Special fertilizer for promoting symbiosis of rice and crabs and preparation method

Abstract

The invention discloses a special fertilizer for promoting symbiosis of rice and crabs and a preparation method, and belongs to the technical field of plant planting and aquaculture. The special fertilizer for promoting symbiosis of rice and crabs comprises the following raw materials in parts by mass: 60-80 parts of calcite, 20-30 parts of plagioclase, 30-40 parts of animal waste, 20-30 parts of straw, 10-12 parts of urea, 5-6 parts of potassium chloride, 3-5 parts of manganese sulfate, 2-3 parts of zinc sulfate, 2-3 parts of copper sulfate, 12-15 parts of humic acid, 2-3 parts of compound microorganisms, 0.5-0.8 part of nitrifying bacteria, 5-6 parts of soybean meal, 5-6 parts of carbon powder and 5-8 parts of montmorillonite. The special fertilizer disclosed by the invention can avoid the problem that the growth of crabs is influenced by poor water quality caused by fertilization, and can reduce the fertilization frequency and improve the utilization rate of the fertilizer.

Description

Technical Field

[0001] The invention relates to the technical field of plant planting and aquaculture, and in particular to a special fertilizer for promoting rice-crab symbiosis and a preparation method thereof. Background Art

[0002] Integrated rice-fish farming is a new type of composite three-dimensional cultivated land ecosystem and a typical ecological green circular agriculture. It organically integrates the growth of rice with the growth of aquatic animals, can effectively develop the shallow water environment in the rice field, and provide a better living environment for the growth and development of aquatic animals, thus forming a new type of complex three-dimensional rice field farming technology with rice-fish symbiosis. Integrated rice-fish farming includes many types, such as rice-fish model, rice-shrimp model, rice-crab model, rice-loach model, rice-duck model, rice-loach model, rice-baby model, etc. At present, the integrated rice-fish farming is mainly based on the rice-crab model. The rice field provides good water quality for the river crab to live, and the river crab provides natural green organic fertilizer for the rice field. The two are mutually beneficial and symbiotic, jointly constructing the green ecosystem of the rice field and forming a benign ecological cycle. Research has found that in rice fields, river crabs can use their hidden environment to avoid natural enemies, and they can also use the shelter provided by rice fields to obtain sufficient nutrients, thereby promoting their molting growth; river crabs can plow and loosen the soil, which is beneficial to the absorption of nutrients by rice; river crabs can prey on weeds and pests, reducing the incidence of diseases, insects, and weeds in rice fields. In addition, river crab excrement and residual bait provide rich nutrients for rice growth, which are absorbed by rice and can promote rice growth and increase rice yield. However, more fertilizers are needed in the early stages of rice growth. The application of fertilizers affects the water quality and dissolved oxygen content of rice fields (fertilizer fermentation and decomposition requires a lot of oxygen, which will lead to a decrease in dissolved oxygen in the water body), thereby affecting the quality of rice and river crabs. Summary of the invention

[0003] The purpose of the present invention is to provide a special fertilizer for promoting rice-crab symbiosis and a preparation method thereof, so as to solve the problems existing in the above-mentioned prior art.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] One of the technical solutions of the present invention: a special fertilizer for promoting rice-crab symbiosis, comprising the following raw materials in parts by mass: 60-80 parts of calcite, 20-30 parts of plagioclase, 30-40 parts of animal feces, 20-30 parts of straw, 10-12 parts of urea, 5-6 parts of potassium chloride, 3-5 parts of manganese sulfate, 2-3 parts of zinc sulfate, 2-3 parts of copper sulfate, 12-15 parts of humic acid, 2-3 parts of composite microorganisms, 0.5-0.8 parts of nitrifying bacteria, 5-6 parts of soybean meal, 5-6 parts of carbon powder and 5-8 parts of montmorillonite.

[0006] Furthermore, the composite microorganism comprises the following components in parts by weight:

[0007] 10-15 parts of iron bacteria, 5-8 parts of coprophilic Rhodococcus, 4-6 parts of Rhodopseudomonas palustris, 3-5 parts of round brown nitrogen-fixing bacteria, 4-7 parts of Bacillus licheniformis, 4-6 parts of lactic acid bacteria and 2-4 parts of Bacillus subtilis.

[0008] Furthermore, the nitrifying bacteria are composed of nitrite bacteria and nitrate bacteria in a mass ratio of 1:1.

[0009] Iron bacteria, coprophilic Rhodococcus, and palustris Rhodopseudomonas in the composite microorganisms can increase the oxygen content in the water and avoid the stress response caused by lack of oxygen during crab farming (crabs will crawl out of the water or escape from their original hiding places (such as escaping to the roots of rice, destroying the roots of rice and affecting the growth of rice)).

[0010] The brown nitrogen-fixing bacteria, Bacillus licheniformis, lactic acid bacteria and Bacillus subtilis in the composite microorganisms can regulate the physical and chemical properties of the soil, improve the permeability of the soil, and thereby increase the dissolved oxygen content, ensuring the symbiotic breeding effect of rice and crabs.

[0011] The combined effects of multiple microorganisms in the composite microorganism can not only maintain the freshness of the water and the dissolved oxygen content in the water, but also improve the disease resistance of rice and crabs, thereby increasing the yield of rice and crabs.

[0012] The second technical solution of the present invention is a method for preparing the above-mentioned special fertilizer for promoting rice-crab symbiosis, comprising the following steps:

[0013] Step (1) drying and crushing animal excrement and straw, then mixing them evenly with composite microorganisms, piling and fermenting them to obtain fermented fertilizer;

[0014] Step (2) mixing calcite, plagioclase, urea, potassium chloride, manganese sulfate, zinc sulfate, copper sulfate, nitrifying bacteria and soybean meal uniformly, spraying starch solution, and granulating at low temperature to obtain fertilizer granules;

[0015] Step (3) crushing humic acid, carbon powder and montmorillonite and mixing them evenly with the fermented fertilizer, and then coating them on the surface of fertilizer particles to obtain composite fertilizer particles;

[0016] Step (4) sprays the coating solution on the surface of the composite fertilizer particles, and obtains the special fertilizer for promoting rice-crab symbiosis after low-temperature drying.

[0017] The soybean meal in the fertilizer granules can provide nutrients for nitrifying bacteria and promote their growth and reproduction; the large number of nitrifying bacteria produced can continuously decompose calcite and plagioclase, providing an absorbable and usable calcium source for rice and crabs.

[0018] Calcium source is one of the important components in plant cell walls. By combining with polysaccharides such as pectin, it participates in the formation of intercellular and intracellular structures of the cell wall, helps to enhance the mechanical stability of the cell, and promotes cell growth and division. Calcium can maintain the structural stability of the plant cell wall, protect the integrity of the plant cell membrane, and promote the development of roots and stems. Calcium can significantly improve the photosynthesis efficiency and stress resistance of crops, and help plants cope with various environmental pressures.

[0019] Crabs molt multiple times during their growth process. Calcium helps the formation and hardening of new shells. When the calcium content is sufficient, the molting speed and success rate of crabs will increase, and the individuals after molting will also be larger. Crabs with sufficient calcium have stronger disease resistance and can better resist various diseases and stress responses. Calcium supplementation can effectively increase the growth rate and health of crabs, thereby improving breeding efficiency and product quality.

[0020] The density of calcite and plagioclase is greater than that of water. Adding them to fertilizers can make the fertilizers stably deposited at the bottom of the water, thus avoiding the problem of fertilizers floating on the water surface and not being fully utilized.

[0021] Furthermore, in step (1), the crushing is to crush to a particle size of 50-100 mesh; the temperature of the pile fermentation is 35-45°C, the time is 25-30 days, and the moisture content is 50-55%; and the pile is turned once every 5 days during the pile fermentation.

[0022] Furthermore, in step (2), the concentration of the starch solution is 5 wt.%; the temperature of the low-temperature granulation is 30-40° C.; and the particle size of the fertilizer particles is 4-5 mm.

[0023] Furthermore, in step (3), the pulverization is pulverization to a particle size of 50 to 100 meshes; and the binder used in the preparation of the composite fertilizer particles is sodium lignin sulfonate.

[0024] Furthermore, in step (4), the method for preparing the coating solution comprises the following steps:

[0025] Hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether and acrylamide are added into water, and after high pressure homogenization, azobisisobutylamidine hydrochloride is added thereto, and the mixture is heated for reaction under nitrogen protection to obtain the coating solution.

[0026] Furthermore, the mass ratio of hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether and acrylamide is 1:0.5:3; the amount of azobisisobutylamidine hydrochloride is 25% of the mass of acrylamide;

[0027] The temperature of the heating reaction is 70-75° C. and the time is 2-3 hours.

[0028] Humic acid, charcoal powder, montmorillonite and fermented fertilizer are coated on the surface of fertilizer particles containing calcite, plagioclase, urea, potassium chloride, manganese sulfate, zinc sulfate, copper sulfate, nitrifying bacteria and soybean meal, and the surface of the obtained composite fertilizer particles is coated with coating material. This can slowly release the nutrients in the fertilizer, avoid the deterioration of water quality caused by the large-scale release of fertilizer nutrients, and thus avoid the problem of affecting crab growth and causing crabs to damage rice. At the same time, it can reduce the number of fertilization times and improve the utilization rate of fertilizer.

[0029] The third technical solution of the present invention: an application of the above-mentioned special fertilizer in rice-crab co-culture.

[0030] The present invention discloses the following technical effects:

[0031] The special fertilizer of the present invention can avoid the problem of water quality deterioration caused by fertilization, thereby affecting the growth of crabs, and can also reduce the number of fertilization times and improve the utilization rate of fertilizers.

[0032] The special fertilizer of the present invention can improve water quality, and prevent crabs from destroying rice due to poor water quality, thereby causing a reduction in rice production.

[0033] The special fertilizer of the present invention can increase the yield of rice and improve the symbiotic effect between crabs and rice. DETAILED DESCRIPTION

[0034] 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 should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0035] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0036] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation 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 a conflict with any incorporated document, the content of this specification shall prevail.

[0037] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0038] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0039] The “parts” described in the following examples are all “parts by mass”.

[0040] The iron bacteria, coprophilic rhodococcus, palustris rhodopseudomonas, round brown nitrogen-fixing bacteria, Bacillus licheniformis, lactic acid bacteria, Bacillus subtilis, nitrite bacteria, nitrate bacteria and cyanobacteria used in the present invention are all commercially available. Among them, the effective viable count of the iron bacteria is 1.0×10 7 cfu / g, and the effective viable count of Rhodococcus faecalis was 2.0×10 9 cfu / g, and the effective viable count of Rhodopseudomonas palustris was 1.0×10 9 cfu / g, the effective viable count of round brown nitrogen-fixing bacteria was 2.0×10 9 cfu / g, the effective viable count of Bacillus licheniformis was 1.0×10 9 cfu / g, the effective viable count of lactic acid bacteria is 5.0×10 9 cfu / g, the effective viable count of Bacillus subtilis was 2.0×10 9 cfu / g, the effective viable count of nitrite bacteria was 5.0×10 8 cfu / g, nitrate bacteria 1.0×10 7 The effective viable count of cyanobacteria is 1.0×10 8 cfu / g.

[0041] Example 1

[0042] (1) A special fertilizer for promoting rice-crab symbiosis is composed of the following raw materials in parts by weight: 70 parts of calcite, 25 parts of plagioclase, 40 parts of animal manure (chicken manure), 30 parts of straw (corn straw), 12 parts of urea, 5.5 parts of potassium chloride, 5 parts of manganese sulfate, 2.5 parts of zinc sulfate, 3 parts of copper sulfate, 15 parts of humic acid, 2.5 parts of composite microorganisms, 0.8 parts of nitrifying bacteria, 6 parts of soybean meal, 6 parts of charcoal powder and 6 parts of montmorillonite.

[0043] Among them, the composite microorganisms are composed of the following components in parts by mass: 12 parts of iron bacteria, 6 parts of coprophilic redococcus, 5 parts of palustris red pseudomonas, 5 parts of round brown nitrogen-fixing bacteria, 6 parts of Bacillus licheniformis, 4 parts of lactic acid bacteria and 2.5 parts of Bacillus subtilis.

[0044] Nitrifying bacteria are composed of nitrite bacteria and nitrate bacteria in a mass ratio of 1:1.

[0045] (2) The animal manure and straw are dried and crushed into 80 mesh, then mixed evenly with the composite microorganisms, the moisture content is adjusted to 55%, and the piles are piled into a fermentation pile with a length, width and height of 1 m for fermentation (the fermentation temperature is 40°C and the time is 30 days). The piles are turned over every 5 days during the fermentation period, and fermented fertilizer is obtained after the fermentation is completed.

[0046] (3) Calcite, plagioclase, urea, potassium chloride, manganese sulfate, zinc sulfate, copper sulfate, nitrifying bacteria and soybean meal were crushed into 100 mesh, added into a granulator and mixed evenly, and then sprayed with a 5 wt.% starch aqueous solution, and granulated at low temperature (30° C.) to obtain fertilizer granules with a particle size of 5 mm.

[0047] (4) Fertilizer particles are added into a granulator, and then a mixture of humic acid, charcoal powder, montmorillonite and fermented fertilizer is added while spraying a 6 wt.% sodium lignin sulfonate aqueous solution, so that the mixture is coated on the surface of the fertilizer particles to obtain composite fertilizer particles.

[0048] The preparation method of the mixture of humic acid, charcoal powder, montmorillonite and fermented fertilizer is as follows: humic acid, charcoal powder and montmorillonite are crushed (the particle size is 100 meshes) and mixed with the fermented fertilizer to obtain a mixture.

[0049] (5) Spraying the coating solution on the surface of the compound fertilizer particles (the mass / volume ratio of the compound fertilizer particles and the coating solution is 10 g:1.5 mL), and drying at low temperature (35° C.) to obtain a special fertilizer for promoting rice-crab symbiosis.

[0050] Wherein, the preparation method of the coating solution is:

[0051] Add hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether and acrylamide into water (the mass ratio of hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether, acrylamide and water is 1:0.5:3:50), add azobisisobutylamidine hydrochloride (the amount of azobisisobutylamidine hydrochloride is 25% of the mass of acrylamide) after high-pressure homogenization, and heat the reaction under nitrogen protection (temperature is 75°C, time is 2.5h) to obtain a coating solution.

[0052] Example 2

[0053] (1) A special fertilizer for promoting rice-crab symbiosis is composed of the following raw materials in parts by weight: 60 parts of calcite, 30 parts of plagioclase, 35 parts of animal manure (chicken manure), 20 parts of straw (corn straw), 10 parts of urea, 5 parts of potassium chloride, 4 parts of manganese sulfate, 2 parts of zinc sulfate, 3 parts of copper sulfate, 12 parts of humic acid, 3 parts of composite microorganisms, 0.6 parts of nitrifying bacteria, 6 parts of soybean meal, 5 parts of carbon powder and 5 parts of montmorillonite.

[0054] Among them, the composite microorganisms are composed of the following components in parts by mass: 10 parts of iron bacteria, 5 parts of coprophilic redococcus, 6 parts of palustris red pseudomonas, 3 parts of round brown nitrogen-fixing bacteria, 7 parts of Bacillus licheniformis, 5 parts of lactic acid bacteria and 3 parts of Bacillus subtilis.

[0055] Nitrifying bacteria are composed of nitrite bacteria and nitrate bacteria in a mass ratio of 1:1.

[0056] (2) The animal manure and straw are dried and crushed to 100 mesh, then mixed evenly with the composite microorganisms, the moisture content is adjusted to 50%, and stacked into a fermentation pile with a length, width and height of 1 m for fermentation (the fermentation temperature is 45°C and the time is 30 days). The pile is turned over every 5 days during the fermentation period, and fermented fertilizer is obtained after the fermentation is completed.

[0057] (3) Calcite, plagioclase, urea, potassium chloride, manganese sulfate, zinc sulfate, copper sulfate, nitrifying bacteria and soybean meal were crushed into 100 mesh, mixed evenly, sprayed with a 5 wt.% starch aqueous solution, and granulated at low temperature (40° C.) to obtain fertilizer granules with a particle size of 4 mm.

[0058] (4) Fertilizer particles are added into a granulator, and then a mixture of humic acid, charcoal powder, montmorillonite and fermented fertilizer is added while spraying a 6 wt.% sodium lignin sulfonate aqueous solution, so that the mixture is coated on the surface of the fertilizer particles to obtain composite fertilizer particles.

[0059] The preparation method of the mixture of humic acid, charcoal powder, montmorillonite and fermented fertilizer is as follows: humic acid, charcoal powder and montmorillonite are crushed (with a particle size of 50 meshes) and mixed evenly with the fermented fertilizer to obtain a mixture.

[0060] (5) Spraying the coating solution on the surface of the compound fertilizer particles (the mass / volume ratio of the compound fertilizer particles and the coating solution is 10 g:1.5 mL), and drying at low temperature (35° C.) to obtain a special fertilizer for promoting rice-crab symbiosis.

[0061] Wherein, the preparation method of the coating solution is:

[0062] Add hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether and acrylamide into water (the mass ratio of hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether, acrylamide and water is 1:0.5:3:50), add azobisisobutylamidine hydrochloride (the amount of azobisisobutylamidine hydrochloride is 25% of the mass of acrylamide) after high-pressure homogenization, and heat the reaction under nitrogen protection (temperature is 70°C, time is 2h) to obtain a coating solution.

[0063] Example 3

[0064] (1) A special fertilizer for promoting rice-crab symbiosis is composed of the following raw materials in parts by weight: 80 parts of calcite, 20 parts of plagioclase, 30 parts of animal manure (chicken manure), 25 parts of straw (corn straw), 12 parts of urea, 6 parts of potassium chloride, 3 parts of manganese sulfate, 3 parts of zinc sulfate, 2 parts of copper sulfate, 15 parts of humic acid, 2 parts of composite microorganisms, 0.5 parts of nitrifying bacteria, 5 parts of soybean meal, 5.5 parts of carbon powder and 8 parts of montmorillonite.

[0065] Among them, the composite microorganisms are composed of the following components in parts by mass: 15 parts of iron bacteria, 8 parts of coprophilic redococcus, 4 parts of palustris red pseudomonas, 5 parts of round brown nitrogen-fixing bacteria, 4 parts of Bacillus licheniformis, 6 parts of lactic acid bacteria and 4 parts of Bacillus subtilis.

[0066] Nitrifying bacteria are composed of nitrite bacteria and nitrate bacteria in a mass ratio of 1:1.

[0067] (2) The animal manure and straw are dried and crushed into 50 mesh, then mixed evenly with the composite microorganisms, the moisture content is adjusted to 55%, and piled into a fermentation pile with a length, width and height of 1 m for fermentation (the fermentation temperature is 35°C and the time is 25 days). The pile is turned over every 5 days during the fermentation period, and fermented fertilizer is obtained after the fermentation is completed.

[0068] (3) Calcite, plagioclase, urea, potassium chloride, manganese sulfate, zinc sulfate, copper sulfate, nitrifying bacteria and soybean meal were crushed into 100 mesh, mixed evenly, sprayed with a 5 wt.% starch aqueous solution, and granulated at low temperature (40° C.) to obtain fertilizer granules with a particle size of 4.5 mm.

[0069] (4) Fertilizer particles are added into a granulator, and then a mixture of humic acid, charcoal powder, montmorillonite and fermented fertilizer is added while spraying a 6 wt.% sodium lignin sulfonate aqueous solution, so that the mixture is coated on the surface of the fertilizer particles to obtain composite fertilizer particles.

[0070] The preparation method of the mixture of humic acid, charcoal powder, montmorillonite and fermented fertilizer is as follows: humic acid, charcoal powder and montmorillonite are crushed (with a particle size of 80 meshes) and mixed evenly with the fermented fertilizer to obtain a mixture.

[0071] (5) Spraying the coating solution on the surface of the compound fertilizer particles (the mass / volume ratio of the compound fertilizer particles and the coating solution is 10 g:1.5 mL), and drying at low temperature (35° C.) to obtain a special fertilizer for promoting rice-crab symbiosis.

[0072] Wherein, the preparation method of the coating solution is:

[0073] Add hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether and acrylamide into water (the mass ratio of hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether, acrylamide and water is 1:0.5:3:50), add azobisisobutylamidine hydrochloride (the amount of azobisisobutylamidine hydrochloride is 25% of the mass of acrylamide) after high-pressure homogenization, and heat the reaction under nitrogen protection (temperature is 75°C, time is 3h) to obtain a coating solution.

[0074] Comparative Example 1

[0075] Same as Example 1, except that the special fertilizer for promoting rice-crab symbiosis does not contain nitrifying bacteria.

[0076] Comparative Example 2

[0077] The same as Example 1, except that the iron bacteria, coprophilic Rhodococcus and Rhodopseudomonas palustris in the composite microorganisms are replaced with cyanobacteria of equal mass.

[0078] Comparative Example 3

[0079] Same as Example 1, except that the special fertilizer for promoting rice-crab symbiosis does not contain soybean meal.

[0080] Comparative Example 4

[0081] The method is the same as Example 1, except that the nitrifying bacteria in step (3) are added to step (2) to be fermented together with animal feces, straw and composite microorganisms.

[0082] Comparative Example 5

[0083] The same as Example 1, except that the special fertilizer for promoting rice-crab symbiosis does not contain charcoal powder and montmorillonite.

[0084] Comparative Example 6

[0085] The same as Example 1, except that the coating solution does not contain hexadecyltrimethylammonium chloride and fatty alcohol polyoxyethylene ether.

[0086] Effect Example 1

[0087] A method for promoting rice-crab symbiosis:

[0088] (1) Breeding rice fields: The rice fields are divided into several interconnected areas, each with a length of 300 m 2;

[0089] A ditch 50 cm deep and 150 cm wide is set along the inner wall of the rice field ridge, and then a number of circulation ditches 70 cm deep and 15 cm wide are evenly dug in the rice field. The multiple circulation ditches form a grid, and the area of ​​the circulation ditch accounts for 15% of the area of ​​the rice field. Water inlets are opened on the ditch, and diversion pipes for water to flow out of the rice field are set between adjacent circulation ditches. The diversion pipes are provided with isolation nets to prevent crabs from escaping, and isolation fences are set on the ditches to prevent crabs from escaping.

[0090] Before rice transplanting, quicklime was spread on the surface of the paddy field, the amount of quicklime was 40 kg / mu, and 15 days after spreading the quicklime, 500 kg of the special fertilizer prepared in the embodiment and the comparative example was applied to the paddy field (repeated 3 times, i.e., each fertilizer was used to treat 3 plots), and the soil was plowed (the plowing depth was 10 cm) and raked flat.

[0091] (2) Rice Planting: Rice (Nanjing 5718) seedlings are planted in rice fields at a planting density of 15,000 holes / mu, with 2 to 3 plants per hole.

[0092] (3) Release young crabs: Release crab fry (Chinese mitten crab, size 200 per kilogram) one week after rice planting, with a stocking density of 2 kg / mu and a water depth of about 10 cm. As the rice and young crabs grow, the water depth increases to 25-30 cm.

[0093] (4) Carry out routine feeding and field management, without re-fertilization, water changes or oxygenation.

[0094] (5) The crabs were caught before the rice matured, and then the rice was harvested. The per-acre yield of rice and crabs was calculated. The results are shown in Table 1.

[0095] Table 1 Yield of rice and river crab per mu

[0096] Grouping Rice yield per mu (kg) Yield of river crab per mu (kg) Example 1 801.5 32.3 Example 2 795.8 31.6 Example 3 798.4 31.8 Comparative Example 1 752.1 22.1 Comparative Example 2 771.2 27.4 Comparative Example 3 770.9 26.1 Comparative Example 4 782.7 29.6 Comparative Example 5 783.1 29.9 Comparative Example 6 761.4 24.5

[0097] It can be seen from Table 1 that the special fertilizer prepared by the embodiment of the present invention can obtain higher rice and crab yields.

[0098] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A special fertilizer for promoting rice-crab symbiosis, characterized in that: The invention comprises the following raw materials in parts by weight: 60-80 parts of calcite, 20-30 parts of plagioclase, 30-40 parts of animal manure, 20-30 parts of straw, 10-12 parts of urea, 5-6 parts of potassium chloride, 3-5 parts of manganese sulfate, 2-3 parts of zinc sulfate, 2-3 parts of copper sulfate, 12-15 parts of humic acid, 2-3 parts of composite microorganisms, 0.5-0.8 parts of nitrifying bacteria, 5-6 parts of soybean meal, 5-6 parts of carbon powder and 5-8 parts of montmorillonite.

2. The special fertilizer according to claim 1, characterized in that: The composite microorganism comprises the following components in parts by weight: 10-15 parts of iron bacteria, 5-8 parts of coprophilic Rhodococcus, 4-6 parts of Rhodopseudomonas palustris, 3-5 parts of round brown nitrogen-fixing bacteria, 4-7 parts of Bacillus licheniformis, 4-6 parts of lactic acid bacteria and 2-4 parts of Bacillus subtilis.

3. The special fertilizer according to claim 1, characterized in that: The nitrifying bacteria are composed of nitrite bacteria and nitrate bacteria in a mass ratio of 1:

1.

4. A method for preparing the special fertilizer for promoting rice-crab symbiosis according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step (1) drying and crushing animal excrement and straw, then mixing them evenly with composite microorganisms, piling and fermenting them to obtain fermented fertilizer; Step (2) mixing calcite, plagioclase, urea, potassium chloride, manganese sulfate, zinc sulfate, copper sulfate, nitrifying bacteria and soybean meal uniformly, spraying starch solution, and granulating at low temperature to obtain fertilizer granules; Step (3) crushing humic acid, charcoal powder and montmorillonite and mixing them evenly with the fermented fertilizer, and then coating them on the surface of fertilizer particles to obtain composite fertilizer particles; Step (4) sprays the coating solution on the surface of the composite fertilizer particles, and obtains the special fertilizer for promoting rice-crab symbiosis after low-temperature drying.

5. The preparation method according to claim 4, characterized in that: In step (1), the crushing is to crush to a particle size of 50-100 mesh; the temperature of the pile fermentation is 35-45° C., the time is 25-30 days, and the moisture content is 50-55%; the pile is turned once every 5 days during the pile fermentation.

6. The preparation method according to claim 4, characterized in that: In step (2), the concentration of the starch solution is 5 wt.%; the temperature of the low-temperature granulation is 30-40° C.; and the particle size of the fertilizer particles is 4-5 mm.

7. The preparation method according to claim 4, characterized in that: In step (3), the pulverization is pulverization to a particle size of 50 to 100 meshes; and the binder used in the preparation of the composite fertilizer particles is sodium lignin sulfonate.

8. The preparation method according to claim 4, characterized in that: In step (4), the method for preparing the coating solution comprises the following steps: Hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether and acrylamide are added into water, and after high pressure homogenization, azobisisobutylamidine hydrochloride is added thereto, and the mixture is heated for reaction under nitrogen protection to obtain the coating solution.

9. The preparation method according to claim 8, characterized in that: The mass ratio of hexadecyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether and acrylamide is 1:0.5:3; the amount of azobisisobutylamidine hydrochloride is 25% of the mass of acrylamide; The temperature of the heating reaction is 70-75° C. and the time is 2-3 hours.

10. Use of the special fertilizer according to any one of claims 1 to 3 in rice-crab co-culture.