Sandy soil matrix soil improvement method

Abstract

The invention discloses a sandy soil matrix soil improvement method, and belongs to the technical field of soil remediation. The method comprises the following steps: loosening to-be-improved gravel matrix soil, applying a soil improvement preparation and watering, and finally airing and sowing soil improvement vegetation to complete sandy soil matrix soil improvement, wherein the soil improvement preparation is prepared from the following components in parts by weight: 80 to 120 parts of straw carbide, 50 to 80 parts of decomposed organic fertilizer, 5 to 10 parts of phosphate, 5 to 10 parts of modified bentonite, 0.1 to 0.5 part of streptomyces microflavus, 0.5 to 0.7 part of bacillus subtilis and 0.1 to 0.5 part of trichoderma harzianum. By improving the water absorption capacity of the soil and the fertility of the soil, growth of vegetation roots is promoted for soil fixation and water utilization, the water storage capacity and the soil fixation capacity of the sandy soil matrix soil are effectively improved, and the sandy soil matrix soil is effectively repaired and improved.

Description

Technical Field

[0001] The invention relates to the technical field of soil remediation, and in particular to a method for improving sandy soil matrix soil. Background Art

[0002] Soil desertification has always been one of the important environmental problems facing mankind. Soil desertification leads to the emergence of a large amount of sandy-based soil. This type of soil has poor water storage capacity and drought resistance, which is not conducive to plant growth and greatly affects the yield and quality of crops. Improving the water storage and soil fixation capacity of sandy-based soil and improving the fertility of sandy-based soil are key issues that need to be urgently addressed.

[0003] Traditional methods of improving sandy soil matrix soil generally use the addition of deposits with strong water absorption capacity to absorb and fix the water in the soil, thereby effectively playing the role of water storage and soil fixation, using a large number of water storage materials such as leaves, algae and moss to absorb water, and then the vegetation absorbs the water in the water storage materials to achieve the increase of water in the sandy soil matrix soil. However, this method has limited ability to improve sandy soil matrix soil, and essentially does not improve the water storage and soil fixation capacity of the sandy soil matrix soil itself. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a sandy soil matrix soil improvement method to solve the problems of poor improvement effect and incomplete improvement of existing sandy soil matrix soil improvement methods.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] A method for improving sandy soil matrix soil comprises the following steps:

[0007] First, loosen the sandy soil matrix to be improved, then apply soil improvement agents and irrigate with water, and finally dry it in the sun and sow soil improvement vegetation to complete the sandy soil matrix soil improvement;

[0008] The soil improvement preparation is composed of the following components in parts by weight:

[0009] 80-120 parts of straw carbonized material, 50-80 parts of decomposed organic fertilizer, 5-10 parts of phosphate, 5-10 parts of modified bentonite, 0.1-0.5 parts of Streptomyces tenuifolius, 0.5-0.7 parts of Bacillus subtilis and 0.1-0.5 parts of Trichoderma harzianum.

[0010] The beneficial effects of the present invention are as follows: the present invention uses straw carbonization, decomposed organic fertilizer, phosphate, modified bentonite and three kinds of microorganisms as raw materials to prepare the soil improvement preparation, and effectively improves the soil fertility through the effects of straw carbonization, decomposed organic fertilizer, phosphate and microorganisms, and effectively improves the soil's ability to absorb water through the combination of straw carbonization and modified bentonite, thereby effectively improving the root growth ability of the sown vegetation, and further realizes the fixation of soil and water through the strong root system of the vegetation, and promotes in both directions, thereby effectively realizing the repair and improvement of the sandy soil matrix soil.

[0011] Furthermore, the soil improvement preparation is composed of the following components in parts by weight:

[0012] 100 parts of straw carbonized material, 65 parts of decomposed organic fertilizer, 8 parts of phosphate, 7 parts of bentonite, 0.3 parts of Streptomyces tenuiflavos, 0.6 parts of Bacillus subtilis and 0.3 parts of Trichoderma harzianum.

[0013] Furthermore, the straw carbonized material is prepared by the following method: corn straw, wheat straw and soybean straw are first chopped and then blended, pyrolyzed and carbonized, and then the carbonized product is sequentially immersed in a citric acid solution and a polyethyleneimine solution, and finally dried to obtain the product.

[0014] Furthermore, the mass ratio of corn straw, wheat straw and soybean straw is 4-6:1-3:1, and the conditions for pyrolysis carbonization are heating to 450-500°C at a heating rate of 4-6°C / min and keeping warm for 2-4h; the mass concentration in the citric acid solution is 1-5%, and the immersion time in the citric acid solution is 4-6h; the mass concentration of the polyethyleneimine solution is 1-5%, and the immersion time in the polyethyleneimine solution is 4-6h; the drying temperature is 70-90°C and the time is 20-30h.

[0015] Preferably, the mass ratio of corn straw, wheat straw and soybean straw is 5:2:1, and the conditions for pyrolysis carbonization are heating to 480°C at a heating rate of 5°C / min and keeping warm for 3 hours; the mass concentration in the citric acid solution is 3%, and the immersion time in the citric acid solution is 5 hours; the mass concentration of the polyethyleneimine solution is 2%, and the immersion time in the polyethyleneimine solution is 5 hours; the drying temperature is 80°C and the time is 24 hours.

[0016] The beneficial effects of adopting the above-mentioned further technical scheme are as follows: the present invention prepares soil improvement preparations using carbonized corn straw, wheat straw and soybean straw as raw materials, which, on the one hand, provides a large amount of available fertility for the soil, and on the other hand, improves the water absorption capacity of the soil through the large amount of carbonized lignin in the straw, thereby avoiding the rapid loss of irrigation water in the early stage of soil restoration, ensuring the root growth of the restored vegetation, and further promoting the water and soil fixing ability of the soil; in addition, by modifying the carbonized material with citric acid and polyethyleneimine, the content of oxygen-containing functional groups on the surface of the carbonized material is increased, thereby effectively improving the adsorption and fixation effect of the carbonized material on water, and improving the soil fixing effect on sandy soil.

[0017] Further, the phosphate includes at least one of calcium phosphate, calcium hydrogen phosphate and hydroxyapatite.

[0018] The beneficial effect of adopting the above further technical solution is that the present invention not only supplements the effective phosphorus content in the soil matrix by adding phosphate, but also improves the water absorption capacity of the soil.

[0019] Furthermore, the modified bentonite is prepared by the following method: immersing calcium-based bentonite in a modifier solution, collecting and drying the precipitate.

[0020] Furthermore, the modifier includes at least one of dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride and octadecyltrimethylammonium chloride, the mass concentration of the modifier solution is 1-3%, the mass volume ratio of calcium-based bentonite and the modifier solution is 10-30g:80-120mL; the immersion time is 1-3h; the drying temperature is 40-60°C, and the time is 8-12h.

[0021] Preferably, the mass concentration of the modifier solution is 2%, the mass volume ratio of calcium-based bentonite to the modifier solution is 20g:100mL; the immersion time is 2h; the drying temperature is 50°C and the time is 10h.

[0022] The beneficial effect of adopting the above-mentioned further technical scheme is as follows: the present invention modifies bentonite and effectively combines quaternary ammonium salt with bentonite to form organic bentonite, which on the one hand improves the cementing effect of bentonite in sandy soil matrix soil and improves the soil-fixing ability; on the other hand, it further improves the ability of bentonite to bind water and enhances the water-fixing ability.

[0023] Furthermore, the application rate of soil improvement agent is 2-4 kg per cubic meter of sandy and gravel matrix soil to be improved, and the watering rate is 5-7 L / m 2 .

[0024] Preferably, the application rate of the soil improvement agent is 3 kg per cubic meter of sandy gravel matrix soil to be improved, and the watering rate is 6 L / m 2 .

[0025] Furthermore, the soil improvement vegetation is bermudagrass, vetiver and clover, the sowing amount is 0.8-1.2:0.8-1.2:0.8-1.2, and the total sowing amount is 20-30g / m 2 .

[0026] Preferably, the soil improving vegetation is bermudagrass, vetiver and clover, the sowing amount is 1:1:1, and the total sowing amount is 25g / m 2 .

[0027] The beneficial effects of adopting the above further technical solution are: perennial Bermuda grass, Vetiver and Clover are heat-resistant, drought-resistant and trample-resistant, grow fast even on slightly saline-alkali land, and have strong invasive ability. After being planted in the restoration site, the plant roots effectively penetrate the rock soil to form a riveting network, thereby stabilizing the sandy soil matrix soil.

[0028] Furthermore, the above-mentioned sandy soil matrix soil improvement method is used in repairing sandy soil matrix soil.

[0029] The present invention has the following beneficial effects:

[0030] The present invention provides a method for improving sandy soil matrix soil. The method effectively improves the water storage capacity and soil fixing capacity of the sandy soil matrix soil by combining a soil improvement preparation and soil improvement vegetation. Through the straw carbonization, decomposed organic fertilizer and modified bentonite in the soil improvement matrix, on the one hand, the lignin carbonization and other substances rich in the straw carbonization and the modified bentonite have strong water absorption capacity and can effectively fix the free water in the soil. On the other hand, the straw carbonization and decomposed organic fertilizer further improve the fertility of the soil, promote the growth of the root system of the soil improvement vegetation, and promote its utilization and fixation of water in the soil. The thriving root system further fixes the soil structure more firmly, thereby realizing the effective repair and improvement of the sandy soil matrix soil. DETAILED DESCRIPTION

[0031] The principles and features of the present invention are described below in conjunction with the examples, which are only used to explain the present invention and are not intended to limit the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0032] Embodiment 1:

[0033] A method for improving sandy soil matrix soil comprises the following steps:

[0034] (1) Corn straw, wheat straw and soybean straw in a mass ratio of 5:2:1 were mixed and crushed into fragments of 2 to 3 cm in length, and then added to a carbonization furnace and heated to 480°C at a heating rate of 5°C / min, kept warm for 3 h, and then immersed in a 3% citric acid solution for 5 h and in a 2% polyethyleneimine solution for 5 h; finally, the mixture was taken out and dried at 80°C for 24 h to obtain straw carbonized material.

[0035] (2) immersing calcium-based bentonite in a 2% dodecyltrimethylammonium chloride solution, wherein the mass volume ratio of calcium-based bentonite to dodecyltrimethylammonium chloride solution is 20 g:100 mL. After immersion at room temperature for 2 h, the precipitate is collected and dried at 50° C. for 10 h to obtain modified calcium-based bentonite.

[0036] (3) The raw materials were mixed according to the following mass fractions: 100 parts of straw carbonized material, 65 parts of decomposed organic fertilizer, 8 parts of calcium phosphate, 7 parts of modified calcium-based bentonite, 0.3 parts of Streptomyces tenuifolius, 0.6 parts of Bacillus subtilis and 0.3 parts of Trichoderma harzianum, and the mixture was evenly mixed to obtain a soil improvement preparation.

[0037] (4) Improve and repair 100 square meters of sandy soil. First, clean the surface of the sandy soil to be repaired and loosen it. Then, apply 3 kg of soil improvement agent per cubic meter of sandy soil to be improved and irrigate it with water at a rate of 6 L / m 2 .

[0038] (5) After drying for 2 days, sow Bermuda grass, Vetiver grass and Clover into the sandy soil matrix to be repaired, with a sowing ratio of 1:1:1 and a total sowing amount of 25 g / m 2 , complete the improvement of sandy soil matrix soil.

[0039] Embodiment 2:

[0040] A method for improving sandy soil matrix soil comprises the following steps:

[0041] (1) Corn straw, wheat straw and soybean straw in a mass ratio of 5:2:1 were mixed and crushed into fragments of 2 to 3 cm in length, and then added to a carbonization furnace and heated to 480°C at a heating rate of 5°C / min, kept warm for 3 h, and then immersed in a 3% citric acid solution for 5 h and in a 2% polyethyleneimine solution for 5 h; finally, the mixture was taken out and dried at 80°C for 24 h to obtain straw carbonized material.

[0042] (2) Calcium-based bentonite was immersed in a 2% dodecyltrimethylammonium chloride solution, the mass volume ratio of calcium-based bentonite to hexadecyltrimethylammonium chloride solution was 20 g:100 mL, after immersion at room temperature for 2 h, the precipitate was collected and dried at 50° C. for 10 h to obtain modified calcium-based bentonite.

[0043] (3) The raw materials were mixed according to the following mass fractions: 120 parts of straw carbonization, 80 parts of decomposed organic fertilizer, 10 parts of calcium hydrogen phosphate, 10 parts of modified calcium-based bentonite, 0.5 parts of Streptomyces tenuifolius, 0.7 parts of Bacillus subtilis and 0.4 parts of Trichoderma harzianum, and the mixture was evenly mixed to prepare a soil improvement preparation.

[0044] (4) Improve and repair 100 square meters of sandy soil. First, clean the surface of the sandy soil to be repaired and loosen it. Then, apply 3 kg of soil improvement agent per cubic meter of sandy soil to be improved and irrigate it with water at a rate of 6 L / m 2 .

[0045] (5) After drying for 2 days, sow Bermuda grass, Vetiver grass and Clover into the sandy soil matrix to be repaired, with a sowing ratio of 1:1:1 and a total sowing amount of 25 g / m 2 , complete the improvement of sandy soil matrix soil.

[0046] Embodiment 3:

[0047] A method for improving sandy soil matrix soil comprises the following steps:

[0048] (1) Corn straw, wheat straw and soybean straw in a mass ratio of 5:2:1 were mixed and crushed into fragments of 2 to 3 cm in length, and then added to a carbonization furnace and heated to 480°C at a heating rate of 5°C / min, kept warm for 3 h, and then immersed in a 3% citric acid solution for 5 h and in a 2% polyethyleneimine solution for 5 h; finally, the mixture was taken out and dried at 80°C for 24 h to obtain straw carbonized material.

[0049] (2) Calcium-based bentonite was immersed in a 2% dodecyltrimethylammonium chloride solution, the mass volume ratio of calcium-based bentonite to octadecyltrimethylammonium chloride solution was 20 g:100 mL, after immersion at room temperature for 2 h, the precipitate was collected and dried at 50° C. for 10 h to obtain modified calcium-based bentonite.

[0050] (3) The raw materials were mixed according to the following mass fractions: 80 parts of straw carbonization, 50 parts of decomposed organic fertilizer, 5 parts of hydroxyapatite, 5 parts of modified calcium-based bentonite, 0.2 parts of Streptomyces tenuifolius, 0.5 parts of Bacillus subtilis and 0.2 parts of Trichoderma harzianum, and the mixture was evenly mixed to prepare a soil improvement preparation.

[0051] (4) Improve and repair 100 square meters of sandy soil. First, clean the surface of the sandy soil to be repaired and loosen it. Then, apply 3 kg of soil improvement agent per cubic meter of sandy soil to be improved and irrigate it with water at a rate of 6 L / m 2 .

[0052] (5) After drying for 2 days, sow Bermuda grass, Vetiver grass and Clover into the sandy soil matrix to be repaired, with a sowing ratio of 1:1:1 and a total sowing amount of 25 g / m 2 , complete the improvement of sandy soil matrix soil.

[0053] Comparative Example 1:

[0054] A method for improving sandy soil matrix soil comprises the following steps:

[0055] (1) Calcium-based bentonite was immersed in a 2% dodecyltrimethylammonium chloride solution, the mass volume ratio of calcium-based bentonite to dodecyltrimethylammonium chloride solution was 20 g:100 mL, after immersion at room temperature for 2 h, the precipitate was collected and dried at 50° C. for 10 h to obtain modified calcium-based bentonite.

[0056] (2) The raw materials are mixed according to the following mass fractions: 65 parts of decomposed organic fertilizer, 8 parts of calcium phosphate, 7 parts of modified calcium-based bentonite, 0.3 parts of Streptomyces tenuifolius, 0.6 parts of Bacillus subtilis and 0.3 parts of Trichoderma harzianum, and the mixture is evenly mixed to prepare a soil improvement preparation.

[0057] (3) Improve and repair 100 square meters of sandy soil. First, clean the surface of the sandy soil to be repaired and loosen it. Then, apply 3 kg of soil improvement agent per cubic meter of sandy soil to be improved and irrigate it with water at a rate of 6 L / m 2 .

[0058] (4) After drying for 2 days, sow Bermuda grass, Vetiver grass and Clover in the sandy soil matrix to be repaired, with a sowing ratio of 1:1:1 and a total sowing amount of 25 g / m 2 , complete the improvement of sandy soil matrix soil.

[0059] Comparative Example 2:

[0060] A method for improving sandy soil matrix soil comprises the following steps:

[0061] (1) Corn straw, wheat straw and soybean straw in a mass ratio of 5:2:1 were mixed and crushed into fragments of 2 to 3 cm in length, and then added to a carbonization furnace and heated to 480°C at a heating rate of 5°C / min, kept warm for 3 h, and then immersed in a 3% citric acid solution for 5 h and in a 2% polyethyleneimine solution for 5 h; finally, the mixture was taken out and dried at 80°C for 24 h to obtain straw carbonized material.

[0062] (2) The raw materials were mixed according to the following mass fractions: 100 parts of straw carbonization, 65 parts of decomposed organic fertilizer, 8 parts of calcium phosphate, 7 parts of calcium-based bentonite, 0.3 parts of Streptomyces tenuifolius, 0.6 parts of Bacillus subtilis and 0.3 parts of Trichoderma harzianum, and the mixture was evenly mixed to obtain a soil improvement preparation.

[0063] (3) Improve and repair 100 square meters of sandy soil. First, clean the surface of the sandy soil to be repaired and loosen it. Then, apply 3 kg of soil improvement agent per cubic meter of sandy soil to be improved and irrigate it with water at a rate of 6 L / m 2 .

[0064] (4) After drying for 2 days, sow Bermuda grass, Vetiver grass and Clover in the sandy soil matrix to be repaired, with a sowing ratio of 1:1:1 and a total sowing amount of 25 g / m 2 , complete the improvement of sandy soil matrix soil.

[0065] Comparative Example 3:

[0066] A method for improving sandy soil matrix soil comprises the following steps:

[0067] (1) Corn straw, wheat straw and soybean straw in a mass ratio of 5:2:1 were mixed and crushed into fragments of 2 to 3 cm in length, and then added to a carbonization furnace and heated to 480°C at a heating rate of 5°C / min, kept warm for 3 h, and then immersed in a 3% citric acid solution for 5 h and in a 2% polyethyleneimine solution for 5 h; finally, the mixture was taken out and dried at 80°C for 24 h to obtain straw carbonized material.

[0068] (2) immersing calcium-based bentonite in a 2% dodecyltrimethylammonium chloride solution, wherein the mass volume ratio of calcium-based bentonite to dodecyltrimethylammonium chloride solution is 20 g:100 mL. After immersion at room temperature for 2 h, the precipitate is collected and dried at 50° C. for 10 h to obtain modified calcium-based bentonite.

[0069] (3) The raw materials were mixed according to the following mass fractions: 100 parts of straw carbonization, 65 parts of decomposed organic fertilizer, 8 parts of calcium phosphate, 7 parts of modified calcium-based bentonite, and 1.0 part of Bacillus subtilis, and the mixture was evenly mixed to prepare a soil improvement preparation.

[0070] (4) Improve and repair 100 square meters of sandy soil. First, clean the surface of the sandy soil to be repaired and loosen it. Then, apply 3 kg of soil improvement agent per cubic meter of sandy soil to be improved and irrigate it with water at a rate of 6 L / m 2 .

[0071] (5) After drying for 2 days, sow Bermuda grass, Vetiver grass and Clover into the sandy soil matrix to be repaired, with a sowing ratio of 1:1:1 and a total sowing amount of 25 g / m 2 , complete the improvement of sandy soil matrix soil.

[0072] Comparative Example 4:

[0073] A method for improving sandy soil matrix soil comprises the following steps:

[0074] (1) Corn straw, wheat straw and soybean straw in a mass ratio of 5:2:1 were mixed and crushed into fragments of 2 to 3 cm in length, and then added to a carbonization furnace and heated to 480°C at a heating rate of 5°C / min, kept warm for 3 h, and then immersed in a 3% citric acid solution for 5 h and in a 2% polyethyleneimine solution for 5 h; finally, the mixture was taken out and dried at 80°C for 24 h to obtain straw carbonized material.

[0075] (2) immersing calcium-based bentonite in a 2% dodecyltrimethylammonium chloride solution, wherein the mass volume ratio of calcium-based bentonite to dodecyltrimethylammonium chloride solution is 20 g:100 mL. After immersion at room temperature for 2 h, the precipitate is collected and dried at 50° C. for 10 h to obtain modified calcium-based bentonite.

[0076] (3) The raw materials were mixed according to the following mass fractions: 100 parts of straw carbonized material, 65 parts of decomposed organic fertilizer, 8 parts of calcium phosphate, 7 parts of modified calcium-based bentonite, 0.3 parts of Streptomyces tenuifolius, 0.6 parts of Bacillus subtilis and 0.3 parts of Trichoderma harzianum, and the mixture was evenly mixed to obtain a soil improvement preparation.

[0077] (4) Improve and repair 100 square meters of sandy soil. First, clean the surface of the sandy soil to be repaired and loosen it. Then, apply 3 kg of soil improvement agent per cubic meter of sandy soil to be improved and irrigate it with water at a rate of 6 L / m 2 .

[0078] (5) After drying for 2 days, sow clover in the sandy soil matrix to be repaired at a sowing rate of 25g / m 2 , complete the improvement of sandy soil matrix soil.

[0079] Comparative Example 5:

[0080] A method for improving sandy soil matrix soil comprises the following steps:

[0081] (1) Corn straw, wheat straw and soybean straw in a mass ratio of 5:2:1 were mixed and crushed into fragments of 2 to 3 cm in length, and then added to a carbonization furnace and heated to 480°C at a heating rate of 5°C / min and kept at this temperature for 3 h to obtain straw carbonization.

[0082] (2) immersing calcium-based bentonite in a 2% dodecyltrimethylammonium chloride solution, wherein the mass volume ratio of calcium-based bentonite to dodecyltrimethylammonium chloride solution is 20 g:100 mL. After immersion at room temperature for 2 h, the precipitate is collected and dried at 50° C. for 10 h to obtain modified calcium-based bentonite.

[0083] (3) The raw materials were mixed according to the following mass fractions: 100 parts of straw carbonized material, 65 parts of decomposed organic fertilizer, 8 parts of calcium phosphate, 7 parts of modified calcium-based bentonite, 0.3 parts of Streptomyces tenuifolius, 0.6 parts of Bacillus subtilis and 0.3 parts of Trichoderma harzianum, and the mixture was evenly mixed to obtain a soil improvement preparation.

[0084] (4) Improve and repair 100 square meters of sandy soil. First, clean the surface of the sandy soil to be repaired and loosen it. Then, apply 3 kg of soil improvement agent per cubic meter of sandy soil to be improved and irrigate it with water at a rate of 6 L / m 2 .

[0085] (5) After drying for 2 days, sow Bermuda grass, Vetiver grass and Clover into the sandy soil matrix to be repaired, with a sowing ratio of 1:1:1 and a total sowing amount of 25 g / m 2 , complete the improvement of sandy soil matrix soil.

[0086] Test example:

[0087] The repaired sandy soil matrix soil of Examples 1-3 and Comparative Examples 1-4 was tested and analyzed.

[0088] The soil moisture content was tested from the 1st week to the 4th week after the sandy soil matrix was improved. The moisture content testing position was located 5 cm away from the soil surface.

[0089] On the 30th day after the sandy soil substrate was improved, clover was sampled and its root length and plant height were measured. Twenty plants were sampled in each group and the average value was taken.

[0090] The experimental results are shown in Table 1.

[0091] Table 1 Soil moisture content and clover root length and plant height

[0092]

[0093] As can be seen from the data in Table 1, the sandy soil matrix soil improvement method of Examples 1-3 of the present invention can effectively maintain the moisture content in the soil and achieve excellent water storage effect. According to the data of Comparative Examples 1-5, when straw carbonization is not added or bentonite is not modified, the water storage capacity of the soil is significantly reduced, and the soil moisture content decreases significantly over time. Although the comparative examples using only a single bacterial agent or only a single vegetation for soil improvement are improved in terms of moisture content compared to Comparative Examples 1 and 2, there is still a significant gap with Examples 1-3. According to the growth of the sown clover, the clover in Examples 1-3 has a better growth condition, and its longer root system can effectively play the effect of consolidating water and soil, while the growth of the clover in Comparative Examples 1 and 2 is significantly reduced, wherein Comparative Examples 3 and 4 also have relatively long root lengths, and have better water and soil consolidation effects relative to Comparative Examples 1 and 2, which is also one of the main reasons why its soil moisture content is higher than Comparative Examples 1 and 2. It can be seen from the data in Comparative Example 5 that when the straw carbonized material is not modified, the rate of decrease of soil moisture content and the root length and plant height of clover are significantly reduced. The results show that the modification of the straw carbonized material can effectively improve the soil's water retention and soil fixation capacity. The modification can effectively increase the oxygen-containing functional groups on the surface of the straw carbonized material. On the one hand, it can adsorb and fix more water. On the other hand, the oxygen-containing functional groups on the surface of the straw carbonized material can form hydrogen bonds with the modified calcium-based bentonite, calcium phosphate and decomposed organic fertilizer in the soil improvement preparation, thereby improving the adsorption and fixation of sand in the soil and effectively improving the water and soil fixation effect.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for improving sandy soil matrix, characterized in that: The following steps are involved: First, loosen the sandy soil matrix to be improved, then apply soil improvement agents and irrigate with water, and finally dry it in the sun and sow soil improvement vegetation to complete the sandy soil matrix soil improvement; The soil improvement preparation is composed of the following components in parts by weight: 80-120 parts of straw carbonized material, 50-80 parts of decomposed organic fertilizer, 5-10 parts of phosphate, 5-10 parts of modified bentonite, 0.1-0.5 parts of Streptomyces tenuifolius, 0.5-0.7 parts of Bacillus subtilis and 0.1-0.5 parts of Trichoderma harzianum.

2. The method for improving sandy soil matrix according to claim 1, characterized in that: The soil improvement preparation is composed of the following components in parts by weight: 100 parts of straw carbonized material, 65 parts of decomposed organic fertilizer, 8 parts of phosphate, 7 parts of modified bentonite, 0.3 parts of Streptomyces tenuifolius, 0.6 parts of Bacillus subtilis and 0.3 parts of Trichoderma harzianum.

3. The sandy soil improvement method according to claim 1 or 2, characterized in that: The straw carbonized material is prepared by the following method: corn straw, wheat straw and soybean straw are first chopped and then mixed, pyrolyzed and carbonized, and then the carbonized product is sequentially immersed in a citric acid solution and a polyethyleneimine solution, and finally dried to obtain the product.

4. The method for improving sandy soil matrix according to claim 3, characterized in that: The mass ratio of corn straw, wheat straw and soybean straw is 4-6:1-3:1, and the conditions for pyrolysis carbonization are heating to 450-500°C at a heating rate of 4-6°C / min and keeping warm for 2-4h; the mass concentration in the citric acid solution is 1-5%, and the immersion time in the citric acid solution is 4-6h; the mass concentration of the polyethyleneimine solution is 1-5%, and the immersion time in the polyethyleneimine solution is 4-6h; the drying temperature is 70-90°C and the time is 20-30h.

5. The method for improving sandy soil according to claim 1 or 2, characterized in that: The phosphate includes at least one of calcium phosphate, calcium hydrogen phosphate and hydroxyapatite.

6. The method for improving sandy soil according to claim 1 or 2, characterized in that: The modified bentonite is prepared by the following method: immersing calcium-based bentonite in a modifier solution, collecting and drying the precipitate.

7. The method for improving sandy soil according to claim 6, characterized in that: The modifier comprises at least one of dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride and octadecyltrimethylammonium chloride, the mass concentration of the modifier solution is 1-3%, the mass volume ratio of calcium-based bentonite and the modifier solution is 10-30g:80-120mL; the immersion time is 1-3h; the drying temperature is 40-60°C and the time is 8-12h.

8. The method for improving sandy soil according to claim 1, characterized in that: The application rate of soil improvement agent is 2-4 kg per cubic meter of sandy and gravel matrix soil to be improved, and the watering rate is 5-7 L / m 2 .

9. The method for improving sandy soil according to claim 1, characterized in that: The soil improving vegetation is bermudagrass, vetiver and clover, the sowing amount is 0.8-1.2:0.8-1.2:0.8-1.2, and the total sowing amount is 20-30g / m 2 .

10. Use of the sandy soil improving method according to any one of claims 1 to 9 in repairing sandy soil.

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