Potamogeton crispus inorganic-organic fertilizer rich in lysine and preparation method thereof

Abstract

The invention discloses a lysine-rich potamogeton crispus inorganic-organic fertilizer and a preparation method thereof, relates to the technical field of organic fertilizers, and belongs to the patent classification number C05G1 / 00. The preparation method of the fertilizer comprises the following steps: cleaning and draining fresh potamogeton crispus, drying until the water content is less than or equal to 10%, crushing the dried potamogeton crispus, and then performing plasma activation treatment to obtain pretreated potamogeton crispus powder; mixing the pretreated potamogeton crispus powder with soybean meal powder, and sequentially carrying out aerobic fermentation and facultative fermentation to obtain a fermented material; the preparation method comprises the following steps: compounding sodium lignin sulfonate, nano montmorillonite and gamma-polyglutamic acid to form a gelatinous slow-release carrier with a three-dimensional network structure; mixing the fermentation material with the slow-release carrier, then adding urea, calcium superphosphate, potassium sulfate and zinc sulfate, and mixing and granulating to obtain the fertilizer. Nutrient substances in the potamogeton crispus are used as fertilizer components to realize resource utilization, in addition, the fertilizer can realize regulation and control of the release rate of lysine nutrients, and the fertilizer efficiency is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of organic fertilizers, belonging to the patent classification number C05G1 / 00, and specifically relates to a Potamogeton crispus inorganic-organic fertilizer rich in lysine and a preparation method thereof. Background Art

[0002] With the advancement of agricultural modernization, people have put forward higher requirements for the quality of fertilizers, expecting fertilizers to not only meet the nutrient requirements of crops throughout the growth period, but also avoid nutrient waste while reducing the number of fertilization times. Inorganic fertilizers have high nutrient content and rapid release, and can provide essential elements for crop growth in a timely manner to meet the needs of the rapid growth stage of crops; organic fertilizers can improve soil structure, enhance the soil's ability to retain fertilizers and water, and create a good soil environment for crop growth. Reasonably compounding inorganic fertilizers and organic fertilizers to develop organic-inorganic slow-release fertilizers to achieve long-term supply and efficient utilization of nutrients has become a key direction in the current fertilizer R & D field.

[0003] Lysine, as an essential amino acid in the process of plant growth, plays an important role in promoting crop growth and enhancing stress resistance. It can significantly promote the growth and development of plant roots, enhance the ability of crops to resist adversity such as drought and salinity, and at the same time participate in the synthesis of proteins and enzymes in plants, effectively improving the yield and quality of crops.

[0004] Potamogeton crispus, as an aquatic plant widely distributed in various waters, grows extremely rapidly and has a huge biomass. It is rich in protein, dietary fiber and various trace elements, and its lysine content is particularly prominent, making it an ideal raw material for preparing fertilizers rich in lysine. However, in the natural environment, after a large amount of Potamogeton crispus dies in summer every year, it will quickly rot, not only consuming a large amount of dissolved oxygen in the water body, but also releasing a large amount of nitrogen, phosphorus and other nutrients into the water body, exacerbating water eutrophication and causing serious damage to the water ecological environment. Currently, the treatment of Potamogeton crispus mostly adopts landfill or incineration methods, which not only causes waste of a large amount of nutrient resources in Potamogeton crispus, but also may cause secondary pollution problems. Therefore, promoting the resource utilization of Potamogeton crispus and converting it into high-value fertilizer products is of great significance for solving the environmental problems caused by Potamogeton crispus and realizing the recycling of resources. Summary of the Invention

[0005] The purpose of the present invention is to provide a Potamogeton crispus inorganic-organic fertilizer rich in lysine and a preparation method thereof to solve the technical problems raised in the above background art. The present invention realizes the resource utilization of the nutrients in Potamogeton crispus as fertilizer components. In addition, the fertilizer can regulate the release rate of lysine nutrients and extend the fertilizer efficiency.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A preparation method of a Potamogeton crispus inorganic-organic fertilizer rich in lysine, comprising the following steps:

[0008] S1. After washing and draining fresh Potamogeton crispus, it is dried until the water content ≤ 10%, and the dried Potamogeton crispus is crushed and then subjected to plasma activation treatment to obtain pretreated Potamogeton crispus powder;

[0009] S2. The pretreated Potamogeton crispus powder is mixed with soybean meal powder and subjected to aerobic fermentation and facultative fermentation in sequence to obtain a fermentation material;

[0010] S3. Sodium lignosulfonate, nano-montmorillonite and γ-polyglutamic acid are compounded to form a gel-like slow-release carrier with a three-dimensional network structure;

[0011] S4. The fermentation material and the slow-release carrier are mixed, and then urea, superphosphate, potassium sulfate and zinc sulfate are added, and granulation is carried out to obtain the product.

[0012] In the technical solution of the present invention, plasma is used to activate the Potamogeton crispus powder. First, the raw materials are subjected to special pretreatment, and physical activation means are adopted to significantly increase the active surface area of the Potamogeton crispus powder, creating favorable conditions for subsequent microbial action. In terms of raw material ratio, by scientifically matching the ratio of Potamogeton crispus to soybean meal, the carbon-nitrogen balance of the fermentation substrate is optimized, providing an ideal environment for the growth and reproduction of microorganisms.

[0013] The fermentation process adopts a multi-strain co-fermentation system, including three functional strains: cellulose-decomposing bacteria, phosphorus-solubilizing bacteria and lysine-producing bacteria. These strains are inoculated in a specific order and subjected to staged fermentation under precisely controlled temperature, humidity and ventilation conditions. The aerobic fermentation stage mainly completes the preliminary decomposition of the raw materials, while the subsequent facultative fermentation stage focuses on promoting the accumulation of functional metabolites. The entire fermentation process is precisely regulated through a control system to ensure that each strain exerts its maximum efficiency under the optimal conditions.

[0014] Due to its layered silicate structure and surface negative charge, nano-montmorillonite adsorbs positively charged lysine molecules through ion exchange and fixes them in the interlayer domain, thus effectively delaying the rapid loss of nutrients. During this process, K in the soil solution + 、Ca 2+Cations such as these will gradually displace the adsorbed lysine to achieve a sustained release effect. Sodium lignosulfonate, a polymer with a three-dimensional network structure, physically coats the montmorillonite-lysine complex through its porous properties. This coating not only provides an additional diffusion barrier, but its biodegradability enables secondary regulation of the nutrient release rate. γ-Polyglutamic acid forms a responsive hydrogel that adjusts its swelling state according to environmental humidity changes: it swells and absorbs water to close pores under wet conditions and shrinks to release nutrients during drought. The carboxyl groups on its molecular chain can also form coordination bonds with the amino groups of lysine, further enhancing the stability of the system. A multi-stage slow-release system of "electrostatic adsorption - physical barrier - environmental response" is constructed through the cooperation of the three materials, significantly improving the slow-release effect of lysine.

[0015] In addition, by adding urea (providing nitrogen), superphosphate (providing phosphorus), potassium sulfate (providing potassium), and zinc sulfate (providing trace elements such as zinc) to the fertilizer, the nutrient composition of the fertilizer is further enriched. These inorganic nutrients exist in a water-soluble chemical form and can be rapidly absorbed by plant roots in the early stage of plant growth to meet the large demand for nutrients during the rapid growth stage of plants. Combined with the organic nutrients and slow-release carriers in the fermentation material, a nutrient supply mode combining quick-acting and slow-acting is formed.

[0016] Preferably, in step S1, the dried Potamogeton crispus is crushed to a particle size of ≤2 mm.

[0017] Preferably, in step S1, the plasma treatment power is 200 - 300 W and the plasma treatment time is 5 - 10 min.

[0018] Preferably, in step S2, the mass ratio of Potamogeton crispus powder to soybean meal powder is 3:1 - 2.

[0019] Preferably, in step S3, the mass ratio of sodium lignosulfonate, nano-montmorillonite, and γ-polyglutamic acid is 2:1.5:1.

[0020] Preferably, in step S3, the nano-montmorillonite is pretreated, including the following steps:

[0021] The nano-montmorillonite is placed in a calcium chloride solution, heated and stirred for reaction, and then obtained through centrifugal separation, washing, and drying.

[0022] In the technical solution of the present invention, as described above, a multi-stage slow-release system of "electrostatic adsorption - physical barrier - environmental response" is constructed by synergistically using three materials, namely sodium lignosulfonate, nano-montmorillonite, and γ-polyglutamic acid. The research team of the present invention unexpectedly found through experiments that since the sulfonic acid groups in the sodium lignosulfonate molecules and the carboxyl groups in γ-polyglutamic acid are both negatively charged, they compete with lysine for the adsorption sites of nano-montmorillonite, resulting in a significant decrease in the adsorption rate of lysine. Therefore, the research team of the present invention further processes the nano-montmorillonite, reacts calcium chloride with the nano-montmorillonite, and inserts Ca 2+ into the interlayer of montmorillonite, and then uses Ca 2+ to form coordination with the sulfonic acid group in sodium lignosulfonate and the carboxyl group in γ-polyglutamic acid respectively. Ca 2+ acts as a bridge to bind the three together, thus avoiding the sulfonic acid group in the sodium lignosulfonate molecule and the carboxyl group in γ-polyglutamic acid from competing with lysine for the adsorption sites of nano-montmorillonite, and further increasing the adsorption amount of nano-montmorillonite for lysine.

[0023] Preferably, the mass ratio of the nano-montmorillonite to calcium chloride is 1:0.2 - 0.5.

[0024] In order to increase the adsorption amount of nano-montmorillonite for lysine in the present invention, a sufficient amount of Ca 2+ must be intercalated into the interlayer of nano-montmorillonite, and a sufficient amount of calcium chloride must be present in the reaction of nano-montmorillonite with calcium chloride. Therefore, the present invention controls the mass ratio of nano-montmorillonite to calcium chloride to be less than 1 / 0.2. However, as the amount of calcium chloride used increases, that is, when the mass ratio of nano-montmorillonite to calcium chloride is less than 1 / 0.5, the research team of the present invention found that the swelling degree of the colloidal slow-release carrier in water suddenly decreases significantly, resulting in the slow-release carrier almost losing its humidity response. This may be because when the amount of calcium chloride used is excessive, too much Ca 2+ causes excessive cross-linking of the carboxyl groups of γ-polyglutamic acid, forming a dense gel network, resulting in an overly slow release performance of lysine, which affects the absorption and utilization of lysine by plants. Therefore, the present invention strictly controls the mass ratio of nano-montmorillonite to calcium chloride to be 1:0.2 - 0.5.

[0025] Preferably, in step S4, the mass ratio of the slow-release carrier to the fermentation material is 1:2 - 3.

[0026] A Potamogeton crispus inorganic-organic fertilizer rich in lysine is prepared by the above method.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] (1) Plasma activation of Potamogeton crispus powder is beneficial to microbial fermentation. Aerobic and facultative fermentation can accelerate the material transformation, enrich the fertilizer components, and increase the organic matter and lysine content;

[0029] (2)Construct a multi-stage slow-release system with materials such as nano-montmorillonite to achieve slow release of lysine, combine with inorganic nutrients, and form a nutrient supply mode combining rapid and slow release;

[0030] (3)Pretreat nano-montmorillonite with calcium chloride to increase the adsorption capacity for lysine, control the mass ratio, and ensure the performance of the slow-release carrier. Specific implementation manners

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] Example 1

[0033] Step 1: Take 5 kg of fresh Potamogeton crispus, repeatedly rinse it 3 times with running tap water to remove sediment impurities, and place it on a stainless-steel screen for 30 minutes to drain until there is no obvious dripping. Evenly spread the drained Potamogeton crispus on the tray of a 60 °C hot air drying oven, control the thickness of the material layer not to exceed 5 cm, and after drying for 12 hours, take a sample to detect that the moisture content ≤ 10%. Use a universal crusher to crush the dried Potamogeton crispus to a particle size ≤ 2 mm (passing through a 10-mesh sieve), then spread the crushed material flat in the plasma treatment chamber, set the treatment power to 250 W, the argon gas flow rate to 8 L / min, and the treatment time to 9 minutes. The treated Potamogeton crispus powder is sealed and stored in a cool and dry place for later use.

[0034] Step 2: Weigh 3 kg of pretreated Potamogeton crispus powder and 1.8 kg of soybean meal powder (80 mesh), and stir them in a mixer for 15 minutes until evenly mixed. Transfer the mixed material to a fermentation tank, and add 2 L of sterile water to adjust the water content to 55%. In the aerobic fermentation stage, inoculate a compound bacterial agent: First, inoculate 300 mL of the cellulosic-degrading bacterium (Bacillus subtilis CEL-12) bacterial solution (the viable bacteria count ≥ 1×10 9 CFU / mL), and the inoculation amount is 7.5% of the total weight of the material; at the same time, inoculate 200 mL of the phosphate-solubilizing bacterium (Pseudomonas fluorescens PSB-6) bacterial solution (the viable bacteria count ≥ 5×10 8 CFU / mL), and the inoculation amount is 5%. Maintain the temperature at 35 ± 1 °C, supply oxygen at a ventilation rate of 0.6 L / min·kg through a sterile air pump, and turn the pile once every 6 hours for 48 hours. After transferring to the facultative fermentation stage, adjust the temperature to 30 ± 1 °C, and inoculate 400 mL of the lysine-producing bacterium (Corynebacterium glutamicum LY-8) bacterial solution (the viable bacteria count ≥ 2×10 9(CFU / mL), the inoculation amount was 10%, the oxygen concentration was controlled within the range of 5 - 8% by nitrogen, the pH value was monitored by sampling every day and was between 6.5 - 7.0, and a dark brown fermentation material was obtained after 72 hours of fermentation.

[0035] Step 3: Place 30 g of anhydrous calcium chloride in 800 mL of deionized water, stir with a magnetic stirrer at a speed of 400 rpm for 15 minutes until completely dissolved to obtain a calcium chloride solution. Add nano - montmorillonite (the mass ratio of nano - montmorillonite to calcium chloride is 1:0.4) to the calcium chloride solution and stir at 60 °C for 2 h. After centrifugal separation, washing, and drying, pretreated nano - montmorillonite is obtained;

[0036] Dissolve 200 g of sodium lignosulfonate in 600 mL of deionized water at 60 °C and stir magnetically until completely dissolved. Take 150 g of pretreated nano - montmorillonite and add it to the solution in three portions (50 g each time). After each addition, perform ultrasonic treatment (300 W, 15 minutes). Then add 100 g of γ - polyglutamic acid and 15 g of citric acid, adjust the pH to 5.0, and stir and react in a water bath at 80 °C for 3 h to form a viscous gel. Place the gel in a refrigerator at 4 °C for aging for 12 h to form a stable three - dimensional network structure, a sustained - release carrier.

[0037] Step 4: Take 2.8 kg of fermentation material and 1 kg of sustained - release carrier and premix them in a double - cone mixer for 10 minutes. Then add 150 g of urea, 100 g of superphosphate, 80 g of potassium sulfate, and 20 g of zinc sulfate in sequence and continue to mix for 20 minutes until uniform. Granulate using a twin - screw extrusion granulator (die hole diameter 3 mm) at 60 °C. The granules are dried in a fluidized bed at 45 °C until the water content ≤ 12%, and the finished granules of 2 - 4 mm are obtained by screening.

[0038] Example 2

[0039] Step 1: Take 5 kg of fresh Potamogeton crispus, rinse it repeatedly 3 times with flowing tap water to remove sediment impurities, and place it on a stainless - steel screen to drain water for 30 minutes until there is no obvious dripping. Spread the drained Potamogeton crispus evenly on the tray of a 60 °C hot - air drying oven, control the thickness of the material layer not to exceed 5 cm, and sample and detect the water content ≤ 10% after drying for 12 h. Use a universal crusher to crush the dried Potamogeton crispus to a particle size ≤ 2 mm (passing through a 10 - mesh sieve). Then spread the crushed material flat in a plasma treatment chamber, set the treatment power at 250 W, the argon flow rate at 8 L / min, and the treatment time at 6 minutes. The treated Potamogeton crispus powder is sealed and stored in a cool and dry place for later use.

[0040] Step 2: Weigh 3 kg of pretreated Potamogeton crispus powder and 1.3 kg of soybean meal powder (80 mesh), and stir them in a mixer for 15 minutes until evenly mixed. Transfer the mixed material to a fermentation tank, and add 2 L of sterile water to adjust the water content to 55%. Inoculate the complex bacterial agent in the aerobic fermentation stage: First, inoculate 300 mL of the bacterial solution of cellulose-degrading bacteria (Bacillus subtilis CEL-12) (the viable bacteria count ≥ 1×10 9 CFU / mL), and the inoculation amount is 7.5% of the total weight of the material; at the same time, inoculate 200 mL of the bacterial solution of phosphate-solubilizing bacteria (Pseudomonas fluorescens PSB-6) (the viable bacteria count ≥ 5×10 8 CFU / mL), and the inoculation amount is 5%. Maintain the temperature at 35 ± 1°C, supply oxygen at an aeration rate of 0.6 L / min·kg through a sterile air pump, turn the pile every 6 hours, and continue for 48 hours. After transferring to the facultative fermentation stage, adjust the temperature to 30 ± 1°C, inoculate 400 mL of the bacterial solution of lysine-producing bacteria (Corynebacterium glutamicum LY-8) (the viable bacteria count ≥ 2×10 9 CFU / mL), and the inoculation amount is 10%. Control the oxygen concentration within the range of 5 - 8% through nitrogen, sample and monitor the pH value between 6.5 - 7.0 every day, and obtain dark brown fermented material after 72 hours of fermentation.

[0041] Step 3: Place 30 g of anhydrous calcium chloride in 800 mL of deionized water, and stir it with a magnetic stirrer at a speed of 400 rpm for 15 minutes until completely dissolved to obtain a calcium chloride solution. Add nano-montmorillonite (the mass ratio of nano-montmorillonite to calcium chloride is 1:0.3) to the calcium chloride solution and stir it at 60°C for 2 h. After centrifugal separation, washing, and drying, obtain pretreated nano-montmorillonite;

[0042] Dissolve 200 g of sodium lignosulfonate in 600 mL of deionized water at 60°C, and stir it magnetically until completely dissolved. Take 150 g of pretreated nano-montmorillonite and add it to the solution in three portions (50 g each time). After each addition, perform ultrasonic treatment (300 W, 15 minutes). Subsequently, add 100 g of γ-polyglutamic acid and 15 g of citric acid, adjust the pH to 5.0, and stir and react in a water bath at 80°C for 3 hours to form a viscous gel. Place the gel in a refrigerator at 4°C for aging for 12 hours to form a stable three-dimensional network structure, a slow-release carrier.

[0043] Step 4: Take 2.4 kg of fermented material and 1 kg of slow-release carrier, premix them in a double-cone mixer for 10 minutes, and sequentially add 150 g of urea, 100 g of superphosphate, 80 g of potassium sulfate, and 20 g of zinc sulfate, and continue to mix for 20 minutes until evenly mixed. Granulate using a twin-screw extrusion granulator (die hole diameter 3 mm) at 60°C, dry the granules in a fluidized bed at 45°C until the water content ≤ 12%, and screen to obtain finished granules of 2 - 4 mm.

[0044] Example 3

[0045] Step 1: Take 5 kg of fresh Potamogeton crispus, rinse it repeatedly 3 times with flowing tap water to remove sediment and impurities, and place it on a stainless-steel screen to drain for 30 minutes until there is no obvious dripping. Evenly spread the drained Potamogeton crispus on the tray of a 60 °C hot air drying oven, control the thickness of the material layer not to exceed 5 cm, and after drying for 12 hours, take a sample to detect that the moisture content ≤ 10%. Use a universal crusher to crush the dried Potamogeton crispus to a particle size ≤ 2 mm (passing through a 10-mesh sieve), then spread the crushed material flat in the plasma treatment chamber, set the treatment power to 250 W, the argon gas flow rate to 8 L / min, and the treatment time to 8 minutes. The treated Potamogeton crispus powder is sealed and stored in a cool and dry place for later use.

[0046] Step 2: Weigh 3 kg of pretreated Potamogeton crispus powder and 1.5 kg of soybean meal powder (80 mesh), and stir them in a mixer for 15 minutes until evenly mixed. Transfer the mixed material to a fermentation tank, and add 2 L of sterile water to adjust the water content to 55%. In the aerobic fermentation stage, inoculate a compound bacterial agent: First, inoculate 300 mL of the cellulolytic bacterium (Bacillus subtilis CEL-12) bacterial solution (the viable bacteria count ≥ 1×10 9 CFU / mL), and the inoculation amount is 7.5% of the total weight of the material; at the same time, inoculate 200 mL of the phosphate-solubilizing bacterium (Pseudomonas fluorescens PSB-6) bacterial solution (the viable bacteria count ≥ 5×10 8 CFU / mL), and the inoculation amount is 5%. Maintain the temperature at 35 ± 1 °C, supply oxygen through a sterile air pump at an aeration rate of 0.6 L / min·kg, and turn the pile once every 6 hours for 48 hours. After transferring to the facultative fermentation stage, adjust the temperature to 30 ± 1 °C, inoculate 400 mL of the lysine-producing bacterium (Corynebacterium glutamicum LY-8) bacterial solution (the viable bacteria count ≥ 2×10 9 CFU / mL), and the inoculation amount is 10%. Control the oxygen concentration within the range of 5 - 8% through nitrogen, sample and monitor the pH value between 6.5 - 7.0 every day, and after 72 hours of fermentation, obtain a dark brown fermented material.

[0047] Step 3: Place 30 g of anhydrous calcium chloride in 800 mL of deionized water, use a magnetic stirrer to stir at a speed of 400 rpm for 15 minutes until completely dissolved to obtain a calcium chloride solution. Add nano-montmorillonite (the mass ratio of nano-montmorillonite to calcium chloride is 1:0.35) to the calcium chloride solution, stir and process it at 60 °C for 2 h, and after centrifugal separation, washing and drying, obtain the pretreated nano-montmorillonite;

[0048] Dissolve 200 g of sodium lignosulfonate in 600 mL of deionized water at 60 °C, and stir magnetically until completely dissolved. Take 150 g of pretreated nano-montmorillonite and add it to the solution in three portions (50 g each time). After each addition, perform ultrasonic treatment (300 W, 15 minutes). Subsequently, add 100 g of γ-polyglutamic acid and 15 g of citric acid, adjust the pH to 5.0, and stir and react in a water bath at 80 °C for 3 hours to form a viscous gel. Place the gel in a refrigerator at 4 °C for aging for 12 hours to form a stable three-dimensional network structure, a sustained-release carrier.

[0049] Step 4: Take 2.5 kg of fermentation material and 1 kg of sustained-release carrier and premix them in a double-cone mixer for 10 minutes. Then, add 150 g of urea, 100 g of superphosphate, 80 g of potassium sulfate, and 20 g of zinc sulfate in sequence, and continue to mix for 20 minutes until homogeneous. Granulate using a twin-screw extrusion granulator (die hole diameter 3 mm) at 60 °C. The granules are dried in a fluidized bed at 45 °C until the water content ≤ 12%, and the finished granules of 2 - 4 mm are obtained by screening.

[0050] Example 4

[0051] Step 1: Take 5 kg of fresh Potamogeton crispus, rinse it repeatedly 3 times with flowing tap water to remove sediment and impurities, and place it on a stainless steel screen for draining for 30 minutes until there is no obvious dripping. Evenly spread the drained Potamogeton crispus on the tray of a 60 °C hot air drying oven, control the thickness of the material layer not to exceed 5 cm, and after drying for 12 hours, take a sample to detect that the water content ≤ 10%. Use a universal grinder to crush the dried Potamogeton crispus to a particle size ≤ 2 mm (passing through a 10-mesh sieve), and then spread the crushed material flat in the plasma treatment chamber. Set the treatment power to 300 W, the argon gas flow rate to 8 L / min, and the treatment time to 10 minutes. The treated Potamogeton crispus powder is sealed and stored in a cool and dry place for later use.

[0052] Step 2: Weigh 3 kg of pretreated Potamogeton crispus powder and 2 kg of soybean meal powder (80 mesh) and stir them in a mixer for 15 minutes until evenly mixed. Transfer the mixed material to a fermentation tank, and add 2 L of sterile water to adjust the water content to 55%. In the aerobic fermentation stage, inoculate a compound microbial agent: First, inoculate 300 mL of the cellulosic-degrading bacterium (Bacillus subtilis CEL-12) bacterial solution (the viable cell count ≥ 1×10 9 CFU / mL), and the inoculation amount is 7.5% of the total weight of the material; at the same time, inoculate 200 mL of the phosphate-solubilizing bacterium (Pseudomonas fluorescens PSB-6) bacterial solution (the viable cell count ≥ 5×10 8CFU / mL), and the inoculation amount was 5%. The temperature was maintained at 35 ± 1 °C, and oxygen was supplied at an aeration rate of 0.6 L / min·kg through a sterile air pump. The pile was turned over every 6 hours for 48 hours. After transferring to the facultative fermentation stage, the temperature was adjusted to 30 ± 1 °C, and 400 mL of the bacterial solution of lysine-producing bacteria (Corynebacterium glutamicum LY-8) (the viable bacteria count ≥ 2 × 10 9 CFU / mL) was inoculated with an inoculation amount of 10%. The oxygen concentration was controlled between 5 - 8% by nitrogen. The pH value was monitored by daily sampling and was between 6.5 - 7.0. After 72 hours of fermentation, a dark brown fermentation material was obtained.

[0053] Step 3: Place 30 g of anhydrous calcium chloride in 800 mL of deionized water, and stir with a magnetic stirrer at a speed of 400 rpm for 15 minutes until completely dissolved to obtain a calcium chloride solution. Add nano-montmorillonite (the mass ratio of nano-montmorillonite to calcium chloride is 1:0.5) to the calcium chloride solution and stir at 60 °C for 2 h. After centrifugal separation, washing, and drying, the pretreated nano-montmorillonite is obtained;

[0054] Dissolve 200 g of sodium lignosulfonate in 600 mL of deionized water at 60 °C and stir magnetically until completely dissolved. Take 150 g of the pretreated nano-montmorillonite and add it in three portions (50 g each time) to the solution. After each addition, ultrasonic treatment (300 W, 15 minutes) is carried out. Then add 100 g of γ-polyglutamic acid and 15 g of citric acid, adjust the pH to 5.0, and stir and react in a water bath at 80 °C for 3 hours to form a viscous gel. Place the gel in a 4 °C refrigerator for aging for 12 hours to form a stable three-dimensional network structure, a slow-release carrier.

[0055] Step 4: Take 3 kg of the fermentation material and 1 kg of the slow-release carrier and premix them in a double-cone mixer for 10 minutes. Then add 150 g of urea, 100 g of superphosphate, 80 g of potassium sulfate, and 20 g of zinc sulfate in sequence, and continue to mix for 20 minutes until uniform. Granulation is carried out at 60 °C using a twin-screw extrusion granulator (the die hole diameter is 3 mm). The granules are dried in a fluidized bed at 45 °C until the water content ≤ 12%, and the finished granules of 2 - 4 mm are obtained by screening.

[0056] Example 5

[0057] Step 1: Take 5 kg of fresh Potamogeton crispus, rinse it repeatedly 3 times with running tap water to remove sediment and impurities, and place it on a stainless-steel screen to drain for 30 minutes until there is no obvious dripping. Evenly spread the drained Potamogeton crispus on the tray of a 60 °C hot air drying oven, control the thickness of the material layer not to exceed 5 cm, and after drying for 12 hours, take a sample to detect that the moisture content ≤ 10%. Use a universal crusher to crush the dried Potamogeton crispus to a particle size ≤ 2 mm (pass through a 10-mesh sieve), then spread the crushed material flat in the plasma treatment chamber, set the treatment power to 200 W, the argon gas flow rate to 8 L / min, and the treatment time to 5 minutes. The treated Potamogeton crispus powder is sealed and stored in a cool and dry place for later use.

[0058] Step 2: Weigh 3 kg of pretreated Potamogeton crispus powder and 1 kg of soybean meal powder (80 mesh), and stir in a mixer for 15 minutes until evenly mixed. Transfer the mixed material into a fermentation tank, and add 2 L of sterile water to adjust the water content to 55%. In the aerobic fermentation stage, inoculate a compound microbial agent: First, inoculate 300 mL of the cellulose-degrading bacterium (Bacillus subtilis CEL-12) bacterial solution (the viable bacteria count ≥ 1×10 9 CFU / mL), and the inoculation amount is 7.5% of the total weight of the material; at the same time, inoculate 200 mL of the phosphate-solubilizing bacterium (Pseudomonas fluorescens PSB-6) bacterial solution (the viable bacteria count ≥ 5×10 8 CFU / mL), and the inoculation amount is 5%. Maintain the temperature at 35 ± 1 °C, supply oxygen at an aeration rate of 0.6 L / min·kg through a sterile air pump, and turn the pile once every 6 hours for 48 hours. After transferring to the facultative fermentation stage, adjust the temperature to 30 ± 1 °C, inoculate 400 mL of the lysine-producing bacterium (Corynebacterium glutamicum LY-8) bacterial solution (the viable bacteria count ≥ 2×10 9 CFU / mL), and the inoculation amount is 10%. Control the oxygen concentration within the range of 5 - 8% through nitrogen, sample and monitor the pH value between 6.5 - 7.0 every day. After fermenting for 72 hours, a dark brown fermented material is obtained.

[0059] Step 3: Place 30 g of anhydrous calcium chloride in 800 mL of deionized water, use a magnetic stirrer to stir at a speed of 400 rpm for 15 minutes until completely dissolved to obtain a calcium chloride solution. Add nano-montmorillonite (the mass ratio of nano-montmorillonite to calcium chloride is 1:0.2) to the calcium chloride solution and stir at 60 °C for 2 h. After centrifugal separation, washing, and drying, pretreated nano-montmorillonite is obtained;

[0060] Dissolve 200 g of sodium lignosulfonate in 600 mL of deionized water at 60 °C, and stir magnetically until completely dissolved. Take 150 g of pretreated nano-montmorillonite and add it to the solution in three portions (50 g each time). After each addition, perform ultrasonic treatment (300 W, 15 minutes). Subsequently, add 100 g of γ-polyglutamic acid and 15 g of citric acid, adjust the pH to 5.0, and stir and react in a water bath at 80 °C for 3 hours to form a viscous gel. Place the gel in a refrigerator at 4 °C for 12 hours to form a stable three-dimensional network structure, and obtain a sustained-release carrier.

[0061] Step 4: Take 2 kg of fermentation materials and premix them with 1 kg of the sustained-release carrier in a double-cone mixer for 10 minutes. Then, sequentially add 150 g of urea, 100 g of superphosphate, 80 g of potassium sulfate, and 20 g of zinc sulfate, and continue to mix for 20 minutes until homogeneous. Granulate using a twin-screw extrusion granulator (die hole diameter 3 mm) at 60 °C. Dry the granules in a fluidized bed at 45 °C until the water content ≤ 12%, and screen to obtain finished granules of 2 - 4 mm.

[0062] Comparative Example 1

[0063] The difference between Comparative Example 1 and Example 1 is that in Step 1, the plasma treatment step is not carried out, and the remaining steps are the same.

[0064] Comparative Example 2

[0065] The difference between Comparative Example 2 and Example 1 is that in Step 3, the nano-montmorillonite is not treated with calcium chloride, and the remaining steps are the same.

[0066] Comparative Example 3

[0067] The difference between Comparative Example 3 and Example 5 is that in Step 3, the mass ratio of nano-montmorillonite to calcium chloride is 1:0.1, and the remaining steps are the same.

[0068] Comparative Example 4

[0069] The difference between Comparative Example 4 and Example 4 is that in Step 3, the mass ratio of nano-montmorillonite to calcium chloride is 1:0.6, and the remaining steps are the same.

[0070] Comparative Example 5

[0071] The difference between Comparative Example 5 and Example 4 is that in Step 3, the mass ratio of nano-montmorillonite to calcium chloride is 1:0.7, and the remaining steps are the same.

[0072] Control Example

[0073] The difference between the Control Example and Example 1 is that the fermentation materials are not mixed with the sustained-release carrier, but directly mixed with urea, superphosphate, potassium sulfate, and zinc sulfate, and the remaining steps are the same.

[0074] Performance Test

[0075] 1. Testing the lysine content in fertilizers:

[0076] The organic matter content was determined by the potassium dichromate oxidation method. 0.5 g of the fertilizer sample was weighed, and an excessive amount of potassium dichromate solution and concentrated sulfuric acid were added. The sample was heated to oxidize the organic matter in it, and the remaining potassium dichromate was titrated with a standard ferrous sulfate solution. The organic matter content (%) in the fertilizer was calculated based on the volume of the ferrous sulfate solution consumed. The lysine content was determined using an amino acid analyzer. First, the fertilizer sample was pretreated to release lysine, and then the treated sample was injected into the amino acid analyzer. The lysine content (%) in the fertilizer was calculated according to the standard curve.

[0077] Table 1.

[0078] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Organic matter content (%) 35.6 35.2 35.5 35.8 35.0 24.7 28.3 33.5 35.5 35.3 Lysine content (%) 3.47 3.40 3.42 3.51 3.37 2.21 2.62 3.10 3.47 3.44

[0079] 2. Testing the slow-release performance of lysine in fertilizers:

[0080] First, a soil solution was simulated with ionic concentrations and pH values close to the actual soil environment. 1 g of the fertilizer samples prepared in the examples and comparative examples was weighed and placed into stoppered conical flasks containing 100 mL of the simulated soil solution. The conical flasks were placed in a constant-temperature shaking incubator at 25 °C and shaken at a speed of 100 rpm. At time intervals of the 3rd day, 7th day, 15th day, and 30th day, the conical flasks were taken out, the solutions were filtered, and the lysine content was measured by HPLC to evaluate the slow-release performance of the fertilizers. The test data are shown in Table 2.

[0081] Table 2.

[0082] Lysine release rate on the 3rd day (%) Lysine release rate on the 7th day (%) Lysine release rate on the 15th day (%) Lysine release rate on the 30th day (%) Example 1 8.2 15.6 32.8 58 Example 2 7.9 15.2 32 57 Example 3 8.1 15.4 32.5 57.5 Example 4 8.3 15.5 32.6 57.8 Example 5 7.8 15.1 31.8 56.5 Comparative Example 1 3.2 5.3 11.6 20.7 Comparative Example 2 6.7 12.6 23.7 41.3 Comparative Example 3 7.0 13.8 26.8 48.5 Comparative Example 4 4.6 7.8 15.6 31.2 Comparative Example 5 3.8 6.5 13.2 26.7 Control Example 12.2 22.6 45.3 72.6

[0083] 3. Testing the lysine adsorption capacity:

[0084] Precisely weigh 0.5 g of the slow-release carriers in the examples and comparative examples and place them in 50 mL centrifuge tubes. Add 20 mL of lysine solution with a concentration of 0.1 mol / L to each tube. Place the centrifuge tubes in a constant-temperature oscillator at 25 °C and shake at a speed of 150 rpm for 24 hours to allow them to come into full contact. After adsorption, centrifuge at 3000 rpm for 10 minutes and take the supernatant. The remaining lysine concentration in the supernatant was determined by high-performance liquid chromatography. Based on the change in lysine concentration before and after adsorption, the adsorption capacity of nano-montmorillonite for lysine was calculated by (the mass of lysine in the initial lysine solution - the mass of lysine in the supernatant) / the mass of nano-montmorillonite. The calculation results are shown in Table 3.

[0085] Table 3.

[0086] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 2 Comparative Example 3 Adsorption capacity (mg / g) 55.6 54.8 55.3 55.8 54.5 37.2 42.5

[0087] 4. Swelling degree test: Take 0.2 g of the sustained-release carriers prepared in the examples and comparative examples, accurately weigh them, record as m0, and place them in nylon mesh bags of known weight respectively. Immerse the nylon mesh bags containing the sustained-release carriers in deionized water and soak them at 25 °C for 24 hours to fully swell the carriers. Take out the nylon mesh bags, gently blot the surface moisture with filter paper, weigh again and subtract the weight of the nylon mesh bag, and record as m1. The swelling degree calculation formula is: Swelling degree (%) = (m1 - m0) / m0 × 100%. The calculation results are shown in Table 4.

[0088] Table 4.

[0089] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 4 Comparative Example 5 Swelling degree (%) 450 442 445 452 440 316 283

[0090] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a Potamogeton crispus inorganic-organic fertilizer rich in lysine, characterized in that, It includes the following steps: S1. After cleaning and draining fresh Potamogeton crispus, it is dried until the water content ≤ 10%, the dried Potamogeton crispus is crushed, and then plasma activation treatment is carried out to obtain pretreated Potamogeton crispus powder; S2. The pretreated Potamogeton crispus powder is mixed with soybean meal powder, and aerobic fermentation and facultative fermentation are carried out successively to obtain a fermentation material; S3. Sodium lignosulfonate, nano-montmorillonite and γ-polyglutamic acid are compounded to form a gel-like slow-release carrier with a three-dimensional network structure; S4. The fermentation material and the slow-release carrier are mixed, and then urea, superphosphate, potassium sulfate and zinc sulfate are added, and granulation is carried out to obtain the product.

2. The preparation method of a Potamogeton crispus inorganic-organic fertilizer rich in lysine according to claim 1, characterized in that, In the step S1, the dried Potamogeton crispus is crushed to a particle size ≤ 2 mm.

3. The preparation method of a Potamogeton crispus inorganic-organic fertilizer rich in lysine according to claim 1, characterized in that, In the step S1, the plasma treatment power is 200 - 300 W, and the plasma treatment time is 5 - 10 min.

4. The preparation method of a Potamogeton crispus inorganic-organic fertilizer rich in lysine according to claim 1, characterized in that, In the step S2, the mass ratio of Potamogeton crispus powder to soybean meal powder is 3:1 - 2.

5. The preparation method of a Potamogeton crispus inorganic-organic fertilizer rich in lysine according to claim 1, characterized in that, In the step S3, the mass ratio of sodium lignosulfonate, nano-montmorillonite and γ-polyglutamic acid is 2:1.5:

1.

6. The preparation method of a Potamogeton crispus inorganic-organic fertilizer rich in lysine according to claim 1, characterized in that, In the step S3, the nano-montmorillonite is pretreated, including the following steps: The nano-montmorillonite is placed in a calcium chloride solution, heated and stirred for reaction, and obtained through centrifugal separation, washing and drying.

7. The preparation method of a Potamogeton crispus inorganic-organic fertilizer rich in lysine according to claim 4, characterized in that The mass ratio of the nano-montmorillonite to calcium chloride is 1:0.2 - 0.

5.

8. The preparation method of a Potamogeton crispus inorganic-organic fertilizer rich in lysine according to claim 1, characterized in that, In the step S4, the mass ratio of the slow-release carrier to the fermentation material is 1:2 - 3.

9. A Potamogeton crispus inorganic-organic fertilizer rich in lysine, characterized in that, Prepared by the method according to any one of claims 1 - 8.