Vegetable soilless cultivation seedling and seedling raising method

Abstract

The present application relates to the technical field of soilless cultivation, and specifically discloses a vegetable soilless cultivation seedling and a seedling raising method thereof. The seedling raising method of the vegetable soilless cultivation seedling comprises the following steps: cleaning and disinfecting the vegetable seeds, soaking the vegetable seeds in a soaking liquid, dark treatment, planting in a soilless cultivation matrix, and obtaining vegetable seedlings. The soilless cultivation matrix includes a solid matrix and a liquid matrix, wherein the solid matrix includes modified rock wool, modified perlite and gravel, and the liquid matrix includes vegetable crop tail vegetables, a fermentation agent, brown sugar, a pH regulator, and a heavy metal ion chelator. The vegetable soilless cultivation matrix prepared in the present application has good water retention, has a certain preventive and therapeutic effect on pests and diseases, and can solve the problem of heavy metal pollution in seedling raising. The seedling raising method used in the present application has a high germination rate of vegetable seeds, strong resistance to pests and diseases, and a good growth state.

Description

Technical Field

[0001] The present application relates to the technical field of soilless cultivation, and more specifically, to a vegetable soilless cultivation seedling and a seedling cultivation method thereof. Background Art

[0002] Vegetable seedling cultivation refers to the process of cultivating vegetable seeds or other vegetable propagation materials into strong seedlings through specific techniques and methods under suitable environmental conditions. Vegetable seedling cultivation plays a vital role in the growth process of vegetables, and the quality of seedlings plays a decisive role in the growth process of vegetables.

[0003] Seedling soil plays a vital role in the quality of seedlings, but traditional seedling soil has many problems: 1. The seedling soil needs to be pre-treated according to different types of vegetables and different growth needs of seedlings, and the process is complicated; 2. The quality of seedling soil is uneven, which is easy to cause diseases, insects and weeds; 3. The looseness of seedling soil is different, and some seedling soils are compact and have high volume, which seriously affects the seedling rate and uniformity of seedlings, causing certain economic benefits losses for industrial vegetable seedling cultivation.

[0004] Due to the many problems of traditional soil seedling cultivation, soilless cultivation substrates are currently used for seedling cultivation. As a mixed lightweight material that can replace the function of soil seedling cultivation, soilless cultivation substrates have good root fixing ability, fertility, water permeability and air permeability. They can provide suitable nutrients and acid-base environment for crop cultivation and cultivate the best quality seedlings. However, soilless cultivation substrates are still facing the following problems at this stage: 1. The production cost of the substrate is high and the production investment is large; 2. The water retention is poor, the nutrients are easily lost, and the vegetable emergence rate is reduced; 3. Pesticides are added for the prevention and control of diseases and pests, which causes certain pollution to the environment and affects the subsequent quality of vegetables; 4. Some substrate materials contain heavy metals, and there is a problem of heavy metal pollution in seedling cultivation, which has a significant impact on vegetable growth and quality. Based on the above statements, the present application provides a vegetable soilless cultivation seedling and a seedling cultivation method thereof. Summary of the invention

[0005] In order to solve the problems mentioned in the background technology, the present application provides a vegetable soilless cultivation seedling and a seedling cultivation method thereof.

[0006] In the first aspect, the present application provides a method for raising vegetable seedlings in soilless culture, which adopts the following technical scheme:

[0007] The steps of a method for raising seedlings of vegetable soilless culture seedlings are as follows:

[0008] S1. Cleaning and disinfection of vegetable seeds: transfer the vegetable seeds to a clean bench, wash them 3-5 times with sterile water, then wash them 3-5 times with a 3-5% NaClO solution, and then rinse them 3-5 times with sterile water;

[0009] S2, soaking the vegetable seeds cleaned and disinfected in step S1 in the soaking solution for 1-2 hours, and then rinsing with sterile water for 3-5 times;

[0010] S3. After soaking in the soaking solution in step S2, the vegetable seeds are treated in the dark for 65-75 hours, taken out, and planted in a soilless culture medium to obtain vegetable seedlings.

[0011] Preferably, the soaking liquid in step S2 is a mixture of wood vinegar, melatonin, salicylic acid and sterile water in a mass ratio of 1-3:1-3:1-3:1000.

[0012] Preferably, the method for preparing the soilless culture medium in step S3 comprises the following steps: filling the bottom of the seedling tray with a solid matrix, and then adding a liquid matrix into the seedling pot so that the liquid level of the liquid matrix is ​​2-3 cm higher than the solid matrix to obtain the desired soilless culture medium.

[0013] Preferably, the method for preparing the solid matrix comprises the following steps:

[0014] A1. Preparation of modified rock wool: rock wool is added to a silver nitrate solution, mixed and stirred to obtain a mixed solution, sodium citrate solution is added to the mixed solution, heated to 40-50° C., mixed and stirred to react for 1-2 hours, and after the reaction is completed, the modified rock wool is obtained by filtering, washing and drying, wherein the mass ratio of rock wool, silver nitrate solution and sodium citrate solution is 1:8-12:12-16;

[0015] A2. Preparation of modified perlite: Add perlite to dilute hydrochloric acid with a mass concentration of 10-20%, treat with acid at 50-80°C for 4-6h, wash with water until neutral and then dry, then place in a carbon tube furnace and roast at 400-600°C for 1-2h to obtain modified perlite; wherein the mass ratio of perlite to dilute hydrochloric acid with a mass concentration of 10-20% is 1:8-10;

[0016] A3, mixing: uniformly mixing modified rock wool, modified perlite and gravel in a mass ratio of 3-5:2-4:2-4 to obtain a mixture 1;

[0017] A4. UV disinfection: Place the mixture 1 in step A3 under an irradiation intensity of 60-80uW / CM 2 Irradiate under ultraviolet light for 20-30 min to obtain a mixture 2;

[0018] A5. High temperature steam sterilization: Place the mixture 2 in step A4 in a high temperature steam sterilizer for 1-2 hours, and cool it to obtain the desired solid matrix.

[0019] Preferably, the size of the rock wool in step A1 is 1-2 cm×1-2 cm×1-2 cm; the particle size of the perlite in step A2 is 3-8 mm; and the particle size of the gravel in step A3 is 3-16 mm.

[0020] Preferably, the method for preparing the liquid matrix comprises the following steps:

[0021] B1. Fermentation: Crush the vegetable crop tails, add brown sugar and stir to obtain the fermented material, add the fermentation agent, and control the number of live bacteria in the fermented material to 2×10 9 -3×10 9 CFU / g, stir evenly and let stand, continue fermentation at a temperature of 40-45°C for 40-50h, raise the temperature to 60-70°C, supply oxygen for reaction for 120-140h, cool to room temperature, let stand for 20-30h, filter and remove residue to obtain fermentation liquid 1;

[0022] B2. Disinfection: The fermentation liquid 1 in step B1 is placed under an irradiation intensity of 60-80uW / CM 2 Irradiate under ultraviolet light for 20-30 minutes, sterilize in high-temperature steam for 1-2 hours, and cool to obtain fermentation liquid 2;

[0023] B3, stirring and mixing the fermentation liquid 2 in step B2, the pH regulator, and the heavy metal ion chelating agent to obtain a liquid matrix.

[0024] Preferably, in step B1, the mass ratio of the vegetable crop tail vegetables to brown sugar is 30-50:2-3; the vegetable crop tail vegetables are cabbage tail vegetables, cabbage tail vegetables, carrot tail vegetables or cauliflower tail vegetables; the fermentation agent is a mixture of Bacillus subtilis, Bacillus cereus and nitrogen-fixing bacteria with a live bacteria count ratio of 3-5:4-6:1; in step B3, the mass ratio of the fermentation liquid 2 to the pH regulator and the heavy metal ion chelator is 35-60:0.3-0.6:0.8-1.2; and the pH regulator includes at least one of sodium phosphate, sodium citrate, phosphoric acid and citric acid.

[0025] Preferably, the preparation method of the heavy metal ion chelating agent is: adding sodium glutamate and deionized water into a reactor, stirring and mixing evenly at room temperature; after mixing evenly, heating the reactor to 60-80°C, adding glyoxylic acid, and reacting for 1-3h; after the reaction is completed, adding citric acid, and reacting for 1-3h; adding polyethylene glycol into the reactor, stirring and mixing evenly; and concentrating under reduced pressure to obtain the desired heavy metal ion chelating agent.

[0026] Preferably, the mass ratio of sodium glutamate, deionized water, glyoxylic acid, citric acid and polyethylene glycol is 1:8-12:2-3:1.2-1.6:1.2-1.8; the molecular weight of polyethylene glycol is 200-600; and the negative pressure is 0.01-0.03Mpa.

[0027] In a second aspect, the present application provides a vegetable soilless cultivation seedling, which adopts the following technical solution:

[0028] Vegetable soilless seedling cultivation is carried out according to the above-mentioned vegetable soilless seedling cultivation method.

[0029] In summary, this application has the following beneficial effects:

[0030] The solid matrix is ​​mixed with the liquid matrix. The solid matrix can be used as a supporting medium to provide a stable growth environment for the plant root system, and the liquid matrix provides nutrient supply to meet the nutrient needs of the vegetable seedling stage. The solid matrix of the present application is prepared by mixing modified rock wool, modified perlite, and gravel. The rock wool is added with a silver nitrate solution, and further modified by adding a sodium citrate solution. The nano silver particles have excellent antibacterial properties and can inhibit the growth of various bacteria and fungi. The modified rock wool has stronger antibacterial ability and can reduce the occurrence of diseases during soilless cultivation. The perlite is modified by acid treatment. The acid treatment can significantly improve the surface properties of the perlite, increase the microporosity of the perlite, and improve its water absorption capacity and water retention performance. At the same time, the acid treatment can remove the trace heavy metal elements present in the perlite and reduce the risk of heavy metal pollution in the seedling matrix. The water-retaining properties of modified rock wool and modified perlite are combined with the air permeability of gravel to form a good growth environment that is both water-retaining and air-permeable. Modified rock wool and modified perlite can absorb and store nutrients in the nutrient solution for absorption and utilization by plant roots. Gravel, as an inert matrix, does not affect the concentration balance of the nutrient solution and helps the stable growth of plants. The main raw material for the preparation of the liquid matrix of this application is the tailings of vegetable crops, which not only saves costs but also solves the problem of handling the tailings of vegetable crops. 4. This application makes a homemade heavy metal ion chelator, reacts sodium glutamate and glyoxylic acid to generate sodium glutamate diacetate, and then adds citric acid and polyethylene glycol to react and modify to obtain a heavy metal ion chelator. Sodium glutamate diacetate is a highly efficient metal ion chelator that can form stable water-soluble complexes with a variety of heavy metal ions. It is environmentally friendly, safe and reliable, and biodegradable. The three carboxyl groups of the citric acid molecule have a strong chelating and coordination effect on many metal ions. They can coordinate with multiple metal ions at the same time to form a stable heterometallic ion chelate. The addition of citric acid to sodium glutamate diacetate for reaction modification has a synergistic effect, which enhances the chelating effect on heavy metal ions. Further adding polyethylene glycol to the reaction can improve the water solubility of the chelating agent, increase the stability of the chelating agent, make it more stable in the solution, and not easy to decompose or fail, which further enhances the chelating effect on heavy metal ions.

[0031] 5. The present application further adopts soaking the seeds in a mixture of wood vinegar, melatonin, salicylic acid and sterile water after cleaning and disinfecting the seeds. Wood vinegar, melatonin and salicylic acid all have the effect of promoting plant germination and growth, and the mixed use of the three can further enhance the germination effect on vegetable seeds. At the same time, melatonin and salicylic acid can enhance the stress resistance of plants, salicylic acid can activate the immune system of plants, melatonin can enhance the disease resistance of plants by regulating the physiological metabolism of plants, and wood vinegar can indirectly improve the stress resistance of plants by regulating the matrix. The mixed use of the three can form a stronger stress resistance protection mechanism. The vegetable seeds soaked in the mixture of wood vinegar, melatonin, salicylic acid and sterile water have a high germination rate and strong resistance to diseases and insect pests.

[0032] 6. The vegetable soilless cultivation substrate prepared in this application has good water retention, has a certain preventive and therapeutic effect on diseases and insect pests, and can solve the problem of heavy metal pollution in seedling cultivation. The seedling cultivation method used in this application has a high germination rate of vegetable seeds, strong resistance to diseases and insect pests, and a good growth state. DETAILED DESCRIPTION

[0033] The present application is further described in detail below with reference to the embodiments.

[0034] The raw materials used in the examples and comparative examples of the present application are as follows:

[0035] Bacillus subtilis was purchased from China General Microbiological Culture Collection Center, with the collection number CGMCC1.821;

[0036] Bacillus cereus was purchased from China General Microbiological Culture Collection Center, with the collection number CGMCC 1.10559;

[0037] The nitrogen-fixing bacteria were purchased from China General Microbial Culture Collection Center with the collection number CGMCC 1.9044.

[0038] Embodiment 1-3 provides a vegetable soilless culture seedling and a seedling raising method thereof.

[0039] Example 1

[0040] Preparation of solid matrix:

[0041] A1. Preparation of modified rock wool: add a 2% silver nitrate solution to rock wool of size 1 cm×1 cm×1 cm, stir at a rate of 100 r / min for 0.3 h to obtain a mixed solution, add a 20% sodium citrate solution to the mixed solution, heat to 40°C, stir at a rate of 30 r / min for 1 h, filter after the reaction, wash with distilled water 3 times, and dry in an oven at 50°C to obtain modified rock wool, wherein the mass ratio of rock wool, 2% silver nitrate solution, and 20% sodium citrate solution is 1:8:12;

[0042] A2. Preparation of modified perlite: perlite with a particle size of 3 mm was added to dilute hydrochloric acid with a mass concentration of 10%, stirred at 30 r / min at 50°C for 4 h, washed with distilled water for 3 times, dried in an oven at 50°C, and then calcined in a carbon tube furnace at 400°C for 1 h to obtain modified perlite; wherein the mass ratio of perlite to dilute hydrochloric acid with a mass concentration of 10% was 1:8;

[0043] A3, mixing: uniformly mix the modified rock wool, modified perlite and gravel with a particle size of 3 mm in a mass ratio of 3:2:2 to obtain a mixture 1;

[0044] A4. UV disinfection: Place the mixture 1 in step A3 under an irradiation intensity of 60uW / CM 2 Irradiate under ultraviolet light for 20 min to obtain a mixture 2;

[0045] A5. High-temperature steam sterilization: sterilize the mixture 2 in step A4 at 100° C. high-temperature steam for 1 h, and cool to room temperature to obtain the desired solid matrix.

[0046] Preparation of liquid matrix:

[0047] B1. Fermentation: Crush the cabbage tails, add brown sugar, and stir at 100 r / min for 10 min to obtain the fermented material. Add the fermentation agent (control the number of live bacteria in the fermented material to be 2×10 9 CFU / g), continued stirring at a rate of 100r / min for 0.3h and then allowed to stand, continued fermentation at a temperature of 40°C for 40h, raised the temperature to 60°C, oxygenated for reaction for 120h, cooled to room temperature, allowed to stand for 20h, filtered and slag removed, and obtained fermentation liquid 1; wherein the mass ratio of Chinese cabbage tail and brown sugar was 30:2; the starter was a mixture of Bacillus subtilis, Bacillus cereus and nitrogen-fixing bacteria with a live bacteria count ratio of 3:4:1;

[0048] B2. Disinfection: The fermentation liquid 1 in step B1 is placed under an irradiation intensity of 60uW / CM 2 Irradiate under ultraviolet light for 20 minutes, sterilize in 100℃ high temperature steam for 1 hour, and cool to obtain fermentation liquid 2;

[0049] B3. Preparation of heavy metal ion chelating agent: sodium glutamate and deionized water are added to a reactor, and stirred at room temperature at a rate of 100 r / min for 0.3 h; after stirring and mixing, the reactor is heated to 60°C, glyoxylic acid is added, and the reaction is stirred at a rate of 40 r / min for 1 h; after the reaction is completed, citric acid is added, and the reaction is stirred at a rate of 40 r / min for 1 h; polyethylene glycol with a molecular weight of 200 is added to the reactor, and the mixture is stirred at a rate of 100 r / min for 0.3 h; the desired heavy metal ion chelating agent is obtained by vacuum drying at a temperature of 50°C and a pressure of 0.01 MPa for 4 h; wherein the mass ratio of sodium glutamate, deionized water, glyoxylic acid, citric acid, and polyethylene glycol with a molecular weight of 200 is 1:8:2:1.2:1.2;

[0050] B4. Fermentation broth 2, sodium citrate and heavy metal ion chelating agent in a mass ratio of 35:0.3:0.8 were mixed at a rate of 100 r / min for 0.3 h to obtain a liquid matrix.

[0051] Preparation of soilless culture medium: fill the bottom of the seedling tray with solid matrix, and then add liquid matrix into the seedling pot so that the liquid level of the liquid matrix is ​​2 cm higher than the solid matrix to obtain the required soilless culture medium.

[0052] The steps of a cucumber soilless culture seedling raising method are as follows:

[0053] S1. Cleaning and disinfection of cucumber seeds: transfer the cucumber seeds to a clean bench, wash them 3 times with sterile water, then wash them 3 times with a 3% NaClO solution, and then rinse them 3 times with sterile water;

[0054] S2, soaking the cucumber seeds after cleaning and disinfection in step S1 in a soaking solution for 1 hour, and then rinsing with sterile water for 3 times, wherein the soaking solution is a mixture of wood vinegar, melatonin, salicylic acid and sterile water in a mass ratio of 1:1:1:1000;

[0055] S3, placing the cucumber seeds soaked in the soaking solution in step S2 in the dark at 4°C for 65 hours, taking them out, and planting them in the above-mentioned soilless culture medium for cultivation. The cultivation conditions are: light 16 hours / darkness 8 hours, and the light intensity is 150 μmol / m 2 / s, the temperature is 22℃, and when two leaves and one heart grow, the cucumber seedlings are obtained.

[0056] Example 2

[0057] Preparation of solid matrix:

[0058] A1. Preparation of modified rock wool: add a silver nitrate solution with a mass concentration of 3% to rock wool with a size of 1.5 cm × 1.5 cm × 1.5 cm, stir at a rate of 100 r / min for 0.45 h to obtain a mixed solution, add a sodium citrate solution with a mass concentration of 25% to the mixed solution, heat to 45°C, stir at a rate of 30 r / min for 1.5 h, filter after the reaction, wash with distilled water 4 times, and dry in an oven at 55°C to obtain modified rock wool, wherein the mass ratio of rock wool, 3% silver nitrate solution, and 25% sodium citrate solution is 1:10:14;

[0059] A2. Preparation of modified perlite: Add perlite with a particle size of 6 mm into dilute hydrochloric acid with a mass concentration of 15%, stir at 65°C at a rate of 30 r / min for 5 h, wash with distilled water 4 times, dry in an oven at 55°C, and then place in a carbon tube furnace and roast at 500°C for 1.5 h to obtain modified perlite; wherein the mass ratio of perlite to dilute hydrochloric acid with a mass concentration of 15% is 1:9;

[0060] A3, mixing: uniformly mix the modified rock wool, modified perlite and gravel with a particle size of 10 mm in a mass ratio of 4:3:3 to obtain a mixture 1;

[0061] A4. UV disinfection: Place the mixture 1 in step A3 under an irradiation intensity of 70uW / CM 2 Irradiate under ultraviolet light for 25 min to obtain a mixture 2;

[0062] A5. High-temperature steam sterilization: sterilize the mixture 2 in step A4 by high-temperature steam sterilization at 100° C. for 1.5 h, and cool to room temperature to obtain the desired solid matrix.

[0063] Preparation of liquid matrix:

[0064] B1. Fermentation: Crush the cauliflower tails, add brown sugar, and stir at 100 r / min for 10 min to obtain the fermented material. Add the fermentation agent (control the number of live bacteria in the fermented material to be 2.5×10 9 CFU / g), continued stirring at a rate of 100r / min for 0.45h, then allowed to stand, continued fermentation at a temperature of 43°C for 45h, raised to 65°C, oxygenated for 130h, cooled to room temperature, allowed to stand for 25h, filtered and slag removed, and fermentation liquid 1 was obtained; wherein the mass ratio of cauliflower tail to brown sugar was 40:2.5; wherein the starter was a mixture of Bacillus subtilis, Bacillus cereus, and nitrogen-fixing bacteria with a live bacteria count ratio of 4:5:1;

[0065] B2. Disinfection: The fermentation liquid 1 in step B1 is placed under an irradiation intensity of 70uW / CM 2Irradiate under ultraviolet light for 25 minutes, sterilize in 100℃ high temperature steam for 1.5 hours, and cool to obtain fermentation liquid 2;

[0066] B3, preparation of heavy metal ion chelating agent: sodium glutamate and deionized water are added to a reactor, and stirred at room temperature at a rate of 100 r / min for 0.45 h; after stirring and mixing, the reactor is heated to 70°C, glyoxylic acid is added, and the reaction is stirred at a rate of 40 r / min for 2 h; after the reaction is completed, citric acid is added, and the reaction is stirred at a rate of 40 r / min for 2 h; polyethylene glycol with a molecular weight of 400 is added to the reactor, and the mixture is stirred at a rate of 100 r / min for 0.45 h; vacuum drying is performed at a temperature of 50°C and a pressure of 0.01 MPa for 4 h to obtain the desired heavy metal ion chelating agent; wherein the mass ratio of sodium glutamate, deionized water, glyoxylic acid, citric acid, and polyethylene glycol with a molecular weight of 400 is 1:10:2.5:1.4:1.5;

[0067] B4. The fermentation broth 2, phosphoric acid and heavy metal ion chelating agent in a mass ratio of 48:0.45:1 were mixed at a rate of 100 r / min for 0.45 h to obtain a liquid matrix.

[0068] Preparation of soilless culture medium: fill the bottom of the seedling tray with solid matrix, and then add liquid matrix into the seedling pot so that the liquid level of the liquid matrix is ​​2.5 cm higher than the solid matrix to obtain the required soilless culture medium.

[0069] The steps of a method for raising radish seedlings in soilless culture are as follows:

[0070] S1. Cleaning and disinfection of radish seeds: transfer the radish seeds to a clean bench, wash them 4 times with sterile water, then wash them 4 times with a 4% NaClO solution, and then rinse them 4 times with sterile water;

[0071] S2, soaking the radish seeds after cleaning and disinfection in step S1 in a soaking solution for 1.5 hours, and then rinsing with sterile water for 4 times, wherein the soaking solution is a mixture of wood vinegar, melatonin, salicylic acid, and sterile water in a mass ratio of 2:2:2:1000;

[0072] S3, the radish seeds soaked in the soaking solution in step S2 were placed in the dark at 4°C for 70 hours, and then planted in the above-mentioned soilless culture medium for cultivation. The cultivation conditions were: light 16 hours / darkness 8 hours, and the light intensity was 150 μmol / m 2 / s, the temperature is 22℃, and when two leaves and one heart grow, the radish seedlings are obtained.

[0073] Example 3

[0074] Preparation of solid matrix:

[0075] A1. Preparation of modified rock wool: add a silver nitrate solution with a mass concentration of 4% to rock wool with a size of 2 cm×2 cm×2 cm, stir at a rate of 100 r / min for 0.6 h to obtain a mixed solution, add a sodium citrate solution with a mass concentration of 30% to the mixed solution, heat to 50°C, stir at a rate of 30 r / min for 2 h, filter after the reaction, wash with distilled water 5 times, and dry in an oven at 60°C to obtain modified rock wool, wherein the mass ratio of rock wool, silver nitrate solution with a mass concentration of 4%, and sodium citrate solution with a mass concentration of 30% is 1:12:16;

[0076] A2. Preparation of modified perlite: add perlite with a particle size of 8 mm into dilute hydrochloric acid with a mass concentration of 20%, stir at 80°C at a rate of 30 r / min for 6 h, wash with distilled water 5 times, dry in an oven at 60°C, and then place in a carbon tube furnace and roast at 600°C for 2 h to obtain modified perlite; wherein the mass ratio of perlite to dilute hydrochloric acid with a mass concentration of 20% is 1:10;

[0077] A3. Mixing: uniformly mix modified rock wool, modified perlite and gravel with a particle size of 16 mm in a mass ratio of 5:4:4 to obtain a mixture 1;

[0078] A4. UV disinfection: Place the mixture 1 in step A3 under an irradiation intensity of 80uW / CM 2 Irradiate under ultraviolet light for 30 min to obtain a mixture 2;

[0079] A5. High-temperature steam sterilization: sterilize the mixture 2 in step A4 at 100° C. high-temperature steam for 2 h, and cool to room temperature to obtain the desired solid matrix.

[0080] Preparation of liquid matrix:

[0081] B1. Fermentation: Crush the cabbage tails, add brown sugar, and stir at 100 r / min for 10 min to obtain the fermented material. Add the fermentation agent (control the number of live bacteria in the fermented material to be 3×10 9 CFU / g), continued stirring at a rate of 100r / min for 0.6h and then allowed to stand, continued fermentation at a temperature of 45°C for 50h, raised to 70°C, oxygenated for 140h, cooled to room temperature, allowed to stand for 30h, filtered and slag removed, and fermentation liquid 1 was obtained; wherein the mass ratio of cabbage tail to brown sugar was 50:3; the starter was a mixture of Bacillus subtilis, Bacillus cereus, and nitrogen-fixing bacteria with a live bacteria count ratio of 5:6:1;

[0082] B2. Disinfection: The fermentation liquid 1 in step B1 is placed under an irradiation intensity of 80uW / CM 2 Irradiate under ultraviolet light for 30 minutes, sterilize in 100℃ high temperature steam for 2 hours, and cool to obtain fermentation liquid 2;

[0083] B3, preparation of heavy metal ion chelating agent: sodium glutamate and deionized water are added to a reactor, and stirred at room temperature at a rate of 100 r / min for 0.6 h; after stirring and mixing, the reactor is heated to 80°C, glyoxylic acid is added, and the reaction is stirred at a rate of 40 r / min for 3 h; after the reaction is completed, citric acid is added, and the reaction is stirred at a rate of 40 r / min for 3 h; polyethylene glycol with a molecular weight of 600 is added to the reactor, and the mixture is stirred at a rate of 100 r / min for 0.6 h; vacuum drying is performed at a temperature of 50°C and a pressure of 0.01 MPa for 4 h to obtain the desired heavy metal ion chelating agent; wherein the mass ratio of sodium glutamate, deionized water, glyoxylic acid, citric acid, and polyethylene glycol with a molecular weight of 600 is 1:12:3:1.6:1.8;

[0084] B4. Fermentation broth 2, sodium phosphate and heavy metal ion chelating agent in a mass ratio of 60:0.6:1.2 were mixed at a rate of 100 r / min for 0.6 h to obtain a liquid matrix.

[0085] Preparation of soilless cultivation medium: fill the bottom of the seedling tray with solid matrix, and then add liquid matrix into the seedling pot so that the liquid level of the liquid matrix is ​​3 cm higher than the solid matrix to obtain the required soilless cultivation medium.

[0086] The steps of a method for raising seedlings of spinach in soilless culture are as follows:

[0087] S1. Cleaning and disinfection of spinach seeds: transfer the spinach seeds to a clean bench, wash them 5 times with sterile water, then wash them 5 times with a 5% NaClO solution, and then rinse them 5 times with sterile water;

[0088] S2, soaking the spinach seeds after cleaning and disinfection in step S1 in a soaking solution for 2 hours, and then rinsing with sterile water for 5 times, wherein the soaking solution is a mixture of wood vinegar, melatonin, salicylic acid and sterile water in a mass ratio of 3:3:3:1000;

[0089] S3, the spinach seeds soaked in the soaking solution in step S2 were placed in the dark at 4°C for 75 hours, and then planted in the above-mentioned soilless culture medium for cultivation. The cultivation conditions were: light 16 hours / darkness 8 hours, and the light intensity was 150 μmol / m 2 / s, the temperature is 22℃, and when two leaves and one heart grow, the spinach seedlings are obtained.

[0090] In order to verify the comprehensive performance of the vegetable soilless seedling raising method prepared in Examples 1-3 of the present application, the applicant set up comparative examples 1-11, which are as follows:

[0091] Comparative Example 1

[0092] Comparative Example 1 is the same as Example 1, except that the rock wool is not modified in the preparation of the solid matrix, as follows:

[0093] Preparation of solid matrix:

[0094] A1. Preparation of modified perlite: Add perlite with a particle size of 3 mm into dilute hydrochloric acid with a mass concentration of 10%, stir at 50°C at a rate of 30 r / min for 4 hours, wash with distilled water 3 times, dry in a 50°C oven, and then place in a carbon tube furnace and roast at 400°C for 1 hour to obtain modified perlite; wherein the mass ratio of perlite to dilute hydrochloric acid with a mass concentration of 10% is 1:8;

[0095] A2. Mixing: rock wool with a size of 1 cm×1 cm×1 cm, modified perlite and gravel with a particle size of 3 mm are uniformly mixed in a mass ratio of 3:2:2 to obtain a mixture 1;

[0096] A3. UV disinfection: Place the mixture 1 in step A2 under an irradiation intensity of 60uW / CM 2 Irradiate under ultraviolet light for 20 min to obtain a mixture 2;

[0097] A4. High-temperature steam sterilization: sterilize the mixture 2 in step A3 by high-temperature steam sterilization at 100° C. for 1 hour, and cool to room temperature to obtain the desired solid matrix.

[0098] Comparative Example 2

[0099] Comparative Example 2 is the same as Example 1, except that the perlite is not modified in the preparation of the solid matrix, as follows:

[0100] Preparation of solid matrix:

[0101] A1. Preparation of modified rock wool: add a 2% silver nitrate solution to rock wool of size 1 cm×1 cm×1 cm, stir at a rate of 100 r / min for 0.3 h to obtain a mixed solution, add a 20% sodium citrate solution to the mixed solution, heat to 40°C, stir at a rate of 30 r / min for 1 h, filter after the reaction, wash with distilled water 3 times, and dry in an oven at 50°C to obtain modified rock wool, wherein the mass ratio of rock wool, 2% silver nitrate solution, and 20% sodium citrate solution is 1:8:12;

[0102] A2. Mixing: uniformly mix the modified rock wool, perlite with a particle size of 3 mm, and gravel with a particle size of 3 mm in a mass ratio of 3:2:2 to obtain a mixture 1;

[0103] A3. UV disinfection: Place the mixture 1 in step A2 under an irradiation intensity of 60uW / CM 2Irradiate under ultraviolet light for 20 min to obtain a mixture 2;

[0104] A4. High-temperature steam sterilization: sterilize the mixture 2 in step A3 by high-temperature steam sterilization at 100° C. for 1 hour, and cool to room temperature to obtain the desired solid matrix.

[0105] Comparative Example 3

[0106] Comparative Example 3 is the same as Example 1, except that only Bacillus subtilis and nitrogen-fixing bacteria are used as the fermentation agent in the preparation of the liquid matrix, as follows:

[0107] Preparation of liquid matrix:

[0108] B1. Fermentation: Crush the cabbage tails, add brown sugar, and stir at 100 r / min for 10 min to obtain the fermented material. Add the fermentation agent (control the number of live bacteria in the fermented material to be 2×10 9 CFU / g), continued stirring at a rate of 100r / min for 0.3h and then allowed to stand, continued fermentation at a temperature of 40°C for 40h, raised the temperature to 60°C, oxygenated for 120h, cooled to room temperature, allowed to stand for 20h, filtered and slag removed, and obtained fermentation liquid 1; wherein the mass ratio of Chinese cabbage tail to brown sugar was 30:2; the starter was a mixture of Bacillus subtilis and nitrogen-fixing bacteria with a live bacteria count ratio of 3:1;

[0109] B2. Disinfection: The fermentation liquid 1 in step B1 is placed under an irradiation intensity of 60uW / CM 2 Irradiate under ultraviolet light for 20 minutes, sterilize in 100℃ high temperature steam for 1 hour, and cool to obtain fermentation liquid 2;

[0110] B3. Preparation of heavy metal ion chelating agent: sodium glutamate and deionized water are added to a reactor, and stirred at room temperature at a rate of 100 r / min for 0.3 h; after stirring and mixing, the reactor is heated to 60°C, glyoxylic acid is added, and the reaction is stirred at a rate of 40 r / min for 1 h; after the reaction is completed, citric acid is added, and the reaction is stirred at a rate of 40 r / min for 1 h; polyethylene glycol with a molecular weight of 200 is added to the reactor, and the mixture is stirred at a rate of 100 r / min for 0.3 h; the desired heavy metal ion chelating agent is obtained by vacuum drying at a temperature of 50°C and a pressure of 0.01 MPa for 4 h; wherein the mass ratio of sodium glutamate, deionized water, glyoxylic acid, citric acid, and polyethylene glycol with a molecular weight of 200 is 1:8:2:1.2:1.2;

[0111] B4. Fermentation broth 2, sodium citrate and heavy metal ion chelating agent in a mass ratio of 35:0.3:0.8 were mixed at a rate of 100 r / min for 0.3 h to obtain a liquid matrix.

[0112] Comparative Example 4

[0113] Comparative Example 4 is the same as Example 1, except that only Bacillus cereus and nitrogen-fixing bacteria are used as the fermentation agent in the preparation of the liquid matrix, as follows:

[0114] Preparation of liquid matrix:

[0115] B1. Fermentation: Crush the cabbage tails, add brown sugar, and stir at 100 r / min for 10 min to obtain the fermented material. Add the fermentation agent (control the number of live bacteria in the fermented material to be 2×10 9 CFU / g), continued stirring at a rate of 100r / min for 0.3h and then allowed to stand, continued fermentation at a temperature of 40°C for 40h, raised the temperature to 60°C, oxygenated for 120h, cooled to room temperature, allowed to stand for 20h, filtered and slag removed, and obtained fermentation liquid 1; wherein the mass ratio of Chinese cabbage tail to brown sugar was 30:2; the starter was a mixture of Bacillus cereus and nitrogen-fixing bacteria with a live bacteria count ratio of 4:1;

[0116] B2. Disinfection: The fermentation liquid 1 in step B1 is placed under an irradiation intensity of 60uW / CM 2 Irradiate under ultraviolet light for 20 minutes, sterilize in 100℃ high temperature steam for 1 hour, and cool to obtain fermentation liquid 2;

[0117] B3. Preparation of heavy metal ion chelating agent: sodium glutamate and deionized water are added to a reactor, and stirred at room temperature at a rate of 100 r / min for 0.3 h; after stirring and mixing, the reactor is heated to 60°C, glyoxylic acid is added, and the reaction is stirred at a rate of 40 r / min for 1 h; after the reaction is completed, citric acid is added, and the reaction is stirred at a rate of 40 r / min for 1 h; polyethylene glycol with a molecular weight of 200 is added to the reactor, and the mixture is stirred at a rate of 100 r / min for 0.3 h; the desired heavy metal ion chelating agent is obtained by vacuum drying at a temperature of 50°C and a pressure of 0.01 MPa for 4 h; wherein the mass ratio of sodium glutamate, deionized water, glyoxylic acid, citric acid, and polyethylene glycol with a molecular weight of 200 is 1:8:2:1.2:1.2;

[0118] B4. Fermentation broth 2, sodium citrate and heavy metal ion chelating agent in a mass ratio of 35:0.3:0.8 were mixed at a rate of 100 r / min for 0.3 h to obtain a liquid matrix.

[0119] Comparative Example 5

[0120] Comparative Example 5 is the same as Example 1, except that no citric acid is added to the homemade heavy metal chelating agent in the preparation of the liquid matrix, and the details are as follows:

[0121] Preparation of liquid matrix:

[0122] B1. Fermentation: Crush the cabbage tails, add brown sugar, and stir at 100 r / min for 10 min to obtain the fermented material. Add the fermentation agent (control the number of live bacteria in the fermented material to be 2×10 9 CFU / g), continued stirring at a rate of 100r / min for 0.3h and then allowed to stand, continued fermentation at a temperature of 40°C for 40h, raised the temperature to 60°C, oxygenated for reaction for 120h, cooled to room temperature, allowed to stand for 20h, filtered and slag removed, and obtained fermentation liquid 1; wherein the mass ratio of Chinese cabbage tail and brown sugar was 30:2; the starter was a mixture of Bacillus subtilis, Bacillus cereus and nitrogen-fixing bacteria with a live bacteria count ratio of 3:4:1;

[0123] B2. Disinfection: The fermentation liquid 1 in step B1 is placed under an irradiation intensity of 60uW / CM 2 Irradiate under ultraviolet light for 20 minutes, sterilize in 100℃ high temperature steam for 1 hour, and cool to obtain fermentation liquid 2;

[0124] B3. Preparation of heavy metal ion chelating agent: sodium glutamate and deionized water are added to a reactor, and stirred at room temperature at a rate of 100 r / min for 0.3 h; after stirring and mixing, the reactor is heated to 60°C, glyoxylic acid is added, and the reaction is stirred at a rate of 40 r / min for 1 h; polyethylene glycol with a molecular weight of 200 is added to the reactor, and the mixture is stirred at a rate of 100 r / min for 0.3 h; the desired heavy metal ion chelating agent is obtained by vacuum drying at a temperature of 50°C and a pressure of 0.01 MPa for 4 h; wherein the mass ratio of sodium glutamate, deionized water, glyoxylic acid, and polyethylene glycol with a molecular weight of 200 is 1:8:2:1.2;

[0125] B4. Fermentation broth 2, sodium citrate and heavy metal ion chelating agent in a mass ratio of 35:0.3:0.8 were mixed at a rate of 100 r / min for 0.3 h to obtain a liquid matrix.

[0126] Comparative Example 6

[0127] Comparative Example 6 is the same as Example 1, except that polyethylene glycol is not added to the homemade heavy metal chelating agent in the preparation of the liquid matrix, and the details are as follows:

[0128] Preparation of liquid matrix:

[0129] B1. Fermentation: Crush the cabbage tails, add brown sugar, and stir at 100 r / min for 10 min to obtain the fermented material. Add the fermentation agent (control the number of live bacteria in the fermented material to be 2×10 9CFU / g), continued stirring at a rate of 100r / min for 0.3h and then allowed to stand, continued fermentation at a temperature of 40°C for 40h, raised the temperature to 60°C, oxygenated for reaction for 120h, cooled to room temperature, allowed to stand for 20h, filtered and slag removed, and obtained fermentation liquid 1; wherein the mass ratio of Chinese cabbage tail and brown sugar was 30:2; the starter was a mixture of Bacillus subtilis, Bacillus cereus and nitrogen-fixing bacteria with a live bacteria count ratio of 3:4:1;

[0130] B2. Disinfection: The fermentation liquid 1 in step B1 is placed under an irradiation intensity of 60uW / CM 2 Irradiate under ultraviolet light for 20 minutes, sterilize in 100℃ high temperature steam for 1 hour, and cool to obtain fermentation liquid 2;

[0131] B3. Preparation of heavy metal ion chelating agent: sodium glutamate and deionized water are added to a reactor, and stirred at room temperature at a rate of 100 r / min for 0.3 h; after stirring and mixing, the reactor is heated to 60°C, glyoxylic acid is added, and the reaction is stirred at a rate of 40 r / min for 1 h; after the reaction is completed, citric acid is added, and the reaction is stirred at a rate of 40 r / min for 1 h; vacuum drying is performed at a temperature of 50°C and a pressure of 0.01 MPa for 4 h to obtain the desired heavy metal ion chelating agent; wherein the mass ratio of sodium glutamate, deionized water, glyoxylic acid, and citric acid is 1:8:2:1.2;

[0132] B4. Fermentation broth 2, sodium citrate and heavy metal ion chelating agent in a mass ratio of 35:0.3:0.8 were mixed at a rate of 100 r / min for 0.3 h to obtain a liquid matrix.

[0133] Comparative Example 7

[0134] Comparative Example 7 is the same as Example 1, except that the homemade heavy metal chelating agent in the preparation of the liquid matrix is ​​replaced by ethylenediaminetetraacetic acid, as follows:

[0135] Preparation of liquid matrix:

[0136] B1. Fermentation: Crush the cabbage tails, add brown sugar, and stir at 100 r / min for 10 min to obtain the fermented material. Add the fermentation agent (control the number of live bacteria in the fermented material to be 2×10 9 CFU / g), continued stirring at a rate of 100r / min for 0.3h and then allowed to stand, continued fermentation at a temperature of 40°C for 40h, raised the temperature to 60°C, oxygenated for reaction for 120h, cooled to room temperature, allowed to stand for 20h, filtered and slag removed, and obtained fermentation liquid 1; wherein the mass ratio of Chinese cabbage tail and brown sugar was 30:2; the starter was a mixture of Bacillus subtilis, Bacillus cereus and nitrogen-fixing bacteria with a live bacteria count ratio of 3:4:1;

[0137] B2. Disinfection: The fermentation liquid 1 in step B1 is placed under an irradiation intensity of 60uW / CM2 Irradiate under ultraviolet light for 20 minutes, sterilize in 100℃ high temperature steam for 1 hour, and cool to obtain fermentation liquid 2;

[0138] B3. Fermentation broth 2, sodium citrate and a heavy metal ion chelating agent in a mass ratio of 35:0.3:0.8 were mixed at a rate of 100 r / min for 0.3 h to obtain a liquid matrix, wherein the heavy metal chelating agent was ethylenediaminetetraacetic acid.

[0139] Comparative Example 8

[0140] Comparative Example 8 is the same as Example 1, except that the seeds are not soaked in the soaking liquid during seedling cultivation, as follows:

[0141] The steps of a cucumber soilless culture seedling raising method are as follows:

[0142] S1. Cleaning and disinfection of cucumber seeds: transfer the cucumber seeds to a clean bench, wash them 3 times with sterile water, then wash them 3 times with a 3% NaClO solution, and then rinse them 3 times with sterile water;

[0143] S2. The cucumber seeds cleaned and disinfected in step S1 were placed in a dark environment at 4°C for 65 hours, and then planted in the soilless culture medium. The cultivation conditions were as follows: 16 hours of light / 8 hours of darkness, and a light intensity of 150 μmol / m 2 / s, the temperature is 22℃, and when two leaves and one heart grow, the cucumber seedlings are obtained.

[0144] Comparative Example 9

[0145] Comparative Example 9 is the same as Example 1, except that the soaking liquid during seedling cultivation is made of only pyroligneous acid, melatonin, and sterile water, as follows:

[0146] The steps of a cucumber soilless culture seedling raising method are as follows:

[0147] S1. Cleaning and disinfection of cucumber seeds: transfer the cucumber seeds to a clean bench, wash them 3 times with sterile water, then wash them 3 times with a 3% NaClO solution, and then rinse them 3 times with sterile water;

[0148] S2, soaking the cucumber seeds after cleaning and disinfection in step S1 in a soaking solution for 1 hour, and then rinsing with sterile water for 3 times, wherein the soaking solution is a mixture of wood acetic acid, melatonin, and sterile water in a mass ratio of 1:1:1000;

[0149] S3, placing the cucumber seeds soaked in the soaking solution in step S2 in the dark at 4°C for 65 hours, taking them out, and planting them in the above-mentioned soilless culture medium for cultivation. The cultivation conditions are: light 16 hours / darkness 8 hours, and the light intensity is 150 μmol / m 2 / s, the temperature is 22℃, and when two leaves and one heart grow, the cucumber seedlings are obtained.

[0150] Comparative Example 10

[0151] Comparative Example 10 is the same as Example 1, except that the soaking liquid during seedling cultivation is made of only wood acetic acid, salicylic acid, and sterile water, as follows:

[0152] The steps of a cucumber soilless culture seedling raising method are as follows:

[0153] S1. Cleaning and disinfection of cucumber seeds: transfer the cucumber seeds to a clean bench, wash them 3 times with sterile water, then wash them 3 times with a 3% NaClO solution, and then rinse them 3 times with sterile water;

[0154] S2, soaking the cucumber seeds after cleaning and disinfection in step S1 in a soaking solution for 1 hour, and then rinsing with sterile water for 3 times, wherein the soaking solution is a mixture of wood acetic acid, salicylic acid, and sterile water in a mass ratio of 1:1:1000;

[0155] S3, placing the cucumber seeds soaked in the soaking solution in step S2 in the dark at 4°C for 65 hours, taking them out, and planting them in the above-mentioned soilless culture medium for cultivation. The cultivation conditions are: light 16 hours / darkness 8 hours, and the light intensity is 150 μmol / m 2 / s, the temperature is 22℃, and when two leaves and one heart grow, the cucumber seedlings are obtained.

[0156] Comparative Example 11

[0157] Comparative Example 11 is the same as Example 1, except that the soaking liquid for seedling cultivation is only made of melatonin, salicylic acid, and sterile water, as follows:

[0158] The steps of a cucumber soilless culture seedling raising method are as follows:

[0159] S1. Cleaning and disinfection of cucumber seeds: transfer the cucumber seeds to a clean bench, wash them 3 times with sterile water, then wash them 3 times with a 3% NaClO solution, and then rinse them 3 times with sterile water;

[0160] S2, soaking the cucumber seeds cleaned and disinfected in step S1 in a soaking solution for 1 hour, and then rinsing with sterile water for 3 times, wherein the soaking solution is a mixture of melatonin, salicylic acid, and sterile water in a mass ratio of 1:1:1000;

[0161] S3, placing the cucumber seeds soaked in the soaking solution in step S2 in the dark at 4°C for 65 hours, taking them out, and planting them in the above-mentioned soilless culture medium for cultivation. The cultivation conditions are: light 16 hours / darkness 8 hours, and the light intensity is 150 μmol / m 2 / s, the temperature is 22℃, and when two leaves and one heart grow, the cucumber seedlings are obtained.

[0162] Performance Testing

[0163] The comprehensive performance of the vegetable soilless cultivation seedlings and seedling raising methods in Examples 1-3 of the present application and Comparative Examples 1-11 were tested respectively.

[0164] Germination rate: 1000 vegetable seeds in each group were grown according to the seedling raising method of the embodiment or comparative example. When the vegetable seeds broke through the soil, they were considered to have germinated successfully. The germination rate was counted every other day. Table 1

[0165]

[0166] 2. The seedling raising substrate and seedling raising method of Example 1 and Comparative Examples 1-11 were used to raise and plant cucumber seedlings. After the cucumber vines were pulled out, the average plant height and stem thickness of each group of plants were measured, and the disease and insect rates during the entire growth process were counted.

[0167] Table 2

[0168]

[0169] It can be seen from the data in Table 1 and Table 2 that the seedling raising substrates prepared in Examples 1-3 and the seedling raising methods adopted have high germination rates, short germination times, good plant growth, and no diseases or insect pests.

[0170] Compared with Example 1-2, Example 1 is based on Example 1 without modifying the rock wool, and Example 2 is based on Example 1 without modifying the perlite. The plant growth of Example 1 is significantly better than that of Example 1-2, and the pest rate is significantly lower than that of Example 1-2, indicating that the modified rock wool has stronger antibacterial ability and can reduce the occurrence of diseases in soilless cultivation. Acid treatment can remove trace heavy metal elements in perlite and reduce the risk of heavy metal contamination of the seedling medium.

[0171] Compared with Comparative Examples 8-11, Example 1 is based on Example 1, but the seeds after cleaning and disinfection are not soaked in soaking liquid. Comparative Example 9 is based on Example 1, but salicylic acid is not added to the soaking liquid. Comparative Example 10 is based on Example 1, but melatonin is not added to the soaking liquid. Comparative Example 11 is based on Example 1, but wood vinegar is not added to the soaking liquid. The germination rates of Comparative Examples 8-11 are significantly lower than those of Example 1, the germination time is significantly longer than that of Example 1, and the plant height and stem are significantly equal to those of Example 1, indicating that wood vinegar, melatonin and salicylic acid all have the effect of promoting plant germination and growth, and the mixed use of the three can further enhance the germination effect on vegetable seeds. At the same time, melatonin and salicylic acid can enhance the plant's resistance to stress. Salicylic acid can activate the plant's immune system, melatonin can enhance the plant's disease resistance by regulating the plant's physiological metabolism, and wood vinegar can indirectly improve the plant's resistance to stress by adjusting the matrix. The combination of the three can form a stronger stress resistance protection mechanism. Vegetable seeds soaked in a mixture of wood vinegar, melatonin, salicylic acid, and sterile water have a high germination rate and strong resistance to diseases and pests.

[0172] 3. Water retention capacity test: Weigh 100g of the soilless culture substrate prepared in Examples 1-3 and Comparative Examples 1-7 respectively, put them in a beaker, place the beaker in a 35°C incubator, weigh them once every 24 hours, repeat the test 5 times for each sample, and take the average value. The test results are shown in Table 3 below:

[0173] Table 3

[0174]

[0175] It can be seen from the data in Table 3 that the seedling culture substrates prepared in Examples 1-3 have good water retention capacity. Compared with Comparative Example 2, Example 1 does not modify the perlite on the basis of Example 1. The water retention capacity of Example 1 is significantly better than that of Comparative Example 2, indicating that the perlite is modified by acid treatment, and the acid treatment can significantly improve the surface properties of the perlite, increase the microporosity of the perlite, and improve its water retention performance. The water retention properties of the modified rock wool and the modified perlite enhance each other, thereby improving the water retention performance of the soilless culture substrate.

[0176] 4. Heavy metal ion adsorption test:

[0177] Weigh 1 g of the heavy metal ion chelating agent of Examples 1-3 and Comparative Examples 5-7, respectively, and add them to 1000 mL of a mixed heavy metal ion solution, wherein the concentration of cadmium ions and lead ions are both 100 mg / L, and shake and adsorb for 12 hours. Then, the concentration of heavy metal ions in the mixed solution is determined, and the determination is performed 3 times, and the average value is taken to calculate the removal rate of heavy metal ions. The test results are shown in Table 4 below:

[0178] Table 4

[0179]

[0180] As can be seen from the data in Table 4, the heavy metal chelating agents prepared by Examples 1-3 of the present application have excellent heavy metal removal capabilities. The heavy metal removal capabilities of the heavy metal chelating agents prepared by Example 1 are better than those of Comparative Examples 5-7. The difference between Comparative Example 5 and Example 1 is that no citric acid reaction modification is added when preparing the heavy metal chelating agent. The difference between Comparative Example 6 and Example 1 is that no polyethylene glycol is added when preparing the heavy metal chelating agent. Comparative Example 7 replaces the homemade heavy metal chelating agent with ethylenediaminetetraacetic acid common in the market. It shows that the three carboxyl groups of the citric acid molecule have a strong chelating coordination effect on many metal ions, and can be coordinated with a variety of metal ions at the same time to form a stable heterometallic ion chelate. Citric acid reaction modification is added to sodium glutamate diacetate, and the synergistic effect of the two enhances the chelating effect on heavy metal ions. Further adding polyethylene glycol to the reaction can improve the water solubility of the chelating agent, improve the stability of the chelating agent, make it more stably present in the solution, not easy to decompose or fail, and further enhance the chelating effect on heavy metal ions.

[0181] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for raising vegetable seedlings in soilless culture, characterized in that: The steps of the seedling raising method of the vegetable soilless culture seedling are as follows: S1. Cleaning and disinfection of vegetable seeds: transfer the vegetable seeds to a clean bench, wash them 3-5 times with sterile water, then wash them 3-5 times with a 3-5% NaClO solution, and then rinse them 3-5 times with sterile water; S2, soaking the vegetable seeds after cleaning and disinfection in step S1 in a soaking solution for 1-2 hours, and then rinsing with sterile water for 3-5 times; the soaking solution is a mixture of wood vinegar, melatonin, salicylic acid and sterile water in a mass ratio of 1-3:1-3:1-3:1000; S3, dark-treating the vegetable seeds soaked in the soaking liquid in step S2 for 65-75 hours, taking them out, and planting them in a soilless culture medium to obtain vegetable seedlings; the preparation method of the soilless culture medium comprises the following steps: filling the bottom of a seedling tray with a solid matrix, and then adding a liquid matrix into the seedling tray so that the liquid level of the liquid matrix is ​​2-3 cm higher than the solid matrix, to obtain the desired soilless culture medium; The method for preparing the solid matrix comprises the following steps: A1. Preparation of modified rock wool: rock wool is added to a silver nitrate solution, mixed and stirred to obtain a mixed solution, sodium citrate solution is added to the mixed solution, heated to 40-50° C., mixed and stirred to react for 1-2 hours, and after the reaction is completed, filtered, washed and dried to obtain modified rock wool, wherein the mass ratio of rock wool, silver nitrate solution and sodium citrate solution is 1:8-12:12-16; A2. Preparation of modified perlite: adding perlite to dilute hydrochloric acid with a mass concentration of 10-20%, acid treatment at 50-80°C for 4-6h, washing with water until neutral and drying, and then placing in a carbon tube furnace at 400-600°C for 1-2h to obtain modified perlite; wherein the mass ratio of perlite to dilute hydrochloric acid with a mass concentration of 10-20% is 1:8-10; A3, mixing: uniformly mixing modified rock wool, modified perlite and gravel in a mass ratio of 3-5:2-4:2-4 to obtain a mixture 1; A4. UV disinfection: Place the mixture 1 in step A3 under an irradiation intensity of 60-80uW / CM 2 Irradiate under ultraviolet light for 20-30 min to obtain a mixture 2; A5. High temperature steam sterilization: Place the mixture 2 in step A4 in a high temperature steam sterilizer for 1-2 hours, and cool it to obtain the desired solid matrix.

2. The method for raising vegetable seedlings in soilless culture according to claim 1, characterized in that: The size of the rock wool in step A1 is 1-2 cm×1-2 cm×1-2 cm; the particle size of the perlite in step A2 is 3-8 mm; and the particle size of the gravel in step A3 is 3-16 mm.

3. The method for raising vegetable seedlings in soilless culture according to claim 1, characterized in that: The preparation method of the liquid matrix comprises the following steps: B1. Fermentation: Crush the vegetable crop tails, add brown sugar and stir to obtain the fermented material, add the fermentation agent, and control the number of live bacteria in the fermented material to 2×10 9 -3×10 9 CFU / g, stir evenly and let stand, continue fermentation at a temperature of 40-45°C for 40-50h, raise the temperature to 60-70°C, supply oxygen for reaction for 120-140h, cool to room temperature, let stand for 20-30h, filter and remove residue to obtain fermentation liquid 1; B2. Disinfection: The fermentation liquid 1 in step B1 is placed under an irradiation intensity of 60-80uW / CM 2 Irradiate under ultraviolet light for 20-30 minutes, sterilize in high-temperature steam for 1-2 hours, and cool to obtain fermentation liquid 2; B3, stirring and mixing the fermentation liquid 2 in step B2, the pH regulator, and the heavy metal ion chelating agent to obtain a liquid matrix.

4. The method for raising vegetable seedlings in soilless culture according to claim 3, characterized in that: In the step B1, the mass ratio of the vegetable crop tail vegetables to the brown sugar is 30-50:2-3; the vegetable crop tail vegetables are Chinese cabbage tail vegetables, cabbage tail vegetables, carrot tail vegetables or cauliflower tail vegetables; the fermentation agent is a mixture of Bacillus subtilis, Bacillus cereus and nitrogen-fixing bacteria with a live bacteria count ratio of 3-5:4-6:1; in the step B3, the mass ratio of the fermentation liquid 2 to the pH regulator and the heavy metal ion chelating agent is 35-60:0.3-0.6:0.8-1.2; the pH regulator includes at least one of sodium phosphate, sodium citrate, phosphoric acid and citric acid.

5. The method for raising vegetable seedlings in soilless culture according to claim 3, characterized in that: The preparation method of the heavy metal ion chelating agent comprises the following steps: adding sodium glutamate and deionized water into a reaction kettle, stirring and mixing them uniformly at room temperature; heating the reaction kettle to 60-80° C. after uniform mixing, adding glyoxylic acid, and reacting for 1-3 hours; adding citric acid after the reaction is completed, and reacting for 1-3 hours; adding polyethylene glycol into the reaction kettle, stirring and mixing them uniformly; and concentrating under reduced pressure to obtain the desired heavy metal ion chelating agent.

6. The method for raising vegetable seedlings in soilless culture according to claim 5, characterized in that: The mass ratio of sodium glutamate, deionized water, glyoxylic acid, citric acid and polyethylene glycol is 1:8-12:2-3:1.2-1.6:1.2-1.8; the molecular weight of polyethylene glycol is 200-600.

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