CN116948654A - An acidic soil conditioner based on calcium and magnesium supplementation and its application - Google Patents

Abstract

The invention discloses an acid soil conditioner based on calcium and magnesium supplement and application thereof, and belongs to the technical field of soil improvement. The acid soil conditioner based on calcium and magnesium supplement comprises the following components in parts by weight: 40-80 parts of phosphorus tailing powder, 10-20 parts of silicon-based yellow phosphorus slag powder and 5-20 parts of silicate mineral. The soil conditioner has the functions of improving the pH value of soil and supplementing calcium and magnesium elements to the soil, and has a very remarkable improvement effect on acid red soil lacking calcium and magnesium; and thereby promote the full utilization of the phosphate tailing resources. The invention is suitable for acid soil, especially for acid red soil in south, and has the effects of improving acid red soil and promoting crop growth, and the product is easy to produce and convenient to apply.

Description

An acidic soil conditioner based on calcium and magnesium supplementation and its application

Technical field

The present invention relates to the technical field of soil improvement, and more specifically to an acidic soil conditioner based on calcium and magnesium supplementation and its application.

Background technique

Acidification of farmland soil is a global soil degradation problem that has a significant impact on sustainable agricultural production. Soil testing and formulated fertilization data show that the area of highly acidic cultivated land (pH ≤ 5.5) in my country reaches 293 million acres, including 203 million acres in the south. Soil acidification has become one of the most important production obstacles in southern farmland. Soil acidification not only manifests as a decrease in pH value, but also leads to the loss of soil exchangeable calcium and magnesium, thereby inhibiting the absorption of calcium, magnesium and other nutrients by plants, resulting in a decrease in crop yield and quality. Research shows that there is a serious lack of calcium and magnesium in the acidic red soil in the south. The acidification of cultivated land in southern Anhui, Jiangxi, Fujian, Guangxi, Sichuan and other places is serious. There is a significant lack of calcium and magnesium in cash crops. Fruits and vegetables such as citrus, bananas, peppers, rapeseed, and tea are economically disadvantaged. Typical nutrient deficiency symptoms such as yellowing of crop leaves and cracked fruits are common. Therefore, carrying out soil acidification control and supplementing calcium and magnesium elements are important measures to improve soil quality, increase soil fertility and crop yields, and are of great significance for improving agricultural productivity and achieving sustainable soil utilization.

Soil conditioner is an important application product in soil remediation technology. For southern red soils with soil acidification and severe calcium and magnesium deficiencies, using appropriate soil conditioners is a key measure to increase productivity. Traditional acidic soil conditioners are mainly lime-based alkaline substances, which have a significant effect on increasing the pH value and calcium ion concentration of the surface soil. However, long-term excessive application can easily lead to soil compaction and imbalance of soil calcium, magnesium, potassium and other elements, which can easily aggravate magnesium deficiency in crops. Organic materials such as biochar, crop straw, organic fertilizer, humic acid, etc. can also improve acidic soil. When applied to the soil, they can improve soil pH, CEC, and increase soil nutrients. Biochar made from organic materials such as manure, straw, agricultural waste, etc. has the characteristics of high pH value, rich nutrients, and high salt-based ion content. It also has a certain improvement effect on soil structure, but the cost is higher; humic acid, peat The cost of soil is low, and it is rich in organic functional groups such as hydroxyl, carboxyl and amino groups, which can improve soil acidity, nutrients and structure. However, there are common problems such as large application volume and high cost. Therefore, in view of the current prominent problems such as high acidity and calcium and magnesium deficiency in red soil in the south, it is crucial to quickly improve soil pH while increasing the calcium and magnesium content in the soil, thereby increasing crop yields.

Using industrial waste to improve acidic soil can not only promote the reuse of waste resources, but also greatly reduce the cost of soil conditioners. Phosphate tailings is a dolomite-based by-product produced during the flotation process of colloidal phosphate rock. my country's annual output is as high as 7 million tons, but its utilization efficiency is less than 20%. The accumulation of large amounts of phosphate tailings has brought dual economic and environmental pressures. Data shows that nearly one-third of my country's tailings stocks have major safety hazards and pose a huge potential threat to the ecological environment. The country is also actively promoting the full utilization of bulk by-products. Therefore, it is necessary to explore the high value and full utilization of phosphate tailings. The resource approach is very important.

Designing and developing an acidic soil conditioner that can improve soil pH and supplement soil calcium and magnesium content with high efficiency and low cost is an urgent need and effective way to collaboratively realize the resource utilization of phosphate tailings and the sustainable utilization of acidic soil.

Contents of the invention

In response to the above problems, the present invention provides an acidic soil conditioner based on calcium and magnesium supplementation and its application. The soil conditioner provided by the invention has the function of increasing soil pH, supplementing soil calcium and magnesium elements, and can treat acidic soil conditioners lacking calcium and magnesium. Red soil has a very significant improvement effect; it promotes the full utilization of phosphate tailings resources. The invention is suitable for acidic soil, especially acidic red soil in the south. It not only has the effect of improving the acidic red soil and promoting crop growth, but also the product is easy to produce and convenient to apply.

The first object of the present invention is to provide an acidic soil conditioner based on calcium and magnesium supplementation, including the following components by weight: 40-80 parts of phosphate tailings powder, 10-20 parts of silicon-based yellow phosphorus slag powder, silicon 5-20 parts of salt minerals.

Preferably, the silicate mineral includes one or more of sepiolite, bentonite, and attapulgite.

Preferably, the phosphate tailings powder is colloidal phosphate flotation tailings, and the effective nutrients are: P ₂ O ₅ 5 to 10%, CaO 30% to 35%, MgO 12% to 18%, and SiO ₂ 5% to 7%.

Preferably, the silicon-based yellow phosphorus slag powder is a by-product of yellow phosphorus produced by the electric furnace method, and the effective nutrients are: SiO ₂ 30% to 38%, CaO 29% to 35%, and MgO 1% to 4%.

Preferably, organic materials are also included, and the mass ratio of phosphate tailings powder to organic materials is 40-80:5-20.

Preferably, the organic material includes one or more of humic acid, peat soil, biochar, and organic fertilizer, and the organic matter content is ≥30%.

Preferably, weigh each component according to the following weight parts: 40-80 parts of phosphate tailings powder, 10-20 parts of silicon-based yellow phosphorus slag powder, 5-20 parts of silicate minerals;

Phosphorus tailings powder, silicon-based yellow phosphorus slag powder and silicate ore are crushed and mixed to obtain an acidic soil conditioner based on calcium and magnesium supplementation, with a moisture content of 8-12%.

The effective nutrients in the acidic soil conditioner prepared by the invention are CaO 23.8% to 30.0%, MgO 11% to 15.4%, SiO ₂ 3.6% to 9.2%, and organic matter >4%. The particle size of acidic soil conditioning is 60-100 mesh, the moisture content is 8-12%, and the pH value is greater than 8.5.

The second object of the present invention is to provide the application of the above-mentioned acidic soil conditioner based on calcium and magnesium supplementation in improving acidified soil. The method of using the acidic soil conditioner based on calcium and magnesium supplementation is to condition the acidic soil conditioner based on calcium and magnesium supplementation. Spread the agent on the soil surface, plow the soil after application, and mix it with the soil in the tillage layer.

Preferably, the amount of acidic soil conditioner based on calcium and magnesium supplementation is 150-300kg/acre.

Compared with the prior art, the present invention has the following beneficial effects:

The invention provides an acidic soil conditioner based on calcium and magnesium supplementation. By using phosphate tailings mixed with alkaline materials and silicate mineral components, it has low cost, is conducive to control, and has significant improvement effects;

The acidic soil conditioner based on calcium and magnesium supplement prepared by the invention has the function of increasing soil pH, supplementing and coordinating soil calcium and magnesium, has a very significant improvement effect on acidic red soil lacking calcium and magnesium, and can effectively supplement calcium and magnesium needed for plant growth. The combination of magnesium and silicon nutrient elements, fast-acting yellow phosphorus slag and slow-acting phosphorus tailings ensures a moderate supply duration and speed, and higher utilization efficiency. Sufficient supply of calcium and magnesium ensures the buffering capacity of the soil against the re-acidification process; a certain amount of silicon is added in the present invention, which can form a complex or hydroxyl aluminum with Al ³⁺ , thereby improving the resistance to active Al ³⁺ Passivation, alleviating the Al ³⁺ poisoning of acidic soil; in addition to supplying certain nutrients, the addition of silicate minerals, its mineral structure and surface properties combined with the conditioner nutrients can give full play to the functional properties of its nutrient elements and improve nutrients active;

In addition, the present invention also adds organic materials in the form of organic-inorganic composites, which not only improves the acidity of the soil, but also has the function of increasing the organic matter and nutrient content of the soil, and improving the fertility and structure of the soil. On this basis, the present invention uses the by-products of the phosphorus chemical industry as the main raw material, which greatly reduces the cost of the conditioning agent and provides a new path for the full utilization of by-products such as flotation phosphate tailings.

Description of the drawings

Figure 1 is a flow chart of the present invention for preparing an acidic soil conditioner based on calcium and magnesium supplementation;

Figure 2 shows the aboveground dry weight of potted plants in different treatment groups;

Figure 3 shows the soil pH values of different treatment groups;

Figure 4 shows the crop yields of different treatment groups.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

The various raw materials and reagents used in the following examples of the present invention are all commercially available reagents and raw materials unless otherwise specified. The phosphate tailings powder and silicon-based yellow phosphorus slag powder used in the present invention are both from Yunnan Phosphate Group Co., Ltd.

Example 1

This embodiment provides an acidic soil conditioner based on calcium and magnesium supplementation, including the following raw materials by weight: 60 parts of phosphate tailings powder, 10 parts of silicon-based yellow phosphorus slag powder, 15 parts of mineral humic acid, and 15 parts of sepiolite powder share.

The phosphate tailings powder used is colloidal phosphate flotation tailings. Its nutrient indicators are: P ₂ O ₅ 5 to 10%, CaO 30% to 35%, MgO 12% to 18%, SiO ₂ 5% to 7%. After the colloidal phosphate flotation tailings are filtered and processed, they are crushed and screened in a crusher. The material has a fineness of 60 mesh and a moisture content of about 15%.

Silicon-based yellow phosphorus slag powder is a by-product of yellow phosphorus produced by the electric furnace method. It is obtained after crushing. The material has a fineness of 60 mesh.

Sepiolite powder is a direct purchase product, which is the product of direct processing of sepiolite mine. The material fineness is 100 mesh.

Humic acid is humic acid purchased from mineral sources. The material has a fineness of 100 mesh and is crushed through a 60 mesh sieve.

Phosphorus tailings powder, silicon-based yellow phosphorus slag powder, mineral humic acid, and sepiolite powder are put into a mixer and stirred to obtain a mixed powder material, that is, an acidic soil conditioner based on calcium and magnesium supplementation; the preparation flow chart is shown in Figure 1 Show.

The acidic soil conditioner based on calcium and magnesium supplement prepared in this example has the following characteristics: the conditioner is in powder form, with a moisture content of 8-12%, a pH value of 9.67, and effective nutrients: CaO 25.4%, MgO 12.6%, SiO ₂ 6.6 %, organic matter ≥9%.

In the present invention, colloidal phosphate flotation tailings and yellow phosphorus production by-products are used as main raw materials, which promotes the reuse of by-product resources in the phosphorus chemical industry. The production process of the conditioner is simple, the main raw materials are sufficient in quantity, and the price is low, making it easy to realize industrial production; the conditioner has a good acid-modifying effect and can supply a large amount of calcium, magnesium and silicon elements to coordinate soil nutrient activity and increase crop yields. ,quality.

In the present invention, the conditioner in the soil can effectively neutralize H ⁺ in the soil, and ensures the continued activity of the calcium and magnesium nutrients in the soil through the combination of the quick-acting state and the slow-acting state of the calcium and magnesium elements. The supplemented silicon element forms a complex or hydroxyl aluminum with Al ³⁺ to improve the passivation effect on Al ³⁺ ; the calcium, magnesium, silicon, organic additives, etc. in the components can increase nutrients through reasonable proportions Utilization efficiency, meeting nutrient needs during crop growth and development, and improving crop yield and quality.

Fifteen days before crop transplantation, apply the acidic soil conditioner based on calcium and magnesium supplement prepared in this example into the soil at a dosage of 150-300kg/acre, spread it evenly, and then plow it to ensure that it is based on calcium and magnesium. Supplementary acidic soil conditioner is mixed with the soil to achieve the best soil acidification improvement effect. The experimental results showed that it performed well in potted plants and field experiments. With an application rate of 200kg/acre, the pH of the soil significantly increased by 0.36, and the crop yield increased by 11% (Figure 3-Figure 4).

Example 2

This embodiment provides an acidic soil conditioner based on calcium and magnesium supplementation, including the following raw materials by weight: 40 parts of colloidal phosphate flotation tailings powder, 20 parts of silicon-based yellow phosphorus slag powder, 5 parts of peat soil, and bentonite. 20 servings.

The colloidal phosphate flotation tailings are filtered and then crushed and screened in a crusher. The material has a fineness of 200 mesh and a moisture content of about 15%.

Silicon-based yellow phosphorus slag powder is a by-product of yellow phosphorus produced by the electric furnace method. It is obtained after crushing. The material has a fineness of 200 mesh.

Bentonite is crushed and passed through a 100-mesh sieve, and peat soil is crushed and passed through a 60-mesh sieve.

Put phosphate tailings powder, silicon-based yellow phosphorus slag powder, peat soil, and bentonite into a mixer and stir and mix to obtain a mixed powder material, that is, an acidic soil conditioner based on calcium and magnesium supplementation;

Example 3

This embodiment provides an acidic soil conditioner based on calcium and magnesium supplementation, including the following raw materials by weight: 70 parts of colloidal phosphate flotation tailings powder, 15 parts of silicon-based yellow phosphorus slag powder, 20 parts of biochar, and 5 parts of stick soil.

The colloidal phosphate flotation tailings are filtered and then crushed and screened in a crusher. The fineness of the material is 100 mesh and the moisture content is about 15%.

Silicon-based yellow phosphorus slag powder is a by-product of yellow phosphorus produced by the electric furnace method. It is obtained after crushing. The material has a fineness of 100 mesh.

The attapulgite soil was crushed and passed through a 100-mesh sieve, and the biochar was crushed and passed through a 60-mesh sieve.

Phosphorus tailings powder, silicon-based yellow phosphorus slag powder, biochar, and attapulgite soil are put into a mixer and stirred to obtain a mixed powder material, that is, an acidic soil conditioner based on calcium and magnesium supplementation.

Example 4

This embodiment provides an acidic soil conditioner based on calcium and magnesium supplementation, including the following raw materials by weight: 70 parts of colloidal phosphate flotation tailings powder, 15 parts of silicon-based yellow phosphorus slag powder, 5 parts of humic acid, organic 5 parts of fertilizer (rotten pig manure), 5 parts of attapulgite, and 5 parts of bentonite.

The colloidal phosphate flotation tailings are filtered and then crushed and screened in a crusher. The fineness of the material is 100 mesh and the moisture content is about 15%.

Silicon-based yellow phosphorus slag powder is a by-product of yellow phosphorus produced by the electric furnace method. It is obtained after crushing. The material has a fineness of 100 mesh.

Attapulgite and bentonite were crushed and passed through a 100-mesh sieve, and humic acid and organic fertilizer were crushed and passed through a 60-mesh sieve.

Phosphorus tailings powder, silicon-based yellow phosphorus slag powder, biochar, and attapulgite soil are put into a mixer and stirred to obtain a mixed powder material, that is, an acidic soil conditioner based on calcium and magnesium supplementation.

Example 5

This embodiment provides an acidic soil conditioner based on calcium and magnesium supplementation, including the following raw materials by weight: 60 parts of colloidal phosphate flotation tailings powder, 20 parts of silicon-based yellow phosphorus slag powder, and 20 parts of sepiolite.

The colloidal phosphate flotation tailings are filtered and then crushed and screened in a crusher. The fineness of the material is 100 mesh and the moisture content is about 15%.

Silicon-based yellow phosphorus slag powder is a by-product of yellow phosphorus produced by the electric furnace method. It is obtained after crushing. The material has a fineness of 100 mesh.

Sepiolite powder is a direct purchase product, which is the product of direct processing of sepiolite mine. The material fineness is 100 mesh.

Phosphorus tailings powder, silicon-based yellow phosphorus slag powder, and sepiolite are put into a mixer for stirring and mixing to obtain a mixed powder material, that is, an acidic soil conditioner based on calcium and magnesium supplementation.

Example 6

This embodiment provides an acidic soil conditioner based on calcium and magnesium supplementation, including the following parts by weight of raw materials: 40 parts of colloidal phosphate flotation tailings powder, 20 parts of silicon-based yellow phosphorus slag powder, 10 parts of sepiolite, 10 parts of bentonite clay.

The colloidal phosphate flotation tailings are filtered and then crushed and screened in a crusher. The fineness of the material is 100 mesh and the moisture content is about 15%.

Silicon-based yellow phosphorus slag powder is a by-product of yellow phosphorus produced by the electric furnace method. It is obtained after crushing. The material has a fineness of 100 mesh.

Sepiolite powder is a direct purchase product, which is the product of direct processing of sepiolite mine. The material fineness is 100 mesh. Bentonite is crushed and passed through a 100 mesh sieve

Phosphorus tailings powder, silicon-based yellow phosphorus slag powder, sepiolite, and bentonite are put into a mixer and stirred to obtain a mixed powder material, that is, an acidic soil conditioner based on calcium and magnesium supplementation.

In order to further prove the effect of the acidic soil conditioner based on calcium and magnesium supplement prepared by the present invention, the acidic soil conditioner based on calcium and magnesium supplement prepared in Example 1 was used, and other treatment groups were set up to conduct pot experiments and field tests.

(1) The treatment group settings are as follows: CK (i.e., blank control group, no soil conditioner added); Treatment one: phosphate tailings powder; Treatment two: 80 parts of phosphate tailings, 20 parts of yellow phosphorus slag; Treatment three: phosphorus tailings 80 parts of mineral powder, 20 parts of humic acid; treatment four: 80 parts of phosphate tailings powder, 20 parts of sepiolite; treatment five: 80 parts of phosphate tailings powder, 10 parts of mineral humic acid, 10 parts of sepiolite; treatment six : 60 parts of phosphate tailings powder, 10 parts of yellow phosphorus slag, 15 parts of sepiolite, 15 parts of mineral humic acid.

Weigh each raw material according to the above treatment group, crush it and pass it through a 60-mesh sieve, mix it and use it for later use. Take a typical acidic red soil to conduct a pot test. Pass the air-dried soil through a 2mm sieve, take 200g and mix it with a conditioner. Use of conditioner The amount was 0.2%, ensuring that the water content was 60% of the field water capacity. Water was added every 3 days. The cultivation time was 30 days. Each treatment was repeated three times.

It can be seen from Table 1 that after 30 days of cultivation test, the acidity index of the soil has changed significantly. Each treatment has achieved relatively good results, the pH has increased by 0.26-0.48, and the exchangeable calcium and magnesium have also increased significantly. Among them, treatment six has the best comprehensive effect. With the use of 0.2% conditioner, the soil pH value increased by 0.45, the exchange acid decreased by 54.3%, and the exchangeable Al ³⁺ decreased by 60.0%, which greatly reduced the activity of the soil. Al ³⁺ content. At the same time, the exchangeable calcium and magnesium in the soil increased significantly, with exchangeable Ca increasing by 64.8% and exchangeable Mg increasing by 180.3%, which has a great effect on targeting and improving the general lack of calcium and magnesium in acidified red soil in the south.

Table 1 Soil acidity index data treated with different conditioners

(2) A typical acidic red soil was used for a pot experiment, and the crops planted were Chinese cabbage. The usage amounts of conditioners are 0.2% and 0.5% respectively, and the treatment design is: CK (i.e., blank control group, no soil conditioner added); Treatment 1: 60 parts of phosphate tailings, 20 parts of humic acid, and 20 parts of sepiolite; Treatment two: 60 parts of phosphate tailings powder, 20 parts of sepiolite, and 20 parts of yellow phosphorus slag; treatment three: 60 parts of phosphate tailings powder, 15 parts of mineral humic acid, 15 parts of sepiolite powder, and 10 parts of yellow phosphorus slag.

The data of potting soil are shown in Table 2. Compared with CK, each treatment has a significant effect. The results of treatment three showed that with the application rate of 320kg/acre, soil pH increased by 0.58, exchangeable Al ³⁺ decreased by 49%, and soil acidity was greatly improved. At the same time, soil exchangeability Ca and Mg increased by 75.7% and 74.1% respectively, and the total salt base increased by 51.4%. The effect was more significant in the treatment with an application rate of 800kg/acre. At the same time, it can be seen that the combination of pure inorganic materials has a stronger acid-modifying effect, but the addition of humic acid is more prominent in reducing exchangeable acid. Moreover, the addition of humic acid has a more prominent effect on increasing plant dry matter weight (Figure 2). As the dosage of conditioner increases, the improvement effect increases significantly. Taken together, different compound conditioners of phosphate tailings, humic acid, sepiolite, and yellow phosphorus residue all have significant effects on acidic soil. Each material has a significant effect on soil pH, exchangeable Al ³⁺ , and exchangeable Ca ²⁺ , Mg ²⁺ , and crop growth effects are different. In practical applications, the ratio can be appropriately adjusted according to the characteristics of the soil and the demand characteristics of the plants.

Table 2 Potted soil indicators treated with different conditioner types and contents

(3) A field experiment was carried out in a typical acidified red soil in Jinning District, Kunming City, Yunnan Province, and the crops planted were pod beans. The dosage of conditioner is 200kg/acre, and the treatment design is: CK (i.e., blank control group, no soil conditioner is added); treatment one: 60 parts of phosphate tailings, 20 parts of yellow phosphorus slag, and 20 parts of sepiolite; treatment two: 60 parts of phosphate tailings powder, 20 parts of sepiolite, and 20 parts of bentonite; treatment three: 60 parts of phosphate tailings powder, 20 parts of mineral source humic acid, and 20 parts of sepiolite powder; treatment four: 60 parts of phosphate tailings powder, mineral source 15 parts of humic acid, 15 parts of sepiolite powder, 10 parts of yellow phosphorus residue.

Table 3 Changes in soil properties

Table 4 Changes in crop attributes

The test results show (Figure 3 and Figure 4) that each treatment can significantly increase the soil pH value. After 2 months of conditioner application, the soil pH value increased by 0.25-0.42. It can be seen that the combination of inorganic materials has a more significant effect on acid modification, that is, the combination of sepiolite and yellow phosphorus slag has the most significant effect on improving acidity, followed by phosphate tailings + humic acid + sepiolite + yellow phosphorus slag deal with. The first crop yield results showed that after the application of conditioners, the yield increased by 6.9% to 15.4%. The yield increase effects of treatments 1, 3, and 4 all exceeded 10%. It can be seen from Tables 3 and 4 that treatment four has the best comprehensive effect. The exchangeable calcium and magnesium in the soil are significantly increased, which promotes nutrient absorption in crops.

The effective nutrients in the acidic soil conditioner prepared by the invention are CaO 23.8% to 30.0%, MgO 11% to 15.4%, SiO ₂ 3.6% to 9.2%, and organic matter >4%. On the basis of acid modification, the activity of soil calcium and magnesium elements is synergistically improved.

Although the preferred embodiments of the present invention have been described, those skilled in the art will be able to make additional changes and modifications to these embodiments once the basic inventive concepts are apparent. Therefore, it is intended that the appended claims be construed to include the preferred embodiments and all changes and modifications that fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the invention. In this way, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims (9)

1. An acid soil conditioner based on calcium and magnesium supplement is characterized by comprising the following components in parts by weight: 40-80 parts of phosphorus tailing powder, 10-20 parts of silicon-based yellow phosphorus slag powder and 5-20 parts of silicate mineral.

2. The acid soil conditioner based on calcium-magnesium supplement according to claim 1, wherein the silicate mineral comprises one or more of sepiolite, bentonite and attapulgite.

3. The acidic soil conditioner based on calcium-magnesium supplement according to claim 1, wherein the phosphate tailing powder is collophanite flotation tailings, and the available nutrients are as follows: p (P) ₂ O ₅ 5～10％，CaO 30％～35％，MgO 12％～18％，SiO ₂ 5％～7％。

4. The acid soil conditioner based on calcium and magnesium supplement as claimed in claim 1, wherein the silicon-based yellow phosphorus slag powder is a byproduct of yellow phosphorus production by an electric furnace method, and is effective in nutrientThe method comprises the following steps: siO (SiO) ₂ 30％～38％，CaO 29％～35％，MgO 1％～4％。

5. The acid soil conditioner based on calcium-magnesium supplement according to claim 1, further comprising an organic material, wherein the mass ratio of the phosphorus tailing powder to the organic material is 40-80:5-20.

6. The acid soil conditioner based on calcium and magnesium supplement according to claim 5, wherein the organic materials comprise, but are not limited to, humic acid, peat soil, biochar and organic fertilizer, and the organic matter content is more than or equal to 30%.

7. The acid soil conditioner based on calcium-magnesium supplement according to claim 1, wherein the components are weighed according to the following parts by weight: 40-80 parts of phosphorus tailing powder, 10-20 parts of silicon-based yellow phosphorus slag powder and 5-20 parts of silicate mineral;

pulverizing phosphorus tailing powder, silicon-based yellow phosphorus slag powder and silicate ore, and mixing to obtain the acid soil conditioner based on calcium-magnesium supplement, wherein the water content is 8-12%.

8. Use of the acid soil conditioner based on calcium-magnesium supplement according to any one of claims 1-7 for improving acidified soil, wherein the acid soil conditioner based on calcium-magnesium supplement is applied to the soil surface by broadcasting, ploughing and uniformly mixing with cultivated layer soil after application.

9. The use of the acid soil conditioner based on calcium-magnesium supplement according to claim 8 for improving acidified soil, wherein the acid soil conditioner based on calcium-magnesium supplement is added in an amount of 150-300 kg/mu.