Biomass composite water culture solution and preparation method thereof

Abstract

The invention relates to a biomass composite water culture solution and a preparation method thereof, and belongs to the technical field of plant water culture. The culture solution is composed of 12 core components including a straw enzymatic hydrolysate, humic acid, a seaweed extract, a nitrogen-phosphorus-potassium compound fertilizer, a silver / carbon microsphere compound bacteriostatic agent, polylactic acid-glycolic acid copolymer loaded EM compound probiotics and the like. The preparation method comprises the following steps: firstly, mixing the straw enzymatic hydrolysate with the humic acid and other basic components, then respectively treating the seaweed extract and the probiotic carrier, and finally mixing step by step to ensure the stability of the components. The straw utilization rate is increased by combining calcium carbonate-hydrogen peroxide pretreatment with a cellulose composite enzymolysis technology; preparing the polylactic acid-glycolic acid copolymer loaded EM composite probiotics through a W / O / W double emulsification method; silver / carbon microspheres and potassium sorbate cooperate to inhibit bacteria; and compound plant hormones can accurately regulate and control growth. The culture solution has the functions of nutrition supply, antibacterial protection and growth regulation and control.

Description

Technical Field

[0001] The present invention belongs to the technical field of agricultural planting, and specifically relates to a biomass composite water culture solution and a preparation method thereof, which is suitable for scenes such as soilless plant cultivation, home gardening, and plant factories. Background Art

[0002] Traditional water culture solutions mostly rely on chemically synthesized nutrient salts, which have the problems of single ingredients, easy to cause secondary salinization of soil, poor biocompatibility, etc. In the prior art, although CN109553486A proposes a nutrient solution containing plant extracts, it does not make sufficient use of biomass resources and lacks an optimized design for the synergistic effect of microorganisms. In addition, soilless culture nutrient solutions generally have the defects of poor stability and easy breeding of pathogens. For example, although patent application CN201310493349A introduces EM probiotics, it does not combine biomass pretreatment technology, resulting in low nutrient release efficiency.

[0003] Existing water culture medium has problems such as single ingredients, poor water and fertilizer retention capacity (swelling rate ≤ 30%), and high cost. Traditional preparation methods do not functionalize biomass materials, resulting in insufficient stability in complex environments, limiting their application in water-saving agriculture and ecological restoration. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a hydroponic nutrient solution based on biomass materials and a preparation method thereof; to solve the problems of the existing hydroponic nutrient solution having a single component and poor water and fertilizer retention capacity.

[0005] Technical solution: A hydroponic nutrient solution based on biomass materials, comprising the following components by weight: 30-40 parts of straw enzymatic hydrolysate, 20-25 parts of humic acid, 5-7 parts of seaweed extract, N:P 2 O 5 :K 2 3-5 parts of nitrogen, phosphorus and potassium compound fertilizer with O=15:15:15, 0.5-0.7 parts of silver / carbon microsphere composite antibacterial agent, 2-5 parts of polylactic acid-glycolic acid copolymer loaded EM composite probiotics, 10-15 parts of glucose, 1000-1200 parts of water, 0.005-0.01 parts of compound plant hormones, 6-9 parts of low-salt soy sauce, 0.1-0.3 parts of β-glucan, 0.05-0.1 parts of potassium sorbate, and 0.4-0.8 parts of EDTA chelated trace metal mixture.

[0006] Preferably, the method for preparing the straw enzymatic hydrolyzate is as follows: crush the straw through a 30-mesh sieve, then soak it in a calcium carbonate-hydrogen peroxide mixed aqueous solution with a mass ratio of 9-10:1, and then stand it at 120-130°C for 70-80 minutes to obtain straw b, then add the straw b to deionized water with a weight of 9-10 times that of the straw b, and stand it at 40-60°C for 10-30 minutes to obtain straw c, and place the straw c in a 60-80°C oven to a constant weight, and then sterilize it with high-pressure steam at 120-125°C for 20-30 minutes. Obtain straw d; send the straw d and water at a mass ratio of 1:10 into an enzymolysis tank at 60-65°C, add a 1% by mass sodium dihydrogen phosphate buffer solution into the uniformly stirred enzymolysis raw material to adjust the pH value to 4.8-6.6, and then add a cellulose complex enzyme containing 1%-3% of a surfactant into the enzymolysis tank in a sealed state, wherein the cellulose complex enzyme consists of endocellulase, exocellulase and cellobiase in a mass ratio of 1:1:2, and when the COD of the enzymolysis product in the enzymolysis tank no longer changes, the enzymolysis reaction is terminated to obtain a straw enzymolysis liquid.

[0007] Preferably, the preparation method of the seaweed extract is: rinse the fresh seaweed with clean water to remove impurities such as mud, salt, and periphyton, dry at a low temperature of 40-60°C, grind the dried seaweed into 20-100 mesh powder with a pulverizer, mix the seaweed powder with deionized water in a ratio of 1:10-1:30, heat to 60-100°C, stir and extract for 1-4h, centrifuge to remove residue, collect the supernatant, and evaporate the water under reduced pressure to obtain the extract.

[0008] Preferably, the preparation method of the silver / carbon microsphere composite antibacterial agent is: weigh glucose, add silver nitrate of 1 / 5 of the weight of glucose, dissolve in deionized water 10 times the weight of glucose, transfer to a reactor, react at 180°C for 7 hours, wait for the reactor to cool naturally to room temperature, wash the product with deionized water and anhydrous ethanol several times, respectively, and dry at 85°C for 4 hours to obtain a brown powder.

[0009] Preferably, the preparation method of the polylactic acid-glycolic acid copolymer-loaded EM composite probiotics is as follows: dissolving polylactic acid-glycolic acid copolymer (PLGA) with a relative molecular weight of 15 kDa in 9 times its weight of ethyl acetate, magnetically stirring until completely dissolved, culturing the EM composite probiotics to the logarithmic growth phase, collecting the bacteria by centrifugation, and resuspending them in a phosphate buffer containing 10% trehalose at pH 7.4, slowly adding the bacterial suspension to a PLGA solution with a volume 10 times that of the bacterial suspension, ultrasonically treating with an amplitude of 40% for 30 seconds to form a W / O emulsion, injecting the W / O emulsion into an aqueous phase containing 2% PVA with a volume 100 times that of the bacterial suspension, homogenizing and emulsifying at 10,000 rpm for 2 minutes, stirring to evaporate the solvent for 4 hours, collecting the microspheres by centrifugation, washing them with ultrapure water 3 times to remove residual PVA, and freeze-drying them at -50°C for 24 hours to obtain polylactic acid-glycolic acid copolymer-loaded EM composite probiotics.

[0010] Preferably, the composite plant hormone is gibberellin: sodium nitrophenolate: ethephon = 2:1:1.

[0011] Preferably, the preparation method of the EDTA chelated trace metal mixture is: dissolving EDTA in water 8 times its weight, adding a mixed salt 2 times the weight of EDTA, wherein the mixed salt is prepared from nickel chloride, copper sulfate, manganese chloride, ferric chloride and magnesium chloride in a ratio of 1:2:1:3:2, stirring and dissolving, and evaporating to dryness at 60°C under reduced pressure to obtain the mixture.

[0012] A method for preparing a biomass composite water culture solution comprises the following preparation steps: (a) adding straw enzymatic hydrolysate, humic acid, nitrogen, phosphorus and potassium compound fertilizer, silver / carbon microsphere compound antibacterial agent, 3 / 5 of the total amount of water, compound plant hormone, 6-9 parts of low-salt soy sauce, β-glucan, 0.05-0.1 parts of potassium sorbate, and EDTA chelated trace metal mixture to a reaction kettle in sequence, stirring and mixing evenly to obtain a mixed solution 1; (b) adding the remaining 1 / 5 of water into the reaction bottle, adding the seaweed extract, and mixing well to obtain a mixed solution 2; (c) adding the remaining 1 / 5 of water into the reaction bottle, adding glucose, and adding polylactic acid-co-glycolic acid copolymer loaded with EM composite probiotics after dissolving, adding the mixed solution 2 obtained in step (b), and mixing evenly to obtain a mixed solution 3; (d) The mixed solution 3 obtained in step (c) and the mixed solution 1 obtained in step (a) are uniformly mixed to obtain the mixture.

[0013] Beneficial effects:

[0014] 1. The present invention significantly improves the enzymatic hydrolysis efficiency of straw by combining calcium carbonate-hydrogen peroxide pretreatment with cellulose composite enzymatic hydrolysis technology, converts agricultural waste into high-value nutrient solution, reduces raw material costs and reduces environmental pollution.

[0015] 2. Silver / carbon microspheres (nanosilver loaded on carbon-based materials) inhibit the growth of bacteria and fungi in hydroponic systems through physical adsorption and reduce root diseases.

[0016] 3. The EM compound probiotics are encapsulated by PLGA microspheres prepared by the W / O / W double emulsification method to achieve the slow release of bacteria, prolong the active period of probiotics, continuously improve the rhizosphere microecology, promote nutrient absorption, and prevent the killing of probiotics by silver / carbon microspheres, so that probiotics and fungicides can coexist in one system.

[0017] 4. Gibberellic acid (growth promotion), sodium nitrophenolate (enhanced stress resistance), and ethephon (maturation regulation) work synergistically in a 2:1:1 ratio to accurately regulate the physiological needs of plants at different growth stages, improve yield and quality. EDTA chelates metal ions such as nickel, copper, manganese, iron, and magnesium, improves the stability and bioavailability of trace elements, prevents nutrient deficiency, and promotes enzyme activity and photosynthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a SEM image of the silver / carbon microsphere composite antibacterial agent of the present invention.

[0019] Figure 2 This is a microscope picture of the PLGA-loaded EM composite probiotic microspheres of the present invention.

[0020] Figure 3 This is a comparison chart of the growth of peppers cultured in the culture solution of Example 1 of the present invention and the culture solution of Comparative Example 2 for 20 days.

[0021] Figure 4 This is a comparison chart of the growth of peppers cultured in the culture solution of Example 1 of the present invention and the culture solution of Comparative Example 4 for 20 days. DETAILED DESCRIPTION

[0022] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Example 1 Raw materials preparation: Preparation of corn straw hydrolysate: 1 kg corn straw was crushed through a 30-mesh sieve and soaked in a mixed aqueous solution of calcium carbonate and hydrogen peroxide (900 g calcium carbonate + 100 g hydrogen peroxide) with a mass ratio of 9:1. 2 O 2+10L water), let it stand at 120℃ for 80min to get straw b, mix straw b with 9 times deionized water (9kg), let it stand at 40℃ for 30min, filter to get straw c, dry straw c in a 60℃ oven to constant weight, sterilize with high pressure steam (120℃, 30min) to get straw d, add straw d and water at a ratio of 1:10 (100g straw d+1L water) into an enzymolysis tank (60℃), adjust the pH to 4.8 with phosphate buffer, add cellulose complex enzyme (50U / g straw) containing 1% Tween-80, seal and enzymolyze until COD is stable (about 48h), and centrifuge to get the supernatant to get the straw enzymolyte.

[0024] Preparation of seaweed extract: Take 500g of fresh brown algae, rinse with clean water, dry at 40℃, crush to 20 mesh, mix with deionized water at a ratio of 1:10 (25g powder + 250g water), extract with stirring at 60℃ for 4h, centrifuge (4000rpm, 15min), and concentrate the supernatant under reduced pressure to a paste.

[0025] Preparation of silver / carbon microsphere composite antibacterial agent: weigh 10g of glucose, add 2g of silver nitrate and dissolve in 100g of deionized water, transfer to a reactor and react at 180℃ for 7h, cool and centrifuge, wash with deionized water and ethanol three times in sequence, dry at 85℃ for 4h to obtain brown-black powder. The SEM image of the silver / carbon microsphere composite antibacterial agent is attached. Figure 1 .

[0026] Preparation of PLGA-loaded EM composite probiotic microspheres: 1 g of PLGA (15 kDa) was dissolved in 9 g of ethyl acetate and stirred magnetically until transparent. 600 =1.0) centrifugation (5000×g, 10min), the bacteria were resuspended in PBS (pH7.4) containing 10% trehalose, 1ml of the bacterial suspension was slowly added to the PLGA solution, and ultrasonication (40% amplitude, 30s) was performed to form a W / O emulsion. The emulsion was injected into 100ml of an aqueous phase containing 2% PVA, homogenized and emulsified (10000rpm, 2min), stirred for 4h to evaporate the solvent, centrifuged (3000×g, 10min), washed and freeze-dried to obtain bacteria-loaded microspheres. Microscope pictures of PLGA-loaded EM composite probiotic microspheres are attached. Figure 2 .

[0027] Preparation of EDTA chelated trace metal mixture: dissolve 5g EDTA in 40g water, add 10g mixed salt (nickel chloride: copper sulfate: manganese chloride: ferric chloride: magnesium chloride = 1:2:1:3:2), stir to dissolve, evaporate to dryness under reduced pressure at 60°C, and grind into powder.

[0028] Culture medium preparation: Prepare according to the following weight parts (total water volume 1000 parts): Mixture 1: 30 parts of straw enzymatic hydrolysate, 20 parts of humic acid, nitrogen, phosphorus and potassium compound fertilizer (N:P 2 O 5 :K 2 O=15:15:15), 3 parts, silver / carbon microsphere composite antibacterial agent 0.5 parts, water (3 / 5 total amount) 600 parts, composite plant hormone (gibberellic acid: sodium nitrophenolate: ethephon = 2:1:1) 0.005 parts, low-salt soy sauce 6 parts, β-glucan 0.1 parts, potassium sorbate 0.05 parts, EDTA chelated metal mixture 0.4 parts, the above components were added into the reactor in turn, and mechanically stirred at room temperature (500rpm, 30min) until homogeneous.

[0029] Mixture 2: 200 parts of water (1 / 5 of the total amount) and 5 parts of seaweed extract are mixed and stirred until dissolved.

[0030] Mixture 3: 200 parts of water (1 / 5 of the total amount), 10 parts of glucose, and 2 parts of polylactic acid-glycolic acid copolymer-loaded EM composite probiotics were added to the mixed solution 2 and stirred to mix.

[0031] Final culture medium: Mix the mixed solution 3 and the mixed solution 1, and mechanically stir at room temperature (300 rpm, 20 min) to obtain the product.

[0032] Example 2

[0033] Raw materials preparation: Preparation of corn straw hydrolysate: 1 kg corn straw was crushed and passed through a 30-mesh sieve, and then soaked in a mixed aqueous solution of calcium carbonate and hydrogen peroxide (950 g calcium carbonate + 100 g hydrogen peroxide) with a mass ratio of 9.5:1. 2 O 2 +10L water), let it stand at 125℃ for 75min to get straw b, mix straw b with 9.5 times deionized water (9.5kg), let it stand at 50℃ for 20min, filter to get straw c, dry straw c in a 70℃ oven to constant weight, sterilize with high pressure steam (123℃, 25min) to get straw d, add straw d and water at a ratio of 1:10 (100g straw d + 1kg water) into an enzymolysis tank (63℃), adjust the pH to 5.5 with phosphate buffer, add cellulose complex enzyme (50U / g straw) containing 2% Tween-80, seal and enzymolyze until COD is stable (about 48h), and centrifuge to get the supernatant to get the straw enzymolyte.

[0034] Preparation of seaweed extract: Take 500g of fresh brown algae, rinse with clean water, dry at 40℃, crush to 60 mesh, mix with deionized water at a ratio of 1:20 (25g powder + 500g water), extract with stirring at 80℃ for 2h, centrifuge (4000rpm, 15min), and concentrate the supernatant under reduced pressure to a paste.

[0035] Preparation of silver / carbon microsphere composite antibacterial agent: weigh 10g of glucose, add 2g of silver nitrate and dissolve in 100g of deionized water, transfer to a reactor and react at 180℃ for 7h, centrifuge after cooling, wash with deionized water and ethanol three times in turn, dry at 85℃ for 4h to obtain a brown-black powder.

[0036] Preparation of PLGA-loaded EM composite probiotic microspheres: 1 g of PLGA (15 kDa) was dissolved in 9 g of ethyl acetate and stirred magnetically until transparent. 600 =1.0) by centrifugation (5000×g, 10min), the bacteria were resuspended in PBS (pH7.4) containing 10% trehalose, 1ml of the bacterial suspension was slowly added with PLGA solution, and a W / O emulsion was formed by ultrasound (40% amplitude, 30s). The emulsion was injected into 100ml of aqueous phase containing 2% PVA, and the mixture was homogenized and emulsified (10000rpm, 2min). The solvent was evaporated by stirring for 4h, and the mixture was centrifuged (3000×g, 10min). The mixture was washed and freeze-dried.

[0037] Preparation of EDTA chelated trace metal mixture: dissolve 5g EDTA in 40g water, add 10g mixed salt (nickel chloride: copper sulfate: manganese chloride: ferric chloride: magnesium chloride = 1:2:1:3:2), stir to dissolve, evaporate to dryness under reduced pressure at 60°C, and grind into powder.

[0038] Culture medium preparation: Prepare according to the following weight parts (total water volume 1100 parts): Mixture 1: 35 parts of straw enzymatic hydrolysate, 22 parts of humic acid, nitrogen, phosphorus and potassium compound fertilizer (N:P 2 O 5 :K 2 O=15:15:15) 4 parts, silver / carbon microsphere composite antibacterial agent 0.6 parts, water (3 / 5 total amount) 660 parts, composite plant hormone (gibberellic acid: sodium nitrophenolate: ethephon = 2:1:1) 0.008 parts, low-salt soy sauce 7 parts, β-glucan 0.2 parts, potassium sorbate 0.08 parts, EDTA chelated metal mixture 0.6 parts, the above components were added into the reactor in turn, and mechanically stirred at room temperature (500rpm, 30min) until homogeneous.

[0039] Mixture 2: 220 parts of water (1 / 5 of the total amount) and 6 parts of seaweed extract are mixed and stirred until dissolved.

[0040] Mixture 3: 220 parts of water (1 / 5 of the total amount), 12 parts of glucose, and 3.5 parts of polylactic acid-glycolic acid copolymer-loaded EM composite probiotics were added to the mixed solution 2 and stirred to mix.

[0041] Final culture medium: Mix the mixed solution 3 and the mixed solution 1, and mechanically stir at room temperature (300 rpm, 20 min) to obtain the product.

[0042] Example 3

[0043] Raw materials preparation: Preparation of corn straw hydrolysate: 1 kg corn straw was crushed and passed through a 30-mesh sieve, and then soaked in a mixed aqueous solution of calcium carbonate and hydrogen peroxide (1000 g calcium carbonate + 100 g hydrogen peroxide) with a mass ratio of 10:1. 2 O 2 +10L water), let it stand at 130℃ for 70min to get straw b, mix straw b with 10 times deionized water (10kg), let it stand at 60℃ for 10min, filter to get straw c, dry straw c in an oven at 80℃ to constant weight, sterilize with high pressure steam (125℃, 20min) to get straw d, add straw d and water at a ratio of 1:10 (100g straw d + 1kg water) into an enzymolysis tank (65℃), adjust the pH to 6.6 with phosphate buffer, add cellulose complex enzyme (50U / g straw) containing 3% Tween-80, seal and hydrolyze until COD is stable (about 48h), and centrifuge to get the supernatant to get the straw hydrolysate.

[0044] Preparation of seaweed extract: Take 500g of fresh brown algae, rinse with clean water, dry at 60℃, crush to 100 mesh, mix with deionized water at a ratio of 1:30 (25g powder + 750g water), extract with stirring at 100℃ for 1h, centrifuge (4000rpm, 15min), and concentrate the supernatant under reduced pressure to a paste.

[0045] Preparation of silver / carbon microsphere composite antibacterial agent: weigh 10g of glucose, add 2g of silver nitrate and dissolve in 100g of deionized water, transfer to a reactor and react at 180℃ for 7h, centrifuge after cooling, wash with deionized water and ethanol three times in turn, dry at 85℃ for 4h to obtain a brown-black powder.

[0046] Preparation of PLGA-loaded EM composite probiotic microspheres: 1 g of PLGA (15 kDa) was dissolved in 9 g of ethyl acetate and stirred magnetically until transparent. 600 =1.0) by centrifugation (5000×g, 10min), the bacteria were resuspended in PBS (pH7.4) containing 10% trehalose, 1ml of the bacterial suspension was slowly added with PLGA solution, and a W / O emulsion was formed by ultrasound (40% amplitude, 30s). The emulsion was injected into 100ml of aqueous phase containing 2% PVA, and the mixture was homogenized and emulsified (10000rpm, 2min). The solvent was evaporated by stirring for 4h, and the mixture was centrifuged (3000×g, 10min). The mixture was washed and freeze-dried.

[0047] Preparation of EDTA chelated trace metal mixture: dissolve 5 g EDTA in 40 g water, add 10 g mixed salt (nickel chloride: copper sulfate: manganese chloride: ferric chloride: magnesium chloride = 1:2:1:3:2), stir to dissolve, evaporate to dryness under reduced pressure at 60°C, and grind into powder.

[0048] Culture medium preparation: Prepare according to the following weight parts (total water volume 1200 parts): Mixture 1: 40 parts of straw enzymatic hydrolysate, 25 parts of humic acid, nitrogen, phosphorus and potassium compound fertilizer (N:P 2 O 5 :K 2 O=15:15:15) 5 parts, silver / carbon microsphere composite antibacterial agent 0.5 parts, water (3 / 5 total amount) 720 parts, composite plant hormone (gibberellic acid: sodium nitrophenolate: ethephon = 2:1:1) 0.01 parts, low-salt soy sauce 9 parts, β-glucan 0.3 parts, potassium sorbate 0.1 parts, EDTA chelated metal mixture 0.8 parts, the above components were added into the reactor in turn, and mechanically stirred at room temperature (500rpm, 30min) until homogeneous.

[0049] Mixture 2: 240 parts of water (1 / 5 of the total amount) and 7 parts of seaweed extract are mixed and stirred until dissolved.

[0050] Mixture 3: 240 parts of water (1 / 5 of the total amount), 15 parts of glucose, and 5 parts of polylactic acid-glycolic acid copolymer-loaded EM composite probiotics were added to the mixed solution 2 and stirred to mix.

[0051] Final culture medium: Mix the mixed solution 3 and the mixed solution 1, and mechanically stir at room temperature (300 rpm, 20 min) to obtain the product.

[0052] Comparative Example 1

[0053] Same as Example 1, except that the silver / carbon microsphere composite antibacterial agent was not added.

[0054] Comparative Example 2

[0055] Same as Example 1, except that the EM compound probiotics were not subjected to PLGA loading treatment.

[0056] Comparative Example 3

[0057] Same as Example 1, except that EDTA was not added, and a mixed salt of nickel chloride: copper sulfate: manganese chloride: ferric chloride: magnesium chloride = 1:2:1:3:2 was directly added.

[0058] Comparative Example 4

[0059] Same as Example 1, except that no compound plant hormone is added.

[0060] Comparative Example 5

[0061] Same as Example 1, except that the straw is not treated with the calcium carbonate-hydrogen peroxide mixed aqueous solution.

[0062] The culture solutions prepared in the comparative example and the example were used to culture pepper seeds respectively, and the culture solutions were tested. The survival rate of probiotics and the microbial contamination rate were monitored by microscopy: the solution was centrifuged to enrich the microorganisms, the enriched microorganisms were smeared, stained and observed under a microscope, and the number of microorganisms in the microscope field was directly counted; the heavy metal Pb was tested by atomic absorption spectrophotometry. 2+ Adsorption rate: take a certain amount of solution sample and dilute it to a certain volume as the sample to be tested. Use an atomic absorption spectrophotometer to measure the absorbance of the sample at the characteristic absorption wavelength of lead ions. According to the standard curve method, the relationship between absorbance and lead ion concentration is established through a standard solution of known concentration, so as to calculate the concentration of lead ions in the sample. The adsorption rate calculation formula is: Adsorption rate (%) = (C 0 -C e ) / C e ×100%, where C 0 is the initial concentration of lead ions in the solution before adsorption, C e is the residual concentration of lead ions in the solution after adsorption. The results are shown in Table 1.

[0063] Table 1 Test results of embodiments and comparative examples

[0064] The difference between Comparative Example 5 and Examples 1 to 3 is that the straw is not treated with a calcium carbonate-hydrogen peroxide mixed aqueous solution. As a result, the root length of Comparative Example 5 at 20 days is 8.9 cm, and that of Examples 1 to 3 is ≥9.7 cm. The plant height of Comparative Example 5 at 30 days is 14.6 cm, and that of Examples 1 to 3 is ≥17.5 cm, indicating that the nutrients of the straw are more sufficient after being treated with a calcium carbonate-hydrogen peroxide mixed aqueous solution, and more nutrients are available for plant growth. In other words, it is obvious that treating the straw with a calcium carbonate-hydrogen peroxide mixed aqueous solution can significantly improve the enzymatic hydrolysis efficiency of the straw, and the biomass utilization rate for plant growth is higher; it can be seen from Examples 1 to 3 and Comparative Example 1 that silver / carbon microspheres can inhibit the growth of bacteria and fungi in the hydroponic system for a long time and reduce root diseases , and can absorb certain heavy metal ions; it can be seen from Examples 1 to 3 and Comparative Example 2 that the PLGA microspheres prepared by the W / O / W double emulsification method encapsulate the EM composite probiotics, realize the slow release of the bacteria, prolong the active period of the probiotics, continuously improve the rhizosphere microecology, promote nutrient absorption, and can block the killing of the probiotics by the silver / carbon microspheres, so that the probiotics and the bactericide can coexist in a system; it can be seen from Examples 1 to 3 and Comparative Example 4 that the addition of composite plant hormones can accurately regulate the physiological needs of plants at different growth stages and improve yield and quality; it can be seen from Examples 1 to 3 and Comparative Example 3 that EDTA chelates metal ions such as nickel, copper, manganese, iron, and magnesium, improves the stability and bioavailability of trace elements, prevents deficiency, and promotes enzyme activity and photosynthesis. Among them, the comparison chart of the growth of peppers cultured in the culture solution of Example 1 and the culture solution of Comparative Example 2 for 20 days is attached. Figure 3 The comparison of the growth of pepper cultured in the culture solution of Example 1 and the culture solution of Comparative Example 4 for 20 days is shown in the attached figure. Figure 4 .

[0065] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A biomass composite water culture solution, characterized in that: The invention comprises the following components in parts by weight: 30-40 parts of straw enzymatic hydrolysate, 20-25 parts of humic acid, 5-7 parts of seaweed extract, 3-5 parts of nitrogen, phosphorus and potassium compound fertilizer with N:P2O5:K2O=15:15:15, 0.5-0.7 parts of silver / carbon microsphere composite antibacterial agent, 2-5 parts of polylactic acid-glycolic acid copolymer loaded with EM composite probiotics, 10-15 parts of glucose, 1000-1200 parts of water, 0.005-0.01 parts of composite plant hormones, 6-9 parts of low-salt soy sauce, 0.1-0.3 parts of beta-glucan, 0.05-0.1 parts of potassium sorbate and 0.4-0.8 parts of EDTA chelated trace metal mixture.

2. The biomass composite water culture solution according to claim 1, characterized in that: The straw enzymatic hydrolysate preparation method comprises the following steps: crushing the straw through a 30-mesh sieve, then soaking the straw in a calcium carbonate-hydrogen peroxide mixed aqueous solution with a mass ratio of 9-10:1, and then standing at 120-130° C. for 70-80 minutes to obtain straw b, then adding the straw b into deionized water 9-10 times its weight, and standing at 40-60° C. for 10-30 minutes to obtain straw c, and drying the straw c in a 60-80° C. oven to constant weight, and then sterilizing the straw with high pressure steam at 120-125° C. for 20-30 minutes to obtain straw c. Straw d; the straw d and water are sent into an enzymolysis tank at a mass ratio of 1:10, and a 1% by mass sodium dihydrogen phosphate buffer solution is added to the enzymolysis raw material after uniform stirring to adjust the pH value to 4.8-6.6, and then a cellulose complex enzyme containing 1%-3% of a surfactant is added to the enzymolysis tank in a sealed state, wherein the cellulose complex enzyme consists of endocellulase, exocellulase, and cellobiase in a mass ratio of 1:1:2, and when the COD of the enzymolysis product in the enzymolysis tank no longer changes, the enzymolysis reaction is terminated to obtain a straw enzymolysis liquid.

3. The biomass composite water culture solution according to claim 1, characterized in that: The preparation method of the seaweed extract comprises the following steps: washing fresh seaweed with clean water to remove mud, salt and epiphytic impurities, drying at a low temperature of 40-60° C., grinding the dried seaweed into 20-100 mesh powder with a pulverizer, mixing the seaweed powder with deionized water in a ratio of 1:10-1:30, heating to 60-100° C., stirring and extracting for 1-4 hours, centrifuging to remove residues, collecting the supernatant, and removing water under reduced pressure to obtain the seaweed extract.

4. The biomass composite water culture solution according to claim 1, characterized in that: The preparation method of the silver / carbon microsphere composite antibacterial agent is as follows: glucose is weighed, and silver nitrate of 1 / 5 of the weight of the glucose is added and dissolved in deionized water of 10 times the weight of the glucose and transferred to a reactor, reacted at 180° C. for 7 hours, and after the reactor is naturally cooled to room temperature, the product is washed several times with deionized water and anhydrous ethanol respectively, and dried at 85° C. for 4 hours to obtain a brown powder, which is the silver / carbon microsphere composite antibacterial agent.

5. The biomass composite water culture solution according to claim 1, characterized in that: The preparation method of the polylactic acid-glycolic acid copolymer loaded EM composite probiotics is as follows: PLGA with a relative molecular weight of 15 kDa is dissolved in ethyl acetate with a volume of 9 times the weight of PLGA, magnetic stirring is performed until the PLGA is completely dissolved, the EM composite probiotics are cultured to a logarithmic growth phase, the bacterial bodies are collected by centrifugation, and the bacterial bodies are resuspended in a phosphate buffer containing 10% trehalose at pH 7.4, the bacterial suspension is slowly added to a PLGA solution with a volume 10 times that of the bacterial suspension, ultrasonic treatment is performed at 40% amplitude for 30 seconds to form a W / O emulsion, the W / O emulsion is injected into an aqueous phase containing 2% PVA with a volume of 100 times that of the bacterial suspension, homogenization and emulsification are performed at 10000 rpm for 2 minutes, the solvent is volatilized by stirring for 4 hours, the microspheres are collected by centrifugation, the residual PVA is removed by washing with ultrapure water for 3 times, and freeze-drying is performed at -50°C for 24 hours to obtain the polylactic acid-glycolic acid copolymer loaded EM composite probiotics.

6. The biomass composite water culture solution according to claim 1, characterized in that: The composite plant hormone is gibberellin: sodium nitrophenolate: ethephon = 2:1:

1.

7. The biomass composite water culture solution according to claim 1, characterized in that: The preparation method of the EDTA chelated trace metal mixture is as follows: dissolving EDTA in water of 8 times its weight, adding a mixed salt of 2 times the weight of EDTA, wherein the mixed salt is prepared from nickel chloride, copper sulfate, manganese chloride, ferric chloride and magnesium chloride in a ratio of 1:2:1:3:2, stirring and dissolving, and evaporating to dryness at 60° C. under reduced pressure to obtain the mixture.

8. A method for preparing a biomass composite water culture solution according to any one of claims 1 to 7, characterized in that: The method comprises the following preparation steps: (a) adding straw enzymatic hydrolysate, humic acid, nitrogen, phosphorus and potassium compound fertilizer, silver / carbon microsphere compound antibacterial agent, 3 / 5 of the total amount of water, compound plant hormone, 6-9 parts of low-salt soy sauce, β-glucan, 0.05-0.1 parts of potassium sorbate, and EDTA chelated trace metal mixture to a reaction kettle in sequence, stirring and mixing evenly to obtain a mixed solution 1; (b) adding the remaining 1 / 5 of water into the reaction bottle, adding the seaweed extract, and mixing well to obtain a mixed solution 2; (c) adding the remaining 1 / 5 of water into the reaction bottle, adding glucose, and adding polylactic acid-co-glycolic acid copolymer loaded with EM composite probiotics after dissolving, adding the mixed solution 2 obtained in step (b), and mixing evenly to obtain a mixed solution 3; (d) The mixed solution 3 obtained in step (c) and the mixed solution 1 obtained in step (a) are uniformly mixed to obtain the mixture.

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