Special ardealite organic fertilizer for saline-alkali soil and preparation method thereof

Abstract

The invention relates to the technical field of preparation of organic fertilizers, and particularly discloses a special ardealite organic fertilizer for saline-alkali soil and a preparation method of the special ardealite organic fertilizer. 30-35 parts of cow dung; 15 to 20 parts of straw powder; the preparation method comprises the following steps: step 1, preparing a porous material, mixing and foaming phosphogypsum and a foaming agent according to a ratio of 100: (1.5-3) at the foaming temperature of 60-80 DEG C for 48 hours; 2, cellulose decomposition bacteria are added, and pretreatment is conducted in the environment with the temperature being 40 DEG C; according to the ardealite organic fertilizer special for the saline-alkali soil and the preparation method of the ardealite organic fertilizer, industrial and agricultural wastes are turned into wealth, the problems of ardealite stockpiling pollution and insufficient straw recycling are solved, the ardealite organic fertilizer conforms to the circular economy concept, and the pore structure of the ardealite-based porous material can improve hardening of the saline-alkali soil and enhance ventilation and water permeability.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of organic fertilizer preparation, in particular to a phosphogypsum organic fertilizer special for saline-alkali soil and a preparation method thereof. BACKGROUND

[0002] The saline-alkali soil is widely distributed, and the area of the saline-alkali soil in China is huge. The characteristics of high salt, high alkali and unbalanced nutrients seriously restrict agricultural production. In the improvement of the saline-alkali soil, the traditional organic fertilizer has poor water and fertilizer retention capacity and is difficult to meet the improvement demand.

[0003] The phosphogypsum is a large industrial by-product in the phosphorus chemical industry. Large-scale stacking not only occupies land, but also pollutes the soil, underground water and atmosphere with harmful substances, causing serious environmental problems. Meanwhile, the traditional treatment method of agricultural waste straw such as burning not only causes resource waste, but also causes air pollution. In addition, the resource utilization rate of the straw is low, and the straw cannot be effectively converted into available resources.

[0004] For example, a saline-alkali soil long-acting improvement fertilizer and a preparation method thereof disclosed in CN106146159A also uses the phosphogypsum and EDTA to improve the saline-alkali soil, reduce the salt content and neutralize the alkalinity. The physicochemical properties of the soil are improved through the chemical reaction of the phosphogypsum and EDTA with the related components in the soil. Then, the livestock and poultry fermented organic fertilizer is applied to supplement the organic matter and nutrient components. However, the water and fertilizer retention capacity and the fertilizer effectiveness are not outstanding.

[0005] Therefore, it is of great significance to develop the saline-alkali soil special organic fertilizer which can solve the defects of the traditional organic fertilizer and realize the resource utilization of the phosphogypsum and the straw for the improvement of the saline-alkali soil and the sustainable development of agriculture. SUMMARY

[0006] To achieve the above object, the application is implemented by the following technical scheme: a saline-alkali soil special phosphogypsum organic fertilizer is composed of the following raw materials in parts by weight:

[0007] Phosphogypsum-based porous material: 40-50 parts;

[0008] Cow dung: 30-35 parts;

[0009] Straw powder: 15-20 parts;

[0010] Compound microbial agent: 0.5-1 part.

[0011] Preferably, the following steps are included:

[0012] Step one: preparing the porous material, mixing and foaming the phosphogypsum and the foaming agent according to the ratio of 100:1.5-3, the foaming temperature is 60-80 DEG C, the curing time is 48h, and the phosphogypsum-based porous material is obtained;

[0013] Step two: put the foamed phosphogypsum-based porous material into a crushing device to obtain granular phosphogypsum-based porous material;

[0014] Step three: straw pretreatment, the straw material is treated by steam explosion combined with cellulase hydrolysis process, the explosion pressure is 2.5 MPa, and the explosion is maintained for 90 seconds, and then the cellulase hydrolysis is carried out under normal pressure at 50 DEG C by adding 10 U / g of cellulase for 4 hours to obtain straw powder;

[0015] Step four: mixing the phosphogypsum-based porous material, cow dung, straw powder and composite microbial agent;

[0016] Step five: mixing bacillus subtilis and trichoderma to obtain a composite microbial agent, and inoculating the composite microbial agent into the mixture obtained in step four;

[0017] Step six: adding cellulose-decomposing bacteria, and carrying out pretreatment at a temperature of 40 DEG C for 7 days;

[0018] Step seven: adding high-temperature actinomycetes, and carrying out main fermentation at a temperature of 55 DEG C for 15 days;

[0019] Step eight: adding nitrogen-fixing bacteria, and carrying out post-ripening treatment at room temperature for 10 days.

[0020] Preferably, the pore size of the porous material after foaming in step one is controlled to be 0.5-2 mm, and the porosity is ≥65%.

[0021] Preferably, the specific process of fermentation in step three is as follows:

[0022] Before main fermentation, the pretreatment and mixing of the material need to be completed, the material pretreated in step two, including the phosphogypsum-based porous material, cow dung, straw powder and the product treated by cellulose-decomposing bacteria, is fully stirred to uniformly mix the material, at this time, the moisture content of the material is controlled to be 55%, if the moisture content is too high, a proper amount of straw powder can be added to adjust it, and if the moisture content is too low, a small amount of water can be sprayed to reach the standard;

[0023] Then, the high-temperature actinomycetes are uniformly added into the material at a ratio of 0.3 kg per 100 kg of material, and the microbial agent and the material are fully contacted by stirring again, the mixed material is stacked into a trapezoidal fermentation pile with a bottom width of 2 meters, a top width of 1 meter and a height of 1.2 meters, and a gas-permeable pipe with a diameter of 8 centimeters is uniformly inserted into the pile, the lower end of the pipe is 25 centimeters away from the ground, and the upper end of the pipe is 30 centimeters above the pile, so as to ensure the air permeability of the pile;

[0024] The first turning is carried out on the third day of fermentation, and when the turning is carried out, the outer material of the pile is turned to the inside, and the inside material is turned to the outside, and meanwhile, larger material clumps are broken, so that the material is uniformly heated. After that, the turning is carried out once every 3 days, and during the turning process, the moisture content of the material needs to be checked, and the moisture content is kept at 55%;

[0025] On the 7th day and the 12th day of fermentation, the organic matter content and the number of high-temperature actinomycetes of the material are detected respectively, so as to ensure that the degradation rate of the organic matter meets the expectation, and the number of high-temperature actinomycetes is kept at 10 8 -10 9 CFU / g. During the fermentation, if white mycelium appears on the surface of the pile and the material emits a faint fermentation aroma, it indicates that the fermentation is proceeding normally.

[0026] By the 15th day, the main fermentation is completed, at this time, the material is dark brown, loose in texture, and has no obvious odor, and part of the straw powder has been broken into small fibrous form.

[0027] The following beneficial effects are provided:

[0028] The salt-alkali soil special phosphogypsum organic fertilizer and the preparation method thereof, by using the phosphogypsum by-product of the phosphorus chemical industry to prepare the porous material, the agricultural waste straw is pretreated, and then is scientifically proportioned with the cow dung and the compound microbial agent, so that the industrial and agricultural waste is changed into treasure, the problems of the pollution caused by the phosphogypsum storage and the shortage of straw resource are solved, the concept of circular economy is met, the pore structure of the phosphogypsum-based porous material can improve the soil compaction of the salt-alkali soil, and the air permeability and water permeability are enhanced, the compound microbial agent can adjust the soil pH, reduce the salt content, and improve the physical and chemical properties, so that the ecological restoration is promoted, meanwhile, the cow dung, the straw powder and the microorganism are cooperated to balance the fertilizer nutrient, the microorganism decomposes the insoluble nutrient, improves the fertilizer efficiency, and enhances the water and fertilizer retention capacity, so that the defects of the traditional organic fertilizer are made up, the plant nutrient supply is ensured, the crop yield and quality are improved, in addition, the standardized preparation process ensures the stable product quality, the large-scale industrial production and popularization are facilitated, and reliable support is provided for the salt-alkali soil improvement. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application.

[0030] In a first embodiment, the present application provides a technical solution: a salt-alkali soil special phosphogypsum organic fertilizer, which is composed of the following raw materials by weight:

[0031] Phosphogypsum-based porous material: 40 parts;

[0032] Cow dung: 30 parts;

[0033] Straw powder: 15 parts;

[0034] Compound microbial agent: 0.5 parts;

[0035] The preparation steps are as follows:

[0036] Step 1: Mix 100kg of phosphogypsum with 2kg of foaming agent and foam at an ambient temperature of 70℃ to obtain phosphogypsum-based porous material;

[0037] Step 2: Place the foamed phosphogypsum-based porous material into the crushing equipment and crush it into 1mm particles to obtain granular phosphogypsum-based porous material.

[0038] Step 3: Straw pretreatment. The straw material is treated by steam explosion combined with cellulase hydrolysis. The explosion pressure is 2.5MPa, maintained for 90 seconds, and then released to normal pressure. Enzyme hydrolysis conditions: 10U / g cellulase is added at 50℃ and treated for 4 hours to produce straw powder.

[0039] Step 4: Mix the phosphogypsum-based porous material, cow dung, straw powder, and compound microbial agent in a ratio of 45:32:18:0.8;

[0040] Step 5: Mix Bacillus subtilis and Trichoderma in a 3:1 ratio to obtain a compound microbial agent, and then inoculate the mixture obtained in Step 4 with the compound microbial agent;

[0041] Step 6: Add cellulose-decomposing bacteria and perform pretreatment at 40℃ for 7 days;

[0042] Step 7: Add thermophilic actinomycetes and carry out primary fermentation at 55℃ for 15 days;

[0043] Before the primary fermentation, the materials need to be pretreated and mixed. The materials that have undergone the pretreatment in step two, including phosphogypsum-based porous materials, cow dung, straw powder, and products treated by cellulose-decomposing bacteria, should be thoroughly stirred to ensure uniform mixing. At this time, the moisture content of the materials should be controlled at 55%. If the moisture content is too high, an appropriate amount of straw powder can be added to adjust it; if the moisture content is too low, a small amount of water should be sprayed until the standard is met.

[0044] Subsequently, the high-temperature actinomycetes were evenly sprinkled into the material at a ratio of 0.3 kg per 100 kg of material, and stirred again to ensure that the inoculant and the material were in full contact. The mixed material was piled into a trapezoidal fermentation pile with a bottom width of 2 meters, a top width of 1 meter, and a height of 1.2 meters. At the same time, 8 cm diameter ventilation pipes were evenly inserted into the inside of the pile, with the lower end of the pipe 25 cm from the ground and the upper end protruding 30 cm from the pile to ensure the air permeability inside the pile.

[0045] On the third day of fermentation, the pile is turned over for the first time. During turning, the outer layer of material is moved to the inside, and the inner layer is moved to the outside. Larger clumps are broken up to ensure even heating. The pile is then turned over every three days thereafter. During turning, the moisture content and pH value of the material should be checked. The moisture content should be maintained at 55%, and the pH value at 7.0. If the pH value is too high, a small amount of phosphogypsum-based porous material can be added to adjust it; if the pH value is too low, an appropriate amount of wood ash can be added to adjust it.

[0046] On days 7 and 12 of fermentation, samples were taken to test the organic matter content and the number of thermophilic actinomycetes to ensure that the organic matter degradation rate met expectations and the number of thermophilic actinomycetes remained at 10. 8 -10 9 CFU / g. During fermentation, if white mycelium is found on the surface of the pile and the material emits a faint fermentation aroma, it indicates that fermentation is proceeding normally;

[0047] By day 15, the primary fermentation is complete. At this point, the material is dark brown, loose in texture, and has no obvious odor. Some of the straw powder has been broken into fine fibers.

[0048] Step 8: Add nitrogen-fixing bacteria and carry out post-ripening treatment at room temperature for 10 days.

[0049] In a second embodiment, the present invention provides a technical solution: a special phosphogypsum organic fertilizer for saline-alkali land, composed of the following raw materials in parts by weight:

[0050] 50 parts of phosphogypsum-based porous material;

[0051] Cow dung: 35 portions;

[0052] Straw powder: 20 parts;

[0053] Compound microbial agent: 1 part;

[0054] The preparation steps are as follows:

[0055] Step 1: Mix 100kg of phosphogypsum with 2kg of foaming agent and foam at an ambient temperature of 70℃ to obtain phosphogypsum-based porous material;

[0056] Step 2: Place the foamed phosphogypsum-based porous material into the crushing equipment and crush it into 1mm particles to obtain granular phosphogypsum-based porous material.

[0057] Step 3: Straw pretreatment. The straw material is treated by steam explosion combined with cellulase hydrolysis. The explosion pressure is 2.5MPa, maintained for 90 seconds, and then released to normal pressure. Enzyme hydrolysis conditions: 10U / g cellulase is added at 50℃ and treated for 4 hours to produce straw powder.

[0058] Step 4: Mix the phosphogypsum-based porous material, cow dung, straw powder, and compound microbial agent in a ratio of 50:35:20:1;

[0059] Step 5: Mix Bacillus subtilis and Trichoderma in a 3:1 ratio to obtain a compound microbial agent, and then inoculate the mixture obtained in Step 4 with the compound microbial agent;

[0060] Step 6: Add cellulose-decomposing bacteria and perform pretreatment at 40℃ for 7 days;

[0061] Step 7: Add thermophilic actinomycetes and carry out primary fermentation at 55℃ for 15 days;

[0062] Before the primary fermentation, the materials need to be pretreated and mixed. The materials that have undergone the pretreatment in step two, including phosphogypsum-based porous materials, cow dung, straw powder, and products treated by cellulose-decomposing bacteria, should be thoroughly stirred to ensure uniform mixing. At this time, the moisture content of the materials should be controlled at 55%. If the moisture content is too high, an appropriate amount of straw powder can be added to adjust it; if the moisture content is too low, a small amount of water should be sprayed until the standard is met.

[0063] Subsequently, the high-temperature actinomycetes were evenly sprinkled into the material at a ratio of 0.3 kg per 100 kg of material, and stirred again to ensure that the inoculant and the material were in full contact. The mixed material was piled into a trapezoidal fermentation pile with a bottom width of 2 meters, a top width of 1 meter, and a height of 1.2 meters. At the same time, 8 cm diameter ventilation pipes were evenly inserted into the inside of the pile, with the lower end of the pipe 25 cm from the ground and the upper end protruding 30 cm from the pile to ensure the air permeability inside the pile.

[0064] On the third day of fermentation, the pile is turned over for the first time. During turning, the outer layer of material is moved to the inside, and the inner layer is moved to the outside. Larger clumps are broken up to ensure even heating. The pile is then turned over every three days thereafter. During turning, the moisture content and pH value of the material should be checked. The moisture content should be maintained at 55%, and the pH value at 7.0. If the pH value is too high, a small amount of phosphogypsum-based porous material can be added to adjust it; if the pH value is too low, an appropriate amount of wood ash can be added to adjust it.

[0065] On days 7 and 12 of fermentation, samples were taken to test the organic matter content and the number of thermophilic actinomycetes to ensure that the organic matter degradation rate met expectations and the number of thermophilic actinomycetes remained at 10. 8 -10 9 CFU / g. During fermentation, if white mycelium is found on the surface of the pile and the material emits a faint fermentation aroma, it indicates that fermentation is proceeding normally;

[0066] By day 15, the primary fermentation is complete. At this point, the material is dark brown, loose in texture, and has no obvious odor. Some of the straw powder has been broken into fine fibers.

[0067] Step 8: Add nitrogen-fixing bacteria and carry out post-ripening treatment at room temperature for 10 days.

[0068] In the third embodiment, the present invention provides a technical solution: a special phosphogypsum organic fertilizer for saline-alkali land, composed of the following raw materials in parts by weight:

[0069] phosphogypsum-based porous material: 45 parts;

[0070] Cow dung: 32 portions;

[0071] Straw powder: 18 parts;

[0072] Compound microbial agent: 0.8 parts;

[0073] The preparation steps are as follows:

[0074] Step 1: Mix 100kg of phosphogypsum with 2kg of foaming agent and foam at an ambient temperature of 70℃ to obtain phosphogypsum-based porous material;

[0075] Step 2: Place the foamed phosphogypsum-based porous material into the crushing equipment and crush it into 1mm particles to obtain granular phosphogypsum-based porous material.

[0076] Step 3: Straw pretreatment. The straw material is treated by steam explosion combined with cellulase hydrolysis. The explosion pressure is 2.5MPa, maintained for 90 seconds, and then released to normal pressure. Enzyme hydrolysis conditions: 10U / g cellulase is added at 50℃ and treated for 4 hours to produce straw powder.

[0077] Step 4: Mix the phosphogypsum-based porous material, cow dung, straw powder, and compound microbial agent in a ratio of 45:32:18:0.8;

[0078] Step 5: Mix Bacillus subtilis and Trichoderma in a 3:1 ratio to obtain a compound microbial agent, and then inoculate the mixture obtained in Step 4 with the compound microbial agent;

[0079] Step 6: Add cellulose-decomposing bacteria and perform pretreatment at 40℃ for 7 days;

[0080] Step 7: Add thermophilic actinomycetes and carry out primary fermentation at 55℃ for 15 days;

[0081] Before the primary fermentation, the materials need to be pretreated and mixed. The materials that have undergone the pretreatment in step two, including phosphogypsum-based porous materials, cow dung, straw powder, and products treated by cellulose-decomposing bacteria, should be thoroughly stirred to ensure uniform mixing. At this time, the moisture content of the materials should be controlled at 55%. If the moisture content is too high, an appropriate amount of straw powder can be added to adjust it; if the moisture content is too low, a small amount of water should be sprayed until the standard is met.

[0082] Subsequently, the high-temperature actinomycetes were evenly sprinkled into the material at a ratio of 0.3 kg per 100 kg of material, and stirred again to ensure that the inoculant and the material were in full contact. The mixed material was piled into a trapezoidal fermentation pile with a bottom width of 2 meters, a top width of 1 meter, and a height of 1.2 meters. At the same time, 8 cm diameter ventilation pipes were evenly inserted into the inside of the pile, with the lower end of the pipe 25 cm from the ground and the upper end protruding 30 cm from the pile to ensure the air permeability inside the pile.

[0083] On the third day of fermentation, the pile is turned over for the first time. During turning, the outer layer of material is moved to the inside, and the inner layer is moved to the outside. Larger clumps are broken up to ensure even heating. The pile is then turned over every three days thereafter. During turning, the moisture content and pH value of the material should be checked. The moisture content should be maintained at 55%, and the pH value at 7.0. If the pH value is too high, a small amount of phosphogypsum-based porous material can be added to adjust it; if the pH value is too low, an appropriate amount of wood ash can be added to adjust it.

[0084] On days 7 and 12 of fermentation, samples were taken to test the organic matter content and the number of thermophilic actinomycetes to ensure that the organic matter degradation rate met expectations and the number of thermophilic actinomycetes remained at 10. 8 -10 9 CFU / g. During fermentation, if white mycelium is found on the surface of the pile and the material emits a faint fermentation aroma, it indicates that fermentation is proceeding normally;

[0085] By day 15, the primary fermentation is complete. At this point, the material is dark brown, loose in texture, and has no obvious odor. Some of the straw powder has been broken into fine fibers.

[0086] Step 8: Add nitrogen-fixing bacteria and carry out post-ripening treatment at room temperature for 10 days.

[0087] Fourth embodiment: The present invention provides a technical solution: a special phosphogypsum organic fertilizer for saline-alkali land, composed of the following raw materials in parts by weight:

[0088] 43 parts of phosphogypsum-based porous material;

[0089] Cow dung: 31 portions;

[0090] Straw powder: 17 parts;

[0091] Compound microbial agent: 0.6 parts;

[0092] The preparation steps are as follows:

[0093] Step 1: Mix 100kg of phosphogypsum with 2kg of foaming agent and foam at an ambient temperature of 70℃ to obtain phosphogypsum-based porous material;

[0094] Step 2: Place the foamed phosphogypsum-based porous material into the crushing equipment and crush it into 1mm particles to obtain granular phosphogypsum-based porous material.

[0095] Step 3: Straw pretreatment. The straw material is treated by steam explosion combined with cellulase hydrolysis. The explosion pressure is 2.5MPa, maintained for 90 seconds, and then released to normal pressure. Enzyme hydrolysis conditions: 10U / g cellulase is added at 50℃ and treated for 4 hours to produce straw powder.

[0096] Step 4: Mix the phosphogypsum-based porous material, cow dung, straw powder, and compound microbial agent in a ratio of 43:31:17:0.6;

[0097] Step 5: Mix Bacillus subtilis and Trichoderma in a 3:1 ratio to obtain a compound microbial agent, and then inoculate the mixture obtained in Step 4 with the compound microbial agent;

[0098] Step 6: Add cellulose-decomposing bacteria and perform pretreatment at 40℃ for 7 days;

[0099] Step 7: Add thermophilic actinomycetes and carry out primary fermentation at 55℃ for 15 days;

[0100] Before the primary fermentation, the materials need to be pretreated and mixed. The materials that have undergone the pretreatment in step two, including phosphogypsum-based porous materials, cow dung, straw powder, and products treated by cellulose-decomposing bacteria, should be thoroughly stirred to ensure uniform mixing. At this time, the moisture content of the materials should be controlled at 55%. If the moisture content is too high, an appropriate amount of straw powder can be added to adjust it; if the moisture content is too low, a small amount of water should be sprayed until the standard is met.

[0101] Subsequently, the high-temperature actinomycetes were evenly sprinkled into the material at a ratio of 0.3 kg per 100 kg of material, and stirred again to ensure that the inoculant and the material were in full contact. The mixed material was piled into a trapezoidal fermentation pile with a bottom width of 2 meters, a top width of 1 meter, and a height of 1.2 meters. At the same time, 8 cm diameter ventilation pipes were evenly inserted into the inside of the pile, with the lower end of the pipe 25 cm from the ground and the upper end protruding 30 cm from the pile to ensure the air permeability inside the pile.

[0102] On the third day of fermentation, the pile is turned over for the first time. During turning, the outer layer of material is moved to the inside, and the inner layer is moved to the outside. Larger clumps are broken up to ensure even heating. The pile is then turned over every three days thereafter. During turning, the moisture content and pH value of the material should be checked. The moisture content should be maintained at 55%, and the pH value at 7.0. If the pH value is too high, a small amount of phosphogypsum-based porous material can be added to adjust it; if the pH value is too low, an appropriate amount of wood ash can be added to adjust it.

[0103] On days 7 and 12 of fermentation, samples were taken to test the organic matter content and the number of thermophilic actinomycetes to ensure that the organic matter degradation rate met expectations and the number of thermophilic actinomycetes remained at 10. 8 -10 9 CFU / g. During fermentation, if white mycelium is found on the surface of the pile and the material emits a faint fermentation aroma, it indicates that fermentation is proceeding normally;

[0104] By day 15, the primary fermentation is complete. At this point, the material is dark brown, loose in texture, and has no obvious odor. Some of the straw powder has been broken into fine fibers.

[0105] Step 8: Add nitrogen-fixing bacteria and carry out post-ripening treatment at room temperature for 10 days.

[0106] Fifth embodiment: The present invention provides a technical solution: a special phosphogypsum organic fertilizer for saline-alkali land, composed of the following raw materials in parts by weight:

[0107] 47 parts of phosphogypsum-based porous material;

[0108] Cow dung: 33 portions;

[0109] Straw powder: 19 parts;

[0110] Compound microbial agent: 0.9 parts;

[0111] The preparation steps are as follows:

[0112] Step 1: Mix 100kg of phosphogypsum with 2kg of foaming agent and foam at an ambient temperature of 70℃ to obtain phosphogypsum-based porous material;

[0113] Step 2: Place the foamed phosphogypsum-based porous material into the crushing equipment and crush it into 1mm particles to obtain granular phosphogypsum-based porous material.

[0114] Step 3: Straw pretreatment. The straw material is treated by steam explosion combined with cellulase hydrolysis. The explosion pressure is 2.5MPa, maintained for 90 seconds, and then released to normal pressure. Enzyme hydrolysis conditions: 10U / g cellulase is added at 50℃ and treated for 4 hours to produce straw powder.

[0115] Step 4: Mix the phosphogypsum-based porous material, cow dung, straw powder, and compound microbial agent in a ratio of 47:33:19:0.9;

[0116] Step 5: Mix Bacillus subtilis and Trichoderma in a 3:1 ratio to obtain a compound microbial agent, and then inoculate the mixture obtained in Step 4 with the compound microbial agent;

[0117] Step 6: Add cellulose-decomposing bacteria and perform pretreatment at 40℃ for 7 days;

[0118] Step 7: Add thermophilic actinomycetes and carry out primary fermentation at 55℃ for 15 days;

[0119] Before the primary fermentation, the materials need to be pretreated and mixed. The materials that have undergone the pretreatment in step two, including phosphogypsum-based porous materials, cow dung, straw powder, and products treated by cellulose-decomposing bacteria, should be thoroughly stirred to ensure uniform mixing. At this time, the moisture content of the materials should be controlled at 55%. If the moisture content is too high, an appropriate amount of straw powder can be added to adjust it; if the moisture content is too low, a small amount of water should be sprayed until the standard is met.

[0120] Subsequently, the high-temperature actinomycetes were evenly sprinkled into the material at a ratio of 0.3 kg per 100 kg of material, and stirred again to ensure that the inoculant and the material were in full contact. The mixed material was piled into a trapezoidal fermentation pile with a bottom width of 2 meters, a top width of 1 meter, and a height of 1.2 meters. At the same time, 8 cm diameter ventilation pipes were evenly inserted into the inside of the pile, with the lower end of the pipe 25 cm from the ground and the upper end protruding 30 cm from the pile to ensure the air permeability inside the pile.

[0121] On the third day of fermentation, the pile is turned over for the first time. During turning, the outer layer of material is moved to the inside, and the inner layer is moved to the outside. Larger clumps are broken up to ensure even heating. The pile is then turned over every three days thereafter. During turning, the moisture content and pH value of the material should be checked. The moisture content should be maintained at 55%, and the pH value at 7.0. If the pH value is too high, a small amount of phosphogypsum-based porous material can be added to adjust it; if the pH value is too low, an appropriate amount of wood ash can be added to adjust it.

[0122] On days 7 and 12 of fermentation, samples were taken to test the organic matter content and the number of thermophilic actinomycetes to ensure that the organic matter degradation rate met expectations and the number of thermophilic actinomycetes remained at 10. 8 -10 9 CFU / g. During fermentation, if white mycelium is found on the surface of the pile and the material emits a faint fermentation aroma, it indicates that fermentation is proceeding normally;

[0123] By day 15, the primary fermentation is complete. At this point, the material is dark brown, loose in texture, and has no obvious odor. Some of the straw powder has been broken into fine fibers.

[0124] Step 8: Add nitrogen-fixing bacteria and carry out post-ripening treatment at room temperature for 10 days.

[0125] In summary, the raw material ratio in the third embodiment is the optimal ratio of this application, which can achieve the best application effect.

[0126] Its physicochemical properties are shown in the table below:

[0127]

[0128]

[0129] The fertilizer produced by this invention has a significantly improved water and fertilizer retention capacity compared to traditional organic fertilizers. Because it contains phosphogypsum-based porous materials with a pore size of 0.5-2 mm and a porosity of ≥65%, it can absorb and store water like a sponge, reducing rapid evaporation and seepage. This increases soil moisture content by 20%-30% compared to fields using traditional organic fertilizers. Simultaneously, the porous structure provides a stable storage space for nutrients, slowly releasing nitrogen, phosphorus, potassium, and other nutrients, extending the duration of the fertilizer effect to 3-4 months, far exceeding the 1-2 months of traditional organic fertilizers. This reduces the frequency of fertilization and nutrient loss, as detailed in the table below.

[0130]

[0131]

[0132] In conclusion, this fertilizer not only demonstrates excellent performance in agricultural production, but also plays a vital role in ecological environmental protection and resource recycling, achieving a balance of economic, social, and ecological benefits.

[0133] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. A phosphogypsum organic fertilizer specifically for saline-alkali land, characterized in that, It consists of the following raw materials in parts by weight: 40-50 parts of phosphogypsum-based porous material; Cow dung: 30-35 parts; Straw powder: 15-20 parts; Compound microbial agent: 0.5-1 part.

2. The method for preparing a special phosphogypsum organic fertilizer for saline-alkali land according to claim 1, characterized in that, Includes the following steps: Step 1: Prepare porous material. Mix phosphogypsum and foaming agent in a ratio of 100:1.5-3 and foam at a foaming temperature of 60-80℃ for 48 hours to obtain phosphogypsum-based porous material. Step 2: Place the foamed phosphogypsum-based porous material into the crushing equipment to obtain granular phosphogypsum-based porous material; Step 3: Straw pretreatment. The straw material is treated by steam explosion combined with cellulase hydrolysis. The explosion pressure is 2.5MPa, maintained for 90 seconds, and then released to normal pressure. Enzyme hydrolysis conditions: 10U / g cellulase is added at 50℃ and treated for 4 hours to produce straw powder. Step 4: Mix the phosphogypsum-based porous material, cow dung, straw powder, and compound microbial agent; Step 5: Mix Bacillus subtilis and Trichoderma to obtain a compound microbial agent, and then inoculate the mixture obtained in Step 4 with the compound microbial agent; Step 6: Add cellulose-decomposing bacteria and perform pretreatment at 40℃ for 7 days; Step 7: Add thermophilic actinomycetes and carry out primary fermentation at 55℃ for 15 days; Step 8: Add nitrogen-fixing bacteria and carry out post-ripening treatment at room temperature for 10 days.

3. The method for preparing a special phosphogypsum organic fertilizer for saline-alkali land according to claim 2, characterized in that: In step two, the pore size of the porous material after crushing is controlled to be 0.5-2 mm, and the porosity is ≥65%.

4. The method for preparing a special phosphogypsum organic fertilizer for saline-alkali land according to claim 2, characterized in that: The specific fermentation process in step seven is as follows: Before the main fermentation, the materials need to be pretreated and mixed. The materials that have been pretreated in step two, including phosphogypsum-based porous materials, cow dung, straw powder and products treated by cellulose decomposing bacteria, are thoroughly stirred to ensure uniform mixing. At this time, the moisture content of the materials is controlled at 55%. Subsequently, the high-temperature actinomycetes were evenly sprinkled into the material at a ratio of 0.3 kg per 100 kg of material, and stirred again to ensure that the inoculant and the material were in full contact. The mixed material was piled into a trapezoidal fermentation pile with a bottom width of 2 meters, a top width of 1 meter, and a height of 1.2 meters. At the same time, 8 cm diameter ventilation pipes were evenly inserted into the inside of the pile, with the lower end of the pipe 25 cm from the ground and the upper end protruding 30 cm from the pile. During the fermentation process, the ambient temperature is strictly controlled to be maintained at 55℃, and the temperature at different locations of the pile is monitored regularly every day, namely 30 cm below the surface, the center of the pile, and 30 cm above the bottom layer. On the third day of fermentation, the pile is turned over for the first time. When turning the pile, the outer layer of material is turned to the inside and the inner layer of material is turned to the outside. At the same time, larger clumps of material are broken up. After that, the pile is turned over once every three days. During the turning process, the moisture content and pH value of the material need to be checked. The moisture content should be kept at 55% and the pH value should be controlled at 7.

0. On the 7th and 12th days of fermentation, samples were taken to test the organic matter content and the number of thermophilic actinomycetes in the material. By day 15, the primary fermentation is complete. At this point, the material is dark brown, loose in texture, and has no obvious odor. Some of the straw powder has been broken into fine fibers.

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