Acid-reducing fertilizing method for southern acidified red soil dry land and application of acid-reducing fertilizing method

Abstract

The invention discloses an acid-reducing and fertility-improving method for southern acidified red soil dry land and application of the acid-reducing and fertility-improving method. The acid-reducing and fertility-improving method can be divided into the following steps that 1, a high-water-solubility soil conditioner is broadcasted to increase the pH value of soil; step 2, applying a compound microbial fertilizer as a base fertilizer; 3, planting leguminous green manure; and 4, returning the leguminous green manure to the field. Aiming at the characteristic of low moisture content of dry land soil, the invention develops a high-water-solubility acid soil conditioner, and the soil pH and organic matter content can be quickly improved; the compound microbial fertilizer containing phosphate ore, potassium feldspar, dolomite and other materials capable of buffering soil acidification is developed, the soil acid buffer capacity is improved, and later soil re-acidification can be prevented; phosphorus-dissolving and potassium-dissolving microorganisms contained in the compound microbial fertilizer can continuously release nutrients in phosphate ore and potassium feldspar, the fertilizer efficiency is lasting, nodule bacteria can be symbiotic with leguminous green manure, the nitrogen fixation efficiency is improved, and the purposes of reducing acid and improving fertilizer are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil improvement, and particularly relates to a method for acid reduction and fertility improvement of acidified red soil dryland in the south and its application. Background Art

[0002] Red soil is the largest part of the soils in China, covering an area of about 2.18 million square kilometers, accounting for 21.8% of the total land area of the country. Among them, the cultivated land area in the red soil region accounts for about 28% of the total cultivated land area in the country. However, the red soil region is not a fertile land. In Hunan, more than two-thirds of the low-yield cultivated land in the red soil region. Unreasonable fertilization and tillage utilization have further exacerbated the degradation of red soil. Red soil is a soil formed by the interaction of the processes of desilication and enrichment of aluminum and the biological enrichment. Chemical elements such as iron and aluminum become relatively accumulated as oxides and hydroxides, making the soil red. The main characteristics of red soil are "acidic, sticky, and infertile". Acidic means that its pH value is generally low and it is also very easy to continue to decrease. Sticky refers to its form, usually sticking together in a mass, not loose enough, and not easy to breathe and permeate water. Infertile mainly refers to its low fertility and low organic matter content, all of which are conditions unfavorable for crop growth.

[0003] Although there are various methods for improving acidic soil, each has its limitations. The currently commonly used method is still to apply soil amendments. Among them, the application of lime has better improvement effect and lower cost. However, the application of lime only significantly increases the soil pH in the short term and does not completely solve the problems of "acidic, sticky, and infertile" of the soil. Long-term application will lead to soil compaction and even re-acidification. Summary of the Invention

[0004] In view of the technical problems existing in the prior art, the present invention provides a method for acid reduction and fertility improvement of acidified red soil dryland in the south and its application, which can effectively increase soil organic matter, improve soil structure, solve the problems of "acidic, sticky, and infertile" of the soil, and promote plant growth.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for acid reduction and fertility improvement of acidified red soil dryland in the south, the acid reduction and fertility improvement method can be divided into the following steps: Step 1: Spread a highly water-soluble soil conditioner to increase the soil pH; Step 2: Apply a compound microbial fertilizer as a base fertilizer; Step 3: Plant leguminous green manure; Step 4: Return the leguminous green manure to the field.

[0007] Preferably, the highly water-soluble soil conditioner is a mixture of mineral source fulvic acid potassium, humic acid potassium and potassium carbonate.

[0008] Preferably, the mixing ratio of the mineral-source fulvic acid potassium, humic acid potassium and potassium carbonate is 30-60:30-60:10-20.

[0009] Preferably, the mineral-source fulvic acid content of the mineral-source fulvic acid potassium ≥50%, and the soluble humic acid content of the humic acid potassium ≥60%.

[0010] Preferably, the preparation method of the compound microbial fertilizer is as follows: Step a: After activating and expanding the culture of phosphate-solubilizing bacteria, potassium-solubilizing bacteria, and rhizobia respectively, centrifuge to obtain bacterial cells A, B, and C, and prepare them into bacterial suspensions of 3.0×10 8 cfu / mL - 1.0×10 9 cfu / mL; Step b: Add attapulgite clay to sulfuric acid with a mass-to-volume ratio of 1-4:10 and a concentration of 2 mol / L, stir and react for 2 h, wash to neutrality, dry and crush, and then mix with wheat straw biochar in a ratio of 1:1-5; Step c: Add the mixture in step b to the 3 kinds of bacterial suspensions respectively according to a solid-to-liquid ratio of 1-4:10 to adsorb microorganisms. After the adsorption is completed, centrifuge and freeze-dry to obtain 3 kinds of microbial agents, and the combination of the 3 kinds of microbial agents is a compound microbial agent. Step d: Mix tea seed cake, rapeseed cake, straw, mushroom residue, attapulgite clay, and raw materials of medium and trace element fertilizers in a ratio of 40-60:10-30:5-15:5-15:2-8:0.1-3, add fermentation agents and adjust the moisture to 50%-60%, and compost and ferment until mature to obtain organic fertilizer. Step e: Mix the organic fertilizer, phosphate rock powder, potassium feldspar powder, dolomite powder, compound fertilizer, and compound microbial agent evenly in a ratio of 30-60:5-20:5-20:5-20:10-30:5-20 to obtain the compound microbial fertilizer.

[0011] Preferably, the particle size of the phosphate rock powder, potassium feldspar powder, and dolomite powder is not less than 100 mesh.

[0012] Preferably, the compound fertilizer is a balanced compound fertilizer with a total nutrient content ≥45%; the leguminous green manure is one of hairy vetch and common vetch.

[0013] Preferably, the application method of the highly water-soluble soil conditioner is: apply it on the soil surface 10-15 days before planting, plow and mix evenly, and wait for the soil to be infiltrated by rain or sprinkle water to infiltrate the soil, with a dosage of 50-100 kg / mu.

[0014] Preferably, the compound microbial fertilizer is used as a base fertilizer, and 100- 200 kg is applied per mu before planting.

[0015] Application of an acid-reducing and soil-fertilizing method for acidified red upland soils in the south, where the acid-reducing and soil-fertilizing method is applied to upland soils in the south with a pH of 5.0 - 5.5

[0016] Advantages of the present invention: The present invention selects a composite of organic and inorganic remediation materials with high water solubility, combined with the application method, to enable the rapid dissolution and penetration of the remediation materials, quickly improve the soil, and is more suitable for improving upland soils with less water content; biochar and attapulgite in the microbial inoculant can improve the soil structure, increase the water and fertilizer retention capacity of the soil, and improve fertilizer efficiency; phosphate rock, potassium feldspar, and dolomite can be used as soil pH stabilizers to prevent soil acidification, and in combination with phosphorus- and potassium-solubilizing microorganisms, can continuously provide phosphorus and potassium nutrients; in addition, by returning green manure to the field, the soil organic matter and nitrogen content are effectively increased. Through the combined use of a series of measures, the problems of "acidic, sticky, and infertile" soil are fundamentally solved. Specific embodiments

[0017] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0018] Method for preparing the soil conditioner: (1) Mix potassium fulvate from mineral sources, potassium humate, and potassium carbonate in a ratio of 40:50:10. (2) Mix potassium fulvate from mineral sources, potassium humate, and potassium carbonate in a ratio of 30:60:10. (3) Mix potassium fulvate from mineral sources, potassium humate, and potassium carbonate in a ratio of 60:30:10. (4) Mix potassium fulvate from mineral sources, potassium humate, and potassium carbonate in a ratio of 40:40:20.

[0019] Method for preparing the compound microbial fertilizer: Step a: After activating and expanding the culture of phosphorus-solubilizing bacteria, potassium-solubilizing bacteria, and rhizobia respectively, centrifuge to obtain bacterial cells A, B, and C, and prepare them into a bacterial suspension of 5.0×10 8 cfu / mL. Step b: Add attapulgite to sulfuric acid with a mass-volume ratio of 1:10 and a concentration of 2 mol / L, stir and react for 2 h, wash to neutrality, dry and crush, and then mix with wheat straw biochar in a ratio of 1:2. Step c: Add the mixture in step b to 3 kinds of bacterial suspensions respectively according to a solid-liquid ratio of 1:10 to adsorb microorganisms. After the adsorption is completed, centrifuge and freeze-dry to obtain 3 kinds of microbial inoculants respectively. The 3 kinds of microbial inoculants are combined into a composite microbial inoculant according to a ratio of 1:1:1. Step d: Mix raw materials such as tea seed cake, rapeseed cake, straw, mushroom residue, attapulgite clay, and medium and trace element fertilizers in a ratio of 54:20:10:10:5:1, add a fermentation inoculant and adjust the moisture to 50%-60%, and carry out compost fermentation until maturity to obtain organic fertilizer. Step e: (1) Mix the organic fertilizer, rock phosphate powder, potassium feldspar powder, dolomite powder, compound fertilizer, and microbial inoculant evenly in a ratio of 40:10:10:10:20:10 to obtain the composite microbial fertilizer. (2) Mix the organic fertilizer, rock phosphate powder, potassium feldspar powder, dolomite powder, compound fertilizer, and microbial inoculant evenly in a ratio of 30:20:10:10:20:10 to obtain the composite microbial fertilizer. (3) Mix the organic fertilizer, rock phosphate powder, potassium feldspar powder, dolomite powder, compound fertilizer, and microbial inoculant evenly in a ratio of 60:15:5:5:10:5 to obtain the composite microbial fertilizer. (4) Mix the organic fertilizer, rock phosphate powder, potassium feldspar powder, dolomite powder, compound fertilizer, and microbial inoculant evenly in a ratio of 50:10:10:10:10:10 to obtain the composite microbial fertilizer.

[0020] Example 1

[0021] Add the 4 kinds of soil conditioners T1-T4 prepared above to beakers containing 1 kg of red soil at a ratio of 0.1% respectively. The addition method is to dissolve in deionized water and evenly sprinkle on the soil surface, then continue to add water to keep the soil at 90% of the field water holding capacity, cover the cup mouth with plastic wrap, make holes in the plastic wrap, and place it in a constant temperature incubator at 25°C for 30 d. Use the addition of deionized water CK as a control, and repeat each treatment 3 times. After the cultivation is completed, measure the physical and chemical indexes of the soil.

[0022] Test results: It can be seen from the experimental results shown in Table 1 that the 4 kinds of soil conditioners provided by the present invention can effectively increase the soil pH, increase the soil organic matter content, and enhance the soil fertility, and the improvement effect of T1 is more balanced. Table 1 Indexes of each treatment after soil cultivation

[0023] Example 2

[0024] The four kinds of compound microbial fertilizers T1 - T4 prepared above were respectively added to beakers containing 1 kg of red soil at a ratio of 0.1%. The addition method was to mix evenly with the soil, add water to keep the soil at 90% of the field water holding capacity, cover the cup mouth with plastic wrap, make holes in the plastic wrap, and place it in an incubator at a constant temperature of 25°C for 30 days. Deionized water CK was added as a control, and each treatment was repeated 3 times. After the cultivation ended, the physical and chemical indexes of the soil were measured. Table 2 Indexes of each treatment after soil cultivation

[0025] Test results: As can be seen from the experimental results shown in Table 1, the four kinds of compound microbial fertilizers provided by the present invention can effectively increase the soil pH, increase the soil organic matter content, and enhance the soil fertility. Among them, the improvement effect of T1 is more balanced.

[0026] Example 3

[0027] The acid reduction and soil fertility improvement method comprises the following steps: Step 1: Apply 50 - 100 kg / acre of highly water-soluble soil conditioner (1) 10 - 15 days before planting; Step 2: Apply 100 - 200 kg / acre of compound microbial fertilizer (1) as the base fertilizer; Step 3: Plant Vicia villosa or Vicia sativa; Step 4: Incorporate Vicia villosa or Vicia sativa into the field. The acid reduction and soil fertility improvement method provided in Example 1 was used for the test. 1. Test location: Beishan Town, Changsha County, Hunan Province. 2. Test time: April 2024 - June 2024. 3. Field test design: Different plots were selected on the same plot and furrows were opened and ridges were formed respectively. Soil samples of each treatment were collected for detection before applying the soil conditioner and 1 month after incorporating the green manure.

[0028] The test treatments were as follows: T1: Apply 50 kg / acre of highly water-soluble soil conditioner 15 days before planting, apply 100 kg / acre of compound microbial fertilizer as the base fertilizer, and plant Vicia villosa; T2: Apply 100 kg / acre of highly water-soluble soil conditioner 15 days before planting, apply 100 kg / acre of compound microbial fertilizer as the base fertilizer, and plant Vicia villosa; T3: Apply 50 kg / acre of highly water-soluble soil conditioner 15 days before planting, apply 200 kg / acre of compound microbial fertilizer as the base fertilizer, and plant Vicia villosa; T4: Apply 100 kg / acre of highly water-soluble soil conditioner 15 days before planting, and apply 200 kg / acre of compound microbial fertilizer as base fertilizer, then plant hairy vetch; T5: Apply 100 kg / acre of highly water-soluble soil conditioner 15 days before planting, and apply 100 kg / acre of compound microbial fertilizer as base fertilizer, then plant common vetch; CK1: No treatment; CK2: Apply 100 kg / acre of quicklime 15 days before planting. CK3: Apply 100 kg / acre of ordinary organic fertilizer as base fertilizer.

[0029] Test results Conduct tests using the acid reduction and soil fertility improvement method provided in Example 3, and the results are shown in Table 3 and Table 4. Table 3 Indexes of each treatment before planting Table 4 Indexes of each treatment after planting

[0030] As can be seen from the experimental results shown in Table 3 and Table 4, the acid reduction and soil fertility improvement method provided by the present invention can effectively increase the soil pH, increase the soil organic matter content, and enhance the soil fertility. It can be predicted that by applying the acid reduction and soil fertility improvement and restoration method of the present invention, the cultivated land grade can be improved.

[0031] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for acid reduction and soil fertility improvement in acidified red soil dryland in the south, characterized in that: The acid reduction and soil fertility improvement method can be divided into the following steps: Step 1: Spread a highly water-soluble soil conditioner to increase the soil pH. Step 2: Apply a compound microbial fertilizer as the base fertilizer. Step 3: Plant leguminous green manure. Step 4: Return the leguminous green manure to the field.

2. A method for acid reduction and soil fertility improvement in acidified red soil dryland in the south, according to claim 1, characterized in that: The highly water-soluble soil conditioner described is a mixture of mineral source fulvic acid potassium, humic acid potassium, and potassium carbonate.

3. A method for acid reduction and fertility improvement in acidified red soil dryland in the south, according to claim 2, characterized in that: The mixing ratio of the mineral source fulvic acid potassium, humic acid potassium, and potassium carbonate is 30 - 60:30 - 60:10 - 20.

4. A method for acid reduction and fertility improvement in acidified red soil dryland in the south, according to claim 2, characterized in that: The mineral source fulvic acid content of the mineral source fulvic acid potassium is ≥50%, and the soluble humic acid content of the humic acid potassium is ≥60%.

5. A method for acid reduction and soil fertility improvement in acidified red soil dryland in the south, as claimed in claim 1, wherein: The preparation method of the compound microbial fertilizer is as follows: Step a: After separately activating and expanding the culture of phosphate-solubilizing bacteria, potassium-solubilizing bacteria, and rhizobia, centrifuge to obtain bacterial cells A, B, and C, and separately prepare bacterial suspensions with a concentration of 3.0×10 8 cfu / mL - 1.0×10 9 cfu / mL; Step b: Add attapulgite clay to sulfuric acid with a mass-to-volume ratio of 1 - 4:10 and a concentration of 2 mol / L, stir and react for 2 h, wash to neutral, dry and crush, and then mix with wheat straw biochar in a ratio of 1:1 - 5. Step c: Add the mixture in Step b to 3 kinds of bacterial suspensions according to a solid-to-liquid ratio of 1 - 4:10 to adsorb microorganisms. After the adsorption is completed, centrifuge and freeze-dry to obtain 3 kinds of microbial agents respectively, and the 3 kinds of microbial agents are combined into a compound microbial agent. Step d: Mix tea seed cake, rapeseed cake, straw, mushroom residue, attapulgite clay, and raw materials of medium and trace element fertilizers in a ratio of 40 - 60:10 - 30:5 - 15:5 - 15:2 - 8:0.1 - 3, add a fermentation agent and adjust the moisture to 50% - 60%, and compost and ferment until mature to obtain organic fertilizer. Step e: Mix the organic fertilizer, phosphorus ore powder, potassium feldspar powder, dolomite powder, compound fertilizer, and compound microbial agent evenly in a ratio of 30 - 60:5 - 20:5 - 20:5 - 20:10 - 30:5 - 20 to obtain the compound microbial fertilizer.

6. A method for acid reduction and fertility improvement in acidified red soil dryland in the south, according to claim 5, characterized in that: The particle size of the phosphorus ore powder, potassium feldspar powder, and dolomite powder is not less than 100 mesh; the compound fertilizer is a balanced compound fertilizer with a total nutrient content of ≥45%.

7. A method for acid reduction and soil fertility improvement in acidified red soil dryland in the south, according to claim 1, characterized in that: The leguminous green manure is one of hairy vetch or common vetch.

8. A method for acid reduction and soil fertility improvement in acidified red soil dryland in the south, as claimed in claim 1, wherein The usage method of the highly water-soluble soil conditioner is: Spread it on the soil surface 10 - 15 days before planting, plow and mix evenly, and wait for the soil to be infiltrated by rain or sprinkle water to infiltrate the soil, with a dosage of 50 - 100 kg / mu.

9. A method for acid reduction and fertility improvement in acidified red soil dryland in the south, as claimed in claim 1, wherein: The compound microbial fertilizer is used as the base fertilizer, and 100 - 200 kg is applied per mu before planting.

10. Use of any of the acid-reducing and fertility-improving methods for acidified red soil dryland in the south as described in claims 1-9, characterized in that: The acid reduction and soil fertility improvement method is applied to southern dryland soils with a pH of 5.0 - 5.5.

Images