High-phosphorus organic fertilizer based on bone black and preparation method thereof

Abstract

The invention discloses a high-phosphorus organic fertilizer based on bone black and a preparation method thereof, and belongs to the technical field of organic fertilizers. Preparation raw materials of the high-phosphorus organic fertilizer based on the bone black comprise a base material and the bone black, wherein the base material comprises the following components in parts by mass: 4-6 parts of cow dung and 0.5-1.5 parts of straw; the bone black accounts for 10% of the total mass of the cow dung and the straw; the preparation method comprises the following steps: (1) fully and uniformly mixing the cow dung and the straw; (2) adding the bone black and uniformly mixing; and (3) continuously composting in a closed device for 42 days, and carrying out aeration treatment for a plurality of times every day with the aeration rate of 0.8-1L / min / kg dry matter. The high-phosphorus low-conductivity organic fertilizer is obtained by adding the bone black for composting, so that wastes of agriculture and animal husbandry are effectively utilized, the problems that an existing compost product is high in conductivity and nitrogen loss easily occurs are solved, and an efficient and environment-friendly fertilizer choice is provided for modern agriculture.

Description

Technical Field

[0001] The invention belongs to the technical field of organic fertilizers, and in particular relates to a high-phosphorus organic fertilizer based on bone char and a preparation method thereof. Background Art

[0002] In the prior art, composting with poultry manure and rice husk as two base materials may result in the problem of too high EC value of compost products, so scholars are committed to finding a reasonable method to reduce the conductivity of compost. Replacing organic nitrogen sources (poultry manure, sludge, etc.) with inorganic nitrogen sources (urea, ammonium salts, nitrates and other fertilizers) is an effective method to reduce the conductivity of compost products, but the addition of inorganic nitrogen sources often leads to more ammonia volatilization and nitrogen loss. Therefore, how to reduce the conductivity of compost products in manure and straw composting systems while avoiding more nitrogen loss has become the focus of composting research. Summary of the invention

[0003] In view of the above-mentioned prior art, the present invention provides a high-phosphorus organic fertilizer based on bone char and a preparation method thereof, which solves the problems of high conductivity and easy nitrogen loss of existing compost products.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: to provide a high-phosphorus organic fertilizer based on bone char, the preparation raw materials include base material and bone char, the base material includes the following components in parts by weight: 4 to 6 parts of cow dung and 0.5 to 1.5 parts of straw; the bone char is 10% of the total weight of the cow dung and the straw.

[0005] Based on the above technical solution, the present invention can also be improved as follows.

[0006] Furthermore, the base material includes the following components in parts by mass: 5 parts of cow dung and 1 part of straw.

[0007] Furthermore, the length of the straw is 2 to 5 cm.

[0008] Furthermore, the bone charcoal is cattle bone charcoal, which is obtained by sintering cattle bones at 600° C. for 6 to 8 hours, and its particle size does not exceed 2 mm.

[0009] The beneficial effects of the above further technical solution adopted by the present invention are: cow dung is the main nitrogen source in the composting process, contains rich organic matter, can provide necessary nutrition for composting, promote the growth and reproduction of microorganisms, and cow dung itself also contains a large number of microorganisms. Straw is rich in cellulose and hemicellulose, and is the main carbon source in composting. Its good structure helps to increase the air permeability of composting and improve the ventilation performance of composting. Cow bone charcoal is rich in calcium and phosphate. In composting applications, its Ca 2+ Mg 2+The advantage of high plasma is that it forms insoluble substances such as calcium carbonate and magnesium carbonate with the compost body to produce phosphorus-rich and calcium-rich organic fertilizer, while achieving the purpose of reducing the conductivity of the compost product.

[0010] Further, the preparation method of the phosphorus-rich, calcium-rich and low-conductivity organic fertilizer comprises the following steps:

[0011] (1) Mix cow dung and straw thoroughly;

[0012] (2) Add bone char and mix well, adjusting the moisture content to 50-70%;

[0013] (3) Composting was continued in a closed device for 42 days, with aeration treatment performed several times a day at an aeration rate of 0.8 to 1 L / min / kg dry matter and each aeration time of 3 to 8 min.

[0014] Furthermore, the water content is 60%.

[0015] Further, the aeration rate was 0.88 L / min / kg dry matter.

[0016] Furthermore, the specific method of aeration treatment is: aeration is performed every two hours for 8 hours a day, and once every hour for the remaining 16 hours, and each aeration time is 5 minutes.

[0017] The beneficial effect of the above-mentioned further technical scheme adopted by the present invention is that the composting device adopted is a closed environment. In order to maintain the aerobic state of the pile and improve the composting efficiency, mechanical forced aeration is adopted in the composting process. Through forced aeration, the temperature, humidity and oxygen concentration inside the pile can be effectively controlled, providing optimal conditions for the growth and metabolic activities of microorganisms.

[0018] The beneficial effects of the present invention are as follows: cattle bone charcoal is a substance formed by high-temperature pyrolysis of cattle bones, which is naturally rich in phosphorus and calcium. These two elements are indispensable nutrients for plant growth and development, especially for promoting plant root development and improving fruit quality. At the same time, cattle bone charcoal has excellent pore structure and adsorption performance, which is conducive to the development of the composting process. 2+ Mg 2+The advantage of high plasma content is to reduce the conductivity of compost products; since cow bone char is rich in phosphorus and calcium, adding it to the composting system can increase the content of phosphorus and calcium in the compost product, produce phosphorus-rich and calcium-rich organic fertilizer, and increase the nutritional value of the product; by adding cow bone char to the manure and straw composting system, the good pore structure and adsorption performance of cow bone char can further improve the soil environment and soil fertility in agricultural applications, thereby promoting the healthy growth of plants. In addition, its environmentally friendly production process is also in line with the current trend of sustainable agricultural production. Therefore, by adding cow bone char to composting to obtain a phosphorus-rich and calcium-rich low-conductivity organic fertilizer, agricultural and animal husbandry waste can be effectively utilized, providing an efficient and environmentally friendly fertilizer option for modern agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a composting device;

[0020] Among them, 1. barrel body; 2. barrel cover; 3. aeration device; 4. aeration hole; 5. greenhouse gas collection device; 6. gas collection hole / temperature measurement hole; 7. three-way valve; 8. ammonia collection device; 11. N2O; 12. CH4; 13. CO2; 14. NH3; 15. compost material;

[0021] Figure 2 for the temperature changes during the composting process;

[0022] Figure 3 is the pH change during composting;

[0023] Figure 4 is the change of conductivity during composting;

[0024] Figure 5 is the daily emission changes of NH3, CO2, N2O and CH4 during the composting process, where a is NH3, b is CO2, c is N2O, and d is CH4;

[0025] Figure 6 It represents the changes of ammonium nitrogen, nitrate nitrogen and total nitrogen during the composting process, as well as the total nutrient content and composition of the final product, where a represents ammonium nitrogen, b represents nitrate nitrogen, c represents total nitrogen, and d represents the total nutrient content and composition of the final product. DETAILED DESCRIPTION

[0026] The specific implementation modes of the present invention are described in detail below with reference to the embodiments.

[0027] Example 1

[0028] A high-phosphorus organic fertilizer based on bone char, the raw materials include 13.5 kg of cow dung, 2.7 kg of wheat straw and 1.62 kg of cow bone char; wherein the wheat straw is crushed to about 4 cm; the cow bone char is obtained by burning cow bones at 600° C. for 6 hours and then passing through a 2 mm sieve; the preparation method of the high-phosphorus organic fertilizer based on bone char is as follows:

[0029] (1) Mix cow dung and wheat straw thoroughly;

[0030] (2) adding cow bone charcoal and mixing evenly, adjusting the moisture content to 60% to obtain a mixed material;

[0031] (3) The mixed materials were placed in a composting device and composted for 42 days. Aeration was performed every day and the compost was fully turned on days 0, 3, 7, 14, 21, 28, 35 and 42 to obtain the obtained product, which was recorded as the CBC 10% treatment group. The specific operation of the aeration treatment was as follows: aeration was performed once every two hours from 0 to 8 a.m. every day and once every hour from 8 to 24 a.m. every day. The aeration rate was set to 0.88 L / min / kg dry matter and the aeration time was 5 min each time.

[0032] The composting device includes a barrel 1, a barrel cover 2, an aeration device 3, a greenhouse gas collection device 5 and an ammonia collection device 8. The barrel 1 is a cylindrical stainless steel barrel with a height of 60 cm, a diameter of 40 cm and a volume of 70 L. There are aeration holes 4 on the lower side wall of the barrel 1. The aeration device 3 is connected to the aeration holes 4 through a pipe with a valve and communicates with the inside of the barrel 1. The aeration device 3 is a HAILEA electromagnetic air compressor (model ACO-328). The barrel cover 2 is movably connected to the barrel 1 and can keep the inside of the device as a closed environment. The center of the barrel cover 2 is provided with an air collection hole / temperature measurement hole 6, which is connected to one end of a three-way valve 7, and the other two ends of the three-way valve 7 are respectively connected to the greenhouse gas collection device 5 and the ammonia collection device 8. In the composting device, 15 represents the mixed material, and 11, 12, 13 and 14 respectively represent N2O, CH4, CO2 and NH3 generated during the composting process.

[0033] The physical and chemical properties of the three composting materials, cow dung, wheat straw and cow bone charcoal, are shown in Table 1.

[0034] Table 1 Basic physical and chemical properties of compost raw materials

[0035]

[0036]

[0037] Note: The indicators with superscript a are measured on air-dried samples and are only used here to indicate the processing method of compost raw material samples.

[0038] Example 2

[0039] A high-phosphorus organic fertilizer based on bone char, the raw materials comprising 10.8 kg of cow dung, 1.35 kg of wheat straw and 1.215 kg of cow bone char; wherein the wheat straw is crushed to about 2 cm; the cow bone char is obtained by calcining cow bones at 600° C. for 8 hours and then passing through a 2 mm sieve; the preparation method of the high-phosphorus organic fertilizer based on bone char is the same as that of Example 1.

[0040] Example 3

[0041] A high-phosphorus organic fertilizer based on bone char, the raw materials comprising 16.2 kg of cow dung, 4.05 kg of wheat straw and 2.025 kg of cow bone char; wherein the wheat straw is crushed to about 5 cm; the cow bone char is obtained by calcining cow bones at 600° C. for 6 hours and then passing through a 2 mm sieve; the preparation method of the high-phosphorus organic fertilizer based on bone char is the same as that of Example 1.

[0042] Comparative Example

[0043] An organic fertilizer, comprising 13.5 kg of cow dung and 2.7 kg of wheat straw, wherein the wheat straw is crushed to about 4 cm; except that no cow bone charcoal is added in step (2), the preparation method of the organic fertilizer is the same as that of Example 1, and is denoted as the CK treatment group.

[0044] Comparative Example 2

[0045] A high-phosphorus organic fertilizer based on bone char, the raw materials of which include 13.5 kg of cow dung, 2.7 kg of wheat straw and 0.81 kg of cow bone char; wherein the wheat straw is crushed to about 4 cm; the cow bone char is obtained by calcining cow bones at 600° C. for 6 hours and then passing through a 2 mm sieve; the preparation method of the high-phosphorus organic fertilizer based on bone char is the same as that in Example 1, recorded as a CBC5% treatment group.

[0046] Experimental example

[0047] The properties of the high-phosphorus organic fertilizer based on bone char prepared in Examples 1 to 3 are similar. Taking Example 1 as an example, the performance of the high-phosphorus organic fertilizer based on bone char is described in detail.

[0048] In Example 1 and Comparative Examples 1 and 2, the compost was fully turned and compost samples were collected on the 0th, 3rd, 7th, 14th, 21st, 28th, 35th and 42nd days after the start of composting. The temperatures of the upper, middle and lower layers of the compost were measured with a probe thermometer every morning, and the average of the three was taken as the compost temperature. At the same time, the ambient temperature was measured.

[0049] (1) A portion of the sample was stored at 4°C to analyze pH, germination index (GI) and electrical conductivity (EC), ammonium nitrogen and nitrate nitrogen.

[0050] (2) Another portion of the sample is air-dried, ground, and sieved, and then used to test indicators such as total nitrogen, total potassium, total phosphorus, and total calcium.

[0051] (3) Detect the production of CO2, CH4, N2O, and NH3 every morning. Detect once a day during the 0-14th day of composting, and once every two days thereafter.

[0052] ① Collect CO2, CH4 and N2O by syringe collection method through greenhouse gas collection device 5, control the three-way valve to connect the air hole on the top of the cover with the syringe, and do not connect it with the ammonia absorption device. Start to extract the gas in the barrel after 15 minutes of aeration, absorb 10mL of gas each time according to the syringe scale, extract 3 times, each time with an interval of 15 minutes, and detect it through gas chromatograph after collection;

[0053] ② Control the three-way valve to be connected with the ammonia absorption device, and at the same time not to be connected with the air hole on the top of the cover and the syringe, and use the boric acid absorption method through the ammonia collection device 8 to absorb and titrate the amount of NH3 produced.

[0054] 1. Temperature changes during composting

[0055] Temperature changes during composting Figure 2 As shown, with the progress of aerobic composting, the three treatment groups quickly entered the high temperature period (≥50°C) on the first day. The high temperature period of the CK treatment group, CBC5%, and CBC10% treatment groups lasted for 10 days, 10 days, and 14 days, respectively. In the whole composting process, the temperature of the CBC10% treatment group was higher than that of the CK treatment group. Although the high temperature period of the CBC5% treatment group lasted the same as that of the CK treatment group, its temperature during the whole process was lower than that of the CBC10% treatment group, and sometimes even lower than that of the CK treatment group. This shows that the addition of 10% bone charcoal increased the temperature and microbial activity of the pile, allowing the pile to reach a high temperature state faster and maintain it for a longer time.

[0056] 2. pH changes during composting

[0057] pH changes during composting Figure 3 As shown in the figure, since the pH value of the cattle bone char itself is relatively high (10.33), adding it to the composting system increases the initial pH of the compost. In the mature stage, the CBC10% treatment group still maintains a high microbial activity, and a large amount of H is produced due to nitrification. + The accumulation of organic acids decreased the pH of the compost, and the activity of nitrifying bacteria caused the pH value of the CBC10% treatment group (8.20) to be slightly lower than that of the CK treatment group (8.44). Compared with the CK treatment, the pH value of the CBC5% treatment group did not change significantly except for the large pH fluctuation in the middle of the composting period, and the final pH was higher than that of the CK treatment group. This shows that the addition of 10% bone charcoal reduced the pH value of the compost, and a lower pH value is conducive to the further application of compost products.

[0058] 3. Changes in conductivity during composting

[0059] The conductivity changes during composting are as follows: Figure 4 As shown in the figure, the conductivity is the basis for judging the soluble salt in the compost. If the conductivity of the compost is too high, it will be toxic to plants. If the conductivity of the compost is too low, it will cause the fertilizer to lose its effect and cause fertilizer loss. During the composting process, organic matter decomposes rapidly, and the soluble salt content of the compost increases. The conductivity of the three treatment groups fluctuated and increased. 2+ Mg 2+ The plasma content is high, forming insoluble substances such as calcium phosphate and magnesium carbonate with the compost body. Therefore, the conductivity of the CBC10% treatment group is lower than that of the CK treatment group during the entire composting process. The conductivity change trend of the CBC5% treatment group in the early stage of composting is roughly the same as that of the CK treatment group, and is slightly lower than that of the CK treatment group. It rises rapidly in the later stage and finally exceeds that of the CK treatment group. The final conductivity of the CK treatment group is 3.47mS / cm, and the conductivity of the CBC10% treatment group is

[0060] 3.03mS / cm, the conductivity of the CBC5% treatment group was 3.77mS / cm, the CBC5% treatment group increased by 9.65% compared with the CK treatment group, and the CBC10% treatment group decreased by 12.68% compared with the CK treatment group.

[0061] 4. Changes in germination index

[0062] From Table 2, we can see that the initial GI (germination index) of the three treatments is relatively high, which may be related to the properties of the cow dung raw material itself, but it does not meet the national standard (≥80%). And as the amount of cattle bone char added increases, the initial GI value decreases, which is related to the fact that the addition of cattle bone char changes the environment of the pile itself. After 42 days of aerobic composting, the seed germination rate of the three treatment groups increased and reached the national standard. Among them, the increase in the CBC10% treatment group was greater. This is because the CBC10% treatment group lasted longer in the high temperature period (14 days) and had a better effect on killing bacteria, so the final germination index was higher than the other two treatment groups.

[0063] Table 2 Germination index (GI) of CBC10% treatment group and CK treatment group

[0064]

[0065] 5. Changes of ammonia and greenhouse gases during composting

[0066] The daily emission changes of NH3, CO2, N2O and CH4 during composting are as follows: Figure 5 As shown in Figure 2, the daily emission of NH3 in the CBC5% treatment group was roughly the same as that in the CK treatment group and was slightly lower than that in the CK treatment group. The daily emission of NH3 in the CBC10% treatment group was much lower than that in the CK treatment group ( Figure 5 a), indicating that adding bone char can reduce ammonia volatilization, and adding 10% bone char has a better effect on reducing ammonia volatilization; in the composting cooling stage (40-20℃), the daily N2O emission of the CBC10% treatment group increased rapidly ( Figure 5 b) This is because mesophilic microorganisms have difficulty decomposing organic matter during the cooling stage, which is related to the activity of nitrifying bacteria. The CBC5% treatment group and CK are roughly the same; since the microbial activity of the CBC10% treatment group is higher than that of the CK treatment group (reflected in the temperature changes of the two, such as Figure 2 Therefore, its daily CO2 emission is higher than that of the CK treatment group ( Figure 5 c), and due to the greater oxygen consumption during the high temperature period, some anaerobic reactions occurred inside the compost, so the daily CH4 emission of the CBC10% treatment group during the high temperature period was higher than that of the CK treatment group ( Figure 5 d); The daily CO2 emission of CBC5% was lower than that of the CK treatment group or roughly the same as that of the CK treatment group during the entire composting process, indicating that the addition of 5% cattle bone charcoal did not play a very good role in stimulating microbial activity. Its daily CH4 emission was higher than that of the CK treatment group on days 2 to 5. The addition of cattle bone charcoal may have increased the activity of some anaerobic bacteria. The higher daily CH4 emission of the CBC10% treatment group during this period was also related to this.

[0067] The cumulative gas emissions of different treatments are shown in Table 3. With the good adsorption performance of cattle bone charcoal on NH3, the cumulative NH3 emissions of the CBC5% and CBC10% treatment groups were significantly lower than those of the CK treatment group, and the effect of CBC10% was better, which was reduced by 89.45% compared with the CK treatment group. However, the addition of cattle bone charcoal promoted the activity of nitrifying bacteria in the cooling stage of composting, resulting in a higher cumulative N2O emission in the CBC10% treatment group than in the CK treatment group. At the same time, the addition of 5% cattle bone charcoal did not promote the activity of aerobic microorganisms, but increased the activity of some anaerobic microorganisms; the addition of 10% cattle bone charcoal increased the microbial activity inside the compost, making the cumulative CO2 and CH4 emissions of the CBC10% treatment group higher than those of the CK treatment group.

[0068] Table 3 Cumulative emissions of gases from different treatments

[0069]

[0070] 6. Compost product nutrients

[0071] Changes in ammonium nitrogen, nitrate nitrogen, and total nitrogen during composting, and the total nutrient content and composition of the final product. Figure 6 As shown, each treatment group NH4 + -N content such as Figure 6 a. After adding cow bone charcoal, the NH4 +-N is converted to NH3, so in the early stage of composting, NH4 + -N increased rapidly, which also explains the reduction of NH3 emission after adding cow bone char; NH4 + -N change trend was similar to that of CK, while NH4 + -N decreases rapidly and more is converted into NO3 - -N( Figure 6 b), while NO3 in the CBC5% treatment group - The change trend of -N was roughly the same as that of CK. This shows that the addition of 10% bone char effectively promoted the conversion of ammonium nitrogen to nitrate nitrogen and reduced nitrogen volatilization.

[0072] The changes of total nitrogen content in each treatment group are as follows Figure 6 As shown in Figure c, the total nitrogen change trends of the three treatments are roughly the same. After adding the bone char, due to its "dilution effect", the total nitrogen content of the pile body decreases with the increase of the amount of bone char added, while the addition of bone char does not play a big role in affecting the total nitrogen change trend during the whole process. The nitrogen increase of the three treatment groups of CK, CBC5%, and CBC10% is 29.61%, 24.75%, and 29.25%, respectively. The nitrogen increase of adding 10% bone char is roughly the same as that of CK, while the nitrogen increase of the treatment group adding 5% bone char is less, which indirectly shows that adding 10% bone char has better nitrogen retention performance than adding 5%.

[0073] The total nutrient content and composition (total nitrogen + total phosphorus + total potassium) of the final compost products of the three treatments are as follows Figure 6 d, the total nutrient content of the compost increased significantly after adding the bone char, which mainly depended on the increase of total phosphorus content in the compost. The properties of the final compost product are shown in Table 4. 2+ Mg 2+ The plasma content is high and the phosphate content is high. The total calcium and total phosphorus of the final compost product with the addition of cattle bone charcoal are significantly increased compared with the CK treatment group, which increased by 115.72% to 392.78% and 140.31% to 353.79% respectively compared with the CK treatment group; the conductivity of the CBC10% treatment group was significantly reduced, which was reduced by 12.68% compared with the CK treatment group.

[0074] Table 4 Properties of final compost product

[0075]

[0076]

[0077] In summary, adding cow bone charcoal to the cow dung and wheat straw composting system in different proportions (0%, 5%, 10%) has an impact on multiple indicators. A comprehensive comparison shows that the product quality obtained after adding 10% cow bone charcoal is better. Adding 10% cow bone charcoal to the composting system increases the temperature and microbial activity of the pile, allowing the pile to reach a high temperature state faster and maintain it for a longer time, while reducing the pH and conductivity of the pile, reducing the release of ammonia, promoting the production of nitrate nitrogen, and increasing the content of total calcium and total phosphorus. After the composting was completed, the conductivity of the CK treatment group and the CBC10% treatment group was 3.47mS / cm and 3.03mS / cm, respectively, and the CBC10% treatment group was 12.68% lower than the CK treatment group. With the help of the good adsorption performance of cow bone charcoal for ammonia, the cumulative emission of NH3 in the treatment with the addition of cow bone charcoal was significantly lower than that in the CK treatment group, and the CBC10% effect was the most significant, reducing it by 89.45% compared with the CK treatment group. The final nitrate nitrogen content of the CK treatment group and the CBC10% treatment group were 13.35mg / kg and 2064.83mg / kg respectively. Compared with the CK treatment group, the nitrate nitrogen content of the CBC10% treatment group increased by 2051.48mg / kg. The total calcium and total phosphorus of the final compost product improved by adding cattle bone charcoal were significantly increased compared with the CK treatment group, and the CBC10% treatment group increased by 392.78% and 353.79% compared with the CK treatment group.

[0078] Although the specific implementation of the present invention is described in detail in conjunction with the embodiments, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A high-phosphorus organic fertilizer based on bone char, characterized in that: The raw materials include base material and bone char. The base material includes the following components in parts by weight: 4-6 parts of cow dung and 0.5-1.5 parts of straw. The bone char is 10% of the total weight of the cow dung and the straw.

2. The high-phosphorus organic fertilizer based on bone char according to claim 1, characterized in that The base material comprises the following components in parts by mass: 5 parts of cow dung and 1 part of straw.

3. The high-phosphorus organic fertilizer based on bone char according to claim 1 or 2, characterized in that: The length of the straw is 2 to 5 cm.

4. The high-phosphorus organic fertilizer based on bone char according to claim 1, characterized in that: The bone charcoal is cattle bone charcoal, which is obtained by sintering cattle bones at 600° C. for 6 to 8 hours, and the particle size thereof does not exceed 2 mm.

5. The method for preparing high-phosphorus organic fertilizer based on bone char according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) mixing the cow dung and straw; (2) adding the bone char and mixing, and adjusting the moisture content to 50-70%; (3) Composting was continued in a closed device for 42 days, with aeration treatment performed several times a day at an aeration rate of 0.8 to 1 L / min / kg dry matter and each aeration time of 3 to 8 min.

6. The method for preparing high-phosphorus organic fertilizer based on bone char according to claim 5, characterized in that: The water content is 60%.

7. The method for preparing high-phosphorus organic fertilizer based on bone char according to claim 5, characterized in that: The aeration rate is 0.88 L / min / kg dry matter.

8. The method for preparing high-phosphorus organic fertilizer based on bone char according to claim 7, characterized in that: The specific method of aeration treatment is: aeration once every two hours for 8 hours a day, and once every hour for the remaining 16 hours, and each aeration time is 5 minutes.

Images