Method for improving soil fertility of sandy grassland by using green manure

Abstract

The application belongs to the technical field of desertification control, and particularly relates to a method for improving soil fertility of desertification grassland by using green manure, which utilizes green manure to improve soil fertility of desertification grassland by adopting the measures of sowing green manure, fertilizing and managing green manure, plowing green manure, applying organic fertilizer and long-term management. The organic fertilizer is a fertilizer prepared by loading organic matter on silicon-based phosphogypsum modified fly ash. Planting green manure in desertification grassland can improve soil structure, increase soil organic matter, improve soil fertility, promote the formation of soil aggregate structure, enhance the water and fertilizer retention capacity of soil, promote the biodiversity of grassland, increase the number of plant populations and vegetation coverage, and improve the productivity and ecological stability of grassland. In addition, the organic fertilizer can also reduce the use amount of chemical fertilizers and pesticides, reduce environmental pollution, convert industrial waste into a fertilizer with high utilization value, and reduce the negative impact on the environment.

Description

Technical Field

[0001] This invention belongs to the field of desertification control technology, specifically relating to a method for improving soil fertility in desertified grasslands using green manure. Background Technology

[0002] Desertified grassland soils, due to their loose, dry, and infertile nature, suffer from poor water retention, low nutrient content, and are susceptible to wind and water erosion. Therefore, improving their fertility and water retention capacity is crucial. Green manure, a plant with high biomass and rapid growth, plays a vital role in improving desertified grassland soils. During its growth, green manure's roots and leaves secrete large amounts of organic matter, increasing soil organic matter, improving soil structure, and enhancing water retention. Furthermore, green manure, through the action of roots and microorganisms, decomposes organic matter, releasing abundant nutrients and further improving soil fertility. Therefore, green manure is considered an important organic fertilizer, playing a vital role in improving soil quality and increasing crop yields.

[0003] In existing technologies, both phosphogypsum and fly ash are industrial wastes. Phosphorus and fluorine in phosphogypsum can pollute soil and water sources, while heavy metals in fly ash can negatively impact the environment and human health. Furthermore, traditional fertilizers have limited effectiveness in desertified grasslands. For example, when phosphate fertilizer is applied to desertified grassland soil, it is easily chemically adsorbed and fixed into inorganic phosphorus forms that are difficult for plants to utilize, resulting in a utilization rate of only 10%-20% in the current season. Summary of the Invention

[0004] The purpose of this invention is to provide a method for improving soil fertility in desertified grasslands by using green manure. This method involves sowing green manure, tilling green manure, applying organic fertilizer, and long-term management to improve soil fertility in desertified grasslands.

[0005] The technical problem this invention aims to solve is that traditional fertilizers have limited effectiveness in desertified grasslands.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for improving soil fertility in desertified grassland using green manure includes the following steps:

[0008] S1. Green manure seeds are sown in desertified grassland using a monoculture method;

[0009] S2. After sowing, apply fertilizer to the green manure, using 8-10 kg of nitrogen fertilizer, 5-7 kg of phosphorus fertilizer and 7-8 kg of potassium fertilizer per mu.

[0010] S3. When the green manure is in its initial or full bloom stage, till the soil and press the green manure into the sandy grassland.

[0011] S4. After the green manure is plowed, apply 15-20 kg of organic fertilizer per acre. After fertilization, carry out long-term management, including watering, weeding and pest and disease control measures.

[0012] The green manure in steps S1-S4 includes one or more of alfalfa, milkvetch, sweet clover, and hairy vetch.

[0013] In step S1, the planting density is 4,000-5,000 plants per acre, the plant spacing is 10-15cm, and the soil covering thickness is 0.5-1cm.

[0014] Furthermore, the organic fertilizer in step S4 is prepared by the following steps:

[0015] A1. Disperse phosphogypsum ultrasonically in a 30wt% sulfuric acid solution, control the temperature at 80℃-90℃, stir evenly, soak for 40min-60min, filter, discard the filtrate, wash, transfer to a stainless steel polytetrafluoroethylene-lined high-temperature reactor, add fly ash, heat to 800℃-1000℃ at a rate of 5℃ / min, calcine under nitrogen protection for 2h-3h, cool to room temperature, wash, dry, add silane coupling agent dropwise, stir evenly, and obtain silicon-based phosphogypsum modified fly ash;

[0016] A2. Put agricultural and sideline products into a crusher for crushing, sieve through a 200-mesh sieve, wash, dry, put into a tank for fermentation, adjust the moisture content to 40%-60%, turn the pile and aerate regularly, compost for 10-14 days to obtain organic matter.

[0017] A3. Mix silicon-based phosphogypsum-modified fly ash and organic matter in a mixer, add microbial agents, urea, potassium nitrate and humus, mix evenly to obtain organic fertilizer.

[0018] In step A1, the ratio of phosphogypsum, sulfuric acid, fly ash and silane coupling agent is (3-4) g: (5-6) mL: (2-3) g: (0.5-0.7) mL.

[0019] The silane coupling agent in step A1 includes one or more of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri(β-methoxyethoxy)silane.

[0020] The agricultural by-products in step A2 include one or more of straw, rice bran, bean pods, sawdust, and grass powder.

[0021] The microbial preparations in step A3 include one or more of the following: rhizobium inoculants, nitrogen-fixing bacteria inoculants, phosphate-solubilizing microbial inoculants, photosynthetic bacteria inoculants, silicate microbial inoculants, and mycorrhizal fungi inoculants.

[0022] The organic fertilizer in step A3, by weight, includes 150-160 parts of silicon-based phosphogypsum modified fly ash, 200-220 parts of organic matter, 5-10 parts of microbial preparation, 15-20 parts of urea, 13-15 parts of potassium nitrate, and 30-40 parts of humus.

[0023] The beneficial effects of this invention are:

[0024] 1. In the technical solution of this invention, planting green manure in desertified grassland can improve soil structure, increase soil organic matter, enhance soil fertility, promote the formation of soil aggregates, strengthen the soil's water and fertilizer retention capacity, promote grassland biodiversity, increase plant populations and vegetation cover, and improve grassland productivity and ecological stability. Furthermore, green manure can reduce the use of chemical fertilizers and pesticides, thus reducing agricultural pollution to the environment.

[0025] 2. In the technical solution of this invention, fluorine and heavy metals in phosphogypsum and fly ash are removed by high-temperature calcination. Furthermore, in the molten state, the molecules and atoms of the two substances diffuse into each other within a silicon-based framework. Under the influence of strong interaction forces, a composite structure with a large specific surface area and numerous pores is formed, which can improve the structure and properties of the soil, enhancing its aeration and water retention. Simultaneously, this material can also promote the growth and reproduction of microorganisms in the soil, further improving soil quality.

[0026] 3. In the technical solution of this invention, the fertilizer formed by combining silicon-based phosphogypsum-modified fly ash in a molten state has high fertilizer efficiency and can provide comprehensive nutrition for crops. This fertilizer improves soil structure and properties, increases soil organic matter content, enhances soil biological activity, promotes crop growth and development, and improves crop yield and quality. Simultaneously, this fertilizer reduces environmental pollution, transforming industrial waste into a fertilizer with high utilization value, thus reducing negative environmental impacts. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] Organic fertilizer is prepared through the following steps:

[0030] A1. Disperse 30g of phosphogypsum ultrasonically in 50mL of 30wt% sulfuric acid solution, control the temperature at 85℃, stir evenly, soak for 40min, filter, discard the filtrate, wash, transfer to a stainless steel polytetrafluoroethylene-lined high-temperature reactor, add 20g of fly ash, heat to 900℃ at a rate of 5℃ / min, calcine for 2h under nitrogen protection, cool to room temperature, wash, dry, add 5mL of silane coupling agent dropwise, stir evenly, and obtain silicon-based phosphogypsum modified fly ash.

[0031] A2. Put agricultural and sideline products into a crusher for crushing, sieve through a 200-mesh sieve, wash, dry, put into a tank for fermentation, adjust the moisture content to 50%, turn the pile and aerate regularly, compost for 10 days to obtain organic matter.

[0032] A3. Mix 150 parts by weight of silicon-based phosphogypsum modified fly ash and 200 parts by weight in a mixer, add 5 parts by weight of microbial preparation, 15 parts by weight of urea, 13 parts by weight of potassium nitrate and 30 parts by weight of humus, mix evenly to obtain organic fertilizer.

[0033] Example 2

[0034] Organic fertilizer is prepared through the following steps:

[0035] A1. Disperse 35g of phosphogypsum ultrasonically in 55mL of 30wt% sulfuric acid solution, control the temperature at 85℃, stir evenly, soak for 40min, filter, discard the filtrate, wash, transfer to a stainless steel polytetrafluoroethylene-lined high-temperature reactor, add 25g of fly ash, heat to 900℃ at a rate of 5℃ / min, calcine for 2h under nitrogen protection, cool to room temperature, wash, dry, add 6mL of silane coupling agent dropwise, stir evenly, and obtain silicon-based phosphogypsum modified fly ash.

[0036] A2. Put agricultural and sideline products into a crusher for crushing, sieve through a 200-mesh sieve, wash, dry, put into a tank for fermentation, adjust the moisture content to 50%, turn the pile and aerate regularly, compost for 10 days to obtain organic matter.

[0037] A3. Mix 155 parts by weight of silicon-based phosphogypsum modified fly ash and 210 parts by weight in a mixer, add 7.5 parts by weight of microbial preparation, 17.5 parts by weight of urea, 14 parts by weight of potassium nitrate and 35 parts by weight of humus, mix evenly to obtain organic fertilizer.

[0038] Example 3

[0039] Organic fertilizer is prepared through the following steps:

[0040] A1. Disperse 40g of phosphogypsum ultrasonically in 60mL of 30wt% sulfuric acid solution, control the temperature at 85℃, stir evenly, soak for 40min, filter, discard the filtrate, wash, transfer to a stainless steel polytetrafluoroethylene-lined high-temperature reactor, add 30g of fly ash, heat to 900℃ at a rate of 5℃ / min, calcine for 2h under nitrogen protection, cool to room temperature, wash, dry, add 7mL of silane coupling agent dropwise, stir evenly, and obtain silicon-based phosphogypsum modified fly ash.

[0041] A2. Put agricultural and sideline products into a crusher for crushing, sieve through a 200-mesh sieve, wash, dry, put into a tank for fermentation, adjust the moisture content to 50%, turn the pile and aerate regularly, compost for 10 days to obtain organic matter.

[0042] A3. Mix 160 parts by weight of silicon-based phosphogypsum modified fly ash and 220 parts by weight in a mixer, add 10 parts by weight of microbial preparation, 20 parts by weight of urea, 15 parts by weight of potassium nitrate and 40 parts by weight of humus, mix evenly to obtain organic fertilizer.

[0043] Example 4

[0044] A method for improving soil fertility in desertified grassland using green manure includes the following steps:

[0045] S1. Green manure seeds are sown in desertified grassland using a monoculture method, with a planting density of 4,000 plants per mu, a plant spacing of 10 cm, and a soil covering thickness of 0.5 cm.

[0046] S2. After sowing, apply fertilizer to the green manure, using 8 kg of nitrogen fertilizer, 5 kg of phosphorus fertilizer and 7 kg of potassium fertilizer per mu.

[0047] S3. When the green manure is in its initial or full bloom stage, till the soil and press the green manure into the sandy grassland.

[0048] S4. After the green manure is plowed, apply 15 kg of the organic fertilizer prepared in Example 1 per acre. After fertilization, carry out long-term management, including watering, weeding and pest and disease control measures.

[0049] Example 5

[0050] A method for improving soil fertility in desertified grassland using green manure includes the following steps:

[0051] S1. Green manure seeds are sown in desertified grassland using a monoculture method, with a planting density of 4,500 plants per mu, a plant spacing of 12.5 cm, and a soil covering thickness of 0.75 cm.

[0052] S2. After sowing, apply fertilizer to the green manure, using 8 kg of nitrogen fertilizer, 5 kg of phosphorus fertilizer and 7 kg of potassium fertilizer per mu.

[0053] S3. When the green manure is in its initial or full bloom stage, till the soil and press the green manure into the sandy grassland.

[0054] S4. After the green manure is plowed, apply 15 kg of the organic fertilizer prepared in Example 2 per acre. After fertilization, carry out long-term management, including watering, weeding and pest and disease control measures.

[0055] Example 6

[0056] A method for improving soil fertility in desertified grassland using green manure includes the following steps:

[0057] S1. Green manure seeds are sown in desertified grassland using a monoculture method, with a planting density of 5,000 plants per mu, a plant spacing of 15cm, and a soil covering thickness of 1cm.

[0058] S2. After sowing, apply fertilizer to the green manure, using 8 kg of nitrogen fertilizer, 5 kg of phosphorus fertilizer and 7 kg of potassium fertilizer per mu.

[0059] S3. When the green manure is in its initial or full bloom stage, till the soil and press the green manure into the sandy grassland.

[0060] S4. After the green manure is plowed, apply 15 kg of the organic fertilizer prepared in Example 3 per acre. After fertilization, carry out long-term management, including watering, weeding and pest and disease control measures.

[0061] According to GB 19377-2003 "Classification Indicators for Degradation, Desertification, and Salinization of Natural Grasslands", moderately desertified grasslands were selected, and a blank control group was set up. The methods in Examples 4-6 were used to improve the soil fertility of the moderately desertified grasslands. After 240 days of treatment, the degree of grassland desertification is shown in Table 1:

[0062] Table 1. Degree of grassland desertification in Examples 4-6 and the control group (after 240 days)

[0063]

[0064] As shown in Table 1, the grassland desertification control in Examples 4-6 was significantly effective. According to the provisions of GB 19377-2003 "Classification Indicators for Degradation, Desertification and Salinization of Natural Grassland", the grassland was restored to the non-desertification level after treatment. This shows that the soil fertility of desertified grassland can be improved by adopting measures such as sowing green manure, tilling green manure, applying organic fertilizer and long-term management.

[0065] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0066] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for improving soil fertility in desertified grassland using green manure, characterized in that, Includes the following steps: S1. Green manure seeds are sown in desertified grassland using a monoculture method; S2. After sowing, apply fertilizer to the green manure, using 8-10 kg of nitrogen fertilizer, 5-7 kg of phosphorus fertilizer and 7-8 kg of potassium fertilizer per mu. S3. When the green manure is in its initial or full bloom stage, till the soil and press the green manure into the sandy grassland. S4. After the green manure is plowed, apply 15-20 kg of organic fertilizer per mu. After fertilization, carry out long-term management, including watering, weeding and pest and disease control measures. The organic fertilizer in step S4 is prepared by the following steps: A1. Disperse phosphogypsum ultrasonically in a 30wt% sulfuric acid solution, control the temperature at 80℃-90℃, stir evenly, soak for 40min-60min, filter, discard the filtrate, wash, transfer to a stainless steel polytetrafluoroethylene-lined high-temperature reactor, add fly ash, heat to 800℃-1000℃ at a rate of 5℃ / min, calcine under nitrogen protection for 2h-3h, cool to room temperature, wash, dry, add silane coupling agent dropwise, stir evenly, and obtain silicon-based phosphogypsum modified fly ash; A2. Put agricultural and sideline products into a crusher for crushing, sieve through a 200-mesh sieve, wash, dry, put into a tank for fermentation, adjust the moisture content to 40%-60%, turn the pile and aerate regularly, compost for 10-14 days to obtain organic matter. A3. Mix silicon-based phosphogypsum-modified fly ash and organic matter in a mixer, add microbial agents, urea, potassium nitrate and humus, mix evenly to obtain organic fertilizer; In step A1, the ratio of phosphogypsum, sulfuric acid, fly ash, and silane coupling agent is (3-4) g : (5-6) mL : (2-3) g : (0.5-0.7) mL; The silane coupling agent in step A1 includes one or more of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri(β-methoxyethoxy)silane; The agricultural by-products in step A2 include one or more of straw, rice bran, bean pods, sawdust, and grass powder; The microbial preparations in step A3 include one or more of the following: rhizobium inoculants, nitrogen-fixing bacteria inoculants, phosphate-solubilizing microbial inoculants, photosynthetic bacteria inoculants, silicate microbial inoculants, and mycorrhizal fungi inoculants. The organic fertilizer in step A3, by weight, includes 150-160 parts of silicon-based phosphogypsum modified fly ash, 200-220 parts of organic matter, 5-10 parts of microbial preparation, 15-20 parts of urea, 13-15 parts of potassium nitrate, and 30-40 parts of humus.

2. The method for improving soil fertility in desertified grassland using green manure according to claim 1, characterized in that, The green manure in steps S1-S4 includes one or more of alfalfa, milkvetch, sweet clover, and hairy vetch.

3. The method for improving soil fertility in desertified grassland using green manure according to claim 1, characterized in that, In step S1, the planting density is 4,000-5,000 plants per acre, the plant spacing is 10-15cm, and the soil covering thickness is 0.5-1cm.

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