Compound fertilizer for improving lotus root quality and preparation method thereof

Abstract

The invention discloses a compound fertilizer for improving lotus root quality and a preparation method thereof, and belongs to the technical field of planting. The compound fertilizer for improving the lotus root quality is prepared from the following raw materials in parts by mass: 40 to 60 parts of rice straw, 20 to 30 parts of bagasse, 40 to 50 parts of animal waste, 10 to 12 parts of activated carbon and microorganism compound, 20 to 30 parts of nitrogen-phosphorus-potassium compound fertilizer, 5 to 8 parts of trace elements, 10 to 15 parts of humic acid, 10 to 12 parts of seaweed, 10 to 12 parts of folium artemisiae argyi, 5 to 8 parts of chitosan, 2 to 3 parts of yeast fermentation product and 2 to 3 parts of compound amino acid. The compound fertilizer disclosed by the invention can improve the quality of the lotus roots (namely increase the content of nutritional ingredients in the lotus roots) while ensuring the yield of the lotus roots.

Description

Technical Field

[0001] The invention relates to the technical field of planting, in particular to a compound fertilizer for improving the quality of lotus roots and a preparation method thereof. Background Art

[0002] Lotus root (Nelumbonucifera), also known as lotus or lotus root, belongs to the Nymphaeaceae family and is a perennial aquatic herb. The entire lotus root is valuable; the lotus root and seeds are edible, while the seeds, rhizomes, nodes, leaves, flowers, and seed embryos are all used medicinally. Raw lotus root has a cooling effect, clearing away heat and relieving restlessness, quenching thirst and stopping vomiting, cooling blood, stopping bleeding, and dispersing blood stasis. Cooked lotus root has a warming effect, nourishing the heart and promoting blood circulation, aiding digestion, quenching thirst, and promoting salivation. It also has nourishing and strengthening properties, as well as strengthening the spleen and stomach. It can also relieve alcohol fatigue, regulate nerve function, regulate blood pressure, improve peripheral blood circulation, promote metabolism, and prevent rough skin. Lotus root is rich in carbohydrates, starch, protein, tannins, and lipids. It is also rich in various active ingredients, such as dietary fiber, flavonoids, volatile oils, alkaloids, and polysaccharides, which have anti-inflammatory, lipid-lowering, anti-hypertensive, anti-diabetes, and anti-HIV, as well as antibacterial properties.

[0003] As awareness of the edible value of lotus root continues to grow and sales channels expand, market demand for lotus root is increasing. The number of lotus root growers is increasing, and the cultivated area is expanding. Lotus root cultivation has become a major way for farmers to increase their income. In recent years, to increase lotus root yields, growers have blindly applied various fertilizers during the actual planting process. This causes a large amount of nutrients to dissolve in the water, leading to eutrophication and a continuous decline in lotus root quality. Therefore, finding a fertilizer that can improve lotus root quality while ensuring yield has become a technical challenge that those skilled in the art urgently need to address. Summary of the Invention

[0004] The purpose of the present invention is to provide a compound fertilizer for improving the quality of lotus root and a preparation method thereof, so as to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is a compound fertilizer for improving the quality of lotus root, comprising the following raw materials in parts by mass: 40-60 parts of rice straw, 20-30 parts of sugarcane bagasse, 40-50 parts of animal feces, 10-12 parts of activated carbon and microbial complex, 20-30 parts of nitrogen, phosphorus and potassium compound fertilizer, 5-8 parts of trace elements, 10-15 parts of humic acid, 10-12 parts of seaweed, 10-12 parts of wormwood, 5-8 parts of chitosan, 2-3 parts of yeast fermentation product and 2-3 parts of complex amino acids.

[0007] Furthermore, the preparation method of the activated carbon and microbial complex comprises the following steps:

[0008] The microorganisms are added to a liquid culture medium for cultivation, and then activated carbon is added, stirred for loading, filtered, and then dried at low temperature to obtain the activated carbon and microorganism complex.

[0009] Furthermore, the microorganism comprises the following components in parts by mass: 10-15 parts of Bacillus velezensis, 5-8 parts of Bacillus amyloliquefaciens, 3-5 parts of Pseudomonas stutzeri, 2-3 parts of Bacillus licheniformis and 4-5 parts of Bacillus cereus.

[0010] Bacillus Velezii can enhance nitrogen fixation, providing lotus roots with a greater nitrogen source and thereby increasing their protein content. Bacillus amyloliquefaciens can promote the secretion of enzymes involved in sugar metabolism, increasing the reducing sugar content in lotus roots. Pseudomonas stutzeri, Bacillus licheniformis, and Bacillus cereus can secrete siderophores, promoting iron absorption and enhancing photosynthesis, thereby increasing both lotus root yield and quality. The synergistic effects of these microorganisms can ensure both lotus root yield and quality.

[0011] Furthermore, the preparation method of the activated carbon comprises the following steps:

[0012] Grinding sugarcane bagasse and banana pseudostem and adding them to an aqueous solution of potassium carbonate and potassium hydroxide to obtain a mixture, and grinding the mixture to obtain a mixed slurry;

[0013] The mixed slurry is filtered, dried, and then calcined under an inert atmosphere to obtain the activated carbon.

[0014] Furthermore, the content of potassium carbonate in the aqueous solution of potassium carbonate and potassium hydroxide is 4-6 wt.%, and the content of potassium hydroxide is 6-7 wt.%;

[0015] The mass ratio of the total mass of the bagasse and banana pseudostem to the aqueous solution of potassium carbonate and potassium hydroxide is 1:15-20;

[0016] The volume ratio of the grinding balls to the mixed material is 1:1, the diameter of the grinding balls is 3-5 mm, and the grinding time is 30-40 min;

[0017] The calcination temperature is 600-700° C., and the calcination time is 60-100 minutes.

[0018] Grinding sugarcane bagasse and banana pseudostem in an aqueous solution of potassium carbonate and potassium hydroxide can increase the specific surface area of ​​activated carbon and improve the adsorption capacity of activated carbon, thereby carrying more microorganisms, providing a shelter environment for microorganisms, and promoting the reproduction of microorganisms in the soil.

[0019] Furthermore, the trace elements include the following components in parts by mass: 6 to 8 parts of magnesium sulfate, 9 to 12 parts of ferrous sulfate, and 4 to 6 parts of zinc sulfate;

[0020] The composite amino acid comprises phenylalanine and tyrosine in a mass ratio of (1-2):(2-3).

[0021] Trace elements such as magnesium sulfate, ferrous sulfate and zinc sulfate participate in the synthesis of vitamin C, increasing the vitamin C content in lotus root; they can enhance the activity of photosynthesis-related enzymes, promote the progress of photosynthesis, and thereby increase the accumulation of reducing sugars.

[0022] The methyl jasmonate contained in wormwood works together with phenylalanine and tyrosine to promote the synthesis of phenolic substances and increase the polyphenol content in lotus root.

[0023] Furthermore, the method for preparing the yeast fermentation product comprises the following steps:

[0024] The brewer's yeast is inoculated into a YPD liquid culture medium and fermented to obtain a yeast fermentation liquid; and the yeast fermentation product is obtained by filtering and drying at low temperature.

[0025] Furthermore, the fermentation culture temperature is 28-32° C., the rotation speed is 170-190 r / min, and the time is 18-24 h.

[0026] The synergistic effect of yeast fermentation and chitosan can promote the synthesis of flavonoids in lotus root and increase the flavonoid content in lotus root. At the same time, chitosan can bind fertilizer components and prevent the loss of fertilizer components.

[0027] The second technical solution of the present invention is a method for preparing the above-mentioned compound fertilizer, comprising the following steps:

[0028] Rice straw, sugarcane bagasse and animal excrement are mixed evenly and then piled up for fermentation to obtain fermented fertilizer;

[0029] The fermented fertilizer is dried and mixed with nitrogen, phosphorus and potassium compound fertilizer, trace elements, humic acid, seaweed, wormwood and compound amino acids, crushed to 200 meshes, and then activated carbon, microbial complex and yeast fermentation product are added. After mixing evenly, chitosan solution is sprayed and granulated to obtain the compound fertilizer.

[0030] Furthermore, the temperature of the pile fermentation is 40-45°C and the time is 40-50 days.

[0031] The present invention discloses the following technical effects:

[0032] The compound fertilizer of the present invention can improve the quality of lotus roots (i.e., increase the content of nutritional components in lotus roots) while ensuring the yield of lotus roots. DETAILED DESCRIPTION

[0033] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0034] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0035] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0036] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0037] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0038] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in this field and are not the focus of the present invention.

[0039] 1. Overview of Lotus Root

[0040] Lotus root (Nelumbonucifera), a perennial aquatic herb of the genus Nelumbo in the family Nymphaeaceae, is the enlarged underground stem of the plant. It is a precious vegetable that combines medicinal, edible, and cultural significance. Raw lotus root has a cooling effect, clearing away heat and relieving restlessness, quenching thirst and stopping vomiting, cooling blood, stopping bleeding, and dispersing blood stasis. Cooked lotus root has a warming effect, nourishing the heart and promoting blood circulation, aiding digestion, quenching thirst, and promoting salivation. It also has nourishing and strengthening properties, as well as strengthening the spleen and stomach. It can also relieve alcohol fatigue, regulate nerve function, regulate blood pressure, improve peripheral blood circulation, promote metabolism, and prevent rough skin. Lotus root is rich in carbohydrates, starch, protein, tannins, and lipids. It is also rich in various active ingredients, such as dietary fiber, flavonoids, volatile oils, alkaloids, and polysaccharides, which have anti-inflammatory, lipid-lowering, anti-hypertensive, anti-diabetes, and anti-bacterial properties.

[0041] 2. Research progress on active substances in lotus root

[0042] 1. Polysaccharides

[0043] Polysaccharides are chain polymers formed by the dehydration of monosaccharides to form glycosidic bonds, which are then linked linearly or branched. Lotus root polysaccharides are mainly found in lotus seeds, lotus seed red skin, and lotus core. Due to the high nutritional value of lotus seeds, research has mainly focused on lotus seed polysaccharides. VanBergenPF et al. found that lotus seed polysaccharides mainly include rhamnose, thunose, ribose, arabinose, xylose, mannose, galactose, and glucose. Cai Baoyu et al. found that the components of the hardened outer seed coat of lotus seeds include polysaccharides, lignin, and soluble tannins, with the main monomers being galactose and mannose.

[0044] Lotus root is also rich in dietary fiber. Dietary fiber refers to the sum of edible plant components, carbohydrates, and similar substances that cannot be digested or absorbed in the small intestine but can be partially or completely fermented in the large intestine. It includes polysaccharides, oligosaccharides, lignin, and related substances and is known as the "seventh nutrient." Dietary fiber is generally divided into two categories based on solubility: water-soluble dietary fiber and insoluble dietary fiber. Liu Chengfang et al. demonstrated that lotus root residue, after juicing and de-starching, is rich in dietary fiber, with a crude fiber content of up to 25.1%, making it an excellent source of cellulose.

[0045] 2. Flavonoids

[0046] Flavonoids are natural products with a C6-C3-C6 structure as their basic core. They often exist in a free form or as glycosides bound to sugars. Currently, valuable flavonoids have been discovered from lotus leaves, rhizomes, stamens, and seed shells. Natural flavonoids also possess antioxidant, anticancer, antibacterial, anti-photosensitive, antimicrobial, detoxifying, whitening, and deodorizing properties. They can scavenge free radicals in the body and skin, preventing them from damaging various cells. They also promote skin metabolism, increase skin elasticity, reduce wrinkles and pigmentation, and moisturize the skin, with a significant whitening effect.

[0047] 3. Polyphenols

[0048] Polyphenols are a general term for a large class of compounds with diverse structures and multiple hydroxyl groups. Plant polyphenols possess numerous biological activities, including free radical scavenging, anti-lipid oxidation, anti-aging, cardiovascular disease prevention, cancer prevention, and radiation protection. Studies by Yan Shoulei et al. and Ling Heping et al. have shown that phenolic compounds in lotus roots are unevenly distributed, with more phenolic compounds in the epidermis than in the interior, and more in the nodes than in the epidermis. The primary polyphenols in lotus roots are DOPA, catechol, gallic acid, D-(+)-catechin, and L-(-)-epicatechin.

[0049] 4. Alkaloid compounds

[0050] The alkaloids present in lotus roots are all isoquinoline alkaloids. Currently, research on alkaloids in plants of the Nelumbo family focuses primarily on lotus leaves and pith, with less research on other tissues. To date, numerous studies have isolated a variety of alkaloid compounds from lotus leaves. Based on differences in their parent nucleus structure, these compounds are divided into four categories: monobenzylisoquinolines, aporphines, dehydroaporphines, and oxyaporphines.

[0051] 5. Volatile oil

[0052] Volatile oils are primarily found in lotus leaves, but the content of volatile oils in lotus root nodes is significantly higher than in lotus root cores and skins. Research by Hu Yan et al. showed that steam distillation of lotus leaf volatile oil yielded 41 peaks, 31 of which were identified, accounting for 94.13% of the total relative content of the volatile oil. Supercritical extraction of lotus leaf volatile oil yielded 66 peaks, 54 of which were identified, accounting for 89.45% of the total relative content.

[0053] 6. Other active ingredients

[0054] Lotus root contains many other active ingredients, such as succinic acid, gluconic acid, tartaric acid, citric acid, gallic acid, n-octadecanoic acid, benzoic acid, and o-hydroxybenzoic acid, which are found in lotus leaves, as well as podophyllotoxin, which is found in plants of the Berberidaceae genera Myrtles and Ilex erythrorhizon. Lotus flowers also contain minerals, vitamin C, and 17 amino acids, seven of which are essential. Myang Hee Im et al. and Yumi Tsuruta et al. studied the effects of cooking methods on the bioactive substances in lotus root. Shuyi Li et al. studied the effects of active substances in lotus root on non-alcoholic fatty liver disease in obese diabetic mice.

[0055] 3. Current status of lotus root fertilization

[0056] Lotus root is a fertilizer-loving crop. During cultivation, in addition to applying sufficient basal fertilizer, topdressing should be applied 2-3 times in stages during the growing season. In a study examining the effects of nitrogen fertilization on lotus root growth and development, lotus roots were treated with no nitrogen, nitrogen, and twice the nitrogen fertilization rate. The number of upright leaves, leaf SPDA values, root activity, and rhizome dry matter content all showed an initial increase followed by a decrease with increasing nitrogen fertilization rates. In summary, both no nitrogen fertilization and twice the nitrogen fertilization rate were detrimental to lotus root growth and development. By comparing the application of organic fertilizer and inorganic fertilizer to lotus roots, it was found that the lotus roots treated with inorganic fertilizer had higher protein and crude fiber content, while the lotus roots treated with organic fertilizer had higher soluble sugar and vitamin C content; and the quality of lotus roots treated with appropriate concentrations of chemical fertilizers and organic fertilizers was significantly improved compared with farmers' conventional fertilization, with their total starch, protein, vitamin C and total sugar contents increased by 3.85%, 25.10%, 36.02% and 40.30% respectively, while the quality of lotus roots treated with high concentrations of chemical fertilizers and organic fertilizers deteriorated, and the total starch, protein, vitamin C and total sugar contents all decreased significantly.

[0057] 4. Problems in the application of lotus root fertilizer

[0058] Traditional lotus root fertilization relies primarily on manual broadcasting. While fertilizer can be broadcast on the bank before the lotus rows are closed, workers still need to go underwater in the middle of the paddy field. Fertilizer application can easily remain on the lotus leaves, causing burns. Once the lotus rows are sealed, the paddy fields are tightly closed, making movement difficult, inefficient, and labor-intensive. Fertilization in summer is extremely dangerous. In recent years, some farmers have blindly pursued high yields and applied excessive amounts of nitrogen fertilizer. This excessive use of nitrogen fertilizer not only reduces nitrogen utilization efficiency but also causes crops to mature late, resulting in lower yields and poorer quality, leading to serious environmental pollution. It also increases cultivation costs, severely contaminates soil with nitrogen, and eutrophicates water bodies, causing the rampant growth of duckweed, algae, and weeds.

[0059] How to improve the quality of lotus roots while ensuring the yield has become a technical problem that needs to be solved urgently in this field.

[0060] The Bacillus velezensis, Bacillus amyloliquefaciens, Pseudomonas stutzeri, Bacillus licheniformis, Bacillus cereus and Saccharomyces cerevisiae used in the specific embodiment of the present invention are all purchased from the China Industrial Microbiological Culture Collection Center, among which the product number of Bacillus velezensis is CICC 22619, the product number of Bacillus amyloliquefaciens is CICC 20229, the product number of Pseudomonas stutzeri is CICC 23002, the product number of Bacillus licheniformis is CICC 20204, the product number of Bacillus cereus is CICC 21290, and the product number of Saccharomyces cerevisiae is CICC 1916.

[0061] The preparation methods of Bacillus Velezii, Bacillus amyloliquefaciens, Pseudomonas stutzeri, Bacillus licheniformis, Bacillus cereus and Saccharomyces cerevisiae used in the specific embodiment of the present invention are as follows:

[0062] Bacillus velezensis, Bacillus amyloliquefaciens, Pseudomonas stutzeri, Bacillus licheniformis, Bacillus cereus and Saccharomyces cerevisiae were inoculated into liquid culture medium for activation culture and fermentation, and the bacterial counts were 5.0×10 8 cfu / mL of Bacillus velezensis, Bacillus amyloliquefaciens, Pseudomonas stutzeri, Bacillus licheniformis, Bacillus cereus and Saccharomyces cerevisiae.

[0063] Liquid culture medium composition: peptone 5.0 g / L, beef extract 3.0 g / L, and sodium chloride 5.0 g / L, pH 7.0; moist heat sterilization for 20 min.

[0064] All “parts” described in the following examples are “parts by mass”.

[0065] Example 1

[0066] Preparation method of compound fertilizer for improving lotus root quality

[0067] (1) A compound fertilizer for improving the quality of lotus root is composed of the following raw materials in parts by mass: 50 parts of rice straw, 30 parts of sugarcane bagasse, 45 parts of animal manure (chicken manure), 12 parts of activated carbon and microbial complex, 25 parts of nitrogen, phosphorus and potassium compound fertilizer, 6 parts of trace elements, 15 parts of humic acid, 12 parts of seaweed (dried seaweed, with a moisture content of about 10%), 10 parts of wormwood (dried wormwood, with a moisture content of about 10%), 8 parts of chitosan, 2.5 parts of yeast fermentation product and 2 parts of complex amino acids.

[0068] Among them, the nitrogen, phosphorus and potassium compound fertilizer is 16-16-16 nitrogen, phosphorus and potassium compound fertilizer;

[0069] Trace elements, composed of the following components in parts by mass: 8 parts magnesium sulfate, 10 parts ferrous sulfate and 6 parts zinc sulfate;

[0070] The average weight molecular weight of chitosan is about 50,000;

[0071] The complex amino acid is composed of phenylalanine and tyrosine in a mass ratio of 1:1.

[0072] (2) Preparation of activated carbon and microbial complex:

[0073] A. Microorganisms, composed of the following components in parts by mass: 12 parts of Bacillus Velez microbial solution, 8 parts of Bacillus amyloliquefaciens microbial solution, 4 parts of Pseudomonas stutzeri microbial solution, 2.5 parts of Bacillus licheniformis microbial solution and 4 parts of Bacillus cereus microbial solution.

[0074] B. Preparation of activated carbon: Sugarcane bagasse and banana pseudostem are dried and ground into a particle size of about 2 mm, and then added to an aqueous solution of potassium carbonate and potassium hydroxide (the content of potassium carbonate is 5 wt.%, and the content of potassium hydroxide is 6.5 wt.%) to obtain a mixture, and the mixture is ground to obtain a mixed slurry;

[0075] The mass ratio of the total mass of bagasse and banana pseudostem to the aqueous solution of potassium carbonate and potassium hydroxide is 1:18;

[0076] The volume ratio of the grinding balls to the mixed material was 1:1, the diameter of the grinding balls was 4 mm, and the grinding time was 30 min;

[0077] The mixed slurry was filtered, dried, and then calcined under an inert atmosphere (calcination temperature was 680° C., time was 90 min) to obtain activated carbon.

[0078] C. Add the microorganisms to LB liquid culture medium (the ratio of microorganisms to LB liquid culture medium is 1 g:100 mL), culture on a 30°C shaker (120 r / min) for 12 h, then add activated carbon (the mass ratio of microorganisms to active carbon is 1:20), stir the load (stirring speed is 30 r / min, time is 12 h), filter and dry at low temperature (temperature is 40°C) to obtain a complex of activated carbon and microorganisms.

[0079] (3) Preparation method of yeast fermentation product:

[0080] The brewer's yeast liquid was inoculated into YPD liquid culture medium (the volume ratio of the brewer's yeast liquid to the YPD liquid culture medium was 1:50), and fermented (the fermentation temperature was 30°C, the rotation speed was 180 r / min, and the time was 24 h) to obtain yeast fermentation liquid, which was filtered (through 10 layers of gauze) and then low-temperature dried (temperature 40°C) to obtain yeast fermentation product.

[0081] (4) mixing rice straw, sugarcane bagasse, and animal manure uniformly, adjusting the moisture content to about 55%, piling them into a fermentation pile of 2 m × 2 m × 1 m in length, width, and height for fermentation, turning the pile every 10 days, and fermenting for 40 days (fermentation temperature is 45° C.) to obtain fermented fertilizer;

[0082] The fermented fertilizer is dried and mixed with nitrogen, phosphorus and potassium compound fertilizer, trace elements, humic acid, seaweed, wormwood and compound amino acids, crushed to 200 mesh, and then activated carbon, microbial complex and yeast fermentation product are added. After mixing evenly, chitosan solution is sprayed on the mixture, and granulation (particle size is 10 mm) is performed at low temperature (30°C) to obtain compound fertilizer.

[0083] The chitosan spraying solution was prepared by weighing 2 g of chitosan, adding 98 g of water and 1 mL of glacial acetic acid, and then stirring and dispersing until dissolved.

[0084] Example 2

[0085] Preparation method of compound fertilizer for improving lotus root quality

[0086] (1) A compound fertilizer for improving the quality of lotus root is composed of the following raw materials in parts by mass: 40 parts of rice straw, 30 parts of sugarcane bagasse, 45 parts of animal manure (chicken manure), 10 parts of activated carbon and microbial complex, 30 parts of nitrogen, phosphorus and potassium compound fertilizer, 5 parts of trace elements, 15 parts of humic acid, 12 parts of seaweed (dried seaweed, with a moisture content of about 10%), 11 parts of wormwood (dried wormwood, with a moisture content of about 10%), 5 parts of chitosan, 2 parts of yeast fermentation product and 2.5 parts of complex amino acids.

[0087] Among them, the nitrogen, phosphorus and potassium compound fertilizer is 16-16-16 nitrogen, phosphorus and potassium compound fertilizer;

[0088] Trace elements, composed of the following components in parts by mass: 6 parts magnesium sulfate, 12 parts ferrous sulfate and 6 parts zinc sulfate;

[0089] The average weight molecular weight of chitosan is about 50,000;

[0090] The complex amino acid is composed of phenylalanine and tyrosine in a mass ratio of 1:3.

[0091] (2) Preparation of activated carbon and microbial complex:

[0092] A. Microorganisms, composed of the following components in parts by mass: 13 parts of Bacillus Velez microbial solution, 5 parts of Bacillus amyloliquefaciens microbial solution, 5 parts of Pseudomonas stutzeri microbial solution, 3 parts of Bacillus licheniformis microbial solution and 4 parts of Bacillus cereus microbial solution.

[0093] B. Preparation of activated carbon: Sugarcane bagasse and banana pseudostem are dried and ground into a particle size of about 2 mm, and then added to an aqueous solution of potassium carbonate and potassium hydroxide (the content of potassium carbonate is 6 wt.%, and the content of potassium hydroxide is 6 wt.%) to obtain a mixture, and the mixture is ground to obtain a mixed slurry;

[0094] The mass ratio of the total mass of sugarcane bagasse and banana pseudostem to the aqueous solution of potassium carbonate and potassium hydroxide is 1:15;

[0095] The volume ratio of the grinding balls to the mixed material was 1:1, the diameter of the grinding balls was 3 mm, and the grinding time was 30 min;

[0096] The mixed slurry was filtered, dried, and then calcined under an inert atmosphere (calcination temperature was 600° C., time was 100 min) to obtain activated carbon.

[0097] C. Add the microorganisms to LB liquid culture medium (the ratio of microorganisms to LB liquid culture medium is 1 g:100 mL), culture on a 30°C shaker (120 r / min) for 12 h, then add activated carbon (the mass ratio of microorganisms to active carbon is 1:20), stir the load (stirring speed is 30 r / min, time is 12 h), filter and dry at low temperature (temperature is 40°C) to obtain a complex of activated carbon and microorganisms.

[0098] (3) Preparation method of yeast fermentation product:

[0099] The brewer's yeast liquid was inoculated into YPD liquid culture medium (the volume ratio of the brewer's yeast liquid to the YPD liquid culture medium was 1:50), and fermented (the fermentation temperature was 28°C, the rotation speed was 170 r / min, and the time was 18 h) to obtain yeast fermentation liquid, which was filtered (through 10 layers of gauze) and then low-temperature dried (temperature 40°C) to obtain yeast fermentation product.

[0100] (4) Mixing rice straw, sugarcane bagasse, and animal manure uniformly, adjusting the moisture content to about 55%, and stacking them into a fermentation pile with a length, width, and height of 2 m × 2 m × 1 m for fermentation. During the fermentation period, the pile is turned over once every 10 days, and the fermentation is continued for 45 days (fermentation temperature is 45° C.) to obtain fermented fertilizer;

[0101] The fermented fertilizer is dried and mixed with nitrogen, phosphorus and potassium compound fertilizer, trace elements, humic acid, seaweed, wormwood and compound amino acids, crushed to 200 mesh, and then activated carbon, microbial complex and yeast fermentation product are added. After mixing evenly, chitosan solution is sprayed on the mixture, and granulation (particle size is 10 mm) is performed at low temperature (30°C) to obtain compound fertilizer.

[0102] The chitosan spraying solution was prepared by weighing 2 g of chitosan, adding 98 g of water and 1 mL of glacial acetic acid, and then stirring and dispersing until dissolved.

[0103] Example 3

[0104] Preparation method of compound fertilizer for improving lotus root quality

[0105] (1) A compound fertilizer for improving the quality of lotus root is composed of the following raw materials in parts by mass: 60 parts of rice straw, 20 parts of sugarcane bagasse, 40 parts of animal manure (chicken manure), 12 parts of activated carbon and microbial complex, 20 parts of nitrogen, phosphorus and potassium compound fertilizer, 8 parts of trace elements, 12 parts of humic acid, 10 parts of seaweed (dried seaweed, with a moisture content of about 10%), 12 parts of wormwood (dried wormwood, with a moisture content of about 10%), 8 parts of chitosan, 3 parts of yeast fermentation product and 3 parts of complex amino acids.

[0106] Among them, the nitrogen, phosphorus and potassium compound fertilizer is 16-16-16 nitrogen, phosphorus and potassium compound fertilizer;

[0107] Trace elements, composed of the following components in parts by weight: 8 parts magnesium sulfate, 9 parts ferrous sulfate and 5 parts zinc sulfate;

[0108] The average weight molecular weight of chitosan is about 50,000;

[0109] The complex amino acid is composed of phenylalanine and tyrosine in a mass ratio of 2:3.

[0110] (2) Preparation of activated carbon and microbial complex:

[0111] A. Microorganisms, composed of the following components in parts by mass: 15 parts of Bacillus velezensis bacterial solution, 8 parts of Bacillus amyloliquefaciens bacterial solution, 3 parts of Pseudomonas stutzeri bacterial solution, 2 parts of Bacillus licheniformis bacterial solution and 5 parts of Bacillus cereus bacterial solution.

[0112] B. Preparation of activated carbon: Sugarcane bagasse and banana pseudostem are dried and ground to a particle size of about 2 mm, and then added to an aqueous solution of potassium carbonate and potassium hydroxide (the content of potassium carbonate is 4 wt.%, and the content of potassium hydroxide is 6.5 wt.%) to obtain a mixture, and the mixture is ground to obtain a mixed slurry;

[0113] The mass ratio of the total mass of bagasse and banana pseudostem to the aqueous solution of potassium carbonate and potassium hydroxide is 1:20;

[0114] The volume ratio of the grinding balls to the mixed material was 1:1, the diameter of the grinding balls was 5 mm, and the grinding time was 40 min;

[0115] The mixed slurry was filtered, dried, and then calcined under an inert atmosphere (calcination temperature was 700° C., time was 90 min) to obtain activated carbon.

[0116] C. Add the microorganisms to LB liquid culture medium (the ratio of microorganisms to LB liquid culture medium is 1 g:100 mL), culture on a 30°C shaker (120 r / min) for 12 h, then add activated carbon (the mass ratio of microorganisms to active carbon is 1:20), stir the load (stirring speed is 30 r / min, time is 12 h), filter and dry at low temperature (temperature is 40°C) to obtain a complex of activated carbon and microorganisms.

[0117] (3) Preparation method of yeast fermentation product:

[0118] The brewer's yeast liquid was inoculated into YPD liquid culture medium (the volume ratio of the brewer's yeast liquid to the YPD liquid culture medium was 1:50), and fermented (the fermentation temperature was 32°C, the rotation speed was 180 r / min, and the time was 24 h) to obtain yeast fermentation liquid, which was filtered (through 10 layers of gauze) and then low-temperature dried (temperature 40°C) to obtain yeast fermentation product.

[0119] (4) mixing rice straw, sugarcane bagasse, and animal manure uniformly, adjusting the moisture content to about 55%, piling them into a fermentation pile of 2 m × 2 m × 1 m in length, width, and height for fermentation, turning the pile every 10 days, and fermenting for 40 days (fermentation temperature is 40° C.) to obtain fermented fertilizer;

[0120] The fermented fertilizer is dried and mixed with nitrogen, phosphorus and potassium compound fertilizer, trace elements, humic acid, seaweed, wormwood and compound amino acids, crushed to 200 mesh, and then activated carbon, microbial complex and yeast fermentation product are added. After mixing evenly, chitosan solution is sprayed on the mixture, and granulation (particle size is 10 mm) is performed at low temperature (30°C) to obtain compound fertilizer.

[0121] The chitosan spraying solution was prepared by weighing 2 g of chitosan, adding 98 g of water and 1 mL of glacial acetic acid, and then stirring and dispersing until dissolved.

[0122] Comparative Example 1

[0123] The same as Example 1, except that the activated carbon and microbial composite are replaced with microorganisms and activated carbon in a mass ratio of 1:20.

[0124] Comparative Example 2

[0125] The same as Example 1, except that the activated carbon preparation method is as follows: sugarcane bagasse and banana pseudostem are dried and crushed to a particle size of about 0.5 mm, and then added to an aqueous solution of potassium carbonate and potassium hydroxide (the content of potassium carbonate is 5 wt.%, the content of potassium hydroxide is 6.5 wt.%), and soaked at 25° C. for 4 h to obtain a mixed material;

[0126] The mass ratio of the total mass of bagasse and banana pseudostem to the aqueous solution of potassium carbonate and potassium hydroxide is 1:18;

[0127] The mixed material was filtered, dried, and then calcined under an inert atmosphere (calcination temperature was 680° C., time was 90 min) to obtain plant waste activated carbon.

[0128] Comparative Example 3

[0129] Same as Example 1, except that the compound fertilizer does not contain seaweed and humic acid.

[0130] Comparative Example 4

[0131] Same as Example 1, except that the compound fertilizer does not contain trace elements.

[0132] Comparative Example 5

[0133] Same as Example 1, except that the chitosan in the compound fertilizer is replaced with starch in an equal amount by weight;

[0134] Preparation of starch solution: weigh 2g starch, add 98g water, and stir to disperse.

[0135] Comparative Example 6

[0136] The same as Example 1, except that the wormwood in the compound fertilizer is replaced with seaweed in an equal mass fraction.

[0137] Effect Example 1

[0138] Effects of using compound fertilizers:

[0139] 1. The test is arranged in several areas of 30m 2 The experiment was conducted in a plot of 6 m long and 5 m wide. There were 9 treatments in total, and each treatment was repeated 3 times, as follows:

[0140] In Examples 1 to 3 and Comparative Examples 1 to 6, 150 kg / mu of the prepared compound fertilizer was applied as base fertilizer respectively; the base fertilizer application method was as follows: before planting lotus roots, the fertilizer was evenly spread on the planting field, and then deep plowing (about 20 cm) was performed to fully mix the fertilizer with the soil.

[0141] 2. In early April, after applying base fertilizer, plant lotus roots (lotus root heads and buds are intact), planting about 450 kg per mu, and the variety is Beauty Red; 30 days after planting lotus roots, apply 15 kg / mu of 16-16-16 nitrogen, phosphorus and potassium compound fertilizer; 50 days after planting lotus roots, apply 15 kg / mu of 16-16-16 nitrogen, phosphorus and potassium compound fertilizer; no other fertilizers are applied during this period; carry out routine field management.

[0142] 3. After the above-ground parts have all withered, all rhizomes in each plot are dug out, washed and weighed, and the per-acre yield of fresh lotus roots is calculated. The results are shown in Table 1; and the content of nutrients in lotus roots is determined. The results are shown in Table 2.

[0143] The contents of vitamin C, reducing sugars, total phenols, total flavonoids in fresh samples (lotus root core) and protein in dry samples (lotus root core) were determined indoors. Specifically, the protein content was determined by the Kjeldahl method; the vitamin C content was determined by the 2,6-dichloroindophenol titration method; the reducing sugar content was determined by the Fehling reagent method; the total phenol content was determined by the Folin-phenol method; and the total flavonoid content was determined by spectrophotometry.

[0144] Table 1. Yield of lotus root

[0145] Grouping Yield (kg / mu) Example 1 2159.8 Example 2 2145.3 Example 3 2150.7 Comparative Example 1 1987.6 Comparative Example 2 2096.4 Comparative Example 3 2052.1 Comparative Example 4 2041.3 Comparative Example 5 2022.7 Comparative Example 6 2102.5

[0146] Table 2 Nutritional components of lotus root

[0147]

[0148]

[0149] It can be seen from Table 1 and Table 2 that the compound fertilizer prepared by the embodiment of the present invention can improve the yield and quality of lotus roots (that is, increase the nutrient content in lotus roots).

[0150] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A compound fertilizer for improving the quality of lotus root, characterized in that: The invention comprises the following raw materials in parts by weight: 40-60 parts of rice straw, 20-30 parts of sugarcane bagasse, 40-50 parts of animal feces, 10-12 parts of activated carbon and microbial complex, 20-30 parts of nitrogen, phosphorus and potassium compound fertilizer, 5-8 parts of trace elements, 10-15 parts of humic acid, 10-12 parts of seaweed, 10-12 parts of wormwood, 5-8 parts of chitosan, 2-3 parts of yeast fermentation product and 2-3 parts of complex amino acids.

2. The compound fertilizer according to claim 1, characterized in that The method for preparing the activated carbon and microbial composite comprises the following steps: The microorganisms are added to a liquid culture medium for cultivation, and then activated carbon is added, stirred for loading, filtered, and then dried at low temperature to obtain the activated carbon and microorganism complex.

3. The compound fertilizer according to claim 2, characterized in that The microorganism comprises the following components in parts by mass: 10-15 parts of Bacillus velezensis, 5-8 parts of Bacillus amyloliquefaciens, 3-5 parts of Pseudomonas stutzeri, 2-3 parts of Bacillus licheniformis and 4-5 parts of Bacillus cereus.

4. The compound fertilizer according to claim 2, characterized in that The preparation method of the activated carbon comprises the following steps: Grinding sugarcane bagasse and banana pseudostem and adding them to an aqueous solution of potassium carbonate and potassium hydroxide to obtain a mixture, and grinding the mixture to obtain a mixed slurry; The mixed slurry is filtered, dried, and then calcined under an inert atmosphere to obtain the activated carbon.

5. The compound fertilizer according to claim 4, characterized in that The content of potassium carbonate in the aqueous solution of potassium carbonate and potassium hydroxide is 4-6 wt.%, and the content of potassium hydroxide is 6-7 wt.%; and / or, the mass ratio of the total mass of the sugarcane bagasse and banana pseudostem to the aqueous solution of potassium carbonate and potassium hydroxide is 1:15-20; And / or, the volume ratio of the grinding balls to the mixed material is 1:1, the diameter of the grinding balls is 3-5 mm, and the grinding time is 30-40 min; And / or, the calcination temperature is 600-700° C. and the calcination time is 60-100 min.

6. The compound fertilizer according to claim 1, characterized in that The trace elements include the following components in parts by weight: 6 to 8 parts of magnesium sulfate, 9 to 12 parts of ferrous sulfate, and 4 to 6 parts of zinc sulfate; And / or, the composite amino acid comprises phenylalanine and tyrosine in a mass ratio of (1-2):(2-3).

7. The compound fertilizer according to claim 1, characterized in that The method for preparing the yeast fermentation product comprises the following steps: The brewer's yeast is inoculated into a YPD liquid culture medium and fermented to obtain a yeast fermentation liquid; and the yeast fermentation product is obtained by filtering and drying at low temperature.

8. The compound fertilizer according to claim 7, characterized in that The fermentation culture temperature is 28-32° C., the rotation speed is 170-190 r / min, and the fermentation time is 18-24 h.

9. A method for preparing the compound fertilizer according to any one of claims 1 to 8, characterized in that: The following steps are involved: Rice straw, sugarcane bagasse and animal excrement are mixed evenly and then piled up for fermentation to obtain fermented fertilizer; The fermented fertilizer is dried and mixed with nitrogen, phosphorus and potassium compound fertilizer, trace elements, humic acid, seaweed, wormwood and compound amino acids, crushed to 200 meshes, and then activated carbon, microbial complex and yeast fermentation product are added. After mixing evenly, chitosan solution is sprayed and granulated to obtain the compound fertilizer.

10. The preparation method according to claim 9, characterized in that The temperature of the pile fermentation is 40-45° C., and the time is 40-50 days.

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