated area according to the signage and cover with 2-3cm of soil. If there is no rainfall for a long time after sowing, water the seeds promptly to ensure smooth germination.

[0064] Field management: During crop growth, closely monitor crop germination and promptly replant areas where germination is not ideal. When the crop reaches 5 cm or has 3-5 true leaves, thin out the seedlings, leaving 1-2 seedlings per hole and transplanting any excess seedlings to ungerminated plots of the same variety. Water, fertilize, and control pests and diseases in a timely manner according to local field management practices.

[0065] Sample collection and yield measurement: Samples of the test crops were collected in batches according to the growth cycle of different crops. The roots, stems, leaves and edible parts of the plants were collected separately, and the amount of each sample was about 1kg. After the collection was completed, the yield of the edible part of the crops in the test area was measured using the sampling method. Each sample plot was about 1m 2 .

[0066] 3. Data analysis and variety screening stage

[0067] The collected soil and plant samples were tested and analyzed to obtain the chromium and nickel content as well as the heavy metal chromium and nickel content data of various plant parts, as shown in the following table:

[0068] (1) The test results and statistical analysis of heavy metals chromium and nickel in cabbage roots and edible parts are shown in Table 1:

[0069] Table 1

[0070]

[0071] (2) The test results and statistical analysis of heavy metals chromium and nickel in the roots and edible parts of green vegetables are shown in Table 2:

[0072] Table 2

[0073]

[0074] (3) The test results and statistical analysis of heavy metal chromium and nickel in radish leaves and edible parts are shown in Table 3:

[0075] Table 3

[0076]

[0077] (4) The test results and statistical analysis of heavy metal chromium and nickel in the roots, leaves and edible parts of lettuce are shown in Table 4:

[0078] Table 4

[0079]

[0080] According to the test data, the enrichment coefficient and transfer coefficient of different crop varieties are calculated, see Figures 2 to 5 .

[0081] A comprehensive comparison of heavy metal content, enrichment coefficients, transfer coefficients, and yield data for each crop variety was conducted, and low-accumulation varieties were identified based on screening criteria. For example, among cabbage varieties, Seminis, Chunhuangfei, and Chunxi Gaokangwang AC-2 performed well across multiple indicators and were selected as relatively low-accumulation varieties. Among green vegetable varieties, gluten-free flat-stem greens and Niu Lieba greens were suitable for cultivation in the region. Among radish varieties, Biyu, Aomeixi, and Yuchanghe white radishes were more suitable for low-accumulation varieties. Among lettuce varieties, Dali Red Tip Leaf Lettuce and Bawangqing were preferred.

[0082] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A multi-index low-accumulation variety screening test method, characterized by: The following steps are involved: Step 1: Selection of test soil: Select representative heavy metal contaminated soil areas as test sites and record basic information on soil type, texture, pH value, and heavy metal background content; Step 2: Selection of test crop varieties: Based on the results of the previous soil and agricultural product collaborative survey and sampling, sensitive crops were selected as research objects, and specific test varieties were determined in combination with local planting conditions; Step 3: Experimental design: Using the field trial method, the test crop varieties were randomly grouped and arranged, with multiple replicates for each variety. The plot area, planting method, and plant spacing were determined, and field management was carried out according to local models. Step 4: Sample collection and analysis: Before planting crops, soil samples were collected to test pH, chromium, and nickel content; after vegetables matured, samples of roots, stems, leaves, and edible parts of plants were collected to test chromium and nickel content; Step 5: Index measurement and analysis: Determine the heavy metal content in plant samples and calculate the enrichment coefficient and transfer coefficient of heavy metals for different crop varieties; Step 6: Screening of low-accumulation varieties: By comprehensively considering multiple indicators such as whether the heavy metal content in the edible part of crops exceeds the standard, the enrichment coefficient, the transfer coefficient, and the output of agricultural products, low-accumulation varieties are screened out.

2. The multi-index low-accumulation variety screening test method according to claim 1, characterized in that: In the step 2, the test crop varieties include cabbage, green vegetables, radish and lettuce, among which the cabbage varieties include Huangfei (BC-HF) and Yuhuang No. 2 (BC-YH2H), the green vegetable varieties include Chunxi Green Stem Green Vegetables (QC-CXLGQC) and Kuanye Green Vegetables (QC-KYQC), the radish varieties include Good Luck Seven Inch (LB-HYQC) and Full Body Red Radish (LB-MSHLB), and the lettuce varieties include Hongsunwang (KJ-HSW) and Bawangqing (KJ-BWQ).

3. The multi-index low-accumulation variety screening test method according to claim 1, characterized in that: In step 3, three replicates were set for each variety, and the plot area was about 10m 2 , it is planted by direct seeding. After the seedlings emerge, they are transplanted when they grow to about 5 cm. The spacing between rows and plants is 20 cm × 30 cm.

4. The multi-index low-accumulation variety screening test method according to claim 1, characterized in that: In step 4, soil samples are collected by multi-point mixing, each sample is no less than 1 kg, and the detection method adopts potentiometric method to determine pH value and flame atomic absorption spectrophotometry to determine chromium and nickel content; The plant samples were washed with tap water and deionized water in turn, dried and crushed, and then the chromium and nickel contents were determined by inductively coupled plasma mass spectrometry.

5. The multi-index low-accumulation variety screening test method according to claim 1, characterized in that: In step 5, the enrichment coefficient is calculated as the ratio of the heavy metal content in a certain part of the crop to the heavy metal content in the soil, and the transfer coefficient is calculated as the ratio of the heavy metal content in the edible part of the crop to the heavy metal content in the root of the crop.

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