A method for improving soil phosphorus

Abstract

The present invention relates to the technical field of soil phosphorus improvement, and more particularly to a soil phosphorus improvement method, wherein soil samples are collected at multiple sampling points in a fir forest, and the initial available phosphorus content and pH value of the soil are detected; different phosphate fertilizers are added to soils with different available phosphorus contents; a composite modifier solution is mixed with porous carbon to obtain modified porous carbon, which is sprinkled on the soil after fertilization to obtain improved soil; the improved soil is repeatedly tested every month within half a year, and corresponding treatment is performed; after half a year, green manure plants are planted under the fir forest, and the green manure plants are mowed when they grow to the flowering stage, and are covered and returned to the forest or composted and then returned to the forest. The present invention adopts a soil phosphorus improvement method of the above steps, specifically selects different types of phosphate fertilizers and controls their dosage, and the precision fertilization strategy cooperates with subsequent soil improvement measures, greatly improving the effectiveness and utilization rate of phosphorus in the soil and reducing the waste of phosphate fertilizers.

Description

Technical Field

[0001] The present invention relates to the technical field of soil phosphorus improvement, and in particular to a soil phosphorus improvement method. Background Art

[0002] Chinese fir is a highly valuable fast-growing timber species in my country and occupies an important position in the forestry industry, especially in timber production. However, due to the establishment of pure Chinese fir forests and continuous planting for multiple generations, soil quality has been declining, with soil phosphorus deficiency being a particularly prominent problem. Phosphorus in the soil is an essential nutrient for Chinese fir growth and plays a decisive role in physiological processes such as cell division, photosynthesis, and energy metabolism. The availability of phosphorus in the soil is not static, but is affected by a combination of complex factors. Soil pH is a crucial factor. In acidic soil environments, the content of iron and aluminum oxides in the soil is high. These substances easily react chemically with phosphate ions to form insoluble phosphates, which leads to a significant reduction in the available phosphorus content in the soil.

[0003] In addition, soil organic matter content also has a significant impact on phosphorus availability. Soils rich in organic matter can provide more adsorption sites for phosphorus, reducing phosphorus fixation. At the same time, organic matter produces organic acids during decomposition, which can dissolve insoluble phosphorus in the soil and increase phosphorus availability. However, in the long-term management of Chinese fir forests, due to unreasonable management practices such as over-logging, destruction of understory vegetation, and multiple generations of continuous planting, the soil organic matter content has gradually decreased, further exacerbating the problem of soil phosphorus deficiency.

[0004] Previous reliance on the application of phosphate fertilizers resulted in low phosphate utilization rates, with most of the fertilizer being fixed in the soil and unable to be effectively absorbed and utilized by Chinese fir trees. This resulted in a significant waste of resources and could also cause a series of environmental problems, such as eutrophication of water bodies. Furthermore, traditional methods often overlooked the complexity of soil ecosystems, failing to fundamentally improve the soil's physical and chemical properties and microbial community structure. This resulted in incomplete soil improvement and made it difficult to maintain the long-term productivity and sustainable management of Chinese fir forests. Summary of the Invention

[0005] The purpose of the present invention is to provide a soil phosphorus improvement method to increase the soil phosphorus content and effectiveness, promote the growth of Chinese fir, and increase the productivity and timber accumulation of Chinese fir.

[0006] To achieve the above object, the present invention provides a method for improving soil phosphorus, comprising the following steps:

[0007] S1. Collect soil samples at multiple sampling points in the Chinese fir forest, remove soil debris and roots, and test the initial available phosphorus content and pH value of the soil at different depths.

[0008] S2. Based on the results obtained in S1, a highly water-soluble phosphate fertilizer is added to the soil with low available phosphorus content, a calcium-magnesium phosphate fertilizer is added to the soil with medium available phosphorus content, and a slow-release phosphate fertilizer is added to the soil with high available phosphorus content;

[0009] S3, dissolving the composite modifier in water to prepare a composite modifier solution, mixing the composite modifier solution with porous carbon to obtain modified porous carbon, and spreading the modified porous carbon on the soil after fertilization in S2 to obtain improved soil;

[0010] S4, repeat step S1 on the improved soil in S3 every month for six months, and proceed to step S2 or S3 according to the results;

[0011] S5. Plant green manure plants under the fir forest half a year later. Cut the green manure plants when they reach the blooming stage, and cover them and return them to the forest or compost them before returning them to the forest.

[0012] Preferably, in S1, the number of sampling points is 100-200 per hectare, and the sampling points are evenly distributed in the Chinese fir forest.

[0013] Preferably, in S2, the low available phosphorus content is 3-10 mg / kg, and the amount of high water-soluble phosphate fertilizer added is 100-200 kg / hectare.

[0014] In the present invention, the water-soluble phosphate fertilizer has strong water solubility, can dissolve quickly in water, quickly release phosphate ions, and quickly diffuse into the soil in the form of ions.

[0015] Preferably, in S2, the available phosphorus content is 10-30 mg / kg, and the amount of calcium magnesium phosphate added is 80-150 kg / hectare.

[0016] In the present invention, the calcium magnesium phosphate fertilizer needs to be gradually dissolved and release phosphorus under acidic conditions in the soil or under the action of microorganisms.

[0017] Preferably, in S2, the high available phosphorus content is 30-100 mg / kg, and the amount of slow-release phosphate fertilizer added is 30-80 kg / hectare.

[0018] In the present invention, the slow-release phosphate fertilizer has slow-release and long-lasting effects, and one-time fertilization can continuously provide phosphorus for a long time.

[0019] Preferably, in S3, the composite improver includes one or more of a pH regulator, phosphate-solubilizing bacteria, starch, chitosan, polyethylene oxide, humic acid and amino acids.

[0020] In the present invention, starch, chitosan and polyethylene oxide form a stable flocculation structure in the soil, thereby increasing the water and fertilizer retention capacity of the soil.

[0021] Preferably, in S3, the porous carbon includes one or more of activated carbon, bamboo fiber porous carbon and onion porous carbon.

[0022] In the present invention, the porous carbon can also improve the air permeability and water permeability of the soil and promote the activities of soil microorganisms.

[0023] Preferably, in S3, the mass ratio of the modified porous carbon to the composite modifier is 1:0.5-2, and the addition amount of the composite modifier is 500-3000 kg / hectare.

[0024] Preferably, in S5, the green manure plants include one or more of Chinese milk vetch, vetch, alfalfa, sesbania, radix serrata and lupine.

[0025] Preferably, in S5, litter from the Chinese fir forest is added during composting.

[0026] Therefore, the present invention adopts a soil phosphorus improvement method of the above steps, and its beneficial effects are:

[0027] 1. The improvement method provided by the present invention accurately detects the initial available phosphorus content in the soil, selectively selects different types of phosphorus fertilizers and controls their dosage. The precise fertilization strategy cooperates with subsequent soil improvement measures, greatly improving the effectiveness and utilization rate of phosphorus in the soil and reducing the waste of phosphorus fertilizers.

[0028] 2. In the composite improver used in the present invention, the pH regulator can be adjusted according to the pH value of the soil, creating a suitable living environment for microorganisms such as phosphate-solubilizing bacteria. The phosphate-solubilizing bacteria can secrete organic acids and phosphatase to convert the insoluble phosphorus in the soil into effective phosphorus that can be absorbed by plants. The remaining components can improve the soil structure, increase the soil's water and fertilizer retention capacity, provide nutrition and habitat for phosphate-solubilizing bacteria, and promote their growth and reproduction.

[0029] 3. The present invention improves the physical and chemical properties of the soil and the structure of the microbial community through the synergistic effect of porous carbon and composite modifiers, enhances the solubility, desorption and activation of soil phosphorus, and further improves the effectiveness of soil phosphorus;

[0030] 4. The present invention mows the green manure plants during their peak flowering period and covers and returns them to the forest or composts them before returning them to the forest. This not only increases the organic matter content in the soil and improves the soil structure, but also provides the soil with nitrogen, phosphorus, potassium and other nutrients. This works in conjunction with the previous fertilization regulation, modified porous carbon addition and other measures to form a sustainable soil phosphorus improvement system, which is beneficial to the long-term and stable development of the Chinese fir forest.

[0031] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a schematic flow chart of a soil phosphorus improvement method. DETAILED DESCRIPTION

[0033] The present invention is further described below with reference to the accompanying drawings and examples. Unless otherwise defined, technical or scientific terms used herein shall have the same meanings as those commonly understood by persons of ordinary skill in the art to which the present invention pertains. The above-mentioned features or features described in the specific examples of the present invention may be combined in any manner. These specific examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention.

[0034] Example 1

[0035] like Figure 1 As shown, the present invention provides a method for improving soil phosphorus, comprising the following steps:

[0036] S1. Collect soil samples at multiple sampling points within the Chinese fir forest, with a total of 200 sampling points per hectare, evenly distributed throughout the forest. Remove soil debris and roots. Test the initial available phosphorus content and pH of the surface, middle (10 cm), and bottom (30 cm) soil layers. The average initial available phosphorus content was 5 mg / kg, and the pH was 5.

[0037] S2. Based on the results obtained in S1, the soil of the Chinese fir forest has a low available phosphorus content. A highly water-soluble phosphate fertilizer is added to the soil with a low available phosphorus content, with the amount of the highly water-soluble phosphate fertilizer added being 200 kg / hectare.

[0038] S3. Dissolve a composite modifier (the mass ratio of pH regulator, phosphate-solubilizing bacteria, starch and humic acid is 6:1.5:1:2) in water to prepare a composite modifier solution, mix the composite modifier solution with activated carbon to obtain modified porous carbon, and sprinkle the modified porous carbon on the soil after fertilization in S2, the mass ratio of modified porous carbon to composite modifier is 1:0.5, and the amount of composite modifier added is 3000 kg / hectare to obtain improved soil.

[0039] S4. Repeat step S1 for the improved soil in S3 every month for half a year. When the soil has a low available phosphorus content or a medium available phosphorus content, perform steps S2 and S3. When the soil has a high available phosphorus content, perform step S3.

[0040] S5. Plant green manure plants (milk vetch and alfalfa) under the fir forest half a year later. Cut the green manure plants when they reach the peak flowering period, cover them and return them to the forest or add them to the litter compost in the fir forest and return them to the forest.

[0041] Example 2

[0042] A method for improving soil phosphorus comprises the following steps:

[0043] S1. Soil samples were collected at multiple sampling points within the Chinese fir forest, with 200 sampling points per hectare distributed evenly throughout the forest. Debris and roots were removed from the soil. Initial available phosphorus content and pH values ​​were measured in the surface, middle (10 cm), and bottom (30 cm) layers of the soil. The average initial available phosphorus content was 23 mg / kg, and the pH was 6.5.

[0044] S2. According to the results obtained in S1, the soil of the Chinese fir forest in this embodiment has a medium available phosphorus content, and 100 kg / hectare of calcium magnesium phosphate fertilizer is added to the soil with a medium available phosphorus content.

[0045] S3. Dissolve a composite modifier (the mass ratio of pH regulator, phosphate-solubilizing bacteria, chitosan and amino acid is 4:1.5:1:3) in water to prepare a composite modifier solution, mix the composite modifier solution with bamboo fiber porous carbon to obtain modified porous carbon, the mass ratio of modified porous carbon to composite modifier is 1:1, the amount of composite modifier added is 2000 kg / hectare, and sprinkle the modified porous carbon on the soil after fertilization in S2 to obtain improved soil.

[0046] S4. Repeat step S1 for the improved soil in S3 every month for half a year. If the soil has a medium available phosphorus content, perform steps S2 and S3; if the soil has a high available phosphorus content, perform step S3.

[0047] S5. Plant green manure plants (potato, radish and lupine) under the fir forest half a year later. Cut the green manure plants when they reach the peak flowering period, cover them and return them to the forest or add them to the litter compost in the fir forest and return them to the forest.

[0048] Example 3

[0049] A method for improving soil phosphorus comprises the following steps:

[0050] S1. Collect soil samples at multiple sampling points within the Chinese fir forest, with a total of 200 sampling points per hectare, evenly distributed throughout the forest. Remove soil debris and roots, and test the initial available phosphorus content and pH of the surface, middle (10 cm), and bottom (30 cm) layers of the soil. The average initial available phosphorus content was 40 mg / kg, and the pH was 7.

[0051] S2. According to the result obtained in S1, the soil of the fir forest in this embodiment has a high available phosphorus content. Slow-release phosphate fertilizer is added to the soil with a high available phosphorus content. The amount of slow-release phosphate fertilizer added is 50 kg / hectare.

[0052] S3. Dissolve a composite amendment (pH regulator, phosphate-solubilizing bacteria, polyethylene oxide, and amino acid in a mass ratio of 3:1.5:2:3) in water to prepare a composite amendment solution, mix the composite amendment solution with onion porous carbon to obtain modified porous carbon, the mass ratio of the modified porous carbon to the composite amendment is 1:2, the amount of the composite amendment added is 2500 kg / hectare, and sprinkle the modified porous carbon on the soil after fertilization in S2 to obtain improved soil.

[0053] S4. Repeat step S1 for the improved soil in S3 every month for half a year. When the soil has a high available phosphorus content, proceed to step S3.

[0054] S5. Plant green manure plants (sesbania and alfalfa) under the fir forest half a year later. Cut the green manure plants when they reach the peak flowering period, cover them and return them to the forest or add them to the litter compost in the fir forest and return them to the forest.

[0055] Comparative Example 1

[0056] A method for improving soil phosphorus comprises the following steps:

[0057] S1. Collect soil samples at multiple sampling points within the Chinese fir forest, with a total of 200 sampling points per hectare, evenly distributed throughout the forest. Remove soil debris and roots, and test the initial available phosphorus content and pH of the surface, middle (10 cm), and bottom (30 cm) layers. The average initial available phosphorus content was 5 mg / kg, and the pH was 4.5.

[0058] S2. Based on the results obtained in S1, the soil in this comparative example has a low available phosphorus content. A highly water-soluble phosphate fertilizer is added to the soil with a low available phosphorus content, and the amount of the highly water-soluble phosphate fertilizer added is 200 kg / hectare to obtain improved soil.

[0059] S3. Repeat step S1 for the improved soil in S2 every month for half a year. If the soil has a low or medium available phosphorus content, perform step S2. If the soil has a high available phosphorus content, do not perform any treatment.

[0060] S4. Plant green manure plants (milk vetch and alfalfa) under the fir forest half a year later. Cut the green manure plants when they reach the peak flowering period, cover them and return them to the forest or add them to the litter compost in the fir forest and return them to the forest.

[0061] Test Example 1

[0062] The average value of available phosphorus content of the improved soils in Examples 1-3 and Comparative Example 1 was tested, and the results are shown in Table 1.

[0063] Table 1. Average data of available phosphorus content in soils of Examples 1-3 and Comparative Example 1

[0064]

[0065] As can be seen from Table 1, in Examples 1-3, by adding modified porous carbon, the available phosphorus content in the soil is maintained in a stable range. Through the synergistic effect of porous carbon and the composite modifier, the physical and chemical properties and microbial community structure of the soil are improved, the solubility, desorption and activation capacity of soil phosphorus are improved, and the effectiveness of soil phosphorus is further improved.

[0066] Therefore, the present invention adopts a soil phosphorus improvement method of the above steps, specifically selecting different types of phosphorus fertilizers and controlling their dosage, and the precise fertilization strategy cooperates with subsequent soil improvement measures, which greatly improves the effectiveness and utilization rate of phosphorus in the soil and reduces the waste of phosphorus fertilizers.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for improving soil phosphorus, characterized in that: The following steps are included: S1. Collect soil samples at multiple sampling points within the Chinese fir forest, remove soil debris and roots, and test the initial available phosphorus content and pH value of the soil at different depths. S2. Based on the results obtained in S1, a highly water-soluble phosphate fertilizer is added to the soil of the Chinese fir forest with low available phosphorus content, a calcium-magnesium phosphate fertilizer is added to the soil of the Chinese fir forest with medium available phosphorus content, and a slow-release phosphate fertilizer is added to the soil of the Chinese fir forest with high available phosphorus content; S3, dissolving the composite modifier in water to prepare a composite modifier solution, mixing the composite modifier solution with porous carbon to obtain modified porous carbon, and spreading the modified porous carbon on the soil after fertilization in S2 to obtain improved soil; S4, repeat step S1 on the improved soil in S3 every month for six months, and proceed to step S2 or S3 according to the results; S5. Plant green manure plants under the fir forest half a year later. Cut the green manure plants when they reach the blooming stage, and cover them and return them to the forest or compost them before returning them to the forest.

2. The method for improving soil phosphorus according to claim 1, wherein: In S1, the number of sampling points was 100–200 / ha, and the sampling points were evenly distributed in the fir forest.

3. The method for improving soil phosphorus according to claim 1, wherein: In S2, the low available phosphorus content is 3-10 mg / kg, and the amount of high water-soluble phosphorus fertilizer added is 100-200 kg / hectare.

4. The method for improving soil phosphorus according to claim 1, wherein: In S2, the available phosphorus content is 10-30 mg / kg, and the amount of calcium magnesium phosphate added is 80-150 kg / hectare.

5. The method for improving soil phosphorus according to claim 1, wherein: In S2, the high available phosphorus content is 30-100 mg / kg, and the addition rate of slow-release phosphorus fertilizer is 30-80 kg / hectare.

6. The method for improving soil phosphorus according to claim 1, wherein: In S3, the composite improver includes one or more of a pH regulator, phosphate-solubilizing bacteria, starch, chitosan, polyethylene oxide, humic acid, and amino acids.

7. The method for improving soil phosphorus according to claim 1, wherein: In S3, the porous carbon includes one or more of activated carbon, bamboo fiber porous carbon and onion porous carbon.

8. The method for improving soil phosphorus according to claim 1, wherein: In S3, the mass ratio of the modified porous carbon to the composite modifier is 1:0.5-2, and the addition amount of the composite modifier is 500-3000 kg / hectare.

9. The method for improving soil phosphorus according to claim 1, wherein: In S5, the green manure plants include one or more of: milk vetch, vetch, alfalfa, sesbania, radix serrata, and lupine.

10. The method for improving soil phosphorus according to claim 1, wherein: In S5, litter from the fir forest was added to the compost.

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