Targeted aluminum control and acidified soil improvement material and method based on soil and material properties

Abstract

The invention discloses a targeted aluminum control and acidified soil improvement material and method for soil and material properties in the technical field of cultivated land improvement, and the targeted aluminum control and acidified soil improvement material is prepared by mixing the following components in parts by weight: 3 parts of water, 1 part of composite biochar and 16 parts of organic compost. The composite biochar is prepared by anaerobic carbonization of the following components in parts by weight: 3 parts of coke, 4 parts of rice husk, 3 parts of straw and 30 parts of modified phosphogypsum; the organic compost is prepared by aerobic decomposition of the following components in parts by weight: 10 parts of pig manure, 25 parts of straw and 3.5 parts of modified phosphogypsum; the modified ardealite is prepared by neutralizing and calcining the following components in parts by weight: 100 parts of deionized water, 1 part of quick lime and 20 parts of ardealite. The method is economical and practical, and the acidified soil improvement material which can be used for a long time and is low in cost is prepared by performing harmless modification on the phosphogypsum and combining an organic composting technology, so that the acidified soil degree is relieved, and the phosphogypsum harmless modification industry and the resource utilization process are promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of farmland improvement, and in particular is a material and method for targeted aluminum control and acidification of soil improvement of soil and material properties. Background Art

[0002] Soil acidification refers to the process in which soil pH value continues to decrease and soil exchangeable acid continues to increase. It is a natural process accompanying soil occurrence and development, mainly caused by the dissociation of carbonic acid and organic acid to produce hydrogen ions (H + ) is driven by the global warming. In recent years, the pace of soil acidification has accelerated year by year. The main reasons are that industrial production has caused rainwater to contain a large amount of acid and alkali components, which has aggravated soil acidification; the amount of fertilizer applied exceeds the standard value, such as the large amount of nitrogen fertilizer used, which has led to the increase of H in the soil. + Excessive accumulation exceeds the soil's ability to decompose acid; the use of physiologically acidic fertilizers, such as superphosphate and potassium sulfate, leads to a decrease in soil pH.

[0003] The harm caused by soil acidification is that it activates aluminum in the soil solid phase and releases it into the soil solution, which is toxic to the roots of crops and affects crop growth. Soil acidification also accelerates the loss of soil nutrients and reduces soil fertility. Soil acidification also aggravates the harm of heavy metal pollution. Soil acidification increases the activity of heavy metals in the soil, which increases the absorption of these harmful heavy metals by plants.

[0004] This means that it is urgent to improve the acidified soil. The existing improvement method is to spread quicklime or other alkaline preparations on the acidified soil. Although this method is simple, long-term and large-scale application of lime will lead to soil compaction and nutrient imbalance, because lime only provides nutrient calcium, and a large amount of calcium will lead to soil magnesium (Mg) and potassium (K) deficiency and reduced phosphorus (P) effectiveness. Even if inorganic improvers such as lime are used in combination with organic improvers such as organic fertilizers, although the problem can be solved to a certain extent, the cost is high and the operation is complicated.

[0005] Phosphogypsum (PG) is the main byproduct of wet production of phosphoric acid and phosphate fertilizer (about 4.5-5 tons of phosphogypsum can be produced for every ton of phosphoric acid produced). It is also one of the largest solid wastes discharged by the chemical industry. Its main component is calcium sulfate dihydrate (CaSO4·2H2O), and it contains a small amount of free acid, phosphate, fluoride, organic matter and trace elements. Large amounts of phosphogypsum storage not only occupies land area, but also causes certain damage to water, soil, atmosphere, and biological environment, increasing the environmental load around the storage area. Long-term accumulation can also cause potential risks to human and animal health through the food chain, seriously restricting the sustainable use of phosphate resources. The comprehensive utilization of phosphogypsum in agriculture mainly involves soil conditioners and fertilizer-related products, which have the potential to regulate and improve saline-alkali land and acidic soil after harmless treatment.

[0006] Therefore, it is necessary to propose a targeted aluminum control and acidified soil improvement material and method that can utilize a large amount of stored phosphoric acid industrial by-product phosphogypsum, which can be used for a long time after harmless modification and can improve the soil and material properties of acidic soil at a lower cost. Summary of the invention

[0007] In order to solve the above problems, the purpose of the present invention is to provide a targeted aluminum control and acidified soil improvement material and method for soil and material properties, by harmlessly modifying phosphogypsum and combining it with organic composting technology, a low-cost acidified soil improvement material that can be used for a long time is prepared, thereby alleviating the degree of soil acidification, promoting agricultural technological progress and environmental protection, and developing the harmless modification industry of phosphogypsum and the process of resource utilization.

[0008] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a soil and material property targeted aluminum control and acidification soil improvement material, comprising a mixture of the following components in a weight ratio: 3 parts of water, 1 part of composite biochar and 16 parts of organic compost.

[0009] The principle of the basic plan is to remove or reduce harmful substances in phosphogypsum, such as heavy metals, fluorides, etc., through specific chemical and biological methods, while retaining its properties of improving soil pH and providing nutrients. The modified phosphogypsum has better biocompatibility and environmental friendliness and can be safely used for soil improvement.

[0010] Composite biochar is a carbonaceous material obtained by high-temperature pyrolysis of biomass materials. It has a rich pore structure and a high specific surface area. It can adsorb harmful substances in the soil, such as heavy metals and organic pollutants, while providing a stable carbon source and promoting the reproduction and activity of soil microorganisms.

[0011] Organic compost is a fertilizer rich in organic matter and microorganisms obtained through the biodegradation process. It can increase the organic matter content of the soil, improve the soil structure, enhance the soil's ability to retain water and fertilizer, and promote the growth and development of crops.

[0012] By adjusting the composition and ratio of the improved materials, especially the addition amount of phosphogypsum and composite biochar, targeted control of aluminum in the soil is achieved. Aluminum is one of the common harmful elements in acidified soil. Excessive aluminum can cause toxicity to crops. The improved materials of the present invention can reduce the effectiveness of aluminum in the soil and reduce the harm to crops.

[0013] The beneficial effects of the basic scheme are: 1. Through the harmlessly modified phosphogypsum, the improved material of the present invention can adjust the pH of the soil, so that the pH value of the soil gradually tends to be neutral or slightly acidic, providing a more suitable environment for crop growth. This regulation not only helps the root development and nutrient absorption of crops, but also reduces the crop disease and insect pest problems caused by soil acidification. The addition of composite biochar and organic compost can significantly improve the physical structure of the soil. The pore structure and specific surface area of ​​composite biochar are large, which can increase the air permeability and water retention of the soil, while the organic compost is rich in organic matter and microorganisms, which can improve the soil aggregate structure and improve the fertility and stability of the soil. This optimized soil structure helps the root growth and nutrient utilization of crops, thereby improving the yield and quality of crops.

[0014] 2. Modified phosphogypsum and organic compost are rich in key nutrients such as calcium, sulfur, and phosphorus required by crops, which are essential for the normal growth and development of crops. Through the improved material of the present invention, these nutrients in the soil can be effectively supplemented to improve the fertility level of the soil. The composite biochar and organic compost in the improved material can increase the organic matter content of the soil, improve the microbial activity of the soil, and thus promote the circulation and transformation of nutrients in the soil. This effect helps to improve the absorption and utilization rate of nutrients by crops and reduce the loss and waste of nutrients.

[0015] 3. By improving the soil environment and providing sufficient nutrients, the improved material of the present invention can significantly enhance the stress resistance of crops, including drought resistance, resistance to diseases and pests, etc. This enhancement helps crops maintain a good growth state under adverse environmental conditions, thereby improving the yield and quality of crops. The improved soil has better fertility and structure, which is conducive to the root growth and nutrient absorption of crops. At the same time, the microbial activity in the soil is enhanced, which helps to promote the growth and development of crops and improve their quality. Therefore, the use of the improved material of the present invention can significantly improve the yield and quality of crops, bringing greater economic benefits to agricultural production.

[0016] 4. By harmlessly modifying phosphogypsum, the improved material of the present invention reduces the potential environmental risks of phosphogypsum, such as heavy metal pollution. At the same time, converting phosphogypsum into soil improvement materials realizes the recycling of resources and helps reduce environmental pollution and waste. The improved material and method of the present invention not only help improve soil quality, increase crop yield and quality, but also promote sustainable agricultural development. By reducing the use of fertilizers and pesticides, the cost and environmental pressure of agricultural production can be reduced, and the greening and sustainability of agricultural production can be achieved.

[0017] Furthermore, the composite biochar is prepared by anaerobic carbonization of the following components in the following weight ratio: 3 parts of coke, 4 parts of rice husk, 3 parts of straw and 30 parts of modified phosphogypsum.

[0018] The beneficial effects of the basic scheme are: 1. Modified phosphogypsum, as an important component of composite biochar, has the function of regulating soil pH. It can effectively neutralize the acidity of the soil, making the soil pH gradually tend to neutral or slightly acidic, providing a more suitable environment for crop growth. The components such as coke, rice husks and straw in composite biochar have rich pore structures and high specific surface areas after anaerobic carbonization. These characteristics help to increase the air permeability and water retention of the soil, improve the physical structure of the soil, make it looser and easier to cultivate. Composite biochar not only retains the organic matter and minerals in the raw materials, but also forms new organic matter during the carbonization process. These organic substances are rich in nutrients required by crops, such as nitrogen, phosphorus, potassium, etc., which can supplement soil nutrients and improve soil fertility.

[0019] 2. Raw materials such as coke, rice husks, and straw are usually regarded as waste or agricultural by-products. By converting them into composite biochar, not only can the recycling of resources be achieved, but also the emission of waste can be reduced, which helps to reduce environmental pressure. The addition of modified phosphogypsum not only helps to improve the soil, but also reduces the environmental pollution that may be caused by phosphogypsum itself. Through harmless modification, the harmful substances in phosphogypsum are removed or reduced, thereby reducing its potential threat to the environment. The use of composite biochar helps to reduce the use of fertilizers and pesticides, and reduce the cost and environmental pressure of agricultural production. At the same time, it can also improve the stress resistance and yield quality of crops, providing strong support for the sustainable development of agriculture.

[0020] Furthermore, the organic compost is made by aerobic decomposition of the following ingredients in the following weight ratio: 10 parts of pig manure, 25 parts of straw and 3.5 parts of modified phosphogypsum.

[0021] The beneficial effects of the basic scheme are: 1. Pig manure and straw, as organic waste, are rich in organic matter. Through the composting process, these organic matters are decomposed and converted into humus by microorganisms, increasing the organic matter content in the soil. The increase of organic matter and humus helps to form the soil aggregate structure, making the soil more loose and breathable, which is conducive to the root respiration and growth of crops. Humus has good water absorption and water retention, which can enhance the water retention capacity of the soil. At the same time, organic matter can also combine with minerals in the soil to form stable colloids and improve the soil's fertilizer retention capacity.

[0022] 2. Pig manure and straw contain a variety of nutrients such as nitrogen, phosphorus, potassium, and trace elements such as calcium, magnesium, iron, copper, and zinc. These elements are necessary for the growth of crops and can meet the nutritional needs of crops. Compared with chemical fertilizers, compost releases nutrients more slowly and is more in line with the fertilizer requirements of crops. This helps reduce nutrient loss and improve nutrient utilization.

[0023] 3. During the composting process, the decomposition of microorganisms converts organic matter into humus. At the same time, these microorganisms also become beneficial microorganisms in the soil, increasing the number of microorganisms in the soil. The increase of beneficial microorganisms can improve the biological activity of the soil, promote the circulation of substances and energy flow in the soil, which helps to improve the soil ecological environment and improve the soil fertility level.

[0024] 4. The organic matter and microbial communities in compost can adjust the pH of the soil, making it more suitable for the growth of crops. This helps to improve the chemical properties of the soil and increase the fertility level of the soil.

[0025] Furthermore, the modified phosphogypsum is prepared by neutralizing and calcining the following ingredients in the following weight ratio: 100 parts of deionized water, 1 part of quicklime and 20 parts of phosphogypsum.

[0026] The beneficial effects of the basic solution are: 1. Modified phosphogypsum can effectively neutralize soil acidity, gradually tending to neutral or weak acidity, providing a more suitable environment for plant growth. This helps to solve the problem of excessive soil acidity in many agricultural production areas, which leads to limited plant growth. Modified phosphogypsum is rich in phosphorus, mainly in the form of effective calcium phosphate, which is easier for the soil to absorb and utilize. This helps to improve the soil fertility level and meet the plant growth demand for phosphorus. Modified phosphogypsum can promote the combination between soil particles, increase the density of the soil, and is beneficial to soil water retention, fertilizer retention, root protection and other aspects. At the same time, it can also continuously release nutrients to further improve the soil structure.

[0027] 2. The phosphorus element in modified phosphogypsum is one of the important nutrients for plant growth. By applying modified phosphogypsum, it can provide continuous nutrient support for crops and promote their healthy growth. The application of modified phosphogypsum can improve the soil environment and increase the fertility level of the soil, thereby providing better conditions for crop growth. This helps to increase the yield and quality of crops and meet the needs of agricultural production.

[0028] 3. The preparation process of modified phosphogypsum utilizes phosphogypsum, an industrial byproduct, which helps reduce the pollution caused by its storage to the environment. At the same time, through neutralization and calcination treatment, the content of harmful substances in phosphogypsum can be reduced, further improving its environmental performance. The preparation and application process of modified phosphogypsum promotes the recycling of resources. By converting phosphogypsum into a valuable soil conditioner, the resource utilization of waste is realized, which helps promote the sustainable development of agricultural production.

[0029] Further, the pH value of the modified phosphogypsum is greater than 5.0, and the pH value of the improved material is 6.0-9.0.

[0030] The beneficial effects of the basic solution are: 1. The pH value of the improved material is between 6.0-9.0, which is neutral or slightly alkaline, which helps neutralize acidic soil and increase the pH value of the soil, making it more suitable for the growth of most crops.

[0031] 2. Compared with traditional soil improvement methods, using modified phosphogypsum as an improvement material can reduce production costs. At the same time, because it is rich in phosphorus, it can also reduce the amount of fertilizer used, further reducing production costs.

[0032] Furthermore, the mass fraction of key nutrients contained in the composite biochar is greater than 71.0%, and the key nutrients include P2O5, K2O, CaO, MgO and SO3.

[0033] The beneficial effects of the basic solution are: 1. The high content of phosphorus ions, potassium ions and other key nutrients in the composite biochar are necessary for plant growth. These nutrients can provide comprehensive nutritional support for plants and promote their healthy growth. Phosphorus ions are a component of important compounds such as nucleic acids, phospholipids and ATP in plants, and play a key role in the energy metabolism and material metabolism of plants. Potassium ions help maintain the osmotic pressure and ion balance of plants and improve the stress resistance of plants.

[0034] 2. Oxides such as CaO and MgO in composite biochar can combine with other components in the soil to form stable soil aggregates, thereby improving soil structure. This helps increase soil aeration and water retention, providing a better growth environment for plant roots. At the same time, the porous structure of composite biochar can also absorb and store a large amount of water and nutrients, improving the fertility level of the soil.

[0035] 3. The oxide components in the composite biochar have a certain regulating effect on the pH of the soil. For example, alkaline oxides such as CaO and MgO can neutralize the acidity of the soil and increase the pH value of the soil. This is of great significance for the improvement of acidic soil and the optimization of the plant growth environment.

[0036] A method for targeted aluminum control and acidification of soil and material properties, comprising the following steps:

[0037] Step 1: neutralize and modify the phosphogypsum. Dry the phosphogypsum to constant weight, crush, grind and sieve the dried phosphogypsum and an appropriate amount of quicklime, mix the phosphogypsum and quicklime according to the corresponding weight ratio, and age them for 24 hours after mixing. Stir and mix the above mixture with deionized water according to the weight ratio, calcine at a calcination temperature of 180°C for 2 hours, let it stand and age for 6 hours after the calcination, take an appropriate amount of the calcined product, crush and sieve it again, and mix it evenly with deionized water at a weight ratio of 1:10. After standing for 5 minutes, take the supernatant to test the pH value;

[0038] Step 2, preparation of composite biochar, crushing coke, rice husk and straw, sieving, mixing coke, rice husk, straw and modified phosphogypsum according to corresponding weight ratio, calcining in a methane fluorine furnace at 800°C for 6 hours without oxygen, taking out the composite biochar after cooling, and using phosphomolybdenum blue spectrophotometry to determine the total P2O5 in phosphogypsum and composite biochar, flame photometry to determine K2O, barium sulfate gravimetric method to determine SO3, EDTA titration subtraction method to determine MgO and EDTA titration method to determine CaO;

[0039] Step 3, organic compost is decomposed, the straw is air-dried and then crushed into straw segments, the pig manure and the straw segments are first mixed evenly according to the corresponding weight ratio, water is added to adjust the moisture content to 50%-60%, and modified phosphogypsum is added according to the weight ratio and mixed evenly again, several foam boxes are connected in parallel using ventilation pipes, and 80% of the volume of the foam box is added for decomposition, the ventilation rate of each box is 6L / min, the ventilation frequency is 10min per hour, the decomposition time is 24 days, the compost is turned every 3 days for the first 6 days of composting, and the compost is turned every 6 days from the 6th to the 24th day;

[0040] Step 4: Mix and spread. Add water to the prepared composite biochar and organic compost according to the corresponding weight ratio and mix them evenly. Test the pH value of the improved material. Spread the mixed product on the surface of the acidified soil. Use a rotary tiller to plow the land to fully mix the topsoil. Test the pH value change of the soil below the topsoil after 7 and 15 days.

[0041] Furthermore, in step 1 and step 2, the sieve mesh apertures used in the sieving operation are both 2 mm.

[0042] Furthermore, in step three, the length of the straw segment is between 1 and 3 cm.

[0043] Furthermore, in step 4, the tillage depth of the topsoil using a rotary tiller is greater than 25 cm. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a bar graph showing changes in pH during the acidified soil improvement process in an embodiment of the present invention.

[0045] Figure 2 It is a bar chart showing the changes in the mass fractions of key nutrients during the composite biochar carbonization process in an embodiment of the present invention.

[0046] Figure 3 Schematic diagram of the targeted aluminum control and acidification soil improvement method of soil and material properties in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The following is further described in detail through specific implementation methods:

[0048] Example 1

[0049] Basically as attached Figure 1 As shown: A soil and material property targeted aluminum control and acidification soil improvement material, comprising the following components in a weight ratio, 3 parts of water, 1 part of composite biochar and 16 parts of organic compost;

[0050] The composite biochar is made by anaerobic carbonization of the following ingredients in the following weight ratio: 3 parts of coke, 4 parts of rice husks, 3 parts of straw and 30 parts of modified phosphogypsum; the organic compost is made by aerobic decomposition of the following ingredients in the following weight ratio: 10 parts of pig manure, 25 parts of straw and 3.5 parts of modified phosphogypsum; the modified phosphogypsum is made by neutralization and calcination of the following ingredients in the following weight ratio: 100 parts of deionized water, 1 part of quicklime and 20 parts of phosphogypsum.

[0051] The pH value of the modified phosphogypsum is greater than 5.0, the pH value of the improved material is 6.0-9.0, the mass fraction of key nutrients contained in the composite biochar is greater than 71.0%, and the key nutrients include P2O5, K2O, CaO, MgO and SO3.

[0052] The specific implementation process is as follows: After spreading the improved materials on the acidified soil farmland, the changes in soil pH after 7 days and 15 days were statistically analyzed, Microsoft Excel 2019 was used to perform basic processing on the experimental data, SPSS19.0 was used to perform statistical analysis on the data, and Microsoft Excel 2019 was used to make graphs.

[0053] The results are shown in Table 1 and Figure 1 As shown:

[0054] Table 1 Changes in pH during acidified soil improvement

[0055]

[0056] Compared with the control group, *P<0.05, the data are significantly different.

[0057] Spreading improved materials brought a significant upward trend in the pH value of acidified soil, and it reached a slightly alkaline range after 15 days, while the pH value of the control cultivated soil remained in the acidic range, indicating that the improved materials have a significant effect on improving acidified soil, thereby achieving targeted control of aluminum and avoiding heavy metal poisoning of crops.

[0058] Example 2

[0059] The difference from the above embodiment is that, as shown in the attached Figure 2 As shown: The key nutrient mass fractions ω(P2O5), ω(K2O), ω(CaO), ω(MgO) and ω(SO3) in phosphogypsum and composite biochar were determined using the method in step 2. The results are shown in Tables 2 and Figure 2 As shown:

[0060] Table 2 Changes in the mass fraction of key nutrients during the carbonization process of composite biochar

[0061]

[0062] Compared with the key nutrients MgO, CaO, P2O5 and K2O in phosphogypsum raw materials, the activation efficiency of composite biochar was increased by 11.40%, 49.09%, 71.42% and 87.78% respectively, which enhanced the nutritional capacity of composite biochar as an inorganic fertilizer and improved the fertility of cultivated land after spreading the improved materials.

[0063] Example 3

[0064] The difference from the above embodiment is that, as shown in the attached Figure 3 As shown: A method for targeted aluminum control and acidification of soil and material properties, comprising the following steps:

[0065] Step 1: neutralize and modify the phosphogypsum. Dry the phosphogypsum to constant weight, crush and grind the dried phosphogypsum and an appropriate amount of quicklime, pass through a sieve with an aperture of 2 mm, mix the phosphogypsum and quicklime according to the corresponding weight ratio, and age them for 24 hours after mixing. Stir and mix the above mixture with deionized water according to a weight ratio, calcine at a calcination temperature of 180°C for 2 hours, let it stand and age for 6 hours after the calcination, take an appropriate amount of the calcined product, re-crush it through a sieve with an aperture of 2 mm, and mix it evenly with deionized water at a weight ratio of 1:10. After standing for 5 minutes, take the supernatant to test the pH value;

[0066] Step 2, preparation of composite biochar, crushing coke, rice husk and straw, passing through a 2 mm sieve, mixing coke, rice husk, straw and modified phosphogypsum according to the corresponding weight ratio, calcining in a muffle furnace at a temperature of 800°C for 6 hours without oxygen, taking out the composite biochar after cooling, and using phosphomolybdenum blue spectrophotometry to determine the total P2O5 in phosphogypsum and composite biochar, flame photometry to determine K2O, barium sulfate gravimetric method to determine SO3, EDTA titration subtraction method to determine MgO and EDTA titration method to determine CaO;

[0067] Step 3, organic compost is decomposed, the straw is air-dried and then crushed into straw segments with a length of 1-3 cm, the pig manure and the straw segments are first mixed evenly according to the corresponding weight ratio, water is added to adjust the moisture content to 50%-60%, and modified phosphogypsum is added according to the weight ratio and mixed evenly again, several foam boxes are connected in parallel using ventilation pipes, and 80% of the volume of the foam box is added for decomposition, the ventilation rate of each box is 6L / min, the ventilation frequency is 10min per hour, the decomposition time is 24 days, the compost is turned every 3 days for the first 6 days of composting, and the compost is turned every 6 days from the 6th to the 24th day;

[0068] Step 4: Mix and spread. Add water to the prepared composite biochar and organic compost according to the corresponding weight ratio and mix them evenly. Test the pH value of the improved material. Spread the mixed product on the surface of the acidified soil. Use a rotary tiller to plow the land to fully mix the topsoil. The plowing depth should be greater than 25 cm. Test the pH value change of the soil below the topsoil after 7 and 15 days.

[0069] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0070] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A soil and material property targeted aluminum control and acidification soil improvement material, characterized by: The mixture comprises the following ingredients in the following weight ratio: 3 parts of water, 1 part of composite biochar and 16 parts of organic compost.

2. The targeted aluminum control and acidification soil improvement material for soil and material properties according to claim 1, characterized in that: The composite biochar is prepared by anaerobic carbonization of the following components in the following weight ratio: 3 parts of coke, 4 parts of rice husk, 3 parts of straw and 30 parts of modified phosphogypsum.

3. The targeted aluminum control and acidification soil improvement material for soil and material properties according to claim 1, characterized in that: The organic compost is made by aerobic decomposition of the following ingredients in the following weight ratio: 10 parts of pig manure, 25 parts of straw and 3.5 parts of modified phosphogypsum.

4. The targeted aluminum control and acidification soil improvement material for soil and material properties according to claim 3, characterized in that: The modified phosphogypsum is prepared by neutralizing and calcining the following components in the following weight ratio: 100 parts of deionized water, 1 part of quicklime and 20 parts of phosphogypsum.

5. The targeted aluminum control and acidification soil improvement material for soil and material properties according to claim 4, characterized in that: The pH value of modified phosphogypsum is greater than 5.0, and the pH value of the improved material is 6.0-9.

0.

6. The targeted aluminum control and acidification soil improvement material for soil and material properties according to claim 2, characterized in that: The mass fraction of key nutrients contained in the composite biochar is greater than 71.0%, and the key nutrients include P2O5, K2O, CaO, MgO and SO3.

7. A method for targeted aluminum control and soil acidification improvement of soil and material properties, characterized in that: The following steps are involved: Step 1: neutralize and modify the phosphogypsum. Dry the phosphogypsum to constant weight, crush, grind and sieve the dried phosphogypsum and an appropriate amount of quicklime, mix the phosphogypsum and quicklime according to the corresponding weight ratio, and age them for 24 hours after mixing. Stir and mix the above mixture with deionized water according to the weight ratio, calcine at a calcination temperature of 180°C for 2 hours, let it stand and age for 6 hours after the calcination, take an appropriate amount of the calcined product, crush and sieve it again, and mix it evenly with deionized water at a weight ratio of 1:

10. After standing for 5 minutes, take the supernatant to test the pH value; Step 2, preparation of composite biochar, crushing coke, rice husk and straw, sieving, mixing coke, rice husk, straw and modified phosphogypsum according to corresponding weight ratio, calcining in a methane fluorine furnace at 800°C for 6 hours without oxygen, taking out the composite biochar after cooling, and using phosphomolybdenum blue spectrophotometry to determine the total P2O5 in phosphogypsum and composite biochar, flame photometry to determine K2O, barium sulfate gravimetric method to determine SO3, EDTA titration subtraction method to determine MgO and EDTA titration method to determine CaO; Step 3, organic compost is decomposed, the straw is air-dried and then crushed into straw segments, the pig manure and the straw segments are first mixed evenly according to the corresponding weight ratio, water is added to adjust the moisture content to 50%-60%, and modified phosphogypsum is added according to the weight ratio and mixed evenly again, several foam boxes are connected in parallel using ventilation pipes, and 80% of the volume of the foam box is added for decomposition, the ventilation rate of each box is 6L / min, the ventilation frequency is 10min per hour, the decomposition time is 24 days, the compost is turned every 3 days for the first 6 days of composting, and the compost is turned every 6 days from the 6th to the 24th day; Step 4: Mix and spread. Add water to the prepared composite biochar and organic compost according to the corresponding weight ratio and mix them evenly. Test the pH value of the improved material. Spread the mixed product on the surface of the acidified soil. Use a rotary tiller to plow the land to fully mix the topsoil. Test the pH value change of the soil below the topsoil after 7 and 15 days.

8. The method for targeted aluminum control and acidification of soil and material properties according to claim 7, characterized in that: In step 1 and step 2, the sieve mesh apertures used in the sieving operation are both 2 mm.

9. The method for targeted aluminum control and acidification of soil and material properties according to claim 7, characterized in that: In step three, the length of the straw segment is between 1 and 3 cm.

10. The method for targeted aluminum control and soil acidification improvement of soil and material properties according to claim 7, characterized in that: In step 4, the tillage depth of the topsoil is greater than 25 cm using a rotary tiller.

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