A combined repair agent for promoting the recovery of tomato continuous cropping obstacle soil micro-ecology and application thereof

Abstract

This invention discloses a combined remediation agent for promoting the restoration of soil microecology under continuous cropping obstacles in tomatoes and its application. The combined remediation agent comprises a chemical fumigant and a mixed solution of rhizosphere metabolites. Using this combined remediation agent to improve soils with continuous cropping obstacles can reduce the number of pathogens, increase soil organic matter and enzyme activity, improve the structure and interactions of the microbial community, reduce the content of allelochemicals such as phenolic acids, effectively increase soil microbial diversity, promote nutrient cycling, and enhance disease suppression and growth-promoting functions, thereby improving crop growth and yield. It can also reduce the amount of fumigants and pesticides used, increasing the economic benefits of greenhouse cultivation.

Description

Technical Field

[0001] This invention belongs to the field of agricultural planting and soil bioremediation technology, specifically relating to the microecological regulation technology of facility farmland, and more specifically to a combined remediation agent for promoting the restoration of soil microecology under tomato continuous cropping obstacles and its application. Background Technology

[0002] The long-term intensive cultivation of greenhouse crops exacerbates soil nutrient imbalance, secondary salinization, acidification, and outbreaks of soil-borne diseases, leading to continuous cropping obstacles, resulting in stunted crop growth, reduced yields, soil degradation, and decreased biodiversity, posing a serious threat to the quality and safety of agricultural products and the ecological environment.

[0003] Currently, methods used to alleviate continuous cropping obstacles include: agronomical cultivation measures, such as crop rotation, intercropping, and breeding resistant varieties; however, these methods have a long time to take effect and are not very targeted; soil disinfection, such as high-temperature fumigation, pesticide drenching, and application of fumigants such as calcium cyanamide, dazomet, and chloropicrin, can effectively kill soil-borne pathogens, but the economic cost is high and improper application may cause environmental risks; biological control, such as inoculation with microbial agents and bio-organic fertilizers such as Bacillus, Trichoderma, and Pseudomonas with biocontrol and growth-promoting functions, may have problems such as low colonization efficiency and unstable effects.

[0004] Therefore, it is urgent to adopt a comprehensive strategy to rationally combine the above-mentioned improvement methods and develop a combined remediation agent and its application method that can effectively improve the soil micro-ecology, promote the synergistic restoration of soil disease suppression, growth promotion and nutrient cycling functions, so as to alleviate continuous cropping obstacles, improve soil health and increase crop yield and quality. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of high economic cost, long cycle, unstable effect and environmental risk of existing technologies, and to provide a method and application for alleviating the continuous cropping obstacles of tomatoes and improving soil micro-ecology.

[0006] To achieve the above objectives, the first aspect of the present invention provides a combined remediation agent for promoting the restoration of soil microecology under continuous cropping obstacles in tomatoes, comprising a chemical fumigant and rhizosphere metabolites, which are packaged separately. The chemical fumigant is selected from at least one of the following: chloropicrin, dazomet, dimethyl disulfide, ethoxylate, and allyl isothiocyanate. The rhizosphere metabolites are selected from stachyose, glycine, galacturonic acid, or mixtures thereof. Preferably, the rhizosphere metabolites are a mixed solution of stachyose, glycine, and galacturonic acid, with each metabolite solution having a concentration of 5-15 mmol / L and an application molar ratio of 10-20:1-10:1-10. More preferably, the chloropicrin is prepared using a 99.5 wt% chloropicrin liquid, the dazomet is prepared using a 98 wt% dazomet microparticle, the dimethyl disulfide is prepared using an 80 wt% dimethyl disulfide emulsifiable concentrate, the allicin is prepared using an 80 wt% allicin emulsifiable concentrate, and the allyl isothiocyanate is prepared using a 40 wt% allyl isothiocyanate water emulsion; the rhizosphere metabolites are a mixed solution of stachyose, glycine, and galacturonic acid, with each metabolite solution having a concentration of 10 mmol / L and an application molar ratio of 12:5:3.

[0007] The second aspect of this invention provides the application of the aforementioned combined remediation agent in improving the soil microecology of tomatoes under continuous cropping obstacles.

[0008] A third aspect of the present invention provides a method for promoting the restoration of soil microecology under continuous cropping obstacles in tomatoes using the aforementioned combined remediation agent, comprising the following steps:

[0009] (1) Disinfect and ventilate the susceptible soil that has been pre-adjusted to 50-80% of field water holding capacity using the chemical fumigant;

[0010] (2) After planting the crop, apply the rhizosphere metabolites by root irrigation.

[0011] Specifically, in step (1) of the method, the chemical fumigant is applied to the soil by means of injection, mixing, or drip irrigation, and immediately evaporates from liquid (or solid precursor) into gas, or rapidly degrades to produce active gas, which dissolves and diffuses in the soil pores, killing pathogenic bacteria, fungi, nematodes and weeds at multiple targets, thereby achieving "broad-spectrum" disinfection of the soil. Among them, chloropicrin acts on the lipids, proteins, and nucleic acids of pathogens, destroying mitochondria, inhibiting cellular respiration and energy metabolism, and ultimately leading to cell death; dazomet, after degradation, produces the reactive gas methyl isothiocyanate, which can cause pathogen cell membranes to contract and fold, mitochondria to swell, destroy the structure and function of hyphal cells, and disrupt the antioxidant and energy metabolism systems; dimethyl disulfide can enter and destroy the structure and important physiological processes of microbial cells through both osmotic and contact action, inhibiting their growth and showing excellent control efficacy against root-knot nematodes; the disulfoxy group on the surface of allicin can precisely attack key enzymes and proteins containing sulfhydryl groups in bacteria, paralyzing cellular metabolism; allyl isothiocyanate directly inhibits key enzymes required for the survival of pathogens, interfering with their metabolism. It has significant inhibitory effects on a variety of fungi, bacteria, and nematodes. Chemical fumigants are suitable for a variety of greenhouse vegetables, flowers and fruit trees, and Chinese medicinal herbs, including cucumbers, tomatoes, ginger, yams, strawberries, Panax notoginseng, peppers, apples, watermelons, and turmeric. They are effective against a wide range of diseases, including various soil-borne bacterial diseases, fungal diseases, root-knot nematodes, and weeds such as Ralstonia solanacearum, Fusarium wilt, Phytophthora, and root-knot nematodes.

[0012] Specifically, the rhizosphere metabolites in step (2) include three metabolites or mixtures of stachyose, glycine, and galacturonic acid, such as a mixture of stachyose and glycine, a mixture of stachyose and galacturonic acid, a mixture of glycine and galacturonic acid, or a mixture of stachyose, glycine, and galacturonic acid. Stachyose, glycine, and galacturonic acid are widely enriched in the rhizosphere of healthy tomato plants, providing carbon and energy sources for beneficial microorganisms, directionally altering the composition of the microbial community, and acting as signaling molecules to induce beneficial microorganisms such as Bacillus and Streptomyces to colonize in the rhizosphere, establishing a symbiotic relationship with native strains through cross-feeding, and reshaping the healthy soil microecology. In addition, these metabolites can enhance microbial activity, promote the secretion of hydrolytic enzymes by microorganisms, improve the availability of nitrogen and phosphorus in the soil, enhance the absorption and utilization efficiency of tomato nutrients, and activate the plant immune system, such as the jasmonic acid pathway, thereby enhancing plant systemic resistance, promoting tomato growth, and resisting pathogen invasion.

[0013] In step (1) of the method, the dosage of the chemical fumigant is generally based on the field recommended dosage. Specifically, the dosage of chloropicrin is 20-30 kg / mu; the dosage of dazomet is 20-40 kg / mu; the dosage of dimethyl disulfide is 40-50 kg / mu; the dosage of allicin is 10-60 kg / mu; and the dosage of allyl isothiocyanate is 10-50 kg / mu. Preferably, the dosage of chloropicrin is 20 kg / mu; the dosage of dazomet is 25 kg / mu; the dosage of dimethyl disulfide is 45 kg / mu; the dosage of allicin is 30 kg / mu; and the dosage of allyl isothiocyanate is 30 kg / mu.

[0014] The disinfection and ventilation in step (1) of the method refers to: adding water to the infected soil to 50-80% of field capacity, thoroughly mixing the required fumigant with the soil, sealing and fumigating for 14-30 days, and then ventilating under ventilated conditions for more than 7 days to ensure the fumigation effect and ensure that there are no pesticide residues in the soil afterward. Preferably, chloropicrin is fumigated for 15-30 days and ventilated for 7-15 days; dazomet is fumigated for 15-30 days and ventilated for more than 7 days; dimethyl disulfide is fumigated for 14-28 days and ventilated for 3-12 days; allicin is fumigated for 5-7 days and ventilated for 7-14 days; and allyl isothiocyanate is fumigated for 3-5 days and ventilated for more than 5 days.

[0015] In step (2) of the method, the rhizosphere metabolite is applied by root irrigation one week after crop transplanting, and can be applied 10-15 times throughout the entire growth period. It can be applied once every 2 weeks within 2 months after transplanting, and once a week thereafter. The application amount is 1 μmol / g soil each time. Specifically, for a potted system containing 200g of soil, 20mL is applied each time.

[0016] In step (2) of the method, the rhizosphere metabolites are applied in solution form. The concentration of each single metabolite solution is 5-15 mmol / L, and the mixed metabolite solution is prepared by mixing the single metabolite solutions of 5-15 mmol / L according to the application molar ratio and then applying them to the crop. Preferably, in step (2) of the method, the rhizosphere metabolites are applied in solution form. The concentration of each single metabolite solution is 10 mmol / L, and the mixed metabolite solution is prepared by mixing the single metabolite solutions of 10 mmol / L according to the application molar ratio and then applying them to the crop. In step (2) of the method, the rhizosphere metabolite is a mixed solution of stachyose, glycine, and galacturonic acid, with each metabolite solution having a concentration of 5-15 mmol / L and an application molar ratio of 10-20:1-10:1-10. Preferably, the rhizosphere metabolite is a mixed solution of stachyose + glycine + galacturonic acid, with each metabolite solution having a concentration of 10 mmol / L and an application molar ratio of 12:5:3.

[0017] The beneficial effects obtained by the present invention through the above technical solution include at least the following:

[0018] This invention improves soils with continuous cropping obstacles by using chemical fumigants and a mixed solution of rhizosphere metabolites. This can reduce the number of pathogens, increase soil organic matter and enzyme activity, improve the structure and interaction of microbial communities, and reduce the content of allelochemicals such as phenolic acids. It can effectively increase soil microbial diversity, promote nutrient cycling, suppress disease and promote growth, improve crop growth and yield, and also reduce the amount of fumigants and pesticides used, thereby increasing the economic benefits of facility cultivation. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result of the description. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of protection defined by the claims of the present invention.

[0020] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that the upper and lower limits of the range and each intermediate value between them are specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0022] Unless otherwise specified, all reagents and materials used in the following examples were purchased from reputable chemical or biological reagent / material suppliers, and all reagents were of analytical grade.

[0023] Dazomet (98% microparticles): Purchased from Nantong Shizhuang Chemical Co., Ltd.

[0024] Soil samples were collected from the tomato wilt disease-affected area of ​​the "Qianhu Qiyuan" picking garden in Dongqianhu Town, Yinzhou District, Ningbo City, Zhejiang Province.

[0025] Tomato seeds (Zhongshu No. 4) were purchased from Shandong Shouhe Seed Industry Co., Ltd.

[0026] Stachyose, glycine, and galacturonic acid were all purchased from Ningbo Hangjing Biotechnology Co., Ltd., under the brand name Aladdin.

[0027] Test method:

[0028] Soil pH and electrical conductivity were measured using the glass electrode method with water as the extractant. The soil-to-water ratios were 1:2.5 and 1:5, respectively. After stirring for 30 minutes, the electrode was inserted into the soil suspension after it had been allowed to settle and clarify.

[0029] Soil soluble organic carbon determination: 0.5M K2SO4 was used as the extraction solvent, the soil-to-water ratio was 1:4, and the mixture was shaken at 180 r / min for 30 min. After centrifugation, the suspension was filtered through a 0.45 μm filter membrane and measured on a total organic carbon analyzer (multi N / C3300, Jena, Germany).

[0030] Soil ammonium nitrogen and nitrate nitrogen determination: 1M KCl was used as the extraction solvent, the soil-to-water ratio was 1:4, the mixture was shaken at 200 r / min for 1 h, filtered through qualitative filter paper, and then measured on a continuous flow analyzer (AA3, SEAL, Germany).

[0031] Soil available phosphorus determination: 0.5M NaHCO3 (pH 8.5) was used as the extraction solvent, the soil-to-water ratio was 1:20, the mixture was shaken at 180 r / min for 30 min, filtered through phosphorus-free quantitative filter paper, and measured on an ELISA reader (Varioskan LUX, Thermo Fisher Scientific, USA).

[0032] Soil microbial biomass carbon, nitrogen, and phosphorus determination: The chloroform fumigation extraction method was used. The soil was placed in a vacuum desiccator and fumigated with ethanol-free chloroform for 24 hours. After fumigation, a portion of the soil was removed and extracted with 0.5 M K2SO4 as the extraction solvent at a soil-to-water ratio of 1:4. The mixture was shaken at 180 r / min for 30 min. The suspension was centrifuged and filtered through a 0.45 μm filter membrane. The carbon and nitrogen content of the fumigated soil extract was determined using a total organic carbon analyzer (multi N / C3300, Jena, Germany). The difference between the extract and the unfumigated sample was used to convert the microbial biomass carbon and nitrogen content using correction factors (Kc = 0.45, Kn = 0.54). Another part used 0.5M NaHCO3 (pH 8.5) as the extraction solvent, with a soil-to-water ratio of 1:20, and was shaken at 180 r / min for 30 min. After filtration with phosphorus-free quantitative filter paper, the phosphorus content in the soil extract after fumigation was determined on an ELISA reader (Varioskan LUX, Thermo Fisher Scientific, USA). The difference between the extract and the unfumigated sample was used to convert the microbial biomass phosphorus content using a correction factor (Kp = 0.4).

[0033] Soil hydrolytic enzyme activity assay: The activities of β-glucosidase, N-acetylglucosidase, leucine aminopeptidase, and acid phosphatase were determined using a 96-well microplate fluorescence colorimetric method. Fresh soil was weighed, added to sodium acetate buffer, and the pH was adjusted. The mixture was shaken at 180 rpm for 30 min. A certain amount of soil suspension was then transferred to a 96-well plate, enzyme substrate was added, and the plate was incubated at 25°C in the dark for 4 h. The fluorescence value was measured using a microplate reader (Varioskan LUX, Thermo Fisher Scientific, USA).

[0034] Plant height, maximum leaf area, and biomass were measured using conventional methods. Root morphology (including root length, root surface area, average root diameter, and root volume) was measured using an in-situ root scanner (RootScan190, Huaxin Zhongke, Beijing) after the roots were fully dispersed in a plastic tray with deionized water.

[0035] To clearly verify the universality of the method provided by this invention, the experiment was designed as follows: parallel experiments were conducted on the addition of metabolites using the test soil after dazomet fumigation as the experimental subject, while unfumigated soil was used as a control, thereby comprehensively demonstrating the practical application effect of the method provided by this invention.

[0036] Example 1

[0037] (1) Tomato seedling raising: Soak tomato seeds in 1% NaClO solution for 5 minutes for disinfection, rinse with sterile water 3 times and then sow in seedling substrate, 3 seeds per hole. The substrate and seeds are incubated in an artificial climate chamber at a temperature of 28±3℃ and a cycle of 16 hours / 8 hours (light / dark). Water daily to maintain soil moisture. Transplant tomato seedlings when they have three to four true leaves.

[0038] (2) Soil fumigation: Weigh 200g of sieved and air-dried soil into several portions and put them into black flower pots (6×6×8cm). Add deionized water to adjust the soil moisture to 70% of the field water holding capacity. Mix dazomet granules (addition amount is 180mg / kg, calculated based on the field application amount of 25kg / mu) thoroughly with the soil, seal with plastic wrap, and fumigate for 15 days under dark conditions, followed by 7 days of ventilation.

[0039] (3) Pot experiment: After ventilation, tomato seedlings were transplanted into flower pots, one seedling per pot. The flower pots were randomly arranged in an artificial climate chamber (day-night temperature difference 28℃ / 26℃, relative humidity 70%, 16h light / 8h dark per day, light intensity 180μmol / m²). 2 / s). On the 5th day after seedling transplanting (once a week for weeks 1-2, and every 3 days for weeks 3-4), apply a stachyose solution to the rhizosphere of the crop, for a total of 5-6 applications. The stachyose concentration is 10mM, with 20mL applied per pot each time, for 4 weeks. Throughout the growing season, irrigate daily with sterile water to maintain soil moisture at 70% field strength. One month after transplanting, the pot experiment ends, and samples are taken to determine plant phenotype and soil physicochemical properties.

[0040] Example 2

[0041] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0042] Apply a 10mM glycine solution to the root zone of the crop on the 5th day after transplanting, for a total of 5-6 times, 20mL per pot each time, for 4 weeks.

[0043] Example 3

[0044] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0045] Apply a 10mM galacturonic acid solution to the root zone of the crop on the 5th day after transplanting the seedlings. Apply 5-6 times in total, 20mL per pot each time, for 4 weeks.

[0046] Example 4

[0047] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0048] Apply a 10mM mixture of stachyose and glycine (molar ratio 3:1) to the rhizosphere of the crop on the 5th day after transplanting. Apply 20mL per pot each time for a total of 5-6 times, for 4 weeks.

[0049] Example 5

[0050] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0051] Apply a 10mM mixture of stachyose and galacturonic acid (molar ratio 17:3) to the rhizosphere of the crop on the 5th day after transplanting. Apply 20mL per pot each time for a total of 5-6 times, for 4 weeks.

[0052] Example 6

[0053] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0054] Apply a 10mM glycine and galacturonic acid mixture (molar ratio 1:1) to the rhizosphere of the crop on the 5th day after transplanting, for a total of 5-6 times, 20mL per pot each time, for 4 weeks.

[0055] Example 7

[0056] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0057] On the 5th day after transplanting, apply a 10mM mixture of stachyose, glycine and galacturonic acid (molar ratio of 12:5:3) to the rhizosphere of the crop. Apply 5-6 times in total, 20mL per pot each time, for 4 weeks.

[0058] Example 8

[0059] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0060] On the 5th day after transplanting the seedlings, apply a 10mM mixture of stachyose, glycine and galacturonic acid (molar ratio of 15:2:3) to the rhizosphere of the crop. Apply 5-6 times in total, 20mL per pot each time, for 4 weeks.

[0061] Example 9

[0062] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0063] On the 5th day after transplanting, apply a 10mM mixture of stachyose, glycine and galacturonic acid (molar ratio of 13:5:2) to the rhizosphere of the crop. Apply 5-6 times in total, 20mL per pot each time, for 4 weeks.

[0064] Example 10

[0065] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0066] On the 5th day after transplanting, apply a 10mM mixture of stachyose, glycine and galacturonic acid (molar ratio of 12:4:4) to the rhizosphere of the crop. Apply 5-6 times, 20mL per pot each time, for 4 weeks.

[0067] Comparative Example 1

[0068] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0069] (1) After adding deionized water to adjust the soil moisture to 70% of field capacity, dazomet fumigation is not carried out.

[0070] (2) Apply water to the root zone of the crop on the 5th day after transplanting the seedlings. Apply 5-6 times in total, 20mL per pot each time, for 4 weeks.

[0071] Comparative Example 2

[0072] A pot experiment was conducted according to the method in Example 1, with the following difference:

[0073] Apply water to the root zone on the 5th day after transplanting the seedlings, for a total of 5-6 times, 20mL per pot each time, for 4 weeks.

[0074] The results are shown in Tables 1, 2 and 3 below.

[0075] Based on the aboveground and root growth characteristics of tomatoes in Table 1 and the soil physicochemical properties in Table 2, it can be found that after applying rhizosphere metabolites, the nutrient supply and enzyme activity of the soil fumigated with dazomet were significantly enhanced, and the growth and development of tomatoes were significantly improved. Plant height, leaf area, root length, root surface area and root fresh weight were significantly increased compared with Comparative Example 1 and Comparative Example 2. Moreover, compared with the treatment of adding one metabolite alone (Examples 1-3) and the treatment of any two metabolites in combination (Examples 4-6), the combination of three metabolites was more conducive to increasing root length, root surface area and root fresh weight (Examples 7-10).

[0076] Table 1 Phenotypes of the above-ground parts and roots of tomatoes 30 days after transplanting

[0077]

[0078] As shown in Tables 1 and 2, among the three metabolite combinations, the treatment with a ratio of 12:5:3 for stachyose, glycine, and galacturonic acid (Example 7) was the most effective in promoting the growth and development of the aboveground parts and roots of tomatoes and improving the soil microecology under continuous cropping obstacles compared to other ratios. Specifically, the activities of β-glucosidase and acid phosphatase were significantly increased, while the activities of N-acetylglucosidase and leucine aminopeptidase were slightly increased. The main mechanism is that the specific ratio of rhizosphere metabolites (stachyose:glycine:galacturonic acid = 12:5:3) conforms to the actual composition of root exudates and carbon source requirements of healthy tomato plants, which can significantly alleviate the problem of soil carbon and phosphorus co-limitation caused by continuous cropping. Therefore, the combined use with dazomet fumigant can further improve the activities of β-glucosidase and acid phosphatase. Since dazomet fumigation itself can significantly improve the soil nitrogen supply and significantly alleviate nitrogen limitation, the activities of nitrogen hydrolases (N-acetylglucosidase and leucine aminopeptidase) only increase slightly after the addition of the metabolite combination.

[0079] Table 2. Soil physicochemical properties before and 30 days after tomato transplanting.

[0080]

[0081] The above-mentioned plant growth and soil physicochemical parameters were further normalized to calculate the growth-promoting coefficients of each treatment. The results are shown in Table 3. It shows that compared with Comparative Example 2 (dazomet fumigation alone), the addition of glycine, stachyose + glycine, stachyose + galacturonic acid, and different proportions of stachyose + glycine + galacturonic acid combination after fumigation can effectively improve the growth-promoting coefficient, promote soil microecology improvement and tomato growth.

[0082] The synergistic effect coefficients of the metabolite combination compared to the addition of a single metabolite were further calculated. The results are shown in Table 3. It was found that compared to the addition of stachyose, glycine, and galacturonic acid alone, the synergistic effect coefficient of stachyose:glycine:galacturonic acid = 12:5:3 (Example 7) was the highest, at 101.5%, 70.5%, and 96.1%, respectively.

[0083] Table 3 Growth-promoting coefficients and synergistic effects indices for each treatment

[0084] .

Claims

1. A combined remediation agent for promoting the restoration of soil microecology under continuous cropping obstacles in tomatoes, characterized in that, It includes a chemical fumigant and rhizosphere metabolites, which are packaged separately; wherein the chemical fumigant is selected from at least one of the following: chloropicrin, dazomet, dimethyl disulfide, ethoxylate, and allyl isothiocyanate; The rhizosphere metabolites are a mixed solution of stachyose, glycine and galacturonic acid, with each metabolite solution having a concentration of 5-15 mmol / L and an application molar ratio of 10-20:1-10:1-10.

2. The combined repair agent as described in claim 1, characterized in that, Chloropicrin uses 99.5wt% chloropicrin liquid, dazomet uses 98wt% dazomet microparticles, dimethyl disulfide uses 80wt% dimethyl disulfide emulsifiable concentrate, allicin uses 80wt% allicin emulsifiable concentrate, and allyl isothiocyanate uses 40wt% allyl isothiocyanate water emulsion. The rhizosphere metabolites were a mixed solution of stachyose, glycine and galacturonic acid, with each metabolite solution having a concentration of 10 mmol / L and an application molar ratio of 12:5:

3.

3. The application of the combined remediation agent as described in claim 1 or 2 in improving the soil microecology of tomatoes under continuous cropping obstacles.

4. A method for promoting soil microecological restoration under continuous cropping obstacles in tomatoes using the combined remediation agent as described in claim 1 or 2, characterized in that, Includes the following steps: (1) Disinfect and ventilate the susceptible soil that has been pre-adjusted to 50-80% of field water holding capacity using the chemical fumigant; (2) After planting the crop, apply the rhizosphere metabolites by root irrigation.

5. The method as described in claim 4, characterized in that, The chemical fumigant in step (1) is applied to the soil by injection, mixing, or drip irrigation; The dosage of chloropicrin is 20 kg / mu; the dosage of dazomet is 25 kg / mu; the dosage of dimethyl disulfide is 45 kg / mu; the dosage of ethoxylate is 30 kg / mu; and the dosage of allyl isothiocyanate is 30 kg / mu.

6. The method as described in claim 4, characterized in that, The disinfection and ventilation in step (1) refer to: adding water to the infected soil to 50-80% of field capacity, thoroughly mixing the chemical fumigant with the soil, sealing and fumigating for 14-30 days, and then placing it under ventilation conditions for more than 7 days to ensure the fumigation effect and ensure that there are no pesticide residues in the soil afterward.

7. The method as described in claim 6, characterized in that, The disinfection and ventilation in step (1) refer to: fumigating with chloropicrin for 15-30 days and ventilating for 7-15 days; or fumigating with dazomet for 15-30 days and ventilating for more than 7 days.

8. The method as described in claim 4, characterized in that, In step (2), the rhizosphere metabolites are applied by root irrigation one week after crop transplanting, and applied 10-15 times throughout the entire growth period. In the first two months after transplanting, it is applied once every two weeks, and in the later period, it is applied once a week. The amount applied each time is 1 μmol / g soil.

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