Method for preparing farmyard manure by solidifying slurry livestock and poultry manure

Abstract

The invention discloses a method for preparing farmyard manure by solidifying slurry livestock and poultry manure, including a method of using a solidifying agent to prepare a solidified body of slurry livestock and poultry manure and using the solidified body to prepare farmyard manure for application; the solidifying agent includes bentonite, silicate cement, quicklime, calcium powder, active magnesium oxide, semi-hydrated gypsum powder, urea, deodorant, polyacrylamide, attapulgite, plant ash, etc. The solidified body of the invention is alkaline, and after solidification, the interior is in an anaerobic state, which can kill some pathogenic microorganisms and insect eggs, and improve the degree of harmlessness and stabilization of livestock and poultry manure; some anions in the solidifying agent can also combine with cations in livestock and poultry manure to be converted into harmless substances, thereby reducing the harm of heavy metals, organic pollutants, etc. to the soil. The method for preparing farmyard manure of the invention is simple to operate, has low energy consumption, less equipment investment, and low cost compared with the existing organic fertilizer production, and can be applied to both large farms and small farms.

Description

Technical Field

[0001] The invention relates to the technical field of poultry manure treatment and disposal, and in particular to a method for preparing farmyard manure by solidifying slurry-like livestock and poultry manure. Background Art

[0002] At present, there are three main ways to treat and dispose of livestock and poultry manure: fertilizer, energy, and feed. Among them, the fertilizer of livestock and poultry manure is the most widely used resource disposal method. The fertilizer of livestock and poultry manure includes direct return to the field, composting, processing into organic fertilizer, etc. The fertilizer utilization of livestock and poultry manure can effectively improve soil structure and reduce the use of chemical fertilizers, and has great development potential. With the country's high attention to the construction of ecological civilization, direct return to the field is no longer advocated, but aerobic composting technology is recommended. However, aerobic composting technology will face the following problems: large equipment and facilities occupy a large area, long single batch production time, high product cost, etc., and aerobic composting is only suitable for relatively dry livestock and poultry manure, not for livestock and poultry manure with high water content. Its production efficiency is also easily restricted by seasons and composting methods, which is not conducive to the operation of small and medium-sized farms.

[0003] The main problem faced in the utilization of livestock and poultry manure as fertilizer is the drying of the manure, especially the thick slurry-like manure. At the same time, in order to ensure the effect of returning it to the field as fertilizer, appropriate amount of environmentally friendly auxiliary materials are added while the livestock and poultry manure is solidified to prepare it into farmyard manure, which can be used as fertilizer by ecological farms, large grain growers, vegetable growers, etc.

[0004] At present, there are reports on methods for drying and stabilizing livestock and poultry manure. For example: Chinese patent document CN112679066A (application number 202110299402.6) provides a livestock and poultry manure evaporation and dewatering system and method. This technology mainly collects livestock and poultry manure into a manure collection tank through a sewage suction pump, and transfers dry manure and manure with a high moisture content to a dry-wet separation shed through an auger and a sewage suction pump. After being treated in the dry-wet separation shed, the manure is divided into solid manure and liquid manure. The solid manure is transferred to the fermentation shed for fermentation, and the liquid manure is transferred to the evaporation bin for evaporation treatment. This technology mainly reduces the moisture content of livestock and poultry manure through air drying and evaporation, which has a drying effect.

[0005] Chinese patent document CN112573797A (application number 202011599528.7) provides a livestock and poultry manure moisture control and transmission system and application method. The technology mainly includes a dehydration conveyor belt, an air pump, an air heating box and an air dryer. It mainly uses air heating and drying to dry and stabilize livestock and poultry manure, which is not suitable for small farms.

[0006] Chinese patent document CN111631193A (application number 202010598159.3) discloses an automated device that uses black soldier flies to achieve rapid reduction and drying of livestock and poultry manure. This technology uses the black soldier flies' scavenging nature and the characteristics of generating heat during activity to accelerate the drying and reduction of livestock and poultry manure. Its technical content mainly uses the heat generation of black soldier flies to quickly dry livestock and poultry manure.

[0007] Chinese patent document CN111330328A (application number 202010162692.5) discloses a solid-liquid separator suitable for a variety of livestock and poultry manure. The technology uses segmented conveying and extrusion to disconnect the rotating blades so that the solids in the manure are gathered and compressed at the disconnected gaps. In short, the current livestock and poultry manure drying and stabilization technology generally targets the entire livestock and poultry manure, with the goal of obtaining solid livestock and poultry manure.

[0008] Therefore, it is a technical problem that technical personnel in this field urgently need to solve to provide a method for drying and stabilizing slurry manure with low investment, wide application range, low energy consumption, and safety and reliability. Summary of the invention

[0009] In view of this, the present invention provides a slurry of livestock and poultry manure solidified farmyard manure and a preparation method thereof.

[0010] In order to achieve the above object, the present invention adopts the following technical solution:

[0011] A slurry of livestock and poultry manure solidified farmyard manure, including slurry of cow manure, pig manure or biogas residue and liquid after anaerobic fermentation of cow manure and pig manure and additives;

[0012] The additives include the following raw materials in parts by weight: 30-40 parts of bentonite, 20-30 parts of Portland cement, 10-15 parts of quicklime, 10-15 parts of calcium powder, 5-10 parts of active magnesium oxide, 5-8 parts of hemihydrate gypsum powder, 1-2 parts of urea, 1-1.5 parts of deodorant, 0.01-0.05 parts of polyacrylamide, and 0-15 parts of attapulgite.

[0013] The present invention also provides a method for preparing farmyard manure by solidifying slurry livestock and poultry manure, comprising the following steps:

[0014] (1) Weigh the slurry of livestock and poultry manure and additives, and then use the original farm manure storage tank as the construction site to treat the slurry of livestock and poultry manure until its solid content is ≥7.5%, and add attapulgite and wood ash to the slurry of livestock and poultry manure;

[0015] The additives include the following raw materials in parts by weight: 30-40 parts of bentonite, 20-30 parts of Portland cement, 10-15 parts of quicklime, 10-15 parts of calcium powder, 5-10 parts of active magnesium oxide, 5-8 parts of hemihydrate gypsum powder, 1-2 parts of urea, 1-1.5 parts of deodorant, 0.01-0.05 parts of polyacrylamide, 0-15 parts of attapulgite, and 0-10 parts of plant ash;

[0016] (2) Mixing bentonite, calcium powder, active magnesium oxide, urea, deodorant, and polyacrylamide to obtain a mixture I, and spreading the mixture I into the slurry of feces and stirring evenly;

[0017] (3) mixing the remaining weighed raw materials to obtain a mixture II, and spreading the mixture II into the slurry of feces and sewage, stirring and mixing the mixture until it becomes a non-flowing slurry;

[0018] (4) The slurry is dug out and spread on a flat drying ground into a 5-10 cm thick surface to dry naturally in the sun. After drying, the slurry forms a solid block.

[0019] (5) The solid block is crushed and mixed with compound fertilizer or composted farmyard manure in a mass ratio of 1-2:1 to obtain slurry-like livestock and poultry manure solidified farmyard manure.

[0020] The beneficial effects of the present invention are:

[0021] (1) After solidification, the thick slurry manure in the present invention can be cleaned by various cleaning methods such as excavators and manual digging, which solves the problem of cleaning manure in farm manure pools and is also convenient for storage and transportation, effectively promoting its resource utilization;

[0022] (2) After the slurry of manure is solidified, it can effectively prevent the decomposition and fermentation of manure, effectively improve the odor emission in the breeding area, improve the human and animal environment and reduce the nuisance of breeding;

[0023] (3) After solidification and stabilization, livestock and poultry manure can be used as a resource, and it can be directly applied to farmland and decomposed and utilized in the soil. Compared with composting or biogas anaerobic treatment, it can effectively reduce carbon emission flux.

[0024] (4) For small farms, anaerobic fermentation or aerobic composting requires not only equipment investment but also maintenance and management, which makes them difficult to promote and implement. The technical solution of the present invention can effectively solve the problem of manure disposal in farms, and can be promoted not only in large farms but also in small and medium-sized farms.

[0025] Furthermore, the mass ratio of the slurry livestock and poultry manure to the mixed additive is 1:0.15-0.2;

[0026] The beneficial effect of adopting the above further scheme is that the above scheme can ensure that the slurry manure has a good solidification effect while reducing the use of mixed additives, thereby reducing costs.

[0027] Furthermore, the bentonite is sodium-based bentonite, the water content of the bentonite is ≤8%, and the blue absorption amount is ≥200g / kg; and the proportion of montmorillonite in the bentonite is ≥65%.

[0028] The beneficial effect of adopting the above further scheme is that the sodium-based bentonite used in the present invention has a larger specific surface area and stronger water absorption than calcium-based bentonite.

[0029] Furthermore, the silicate cement is 625 or 625R high-grade cement, and its particle size is ≤200 mesh.

[0030] The beneficial effect of adopting the above further solution is that the use of high-grade cement can reduce the amount of cement used while increasing the strength of the solidified body.

[0031] Furthermore, the particle size of the active magnesium oxide is ≤80 meshes, and the activity value is 80-120.

[0032] The beneficial effect of adopting the above further scheme is: absorbing the odor in the slurry-like livestock and poultry manure.

[0033] Furthermore, the particle size of the semi-hydrated gypsum powder is ≤80 mesh.

[0034] The beneficial effect of adopting the above further scheme is to reduce the free water in the slurry livestock and poultry manure.

[0035] Furthermore, the deodorant used in the present invention is a bacterial agent that has the effect of inhibiting the reproduction of putrefactive bacteria in livestock and poultry manure. It is a commercially available product produced by Jinan Guanlong Chemical Co., Ltd. and its brand is "Zhen Guanlong". Its microbial components are mainly lactic acid bacteria, Bacillus and photosynthetic bacteria, etc. The main effect is that the live bacteria produce antioxidant biodegradation reactions during the growth and reproduction process, thereby inhibiting the reproduction of putrefactive bacteria.

[0036] Furthermore, the drying time in step (4) is 24-48 hours.

[0037] The beneficial effect of adopting the above further scheme is that the slurry manure can be solidified and made into farmyard manure in a short time.

[0038] The beneficial effects of the present invention are:

[0039] 1. The present invention uses physical and chemical measures such as water absorption drying and blending solidification to solidify and stabilize the slurry of poultry and livestock manure. The bentonite and polyacrylamide contained therein have a large specific surface area and strong water absorption, and can quickly react with the water in the livestock and poultry manure to produce a gel, thereby reducing the water content of the livestock and poultry manure; calcium powder and active magnesium oxide increase the aggregate and lubrication of the mixture, which is conducive to stirring and mixing; the addition of urea and deodorant is conducive to inhibiting the fermentation of microorganisms, reducing the generation of odors, and optimizing the working environment; semi-hydrated gypsum, quicklime and silicate cement can accelerate the solidification of slurry manure, allowing it to eventually become a solid with higher strength. At the same time, the addition of cement, lime and gypsum can make the final solidified body alkaline, which can not only further prevent the decomposition of the solidified body, but also effectively alleviate the acidification of the soil after being applied to the soil.

[0040] 2. The solidified body of the present invention is alkaline, and after solidification, the interior is in an anaerobic state, which can kill some pathogenic microorganisms and insect eggs, thereby improving the degree of harmlessness and stabilization of livestock and poultry manure; some anions in the curing agent can also combine with cations in livestock and poultry manure and transform them into harmless substances, thereby reducing the harm of heavy metals, organic pollutants, etc. to the soil, making the resource utilization of livestock and poultry manure safer.

[0041] 3. The method for preparing farmyard manure of the present invention is simple to operate and has many advantages compared with the existing organic fertilizer production, such as low energy consumption, less equipment investment, and low cost. It can be applied to both large and small farms. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a comparison chart of the volume increase of the livestock and poultry manure solidification body provided by the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] Method for preparing farmyard manure by solidifying slurry piggery:

[0046] The livestock and poultry manure selected was pig manure, which was obtained from Changshan Shili Farm, Quzhou City, Zhejiang Province on November 20, 2021. Its indicators were: solid content of 7.61%, moisture content of 92.39%, and bulk density of 1028kg / m 3 .

[0047] (1) The solid content of slurry livestock and poultry manure is low. Take 1 cubic meter of raw material, add 5 kg of attapulgite and 5 kg of wood ash, and mix well for use;

[0048] (2) Weigh 30 kg of bentonite, 10 kg of calcium powder, 5 kg of active magnesium oxide, 1 kg of urea, 1 kg of deodorant, and 10 g of polyacrylamide, and mix them evenly to obtain a mixture I. Weigh 10 kg of the mixture I, sprinkle it into the slurry of feces, and stir evenly.

[0049] (3) Weigh 20 kg of silicate cement, 15 kg of quicklime, and 8 kg of hemihydrate gypsum powder, mix them evenly to prepare mixture II, weigh 8 kg of mixture II, sprinkle it into the treatment pool, and stir it with the muddy manure to form a non-fluid mud.

[0050] (4) digging out the muddy manure obtained in step (3), spreading it into a 5-10 cm plane on a flat drying ground, and drying it naturally in the sun for 24 hours. After drying, the muddy manure becomes a solid block;

[0051] (5) The solid block obtained in step (4) is crushed, mixed evenly with composted farmyard manure in a mass ratio of 1:1, and sieved with a sieve with a pore size of 2 cm to use as farmyard manure for vegetable cultivation.

[0052] Example 2

[0053] Method for preparing farmyard manure by solidifying slurry biogas residue and liquid biogas:

[0054] Implementation location: Zhejiang Yijing Ecological Animal Husbandry Co., Ltd., using biogas residues and liquid from cattle farm manure treatment, with the following indicators: solid content of 9.87%, water content of 90.13%, bulk density of 924kg / m 3 .

[0055] (1) The solid content of slurry livestock and poultry manure is low. Take 1 cubic meter of raw material, add 5 kg of attapulgite and 5 kg of wood ash, and mix well for use;

[0056] (2) Weigh 30 kg of bentonite, 10 kg of calcium powder, 5 kg of active magnesium oxide, 1 kg of urea, 1 kg of deodorant, and 10 g of polyacrylamide, and mix them evenly to obtain a mixture I. Weigh 10 kg of the mixture I, sprinkle it into the slurry of feces, and stir evenly.

[0057] (3) Weigh 20 kg of silicate cement, 15 kg of quicklime, and 8 kg of hemihydrate gypsum powder, mix them evenly to prepare mixture II, weigh 8 kg of mixture II, sprinkle it into the treatment pool, and stir it with the muddy manure to form a non-fluid mud.

[0058] (4) digging out the muddy manure obtained in step (3), spreading it into a 5-10 cm plane on a flat drying ground, and drying it naturally in the sun for 24 hours. After drying, the muddy manure becomes a solid block;

[0059] (5) The solid block obtained in step (4) is crushed, mixed evenly with composted farmyard manure in a mass ratio of 1:1, and sieved through a sieve with a pore size of 2 cm before use as farmyard manure for vegetable cultivation.

[0060] Example 3

[0061] A method for preparing special fertilizer for tea trees by solidifying cattle manure,

[0062] Using dairy manure from Zhejiang Yijing Ecological Animal Husbandry Co., Ltd., the solid content of which is 8.53%, the specific steps are as follows:

[0063] (1) Measure 1 cubic meter of raw material, add 5 kg of attapulgite and 5 kg of wood ash, mix well and set aside;

[0064] (2) Weigh 33 kg of bentonite, 10 kg of calcium powder, 5 kg of active magnesium oxide, 1 kg of urea, 1 kg of deodorant, and 10 g of polyacrylamide, and mix them evenly to obtain a mixture I. Weigh 10 kg of the mixture I, sprinkle it into the slurry of feces, and stir evenly.

[0065] (3) Weigh 20 kg of silicate cement, 15 kg of quicklime, and 8 kg of hemihydrate gypsum powder, mix them evenly to prepare mixture II, weigh 8 kg of mixture II, sprinkle it into the treatment pool, and stir it with the muddy manure to form a non-fluid mud.

[0066] (4) digging out the slurry of manure obtained in step (3), spreading it into a 5-10 cm plane on a flat drying ground, and drying it naturally in the sun for 24 hours, until the slurry of manure becomes a solid block after drying;

[0067] (5) The block solid obtained in step (4) is crushed to obtain 270 kg of powdered solid with a moisture content of 33.24%, and 50 kg of urea, 60 kg of diammonium phosphate, and 70 kg of potassium sulfate are added and mixed evenly to obtain a special fertilizer for tea trees with a total nutrient content of 25% of nitrogen, phosphorus and potassium and a nitrogen, phosphorus and potassium content of 9-7-9, respectively. The recommended dosage is 50 kg per mu, which is suitable for application in tea gardens in the hilly and mountainous areas in the south.

[0068] Comparative Example 1

[0069] The livestock and poultry manure is dried under natural conditions without adding any curing agent. The livestock and poultry manure selected is pig manure, as described in Example 1.

[0070] Comparative Example 2

[0071] The poultry manure solidification, the selected solidifying agent is the bentonite in Example 1 removed, and the proportions of other components remain unchanged. The operation steps are also the same as in Example 1.

[0072] Comparative Example 3

[0073] The curing agent selected for the poultry manure solidification is the silicate cement in Example 1 removed, and the proportions of other components remain unchanged. The operation steps are also the same as in Example 1.

[0074] Experiment and implementation results

[0075] 1. Product performance test

[0076] Table 1 Changes in moisture content

[0077] Placement time 12h 24h 48h 72h 96h Example 1 78.41％ 74.31％ 59.37％ 38.47％ 29.79％ Comparative Example 1 89.29％ 86.92％ 82.96％ 78.78％ 74.15％ Comparative Example 2 77.71％ 74.22％ 66.46％ 54.34％ 40.07％ Comparative Example 3 81.28％ 79.38％ 69.84％ 59.23％ 45.37％

[0078] As shown in Table 1 above, compared with Comparative Example 1, the moisture content of livestock and poultry manure after solidification in Example 1 was reduced by 10.88% after 12 hours, 12.61% after 24 hours, 23.59% after 48 hours, 40.31% after 72 hours, and 44.36% after 96 hours. The moisture content of livestock and poultry manure was significantly reduced after solidification for 96 hours, and its index met the moisture content requirements in the "Agricultural Sludge Pollutant Control Standard" (GB4284-2018). Although the moisture content of Comparative Examples 2 and 3 was also reduced after the addition of the curing agent, the effect was not as good as that of Example 1. It is indicated that the curing agent component in this technology plays a key role in the solidification of the award-winning manure.

[0079] Changes in volume increase ratio of solidified bodies under different treatments Figure 1 As shown, from Figure 1 It can be seen that the volume of livestock and poultry manure is significantly reduced after solidification. The volume increase ratio of Example 1 after 7-8 days is reduced by 15.37% compared with that of Comparative Example 1. This shows that this solidification method meets the requirements of "reduction and stabilization" for resource utilization of solid waste.

[0080] 2. Sensory evaluation of curing effect

[0081] The curing effect was evaluated by sensory evaluation based on whether the solidified body had fluidity, shaping condition, and hardness when pressed with a glass rod, and the evaluation results were presented in the form of assignment. The basis for sensory evaluation assignment is shown in Table 2.

[0082] Table 2 Basis for sensory evaluation

[0083]

[0084] The curing effect was sensory evaluated at 0h, 12h, 24h, 48h, 72h and 96h respectively. The evaluation results are shown in Table 3.

[0085] Table 3 Sensory evaluation assignment table

[0086]

[0087]

[0088] The results show that the fluidity of livestock and poultry manure can be significantly reduced and the hardness after curing can be improved after curing. After curing for 24 hours, the 5 sensory values ​​of Example 1 are increased by 250%, 55.56% and 75% respectively compared with Comparative Example 1, Comparative Example 2 and Comparative Example 3. After curing for 48 hours, Example 1 has a strong tolerance and achieves a good curing effect. By analyzing Comparative Example 1, Comparative Example 2 and Comparative Example 3, it can be concluded that not adding bentonite will make the curing effect poor in a short time. This is because the lack of bentonite's water absorption property makes the cement hydration reaction slow. Not adding silicate cement can reduce the fluidity of livestock and poultry manure in a short time, but overall due to the lack of cement hydration reaction, the curing rate is slow.

[0089] 3. Comparison of odors produced by static corruption

[0090] The solidified livestock and poultry manure samples were placed in a small bottle with a height of about 15 cm and a radius of about 2 cm. The odor in the small bottle was evaluated every 3 days, 7 days, 14 days, and 28 days.

[0091] The odor index was classified into six levels: Ⅰ: no odor, Ⅱ: barely perceptible odor, Ⅲ: weak odor, Ⅳ: obvious odor, Ⅴ: strong odor. Ⅵ: extremely strong odor. Results Five experts were invited to evaluate the odor produced by livestock and poultry manure, and the results are shown in Table 4.

[0092] Table 4 Comparison of odors produced by static corruption

[0093]

[0094]

[0095] The results show that the odor of livestock and poultry manure is significantly reduced after solidification, and basically no odor is generated after one week. It can be seen from Example 1 that no curing agent is added, and there is still a strong odor in a short time, indicating that the deodorant can play a good effect in controlling the odor in a short time. Therefore, adding a deodorant can significantly inhibit the generation of odor, which is necessary in production. The solidified livestock and poultry manure can be stored for a long time, solving the problem of air pollution caused by the treatment and storage of livestock and poultry manure.

[0096] 4. Economic benefit analysis of curing agent

[0097] According to the experimental conditions of livestock and poultry manure composite curing agent, 4 tons of livestock and poultry manure were prepared and cured to calculate the cost of curing livestock and poultry manure. The market reference prices of various materials found on China Supplier Network, China Building Materials Purchasing Network and other websites are shown in the table:

[0098] Table 4 Price list of livestock and poultry manure solidifying agent

[0099]

[0100] The curing agent of Example 1 can roughly cure 4 tons of livestock and poultry manure. According to calculation, the price of curing each ton of livestock and poultry manure is roughly 97.84 yuan, which has certain economic benefits for subsequent resource utilization.

[0101] Test Example 1

[0102] In order to verify the application effect of the farmyard manure in Example 1, an application effect test was conducted in tomato cultivation of Yijing Ecological Animal Husbandry in Shaoxing City, Zhejiang Province. Treatment 1 was the test effect without applying any fertilizer, treatment 2 was the test effect of applying a certain brand of chemical fertilizer, and treatment 3 was the farmyard manure prepared in Example 1, and the application amount was 5000 kg / hm 2 The results of tomato yield in the experiment are shown in Table 5.

[0103] Table 5 Effects of farmyard manure prepared by solidification of slurry livestock and poultry manure on tomato growth and yield

[0104]

[0105] As can be seen from Table 5, after applying the farmyard manure of the present invention, compared with tomatoes without any fertilizer, the yield increased by 91.71%, the plant height increased by 28.63%, the stem thickness increased by 77.14%, and the plant biomass increased by 77.05. Compared with tomatoes applied with a certain chemical fertilizer, the yield increased by 13.30%, the plant height increased by 14.47%, the stem thickness increased by 28.28%, and the plant biomass increased by 25.58%. This shows that the farmyard manure can effectively promote the increase in tomato yield and the effect is remarkable.

[0106] Test Example 2

[0107] Test Example 2 An application test was conducted on the yield and quality of potatoes at Yijing Ecological Animal Husbandry in Shaoxing, Zhejiang. Treatments 1 and 2 were the same as in Test Example 1, and Treatment 3 was the farmyard manure prepared in Example 3, with an application rate of 5000 kg / hm 2 The results of potato yield in the experiment are shown in Table 6.

[0108] Table 6 Effects of farmyard manure prepared by solidification of slurry livestock and poultry manure on potato yield and quality

[0109]

[0110]

[0111] As can be seen from Table 6, after applying the farmyard manure of the present invention, the yield increased by 161.52% compared with the potatoes without any fertilizer, and the yield increased by 11.9% compared with the potatoes with a certain chemical fertilizer. This shows that the farmyard manure can effectively promote the increase of potato yield. Compared with treatment 1 and treatment 2, the big potato rate of treatment 3 is also significantly improved, which shows that the farmyard manure also significantly improves the quality of potatoes.

[0112] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing farmyard manure by solidifying slurry livestock and poultry manure, characterized in that: The following steps are involved: (1) Weighing slurry of livestock and poultry manure and additives, then taking 1 cubic meter of slurry of livestock and poultry manure, adding 5 kg of attapulgite and 5 kg of wood ash, and stirring evenly to make the solid content ≥ 7.5% for standby use; The mass ratio of the slurry of livestock and poultry manure to the additive is 1:0.15-0.2; the slurry of livestock and poultry manure is biogas residue and liquid after anaerobic fermentation of cow manure and / or pig manure; The additives include the following raw materials in parts by weight: 30-40 parts of bentonite, 20-30 parts of Portland cement, 10-15 parts of quicklime, 10-15 parts of calcium powder, 5-10 parts of active magnesium oxide, 5-8 parts of hemihydrate gypsum powder, 1-2 parts of urea, 1-1.5 parts of deodorant, and 0.01-0.05 parts of polyacrylamide; (2) Mixing bentonite, calcium powder, active magnesium oxide, urea, deodorant, and polyacrylamide to obtain a mixture I, and spreading the mixture I into the slurry of feces and stirring evenly; (3) Mixing silicate cement, quicklime and semi-hydrated gypsum powder to obtain a mixture II, and spreading the mixture II into the slurry of feces and sewage, stirring and mixing the mixture until it becomes a non-flowing slurry; (4) The slurry is dug out and spread on a flat drying ground into a 5-10 cm thick surface to dry naturally in the sun. After drying, the slurry forms a solid block. (5) Crush the solid blocks and mix them with compound fertilizer or composted farmyard manure in a ratio of 1 to 2 to obtain slurry-like livestock and poultry manure solidified farmyard manure.

2. The method for preparing farmyard manure by solidifying slurry livestock and poultry manure according to claim 1, characterized in that: The bentonite is sodium-based bentonite, the water content of the bentonite is ≤8%, and the blue absorption amount is ≥200g / kg; the proportion of montmorillonite in the bentonite is ≥65%.

3. The method for preparing farmyard manure by solidifying slurry livestock and poultry manure according to claim 1, characterized in that: The silicate cement is 625 or 625R high-grade cement, and its particle size is ≤200 meshes.

4. The method for preparing farmyard manure by solidifying slurry livestock and poultry manure according to claim 1, characterized in that: The particle size of the active magnesium oxide is ≤80 meshes, and the activity value is 80-120.

5. The method for preparing farmyard manure by solidifying slurry livestock and poultry manure according to claim 1, characterized in that: The particle size of the semi-hydrated gypsum powder is ≤80 mesh.

6. The method for preparing farmyard manure by solidifying slurry livestock and poultry manure according to claim 1, characterized in that: The drying time in step (4) is 24-48 hours.

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