Controllable-release multi-effect cabbage carbon-based biogas manure and preparation method thereof

Abstract

The invention discloses a controlled-release and multi-effect cabbage carbon-based biogas manure and a preparation method thereof. The cabbage carbon-based biogas manure is prepared from the following components: biomass charcoal, biogas slurry, a coated slow-release coating, a compound chemical fertilizer, indolebutyric acid, naphthylacetic acid, quintozene, thiram and bentonite. The biomass charcoal, the biogas slurry, the composite chemical fertilizer and the bentonite are mixed and granulated to form particles, and the particles are sequentially coated with a coated slow-release coating, an indolebutyric acid and naphthylacetic acid mixing layer, a coated slow-release coating, a quintozene and thiram mixing layer and a coated slow-release coating. According to the present invention, the effects of soil disinfection and sterilization can be achieved, crop rooting can be promoted, the crop survival rate can be improved, cabbage soil-borne diseases can be prevented and treated, the problem of single nutrient and single effect of the traditional carbon-based biogas fertilizer can be avoided, and the multiple effects of the fertilizer can be achieved. Meanwhile, slow-release fertilization is realized by controlling the coating thickness.

Description

Technical Field

[0001] The invention belongs to the technical field of environmentally friendly organic fertilizers, and in particular relates to a controllable-release and multi-effect cabbage charcoal-based biogas fertilizer and a preparation method thereof. Background Art

[0002] As a major agricultural country, my country uses a huge amount of fertilizers in agricultural planting every year to ensure the output of grain crops. At present, the area of ​​acidic soil (pH <6.5) in my country is about 919 million mu, among which the acidification of cultivated land in the main production areas of cash crops and grain in the south and the northeast is particularly prominent. Excessive application of nitrogen fertilizer and unreasonable fertilization structure are important causes of soil acidification. In recent years, my country has vigorously promoted the policy of reducing the amount of chemical fertilizers and increasing their efficiency in order to achieve green and sustainable development of agriculture, build high-standard farmland, and protect food security. Biochar and biogas slurry prepared from agricultural organic waste have become the mainstream of green and sustainable agricultural cultivation. This type of organic fertilizer is rich in a large amount of organic matter, humus and a variety of trace elements and fast-acting nutrients required for crop growth. It can be quickly absorbed by plants, prevent pests and diseases, and increase yields. In addition, due to its overall alkaline characteristics, it is conducive to alleviating soil acidification and compaction. Therefore, this type of organic fertilizer can partially replace chemical fertilizers for crops, achieving green and sustainable weight loss and efficiency.

[0003] Cabbage is favored by agricultural workers all over the country due to its strong adaptability to the growing environment, low planting difficulty, large market demand, good economic benefits, and high nutritional value. There are still the following technical problems in the application of organic fertilizers in the cabbage planting process:

[0004] 1. The main raw materials of pyrolysis carbonized biochar on the market are mainly agricultural and forestry wastes, and the content of nutrients such as nitrogen is limited. When applied alone, it cannot meet the growth needs of crops with high nutrient requirements; biogas slurry is mainly made of livestock and poultry manure or domestic sewage. Irrational application will not only lead to the accumulation of heavy metals, but also pollute groundwater resources, affect crop yield and quality, and ultimately endanger human health through the food chain. In addition, due to the weather conditions for application, when encountering windy and rainy weather, it will lead to the loss of biochar and biogas slurry, affecting the absorption and utilization of nutrients in carbon-based biogas fertilizer by crops.

[0005] 2. Black rot, soft rot, black spot and other diseases of cabbage will reduce the quality of cabbage and even cause the death of plants, ultimately leading to loss of economic value. In order to reduce the economic losses caused by crop diseases and insect pests, it is necessary to spray pesticides and fungicides repeatedly, which not only increases labor time and economic costs, but also increases the risk of environmental pollution. In particular, spraying pesticides and fungicides can only reduce harmful bacteria and pests on the surface of crops and soil, and cannot effectively prevent and control pathogenic bacteria and pests in deeper soil, so it is necessary to spray pesticides and fungicides repeatedly.

[0006] 3. The commonly used fungicides pentachloronitrobenzene and thiram are weakly acidic in nature. Mixing them with alkaline organic fertilizers will lead to the decomposition of pentachloronitrobenzene and thiram, which not only reduces the efficacy but also easily causes pesticide damage. However, pentachloronitrobenzene and thiram are widely used and inexpensive. Replacing them with other fungicides will increase costs. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a controllable release and multi-effect cabbage charcoal-based biogas fertilizer and a preparation method thereof in view of the deficiencies of the above-mentioned prior art.

[0008] A controlled-release and multi-effect cabbage charcoal-based biogas fertilizer is prepared from the following ingredients: biochar, biogas slurry, a coated slow-release coating, a composite fertilizer, indolebutyric acid, naphthylacetic acid, pentachloronitrobenzene, thiram and bentonite, wherein the biochar, biogas slurry, composite fertilizer and bentonite are mixed and granulated to form particles, and the particles are sequentially coated with a coated slow-release coating, a mixed layer of indolebutyric acid and naphthylacetic acid, a coated slow-release coating, a mixed layer of pentachloronitrobenzene and thiram and a coated slow-release coating.

[0009] To optimize the above technical solutions, the specific measures taken also include:

[0010] The components of the cabbage charcoal-based biogas fertilizer are as follows by mass percentage: biochar 40% to 45%, biogas slurry 40% to 45%, coated slow-release coating 1.2% to 2%, compound fertilizer 0.4% to 0.5%, indolebutyric acid 0.02% to 0.03%, naphthylacetic acid 0.02% to 0.03%, pentachloronitrobenzene 0.2% to 0.3%, thiram 0.2% to 0.3%, and bentonite 8% to 10%.

[0011] The compound fertilizer is prepared from potassium chloride, urea and calcium magnesium phosphate in a mass ratio of 2:1:4.

[0012] The film-encapsulated sustained-release coating is composed of polyhydroxyalkanoate and bentonite and is prepared in a mass ratio of 47:1.

[0013] A method for preparing a controlled-release and multi-effect cabbage charcoal-based biogas fertilizer, comprising the following steps:

[0014] (1) Carbonizing pig manure to produce biochar products;

[0015] (2) subjecting the pig farm wastewater to anaerobic fermentation to prepare biogas slurry, and subjecting the biogas slurry to standardized biogas fertilizer treatment to obtain biogas slurry that meets agricultural irrigation water quality standards;

[0016] (3) mixing potassium chloride, urea and calcium magnesium phosphate fertilizer to prepare a composite fertilizer;

[0017] (4) mixing the biochar product obtained in step (1), the biogas slurry that meets the agricultural irrigation water quality standard in step (2), and the composite fertilizer prepared in step (3), fully mixing for 48 hours, and then taking out and drying in the shade at room temperature to obtain an improved biochar-based fertilizer;

[0018] (5) mixing the improved biomass charcoal-based fertilizer and bentonite, and then granulating to obtain improved biomass charcoal-based fertilizer granules;

[0019] (6) coating the granules after granulation in step (5) to provide a sustained-release film layer on the outer surface of the granules;

[0020] (7) spraying a glucose solution on the surface of the particles prepared in step (6), and adding indolebutyric acid and naphthaleneacetic acid to form a rooting powder shell on the surface of the particles, and performing the operation of step (6) again to make the sustained-release coating layer cover the rooting powder shell;

[0021] (8) spraying a glucose solution on the surface of the particles prepared in step (7), and adding pentachloronitrobenzene and thiram to form a fungicide shell on the surface of the particles;

[0022] (9) The particles prepared in step (8) are subjected to the coating treatment of step (6), and finally, the particles are dehydrated and dried to fully solidify the slow-release coating layer, thereby obtaining a controllable-release and multi-effect cabbage charcoal-based biogas fertilizer.

[0023] A method for preparing a controlled-release and multi-effect cabbage charcoal-based biogas fertilizer, comprising the following steps:

[0024] (1) Putting pig manure into a carbonization gas furnace, setting the temperature of the carbonization furnace to 350° C., and making biomass charcoal products;

[0025] (2) collecting the pig farm wastewater into an anaerobic fermentation tank for anaerobic fermentation to prepare biogas slurry, and subjecting the biogas slurry produced in the fermentation tank to standardized biogas fertilizer treatment to obtain biogas slurry that meets the agricultural irrigation water quality standards;

[0026] (3) Mix potassium chloride, urea and calcium magnesium phosphate in a mass ratio of 2:1:4 to prepare a composite fertilizer;

[0027] (4) mixing the biochar product obtained in step (1), the biogas slurry meeting the agricultural irrigation water quality standard in step (2), and the composite fertilizer prepared in step (3) in a mass ratio of 1:1:0.01, mixing for 48 hours, taking out and drying in the shade at room temperature to reduce the water content to 10%-20%, thereby obtaining an improved biochar-based fertilizer;

[0028] (5) mixing the improved biomass charcoal-based fertilizer and bentonite in a mass ratio of 10:1, and then granulating to obtain improved biomass charcoal-based fertilizer particles with a particle size of 2.5 to 3 mm;

[0029] (6) performing a sustained-release coating treatment on the granules after granulation in step (5), so as to form a sustained-release coating layer with an average thickness of 10 to 35 μm on the surface of the granules;

[0030] (7) spraying a 10% glucose solution on the surface of the particles prepared in step (6), and adding indolebutyric acid and naphthylacetic acid mixed in a mass ratio of 1:1 to form a rooting powder shell with a thickness of 5 to 10 μm on the surface of the particles, and performing the operation of step (6) again to make the sustained-release coating layer cover the rooting powder shell;

[0031] (8) spraying a 10% glucose solution on the surface of the particles prepared in step (7), and adding pentachloronitrobenzene and thiram in a mass ratio of 1:1 to form a fungicide shell with a thickness of 10 to 35 μm on the surface of the particles;

[0032] (9) The particles prepared in step (8) are subjected to the coating treatment of step (6), and finally, the particles are dehydrated and dried to fully solidify the slow-release coating layer, thereby obtaining a controllable-release and multi-effect cabbage charcoal-based biogas fertilizer.

[0033] The film-encapsulated sustained-release coating material is prepared from polyhydroxyalkanoate and bentonite in a mass ratio of 47:1.

[0034] The preparation method of the film-encapsulated sustained-release coating is as follows:

[0035] Step 1: Dissolve polyhydroxyalkanoate and bentonite in dichloromethane in sequence, and stir at room temperature to obtain a coating solution.

[0036] Step 2: spray the coating solution in step 1 evenly on the surface of the particles to form a coating sustained-release coating.

[0037] The fluidized bed is used for spray coating and slow-release coating. The operating parameters of the fluidized bed are as follows: the preheating temperature of the fertilizer particles is 45-50°C; the atomization pressure of the nozzle is 0.5-1Mpa.

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

[0039] 1. The biochar, biogas slurry, composite fertilizer and bentonite of the present invention are mixed and granulated to form particles, and the particles are sequentially coated with a coating slow-release coating, a mixed layer of indolebutyric acid and naphthylacetic acid, a coating slow-release coating, a mixed layer of pentachloronitrobenzene and thiram, and a coating slow-release coating. The film material that can be harmlessly decomposed in the soil is used to control the thickness of the coating to achieve a controlled release effect, and alkaline substances (biochar, biogas slurry) and acidic substances (indolebutyric acid, naphthylacetic acid, pentachloronitrobenzene, thiram) appear in a hierarchical structure in one fertilizer, which avoids the singleness of nutrients and functions of traditional carbon-based biogas fertilizers and achieves multiple effects of one fertilizer, and realizes slow-release fertilization by controlling the thickness of the coating and adjusting the release timing.

[0040] 2. The fertilizer of the present invention is based on biochar prepared by high-temperature pyrolysis and biogas slurry after anaerobic fermentation during the preparation process, which can reduce harmful substances such as antibiotics and pathogens carried in agricultural waste water. Biogas slurry can also be loaded by biochar, so that the prepared charcoal-based biogas fertilizer has both the porous structure and adsorption characteristics of biochar, and is rich in a variety of fast-acting nutrients and probiotics required by plants in biogas slurry.

[0041] 3. The biochar used in the present invention has a special porous structure and excellent adsorption properties. When mixed with materials such as biogas slurry and compound fertilizer, it can play a role in slow release of nutrients, and increase the nutrient content of the prepared carbon-based biogas fertilizer, ensuring the nutrient supply capacity required for cabbage growth. At the same time, it can also provide a place for soil microorganisms to gather and reproduce.

[0042] 4. The present invention uses biomass charcoal, biogas slurry and compound fertilizer as the base core to prepare the particles, which can not only reduce the cost of laying pipelines for applying biogas slurry, but also avoid the inconvenience of transporting and storing biogas slurry.

[0043] 5. The present invention adds a certain proportion of indolebutyric acid, naphthylacetic acid, pentachloronitrobenzene and thiram to the charcoal-based biogas fertilizer. The charcoal-based biogas fertilizer prepared in this way can achieve the effect of disinfecting the soil, promoting crop rooting, and improving crop survival rate, and can also prevent and control soil-borne diseases of cabbage, reduce economic losses caused by diseases, and the like.

[0044] 6. The charcoal-based biogas fertilizer of the present invention is suitable for various types of acidic soils (brown soil, brown soil, loess soil, gray-brown soil, irrigated silt soil, etc.). It can effectively improve soil health, regulate soil pH, and prevent soil compaction, and can also achieve the effect of one fertilizer with multiple effects and one fertilizer with multiple uses. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated by examples below. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0046] The present invention provides a carbon-based biogas fertilizer for cabbage and a production method thereof. The biogas slurry is adsorbed to prepare solid fertilizer by utilizing the unique water-retaining and fertilizer-fixing properties of biochar, thereby improving the utilization rate of biogas slurry, facilitating the application of biogas slurry, and reducing the volatilization and leaching of biogas slurry. Indolebutyric acid, naphthylacetic acid, thiram and pentachloronitrobenzene are added to promote the survival rate of cabbage transplanted at the seedling stage, reduce multiple diseases of cabbage at the peak leaf stage and harvest stage, and improve economic benefits. In addition, the slow-release coating technology is utilized to make alkaline substances (biochar and biogas slurry) and fungicides (thiram and pentachloronitrobenzene) coexist in one fertilizer.

[0047] The technical solution adopted to achieve the purpose of the present invention is: the following components are composed by mass percentage: 40% to 45% biochar, 40% to 45% biogas slurry, 1.2% to 2% coated slow-release coating, 0.4% to 0.5% composite fertilizer, 0.02% to 0.03% indolebutyric acid, 0.02% to 0.03% naphthaleneacetic acid, 0.2% to 0.3% pentachloronitrobenzene, 0.2% to 0.3% thiram and 8% to 9% bentonite. The composite fertilizer is potassium chloride, urea and calcium magnesium phosphate, prepared in a mass ratio of 2:1:4. The coated slow-release coating is prepared by polyhydroxyalkanoate and bentonite in a mass ratio of 47:1.

[0048] The method for preparing cabbage charcoal-based biogas fertilizer of the present invention is characterized by the following steps:

[0049] (1) Putting pig manure into a carbonization gas furnace, setting the temperature of the carbonization furnace to 350° C., and making biomass charcoal products;

[0050] (2) collecting the pig farm wastewater into an anaerobic fermentation tank for anaerobic fermentation to prepare biogas slurry, and subjecting the biogas slurry produced in the fermentation tank to standardized biogas fertilizer treatment to obtain biogas slurry that meets the agricultural irrigation water quality standards;

[0051] (3) Mix potassium chloride, urea and calcium magnesium phosphate in a mass ratio of 2:1:4 to prepare a composite fertilizer;

[0052] (4) mixing the biochar product obtained in step (1), the biogas slurry meeting the agricultural irrigation water quality standard in step (2), and the composite fertilizer prepared in step (3) in a mass ratio of 1:1:0.01, fully mixing for 48 hours, taking out and drying in the shade at room temperature to reduce the water content to 10%-20%, thereby obtaining an improved biochar-based fertilizer;

[0053] (5) mixing the improved biomass charcoal-based fertilizer and bentonite in a mass ratio of 10:1, and then granulating to obtain improved biomass charcoal-based fertilizer particles with a particle size of 2.5 to 3 mm;

[0054] (6) performing a sustained-release coating treatment on the granules after granulation in step (5), so as to form a sustained-release coating layer with an average thickness of 10 to 35 μm on the surface of the granules;

[0055] (7) spraying a 10% glucose solution on the surface of the particles prepared in step (6), and adding indolebutyric acid and naphthylacetic acid mixed in a mass ratio of 1:1 to form a rooting powder shell with a thickness of 5 to 10 μm on the surface of the particles, and performing the operation of step (6) again to make the sustained-release coating layer cover the rooting powder shell;

[0056] (8) spraying a 10% glucose solution on the surface of the particles prepared in step (7), and adding pentachloronitrobenzene and thiram in a mass ratio of 1:1 to form a fungicide shell with a thickness of 10 to 35 μm on the surface of the particles;

[0057] (9) The particles prepared in step (8) are subjected to the coating treatment of step (6), and finally, the particles are dehydrated and dried to fully solidify the slow-release coating layer, thereby obtaining a controllable-release and multi-effect cabbage charcoal-based biogas fertilizer.

[0058] The present invention was implemented in a case process. At room temperature of 24-30°C, cabbage was used as the test object, and a total of 28 groups of planting experiments were carried out, of which 27 groups of test cases were the adjustment of the concentrations of various substances in the new charcoal-based biogas fertilizer, and 1 group of unfertilized planting cases was used as a control. Each group processed 12 cabbage seedlings. After multiple comparative tests, the optimal raw material mass percentage was obtained.

[0059] Case study 1: Applying 12,000 kg / ha of biochar

[0060] Actual effect 1: The changes in soil nutrient content are as follows: total organic carbon in the soil increased by 27%, and there were no significant changes in total nitrogen, total phosphorus, and total potassium. The changes in soil physical properties are as follows: porosity increased by 6%, saturated hydraulic conductivity increased by 7%, and bulk density decreased by 11%. There were no significant changes in the length of the taproot and the number of lateral roots of the cabbage root system. There was no change in the number of plants infected with soft rot, black spot, and anthracnose. The block yield increased by 19%. Compared with the control treatment, the soil carbon nutrient content increased significantly, the soil physical properties were improved, the degree of soil compaction was improved, the root system grew weakly, the taproot length and the number of lateral roots did not change significantly, the incidence of common diseases did not change, and the cabbage quality, growth status, and block yield were all better than the control treatment.

[0061] Case study 2: Applying 12,000 kg / ha of biogas slurry

[0062] Actual effect 2: The changes in soil nutrient content are as follows: total organic carbon increased by 14%, total nitrogen increased by 17%, total phosphorus increased by 4%, and total potassium increased by 5%. The changes in soil physical properties are as follows: porosity increased by 4%, saturated hydraulic conductivity increased by 3%, and bulk density decreased by 3%. There was no significant change in the length of the main root and the number of lateral roots of the cabbage root system. The number of plants with soft rot increased by 5%, the number of plants with black spot increased by 4%, and the number of plants with anthracnose increased by 5%. The block yield increased by 24%. Compared with Case 1, the carbon nutrient content of the soil decreased significantly, the content of total nitrogen, total phosphorus and total potassium increased, the physical properties of the soil decreased, the degree of soil compaction did not improve significantly, the root system grew weakly, the length of the main root and the number of lateral roots did not change significantly, the incidence of common diseases increased slightly, and the overall effect was not as good as Case 1 but better than the control case.

[0063] Implementation case 3: Applying biochar 12000kg / ha + biogas slurry 12000kg / ha + bentonite 3000kg / ha.

[0064] Actual effect 3: The changes in soil nutrient content are as follows: total organic carbon increased by 47%, total nitrogen increased by 34%, total phosphorus increased by 5%, and total potassium increased by 7%. The changes in soil physical properties are as follows: porosity increased by 6%, saturated hydraulic conductivity increased by 6%, and bulk density decreased by 11%. The length of the main root of the cabbage root system increased by 4%, and the number of lateral roots increased by 7%. There was no significant improvement in the symptoms of soft rot, black spot and anthracnose. The block yield increased by 33%. Compared with cases 1 and 2, the soil nutrient content increased significantly, the soil physical properties were improved, the degree of soil compaction decreased, the root growth condition improved, the main root length and the number of lateral roots increased, the incidence of common diseases did not change, the cabbage quality, growth condition, and block yield were significantly improved, and the overall effect was stronger than cases 1 and 2.

[0065] Implementation case 4: Apply biochar 12000kg / ha + biogas slurry 12000kg / ha + compound fertilizer 120kg / ha + bentonite 3000kg / ha.

[0066] Actual effect 4: The changes in soil nutrient content are as follows: total organic carbon increased by 46%, total nitrogen increased by 47%, total phosphorus increased by 20%, and total potassium increased by 33%. The changes in soil physical properties are as follows: porosity increased by 5%, saturated hydraulic conductivity increased by 4%, and bulk density decreased by 9%. The length of the main root of the cabbage root system increased by 8%, and the number of lateral roots increased by 8%. There was no significant improvement in the symptoms of soft rot, black spot and anthracnose. The block yield increased by 54%. Compared with cases 1, 2, and 3, there was no significant change in the content of soil carbon nutrients, the content of total nitrogen, total phosphorus and total potassium increased, and the soil physical properties were stronger than cases 2 and 3, and weaker than case 1. The degree of soil compaction was low, the root growth condition was improved, the main root length and the number of lateral roots increased, the incidence of common diseases did not change, the quality, growth condition, and block yield of cabbage were significantly improved, and the overall effect was stronger than cases 1, 2, and 3.

[0067] Implementation case 5: Applying biochar 12000kg / ha + sludge 12000kg / ha + indolebutyric acid 6kg / ha + naphthaleneacetic acid 6kg / ha + bentonite 3000kg / ha.

[0068] Actual effect 5: The changes in soil nutrient content are as follows: total organic carbon increased by 45%, total nitrogen increased by 34%, and total phosphorus and total potassium remained unchanged. The changes in soil physical properties are as follows: porosity increased by 6%, saturated hydraulic conductivity increased by 6%, and bulk density decreased by 10%. The length of the main root of the cabbage root system increased by 9%, and the number of lateral roots increased by 11%. There was no significant improvement in the symptoms of soft rot, black spot and anthracnose. The block yield increased by 41%. Compared with cases 3 and 4, the soil nutrient content is not as good as case 4, the soil physical properties are stronger than case 4, the degree of soil compaction is reduced, the root growth condition is improved, the main root length and the number of lateral roots increase, the incidence of common diseases has not changed, the cabbage quality has not changed significantly, the growth condition has improved, and the block yield is significantly higher than case 3 but lower than case 4.

[0069] Implementation Case 6: Apply 12000kg / ha of biochar + 12000kg / ha of sludge + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0070] Actual effect 6: The changes in soil nutrient content are as follows: total organic carbon increased by 46%, total nitrogen increased by 30%, and total phosphorus and total potassium did not change. The changes in soil physical properties are as follows: porosity increased by 6%, saturated hydraulic conductivity increased by 6%, and bulk density decreased by 10%. The length of the main root of the cabbage root system increased by 6%, and the number of lateral roots increased by 7%. The number of plants with soft rot decreased by 23%, the number of plants with black spot decreased by 32%, and the number of plants with anthracnose decreased by 29%. The block yield increased by 28%. Compared with cases 3, 4, and 5, the soil nutrient content is not as good as case 4, the soil physical properties have not changed significantly, the degree of soil compaction has not changed, the root growth condition, the main root length and the number of lateral roots are not as good as case 5, but the incidence of common diseases has been significantly reduced, which is the best combination for cabbage disease prevention and control among the four groups. The quality of cabbage has improved, the growth condition has improved, and the block yield effect is similar to cases 3 and 5, but lower than case 4.

[0071] Implementation Case 7: Apply 12000kg / ha of biochar + 12000kg / ha of sludge + 120kg / ha of compound fertilizer + 6kg / ha of indolebutyric acid + 6kg / ha of naphthaleneacetic acid + 3000kg / ha of bentonite.

[0072] Actual effect 7: The changes in soil nutrient content are as follows: total organic carbon increased by 46%, total nitrogen increased by 36%, total phosphorus increased by 22%, and total potassium increased by 29%. The changes in soil physical properties are as follows: porosity increased by 6%, saturated hydraulic conductivity increased by 5%, and bulk density decreased by 10%. The length of the main root of the cabbage root system increased by 11%, and the number of lateral roots increased by 15%. There was no significant improvement in the symptoms of soft rot, black spot and anthracnose. The block yield increased by 35%. Compared with cases 4 and 5, the soil nutrient content is higher than that of case 5, the soil physical properties are better than those of case 4, the degree of soil compaction is reduced, the root growth condition is improved, the main root length and the number of lateral roots increase, the incidence of common diseases has not changed, the cabbage quality, growth condition, and block yield have all been significantly improved, and the overall effect is stronger than that of cases 4 and 5.

[0073] Implementation Case 8: Apply 12,000 kg / ha of biochar + 12,000 kg / ha of sludge + 120 kg / ha of compound fertilizer + 70 kg / ha of pentachloronitrobenzene + 70 kg / ha of thiram + 3,000 kg / ha of bentonite.

[0074] Actual effect 8: The changes in soil nutrient content are as follows: total organic carbon increased by 49%, total nitrogen increased by 47%, total phosphorus increased by 20%, and total potassium increased by 35%. The changes in soil physical properties are as follows: porosity increased by 6%, saturated hydraulic conductivity increased by 6%, and bulk density decreased by 9%. The length of the main root of the cabbage root system increased by 8%, and the number of lateral roots increased by 7%. The number of plants with soft rot decreased by 25%, the number of plants with black spot decreased by 36%, and the number of plants with anthracnose decreased by 30%. The block yield increased by 37%. Compared with cases 4 and 6, the soil nutrient content is better than that of case 6, and there is no significant change in soil physical properties. The degree of soil compaction is low, the root growth condition is improved, the increase in the length of the main root and the number of lateral roots is stronger than that of case 6, the incidence of common diseases is better than that of case 4, the quality, growth condition, and block yield of cabbage are significantly improved, and the overall effect is stronger than that of cases 4 and 6.

[0075] Implementation Case 9: Take 12000kg / ha of biochar + 12000kg / ha of sludge + 120kg / ha of compound fertilizer + 6kg / ha of indolebutyric acid + 6kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0076] Actual effect 9: The changes in soil nutrient content are as follows: total organic carbon increased by 53%, total nitrogen increased by 55%, total phosphorus increased by 22%, and total potassium increased by 36%. The changes in soil physical properties are as follows: porosity increased by 8%, saturated hydraulic conductivity increased by 7%, and bulk density decreased by 9%. The length of the main root of the cabbage root system increased by 13%, and the number of lateral roots increased by 16%. The number of plants with soft rot decreased by 46%, the number of plants with black spot decreased by 54%, and the number of plants with anthracnose decreased by 47%. The block yield increased by 43%. Compared with cases 7 and 8, the soil nutrient content increased significantly, the soil physical properties were improved, the degree of soil compaction decreased, the root growth condition improved, the main root length and the number of lateral roots increased, the incidence of common diseases decreased significantly, the cabbage quality, growth condition, and block yield were significantly improved, and the overall effect was better than cases 7 and 8.

[0077] Implementation Case 10: Take 13000kg / ha of biochar + 13000kg / ha of sludge + 120kg / ha of compound fertilizer + 6kg / ha of indolebutyric acid + 6kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0078] Actual effect 10: The changes in soil nutrient content are as follows: total organic carbon increased by 57%, total nitrogen increased by 59%, total phosphorus increased by 23%, and total potassium increased by 36%. The changes in soil physical properties are as follows: porosity increased by 10%, saturated hydraulic conductivity increased by 9%, and bulk density decreased by 11%. The length of the main root of the cabbage root system increased by 14%, and the number of lateral roots increased by 16%. The number of plants with soft rot decreased by 43%, the number of plants with black spot decreased by 56%, and the number of plants with anthracnose decreased by 43%. Compared with Case 9, the carbon and nitrogen nutrient content increased slightly, the total phosphorus and total potassium content did not increase significantly, the soil physical properties improved slightly, the degree of soil compaction decreased, the root system was weak, the main root length and the number of lateral roots did not change significantly, the incidence of common diseases did not change, and the cabbage quality, growth status, and block yield all increased slightly.

[0079] Implementation Case 11: Take 14000kg / ha of biochar + 14000kg / ha of sludge + 120kg / ha of compound fertilizer + 6kg / ha of indolebutyric acid + 6kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0080] Actual effect 11: The changes in soil nutrient content are as follows: total organic carbon increased by 64%, total nitrogen increased by 65%, total phosphorus increased by 23%, and total potassium increased by 36%. The changes in soil physical properties are as follows: porosity increased by 13%, saturated hydraulic conductivity increased by 10%, and bulk density decreased by 12%. The length of the main root of the cabbage root system increased by 16%, and the number of lateral roots increased by 18%. The number of plants with soft rot decreased by 45%, the number of plants with black spot decreased by 55%, and the number of plants with anthracnose decreased by 48%. Compared with cases 9 and 10, the carbon and nitrogen nutrient content increased slightly, the total phosphorus and total potassium content did not increase significantly, the soil physical properties increased slightly, the degree of soil compaction decreased, the root system was weak, the main root length and the number of lateral roots did not change significantly, the incidence of common diseases did not change significantly, and the cabbage quality, growth status, and block yield all increased slightly.

[0081] Implementation Case 12: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 120kg / ha of compound fertilizer + 6kg / ha of indolebutyric acid + 6kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0082] Actual effect 12: The changes in soil nutrient content are as follows: total organic carbon increased by 71%, total nitrogen increased by 73%, total phosphorus increased by 22%, and total potassium increased by 37%. The changes in soil physical properties are as follows: porosity increased by 14%, saturated hydraulic conductivity increased by 12%, and bulk density decreased by 14%. The length of the main root of the cabbage root system increased by 16%, and the number of lateral roots increased by 18%. The number of plants with soft rot decreased by 47%, the number of plants with black spot decreased by 54%, and the number of plants with anthracnose decreased by 47%. Compared with cases 9, 10, and 11, the carbon and nitrogen nutrient content increased slightly, the total phosphorus and total potassium content did not increase significantly, the soil physical properties improved slightly, the degree of soil compaction decreased, the root system grew well, the main root length and the number of lateral roots did not change significantly, the incidence of common diseases did not change significantly, and the cabbage quality, growth status, and block yield all increased slightly.

[0083] Implementation Case 13: Take 16000kg / ha of biochar + 16000kg / ha of sludge + 120kg / ha of compound fertilizer + 6kg / ha of indolebutyric acid + 6kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0084] Actual effect 13: The changes in soil nutrient content are as follows: total organic carbon increased by 75%, total nitrogen increased by 78%, total phosphorus increased by 23%, and total potassium increased by 37%. The changes in soil physical properties are as follows: porosity increased by 16%, saturated hydraulic conductivity increased by 13%, and bulk density decreased by 16%. The length of the main root of the cabbage root system increased by 15%, and the number of lateral roots increased by 18%. The number of plants with soft rot decreased by 43%, the number of plants with black spot decreased by 51%, and the number of plants with anthracnose decreased by 44%. Compared with cases 9, 10, 11, and 12, the total organic carbon content increased slightly, the total nitrogen, total phosphorus, and total potassium content did not increase significantly, the soil physical properties increased slightly, the degree of soil compaction decreased, the root system grew better, the length of the main root and the number of lateral roots did not change significantly, the incidence of common diseases increased, and the yield of the cabbage block improved slightly. With the addition of biochar and biogas slurry, the growth of cabbage and soil quality improved, but the incidence of plants increased, and the overall effect was not as good as case 12.

[0085] Implementation Case 14: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 130kg / ha of compound fertilizer + 6kg / ha of indolebutyric acid + 6kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0086] Actual effect 14: The changes in soil nutrient content are as follows: total organic carbon increased by 76%, total nitrogen increased by 84%, total phosphorus increased by 37%, and total potassium increased by 45%. The changes in soil physical properties are as follows: porosity increased by 15%, saturated hydraulic conductivity increased by 13%, and bulk density decreased by 16%. The length of the main root of the cabbage root system increased by 16%, and the number of lateral roots increased by 18%. The number of plants with soft rot decreased by 43%, the number of plants with black spot decreased by 55%, and the number of plants with anthracnose decreased by 42%. Compared with cases 12 and 13, the total organic carbon content did not change significantly, the total nitrogen, total phosphorus and total potassium contents increased slightly, the soil physical properties did not change significantly, the degree of soil compaction did not change significantly, the root system grew well, the main root length and the number of lateral roots did not change significantly, the prevention of common diseases was better than case 13, the increase in overall nutrients was better than case 12, and the cabbage quality, growth status, and block yield were slightly improved.

[0087] Implementation Case 15: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 6kg / ha of indolebutyric acid + 6kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0088] Actual effect 15: The changes in soil nutrient content are as follows: total organic carbon increased by 76%, total nitrogen increased by 92%, total phosphorus increased by 41%, and total potassium increased by 49%. The changes in soil physical properties are as follows: porosity increased by 15%, saturated hydraulic conductivity increased by 13%, and bulk density decreased by 15%. The length of the main root of the cabbage root system increased by 16%, and the number of lateral roots increased by 18%. The number of plants with soft rot decreased by 46%, the number of plants with black spot decreased by 59%, and the number of plants with anthracnose decreased by 48%. Compared with case 14, the total organic carbon content did not change significantly, the total nitrogen, total phosphorus and total potassium contents increased slightly, the soil physical properties did not change significantly, the degree of soil compaction did not change, the root system grew well, the main root length and the number of lateral roots did not change significantly, and the incidence of common diseases did not change significantly. The growth status, block yield and quality of cabbage are better than those of case 14.

[0089] Implementation Case 16: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 165kg / ha of compound fertilizer + 6kg / ha of indolebutyric acid + 6kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0090] Actual effect 16: The changes in soil nutrient content are as follows: total organic carbon increased by 77%, total nitrogen increased by 98%, total phosphorus increased by 47%, and total potassium increased by 55%. The changes in soil physical properties are as follows: porosity increased by 9%, saturated hydraulic conductivity increased by 12%, and bulk density decreased by 11%. The length of the main root of the cabbage root system increased by 14%, and the number of lateral roots increased by 17%. The number of plants with soft rot decreased by 47%, the number of plants with black spot decreased by 58%, and the number of plants with anthracnose decreased by 48%. Compared with case 15, the total organic carbon content did not change significantly, the total nitrogen, total phosphorus and total potassium contents increased slightly, the soil physical properties decreased, the soil compaction intensified, the root system grew strongly, the main root length and the number of lateral roots did not change significantly, the incidence of common diseases was similar to that of case 15, and the soil physical properties, cabbage growth conditions and quality were not as good as those of case 15.

[0091] Implementation Case 17: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 7kg / ha of indolebutyric acid + 7kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0092] Actual effect 17: The changes in soil nutrient content are as follows: total organic carbon increased by 74%, total nitrogen increased by 90%, total phosphorus increased by 44%, and total potassium increased by 51%. The changes in soil physical properties are as follows: porosity increased by 15%, saturated hydraulic conductivity increased by 14%, and bulk density decreased by 16%. The length of the main root of the cabbage root system increased by 19%, and the number of lateral roots increased by 22%. The number of plants with soft rot decreased by 49%, the number of plants with black spot decreased by 55%, and the number of plants with anthracnose decreased by 46%. Compared with case 15, there was no significant change in the nutrient content of total organic carbon, total nitrogen, total phosphorus, and total potassium, no significant change in soil physical properties, no change in the degree of soil compaction, good root growth, a small increase in the length of the main root and the number of lateral roots, and no significant change in the incidence of common diseases. The growth condition and quality of cabbage are better than case 15.

[0093] Implementation Case 18: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 8kg / ha of indolebutyric acid + 8kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0094] Actual effect 18: The changes in soil nutrient content are as follows: total organic carbon increased by 75%, total nitrogen increased by 93%, total phosphorus increased by 45%, and total potassium increased by 50%. The changes in soil physical properties are as follows: porosity increased by 16%, saturated hydraulic conductivity increased by 14%, and bulk density decreased by 16%. The length of the main root of the cabbage root system increased by 22%, and the number of lateral roots increased by 25%. The number of plants with soft rot decreased by 48%, the number of plants with black spot decreased by 57%, and the number of plants with anthracnose decreased by 47%. Compared with case 17, there was no significant change in the nutrient content of total organic carbon, total nitrogen, total phosphorus, and total potassium, no significant change in soil physical properties, no change in the degree of soil compaction, good root growth, a small increase in the length of the main root and the number of lateral roots, and no significant change in the incidence of common diseases. The quality, growth status, and block yield of cabbage have all increased slightly, and the overall effect is better than case 17.

[0095] Implementation Case 19: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 9kg / ha of indolebutyric acid + 9kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0096] Actual effect 19: The changes in soil nutrient content are as follows: total organic carbon increased by 81%, total nitrogen increased by 93%, total phosphorus increased by 48%, and total potassium increased by 55%. The changes in soil physical properties are as follows: porosity increased by 17%, saturated hydraulic conductivity increased by 18%, and bulk density decreased by 19%. The length of the main root of the cabbage root system increased by 34%, and the number of lateral roots increased by 39%. The number of plants with soft rot decreased by 51%, the number of plants with black spot decreased by 59%, and the number of plants with anthracnose decreased by 51%. Compared with case 18, there was no significant change in the nutrient content of total organic carbon, total nitrogen, total phosphorus, and total potassium, no significant change in soil physical properties, and no change in the degree of soil compaction. The root system grew well, the length of the main root and the number of lateral roots increased significantly, and the incidence of common diseases did not change significantly. The quality, growth status, and block yield of cabbage were slightly improved, and the overall effect was better than case 18.

[0097] Implementation Case 20: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 10kg / ha of indolebutyric acid + 10kg / ha of naphthylacetic acid + 70kg / ha of pentachloronitrobenzene + 70kg / ha of thiram + 3000kg / ha of bentonite.

[0098] Actual effect 20: The changes in soil nutrient content are as follows: total organic carbon increased by 77%, total nitrogen increased by 94%, total phosphorus increased by 46%, and total potassium increased by 53%. The changes in soil physical properties are as follows: porosity increased by 15%, saturated hydraulic conductivity increased by 14%, and bulk density decreased by 16%. The length of the main root of the cabbage root system increased by 27%, and the number of lateral roots increased by 29%. The number of plants with soft rot decreased by 50%, the number of plants with black spot decreased by 56%, and the number of plants with anthracnose decreased by 55%. Compared with case 19, there was no significant change in the nutrient content of total organic carbon, total nitrogen, total phosphorus, and total potassium, no significant change in soil physical properties, no change in soil compaction, good root growth, no significant change in main root length, a small increase in the number of lateral roots, and no significant change in the incidence of common diseases. The growth status and quality of cabbage are not as good as case 19. The cabbage root system has more nutrients for growth, and the nutrients of the upstream leaves are reduced, resulting in slow growth of cabbage plants.

[0099] Implementation Case 21: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 9kg / ha of indolebutyric acid + 9kg / ha of naphthylacetic acid + 80kg / ha of pentachloronitrobenzene + 80kg / ha of thiram + 3000kg / ha of bentonite.

[0100] Actual effect 21: The changes in soil nutrient content are as follows: total organic carbon increased by 78%, total nitrogen increased by 92%, total phosphorus increased by 43%, and total potassium increased by 55%. The changes in soil physical properties are as follows: porosity increased by 16%, saturated hydraulic conductivity increased by 12%, and bulk density decreased by 15%. The length of the main root of the cabbage root system increased by 21%, and the number of lateral roots increased by 24%. The number of plants with soft rot decreased by 56%, the number of plants with black spot decreased by 63%, and the number of plants with anthracnose decreased by 59%. Compared with case 19, there was no significant change in the nutrient content of total organic carbon, total nitrogen, total phosphorus, and total potassium, no significant change in soil physical properties, no change in the degree of soil compaction, good root growth, no significant change in the length of the main root and the number of lateral roots, and a significant reduction in the incidence of common diseases. The quality, growth status, and block yield of cabbage have all increased slightly, and the overall effect is better than case 19.

[0101] Implementation Case 22: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 9kg / ha of indolebutyric acid + 9kg / ha of naphthylacetic acid + 90kg / ha of pentachloronitrobenzene + 90kg / ha of thiram + 3000kg / ha of bentonite.

[0102] Actual effect 22: The changes in soil nutrient content are as follows: total organic carbon increased by 79%, total nitrogen increased by 90%, total phosphorus increased by 45%, and total potassium increased by 54%. The changes in soil physical properties are as follows: porosity increased by 16%, saturated hydraulic conductivity increased by 14%, and bulk density decreased by 16%. The length of the main root of the cabbage root system increased by 22%, and the number of lateral roots increased by 24%. The number of plants with soft rot decreased by 62%, the number of plants with black spot decreased by 67%, and the number of plants with anthracnose decreased by 64%. Compared with Case 21, there was no significant change in the nutrient content of total organic carbon, total nitrogen, total phosphorus, and total potassium, no significant change in soil physical properties, no change in the degree of soil compaction, good root growth, no significant change in the length of the main root and the number of lateral roots, and a significant reduction in the incidence of common diseases. The quality, growth status, and block yield of cabbage have all increased slightly, and the overall effect is better than Case 21.

[0103] Implementation Case 23: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 9kg / ha of indolebutyric acid + 9kg / ha of naphthylacetic acid + 100kg / ha of pentachloronitrobenzene + 100kg / ha of thiram + 3000kg / ha of bentonite.

[0104] Actual effect 23: The changes in soil nutrient content are as follows: total organic carbon increased by 73%, total nitrogen increased by 87%, total phosphorus increased by 42%, and total potassium increased by 47%. The changes in soil physical properties are as follows: porosity increased by 15%, saturated hydraulic conductivity increased by 15%, and bulk density decreased by 16%. The length of the main root of the cabbage root system increased by 21%, and the number of lateral roots increased by 19%. The number of plants with soft rot decreased by 60%, the number of plants with black spot decreased by 63%, and the number of plants with anthracnose decreased by 66%. Compared with case 22, the nutrient content of total organic carbon, total nitrogen, total phosphorus, and total potassium decreased significantly, the physical properties of the soil did not change significantly, the degree of soil compaction did not change, the root system grew weakly, the length of the main root and the number of lateral roots decreased significantly, the incidence of common diseases did not change significantly, and the overall effect was not as good as case 22.

[0105] Implementation Case 24: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 9kg / ha of indolebutyric acid + 9kg / ha of naphthylacetic acid + 90kg / ha of pentachloronitrobenzene + 90kg / ha of thiram + 3000kg / ha of bentonite + slow-release coating technology, and the layered structure granulation coating thickness is 10μm.

[0106] Actual effect 24: The changes in soil nutrient content are as follows: total organic carbon increased by 82%, total nitrogen increased by 92%, total phosphorus increased by 46%, and total potassium increased by 55%. The changes in soil physical properties are as follows: porosity increased by 13%, saturated hydraulic conductivity increased by 14%, and bulk density decreased by 16%. The length of the main root of the cabbage root system increased by 57%, and the number of lateral roots increased by 41%. The number of plants with soft rot decreased by 94%, the number of plants with black spot decreased by 96%, and the number of plants with anthracnose decreased by 97%. Compared with Case 22, the yield increased by 7%, the total organic carbon, total nitrogen, total phosphorus, and total potassium nutrient content did not change significantly, the soil physical properties did not change significantly, the degree of soil compaction did not change, the root system grew well, the main root length and the number of lateral roots increased significantly, and the incidence of common diseases decreased significantly. The new cabbage charcoal-based biogas fertilizer released each layer of material every 8 days.

[0107] Implementation Case 25: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 9kg / ha of indolebutyric acid + 9kg / ha of naphthylacetic acid + 90kg / ha of pentachloronitrobenzene + 90kg / ha of thiram + 3000kg / ha of bentonite + slow-release coating technology, and the layered structure granulation coating thickness is 20μm.

[0108] Actual effect 25: The changes in soil nutrient content are as follows: total organic carbon increased by 83%, total nitrogen increased by 93%, total phosphorus increased by 48%, and total potassium increased by 58%. The changes in soil physical properties are as follows: porosity increased by 14%, saturated hydraulic conductivity increased by 15%, and bulk density decreased by 17%. The length of the main root of the cabbage root system increased by 59%, and the number of lateral roots increased by 44%. The number of plants with soft rot decreased by 95%, the number of plants with black spot decreased by 97%, and the number of plants with anthracnose decreased by 96%. Compared with Case 24, the yield increased by 15%, the total organic carbon, total nitrogen, total phosphorus, and total potassium nutrient content did not change significantly, the soil physical properties did not change significantly, the degree of soil compaction did not change, the root system grew well, the main root length and the number of lateral roots increased slightly, and the incidence of common diseases did not decrease significantly. The new cabbage charcoal-based biogas fertilizer released each layer of material every 13 days.

[0109] Implementation Case 26: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 9kg / ha of indolebutyric acid + 9kg / ha of naphthylacetic acid + 90kg / ha of pentachloronitrobenzene + 90kg / ha of thiram + 3000kg / ha of bentonite + slow-release coating technology, and the layered structure granulation coating thickness is 30μm.

[0110] Actual effect 26: The changes in soil nutrient content are as follows: total organic carbon increased by 80%, total nitrogen increased by 90%, total phosphorus increased by 47%, and total potassium increased by 58%. The changes in soil physical properties are as follows: porosity increased by 16%, saturated hydraulic conductivity increased by 18%, and bulk density decreased by 19%. The length of the main root of the cabbage root system increased by 62%, and the number of lateral roots increased by 45%. The number of plants with soft rot decreased by 94%, the number of plants with black spot decreased by 96%, and the number of plants with anthracnose decreased by 97%. Compared with Case 25, the yield decreased by 4%, and there was no significant change in the nutrient content of total organic carbon, total nitrogen, total phosphorus, and total potassium. There was no significant change in soil physical properties, the degree of soil compaction did not change, and there was no significant change in root growth and the incidence of common diseases. The new cabbage charcoal-based biogas fertilizer released each layer of material every 32 days.

[0111] Implementation Case 27: Take 15000kg / ha of biochar + 15000kg / ha of sludge + 145kg / ha of compound fertilizer + 9kg / ha of indolebutyric acid + 9kg / ha of naphthylacetic acid + 90kg / ha of pentachloronitrobenzene + 90kg / ha of thiram + 3000kg / ha of bentonite + slow-release coating technology, and the layered structure granulation coating thickness is 40μm.

[0112] Actual effect 27: The changes in soil nutrient content are as follows: total organic carbon increased by 82%, total nitrogen increased by 92%, total phosphorus increased by 47%, and total potassium increased by 56%. The changes in soil physical properties are as follows: porosity increased by 15%, saturated water conductivity increased by 16%, and bulk density decreased by 17%. The length of the main root of the cabbage root system increased by 59%, and the number of lateral roots increased by 42%. The number of plants with soft rot decreased by 95%, the number of plants with black spot decreased by 96%, and the number of plants with anthracnose decreased by 96%. Compared with Case 26, the yield decreased by 5%, and there was no significant change in the nutrient content of total organic carbon, total nitrogen, total phosphorus, and total potassium. There was no significant change in soil physical properties, the degree of soil compaction did not change, and there was no significant change in root growth and the incidence of common diseases. The new cabbage charcoal-based biogas fertilizer released each layer of material every 78 days.

[0113] Control case: Planting without fertilizer

[0114] Actual effect: The soil has low content of total organic carbon, total nitrogen, total phosphorus and total potassium, poor soil quality, high degree of soil compaction, fragile root growth, short taproot, sparse and small lateral roots, easy lodging of plants, and the incidence of common diseases is over 70%. Cabbage grows slowly, has poor quality and low yield.

[0115] The above experimental results show that: since the growth cycle of cabbage is 3 to 4 months, a new type of cabbage charcoal-based biogas fertilizer with different release cycles is prepared according to different needs. The above implementation case 25 is the best ratio of the new cabbage charcoal-based biogas fertilizer. 15,000 kg of biochar, 15,000 kg of biogas slurry, 145 kg of compound fertilizer, 9 kg of indolebutyric acid, 9 kg of naphthaleneacetic acid, 90 kg of pentachloronitrobenzene, 90 kg of thiram and 3,000 kg of bentonite, with a coating thickness of 20 μm, can better meet the growth cycle and nutrient requirements of cabbage.

[0116] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solution described in the implementation of the calculation method of the present invention. Ordinary technicians in the field should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effect; as long as the requirements of the calculation method are met, they are all within the protection scope of the present invention.

Claims

1. A controlled-release and multi-effect cabbage charcoal-based biogas fertilizer, characterized by: The invention is prepared from the following ingredients: biochar, biogas slurry, coated slow-release coating, compound fertilizer, indolebutyric acid, naphthylacetic acid, pentachloronitrobenzene, thiram and bentonite, wherein the biochar, biogas slurry, compound fertilizer and bentonite are mixed and granulated to form particles, and the particles are sequentially coated with a coated slow-release coating, a mixed layer of indolebutyric acid and naphthylacetic acid, a coated slow-release coating, a mixed layer of pentachloronitrobenzene and thiram and a coated slow-release coating.

2. The controlled-release and multi-effect cabbage charcoal-based biogas fertilizer according to claim 1 is characterized in that: The components of the cabbage charcoal-based biogas fertilizer are as follows by mass percentage: biochar 40% to 45%, biogas slurry 40% to 45%, coated slow-release coating 1.2% to 2%, compound fertilizer 0.4% to 0.5%, indolebutyric acid 0.02% to 0.03%, naphthylacetic acid 0.02% to 0.03%, pentachloronitrobenzene 0.2% to 0.3%, thiram 0.2% to 0.3%, and bentonite 8% to 10%.

3. The controlled-release and multi-effect cabbage charcoal-based biogas fertilizer according to claim 2 is characterized in that: The composite fertilizer is prepared from potassium chloride, urea and calcium magnesium phosphate fertilizer in a mass ratio of 2:1:

4.

4. The controlled-release and multi-effect cabbage charcoal-based biogas fertilizer according to claim 2 is characterized in that: The film-encapsulated sustained-release coating is composed of polyhydroxyalkanoate and bentonite and is prepared according to a mass ratio of 47:

1.

5. A method for preparing a controlled-release and multi-effect cabbage charcoal-based biogas fertilizer, characterized in that: The steps are as follows: (1) Carbonizing pig manure to produce biochar products; (2) subjecting the pig farm wastewater to anaerobic fermentation to prepare biogas slurry, and subjecting the biogas slurry to standardized biogas fertilizer treatment to obtain biogas slurry that meets agricultural irrigation water quality standards; (3) mixing potassium chloride, urea and calcium magnesium phosphate fertilizer to prepare a composite fertilizer; (4) mixing the biochar product obtained in step (1), the biogas slurry that meets the agricultural irrigation water quality standard in step (2), and the composite fertilizer prepared in step (3), fully mixing for 48 hours, and then taking out and drying in the shade at room temperature to obtain an improved biochar-based fertilizer; (5) mixing the improved biomass charcoal-based fertilizer and bentonite, and then granulating to obtain improved biomass charcoal-based fertilizer granules; (6) coating the granules after granulation in step (5) to provide a sustained-release film layer on the outer surface of the granules; (7) spraying a glucose solution on the surface of the particles prepared in step (6), and adding indolebutyric acid and naphthaleneacetic acid to form a rooting powder shell on the surface of the particles, and performing the operation of step (6) again to make the sustained-release coating layer cover the rooting powder shell; (8) spraying a glucose solution on the surface of the particles prepared in step (7), and adding pentachloronitrobenzene and thiram to form a fungicide shell on the surface of the particles; (9) The particles prepared in step (8) are subjected to the coating treatment of step (6), and finally, the particles are dehydrated and dried to fully solidify the slow-release coating layer, thereby obtaining a controllable-release and multi-effect cabbage charcoal-based biogas fertilizer.

6. A method for preparing a controlled-release and multi-effect cabbage charcoal-based biogas fertilizer, characterized by: The steps are as follows: (1) Putting pig manure into a carbonization gas furnace, setting the temperature of the carbonization furnace to 350° C., and making biomass charcoal products; (2) collecting the pig farm wastewater into an anaerobic fermentation tank for anaerobic fermentation to prepare biogas slurry, and subjecting the biogas slurry produced in the fermentation tank to standardized biogas fertilizer treatment to obtain biogas slurry that meets the agricultural irrigation water quality standards; (3) Mix potassium chloride, urea and calcium magnesium phosphate in a mass ratio of 2:1:4 to prepare a composite fertilizer; (4) mixing the biochar product obtained in step (1), the biogas slurry meeting the agricultural irrigation water quality standard in step (2), and the composite fertilizer prepared in step (3) in a mass ratio of 1:1:0.01, mixing for 48 hours, taking out and drying in the shade at room temperature to reduce the water content to 10%-20%, thereby obtaining an improved biochar-based fertilizer; (5) mixing the improved biomass charcoal-based fertilizer and bentonite in a mass ratio of 10:1, and then granulating to obtain improved biomass charcoal-based fertilizer particles with a particle size of 2.5 to 3 mm; (6) performing a sustained-release coating treatment on the granules after granulation in step (5), so as to form a sustained-release coating layer with an average thickness of 10 to 35 μm on the surface of the granules; (7) spraying a 10% glucose solution on the surface of the particles prepared in step (6), and adding indolebutyric acid and naphthylacetic acid mixed in a mass ratio of 1:1 to form a rooting powder shell with a thickness of 5 to 10 μm on the surface of the particles, and performing the operation of step (6) again to make the sustained-release coating layer cover the rooting powder shell; (8) spraying a 10% glucose solution on the surface of the particles prepared in step (7), and adding pentachloronitrobenzene and thiram in a mass ratio of 1:1 to form a fungicide shell with a thickness of 10 to 35 μm on the surface of the particles; (9) The particles prepared in step (8) are subjected to the coating treatment of step (6), and finally, the particles are dehydrated and dried to fully solidify the slow-release coating layer, thereby obtaining a controllable-release and multi-effect cabbage charcoal-based biogas fertilizer.

7. The method for preparing a controlled-release and multi-effect cabbage charcoal-based biogas fertilizer according to claim 5, characterized in that: The film-encapsulated sustained-release coating material is prepared from polyhydroxyalkanoate and bentonite in a mass ratio of 47:

1.

8. The method for preparing a controlled-release and multi-effect cabbage charcoal-based biogas fertilizer according to claim 5, characterized in that: The method for preparing the film-encapsulated sustained-release coating solution is as follows: Step 1: dissolving polyhydroxyalkanoate and bentonite in dichloromethane in sequence, and stirring at room temperature to obtain a coating solution. Step 2: spray the coating solution in step 1 evenly on the surface of the particles to form a coating sustained-release coating.

9. The method for preparing a controlled-release and multi-effect cabbage charcoal-based biogas fertilizer according to claim 7, characterized in that: The fluidized bed is used for spray coating and slow-release coating. The operating parameters of the fluidized bed are as follows: the preheating temperature of the fertilizer particles is 45-50°C; the atomization pressure of the nozzle is 0.5-1Mpa.