Carbon-increasing and carbon-stabilizing storage-retaining agent for sandy soil and preparation method of carbon-increasing and carbon-stabilizing storage-retaining agent

Abstract

The invention provides a recarburization and carbon stabilization retention agent for sandy soil and a preparation method of the recarburization and carbon stabilization retention agent for sandy soil, and the retention agent comprises a plant straw fermentation solid and water, the preparation method of the plant straw fermentation solid comprises the following steps: preparing slurry, carrying out enzymolysis on the slurry by using pectin methylesterase, xylanase, alpha-amylase and alpha-glucosidase, fermenting by using photosynthetic bacteria to prepare fermentation liquor, and drying; the preparation method of the retention agent comprises the step of mixing the plant straw fermentation solid with water before the recarburization and carbon stabilization retention agent is put into sandy soil. The retention agent can bring organic carbon into soil, and under the synergistic effect of plant fibers and pectin, organic carbon loss caused by water flow scouring can be reduced, so that the organic carbon can be retained in the soil for a long time, and the purposes of recarburization and carbon stabilization are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of soil improvement, and in particular to a carbon-enhancing, carbon-stabilizing and storage agent for sandy soil and a preparation method thereof. Background Art

[0002] Sandy soil is mainly composed of granular sand particles. There is a lack of sticky particles, such as clay, between the sand particles, which makes the sandy soil loose. The gaps between the sand particles are large, making the sandy soil have good air permeability and water permeability.

[0003] The above characteristics of sandy soil result in poor water and fertilizer retention capacity and large temperature difference between day and night. These disadvantages make sandy soil unsuitable for crop cultivation.

[0004] Therefore, providing a storage agent that can improve the water and fertilizer retention capacity of sandy soil is of great significance for improving the fertility of sandy soil. Summary of the invention

[0005] In view of this, the present invention provides a carbon-increasing, carbon-stabilizing and storage agent for sandy soil and a preparation method thereof. The storage agent can bring organic carbon into the soil, and under the synergistic effect of plant fiber and pectin, can reduce the loss of organic carbon caused by water erosion, so that the organic carbon can be retained in the soil for a longer period of time, thereby achieving the purpose of carbon increase and carbon stabilization.

[0006] The technical solution of the present invention is as follows: A carbon-increasing, stabilizing and storing agent for sandy soil, comprising plant straw fermentation solids and water, wherein the preparation method of the plant straw fermentation solids is as follows: S1, crushing the plant straw, adding a 0.3% sodium hydroxide solution until the solution covers the plant straw, and soaking at room temperature for 10-20 hours; then adding water thereto, stirring, and obtaining a slurry; The straw is crushed to make the plant fiber loose and maintain its integrity as much as possible, thereby effectively improving the water absorption of the fiber and facilitating the preservation of water and fertilizer. After adding the sodium hydroxide solution, the hemicellulose in the plant straw is separated from the cellulose and enters the pulp. S2, adjusting the pH of the slurry to 5.7-6.2, and then adding pectin methylesterase, xylanase, α-amylase and α-glucosidase to the slurry; the amount of pectin methylesterase added is 1.7-2.2u / g, the amount of xylanase added is 2.5-3.0u / g, the amount of α-amylase added is 2.1-2.5u / g, and the amount of α-glucosidase added is 4.3-4.7u / g, the enzymolysis temperature is 40-45°C, the enzymolysis time is 3.5-4.5 hours, the enzymes are inactivated, and an enzymolysis solution is obtained; S3, adding sterilized magnesium sulfate, disodium hydrogen phosphate, disodium hydrogen carbonate, and ammonium sulfate to the enzymatic hydrolyzate to obtain a fermentation matrix; adding photosynthetic bacterial powder to the fermentation matrix, controlling the wavelength of the light source to 700-720nm, the light intensity to 1800-2000lux, and intermittent illumination; then performing anaerobically fermentation at 35±0.5℃ for 5-7 days, sterilizing, and obtaining a fermentation liquid; Photosynthetic bacteria use glucose and other substances in the enzymatic hydrolysate to ferment, while ensuring the pectin and cellulose content in the fermentation liquid, while increasing the organic carbon content in the fermentation liquid; S4, drying the fermentation liquid to obtain plant straw fermentation solid.

[0007] The fermented solids of plant straw contain a large amount of plant fiber. The presence of plant fiber can, on the one hand, achieve the effect of increasing and stabilizing carbon, and on the other hand, absorb and store water in the soil, so that trace elements in the soil remain in the soil, providing nutrients for plant growth. In addition, the fiber in the soil can provide breathing space for crop growth and promote root reproduction.

[0008] Preferably, in step S1, the plant straw includes one of wheat straw, corn straw, peanut straw and rice straw.

[0009] Preferably, in step S1, during the soaking process, the plant straw is turned over once every 3 hours; and the weight ratio of the plant straw to water is 1:3-5.

[0010] Preferably, in step S2, the intermittent lighting control is: lighting for 3 hours, off for 3 hours, and repeating.

[0011] Preferably, in step S3, 0.5-0.7 g of magnesium sulfate, 0.5-1.0 g of disodium hydrogen phosphate, 0.7-1.5 g of disodium hydrogen carbonate, and 1.0-2.0 g of ammonium sulfate are added to every 1 kg of the enzymatic hydrolyzate.

[0012] Preferably, in step S3, the weight ratio of photosynthetic bacteria powder to fermentation substrate is 50-70:1000; and the number of effective live bacteria in the photosynthetic bacteria powder is ≥5 billion / g.

[0013] Preferably, in the above-mentioned carbon-increasing, carbon-stabilizing and storage agent for sandy soil, the weight ratio of plant straw fermentation solids to water is 90-95:5-10.

[0014] After enzymatic hydrolysis, the fermented solids of plant straw contain pectin. After the pectin combines with water, the viscosity of the pectin increases. Therefore, after the obtained carbon-increasing and carbon-stabilizing storage agent is put into sandy soil, it can improve the adhesion between the sand and soil. Even if it is washed by rain, the fiber can still exist well in the sandy soil, so that the sandy soil has good water and fertilizer retention capabilities. And because the fermented solids of plant straw produce amino acids, organic acids and other substances after being fermented by photosynthetic bacteria, while pectin improves the water retention of sandy soil, it can effectively retain organic matter in the sandy soil, which not only increases the organic carbon content of the sandy soil, but also can stably retain the organic carbon in the sandy soil, thereby achieving the purpose of fertilizer retention.

[0015] The preparation method of the carbon increasing, stabilizing and storing agent for sandy soil is specifically to mix the carbon increasing, stabilizing and storing agent before adding it into the sandy soil, and the process is as follows: (1) Place the fermented plant straw solids in a stirring container, control the stirring speed to 30-50 r / min, and stir for 20-30 min; (2) While stirring, spray water into the stirring container in the form of water mist. Continue stirring for 10-15 minutes after spraying to obtain a carbon-increasing, carbon-stabilizing and storage agent.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. In the present invention, straw is used as raw material, and after being crushed, alkaline soaked, enzymolyzed and fermented, the obtained plant straw fermentation solid is rich in pectin, fiber and organic carbon. After the plant straw fermentation solid is mixed with water, the obtained carbon-increasing and carbon-stabilizing agent for sandy soil is put into sandy soil, which can increase the viscosity between sands; and the solution absorbed by the fiber expansion contains organic carbon produced by fermentation. Therefore, after the plant straw fermentation solid is in the soil, pectin and fiber can work synergistically, and the organic matter in the fermentation product can be better retained in the soil, thereby achieving the purpose of carbon increase and carbon stabilization.

[0017] 2. The addition of enzymes in the present invention can specifically hydrolyze pectin, hemicellulose and starch in the slurry while keeping the fiber intact, so that the obtained fiber is looser and has higher water absorption; and the enzymatic hydrolyzate after enzymatic hydrolysis contains glucose that can be used as a carbon source, which provides a carbon source for the fermentation of photosynthetic bacteria and reduces the sugar content in the fermented solids of plant straw. Therefore, after the preservative is put into the soil, the microbial activity can be reduced under low sugar conditions. First, the fiber and pectin can be present in the soil for a longer time, thereby improving the water and fertilizer retention performance of sandy soil; second, the microbial metabolites can be reduced to provide nutrients for pests, thereby reducing soil diseases and insect pests.

[0018] 3. The storage agent of the present invention can bring organic carbon into the soil, and under the synergistic effect of plant fiber and pectin, it can reduce the loss of organic carbon caused by water erosion, so that the organic carbon can be retained in the soil for a longer period of time, thereby achieving the purpose of increasing and stabilizing carbon.

[0019] 4. In the present invention, plant straw is used as raw material, which has the advantages of low cost and renewability, and can improve the resource utilization of plant straw.

[0020] 5. When the storage agent of the present invention is used, the storage agent is sprinkled on the sandy soil, and then the soil is turned over to mix the storage agent with the sandy soil, and then plants are planted according to demand. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0022] In the following examples and comparative examples of the present invention, the reagents and raw materials used are all commercially available products.

[0023] Example 1 A carbon-increasing, stabilizing and storing agent for sandy soil, comprising plant straw fermentation solids and water, wherein the weight ratio of the plant straw fermentation solids to the water is 92:8; The preparation method of plant straw fermentation solid is as follows: S1, crushing the wheat straw, adding a 0.3% sodium hydroxide solution until the solution covers the wheat straw, and soaking at room temperature for 15 hours; then adding water thereto, stirring, and obtaining a slurry; During the soaking process, the wheat straw was turned over every 3 hours; the weight ratio of wheat straw to water was 1:4; S2, adjusting the pH of the slurry to 5.9, and then adding pectin methylesterase, xylanase, α-amylase and α-glucosidase to the slurry; the amount of pectin methylesterase added is 2.0u / g, the amount of xylanase added is 2.8u / g, the amount of α-amylase added is 2.3u / g, and the amount of α-glucosidase added is 4.4u / g, the enzymolysis temperature is 42°C, the enzymolysis time is 4 hours, the enzymes are inactivated, and an enzymolysis solution is obtained; S3, adding sterilized magnesium sulfate, disodium hydrogen phosphate, disodium hydrogen carbonate, and ammonium sulfate to the enzymatic hydrolyzate to obtain a fermentation matrix; adding photosynthetic bacterial powder to the fermentation matrix, controlling the wavelength of the light source to 710nm, the light intensity to 1900lux, and intermittent illumination; then, performing anaerobically fermentation at 35±0.1℃ for 6 days, sterilizing, and obtaining a fermentation liquid; Add 0.6 g of magnesium sulfate, 0.7 g of disodium hydrogen phosphate, 1.3 g of disodium hydrogen carbonate, and 1.5 g of ammonium sulfate to every 1 kg of enzymatic hydrolysate; The weight ratio of photosynthetic bacteria powder to fermentation substrate is 60:1000; the number of effective live bacteria in the photosynthetic bacteria powder is 6 billion / g; Intermittent light control is: 3 hours on, 3 hours off, repeated; S4, drying the fermentation liquid to obtain plant straw fermentation solid; The preparation method of the carbon increasing, stabilizing and storing agent for sandy soil is specifically to mix the carbon increasing, stabilizing and storing agent before adding it into the sandy soil, and the process is as follows: (1) preparing the fermented solids of plant straw and water according to a certain ratio; (2) placing the fermented plant straw solids in a stirring container, controlling the stirring speed to 40 r / min, and stirring for 25 min; (2) While stirring, spray water into the stirring container in the form of water mist. Continue stirring for 12 minutes after spraying to obtain a carbon-increasing, carbon-stabilizing and storage agent.

[0024] Comparative Example 1 The difference from Example 1 is that, in step S2, the process is as follows: The pH of the slurry is adjusted to 5.9, and then pectin methylesterase, xylanase, α-amylase and α-glucosidase are added to the slurry; the amount of pectin methylesterase added is 1.5u / g, the amount of xylanase added is 2.8u / g, the amount of α-amylase added is 2.3u / g, and the amount of α-glucosidase added is 4.4u / g, the enzymolysis temperature is 42°C, the enzymolysis time is 4 hours, and the enzymes are inactivated to obtain an enzymolysis solution; The rest is the same as in Example 1.

[0025] Comparative Example 2 The difference from Example 1 is that, in step S2, the process is as follows: The pH of the slurry is adjusted to 5.9, and then pectin methylesterase, xylanase, α-amylase and α-glucosidase are added to the slurry; the amount of pectin methylesterase added is 2.4u / g, the amount of xylanase added is 2.8u / g, the amount of α-amylase added is 2.3u / g, and the amount of α-glucosidase added is 4.4u / g, the enzymolysis temperature is 42°C, the enzymolysis time is 4 hours, and the enzymes are inactivated to obtain an enzymolysis solution; The rest is the same as in Example 1.

[0026] Comparative Example 3 The difference from Example 1 is that step S1 is as follows: The wheat straw is crushed into 2-3 mm, and a 0.3% sodium hydroxide solution is added until the solution covers the wheat straw, and the mixture is soaked at room temperature for 15 hours; water is then added thereto, and the mixture is stirred to obtain a slurry; The rest is the same as in Example 1.

[0027] Comparative Example 4 The difference from Example 1 is that step S1 is as follows: Crush the wheat straw, add a 0.3% sodium hydroxide solution until the solution covers the wheat straw, and soak at room temperature for 9 hours; then add water and stir to obtain a slurry; The rest is the same as in Example 1.

[0028] Example 2 A carbon-increasing, stabilizing and storing agent for sandy soil, comprising plant straw fermentation solids and water, wherein the weight ratio of the plant straw fermentation solids to the water is 90:10; The preparation method of plant straw fermentation solid is as follows: S1, crushing the wheat straw, adding a 0.3% sodium hydroxide solution until the solution covers the wheat straw, and soaking at room temperature for 10 hours; then adding water thereto, stirring, and obtaining a slurry; During the soaking process, the wheat straw was turned over every 3 hours; the weight ratio of wheat straw to water was 1:3; S2, adjusting the pH of the slurry to 5.7, and then adding pectin methylesterase, xylanase, α-amylase and α-glucosidase to the slurry; the amount of pectin methylesterase added is 1.7u / g, the amount of xylanase added is 2.5u / g, the amount of α-amylase added is 2.1u / g, and the amount of α-glucosidase added is 4.3u / g, the enzymolysis temperature is 40°C, the enzymolysis time is 3.5 hours, the enzymes are inactivated, and an enzymolysis solution is obtained; S3, adding sterilized magnesium sulfate, disodium hydrogen phosphate, disodium hydrogen carbonate, and ammonium sulfate to the enzymatic hydrolyzate to obtain a fermentation matrix; adding photosynthetic bacterial powder to the fermentation matrix, controlling the wavelength of the light source to 700nm, the light intensity to 1800lux, and intermittent illumination; then performing anaerobically fermentation at 35±0.1℃ for 7 days, sterilizing, and obtaining a fermentation liquid; Add 0.5 g of magnesium sulfate, 0.5 g of disodium hydrogen phosphate, 0.7 g of disodium hydrogen carbonate, and 1.0 g of ammonium sulfate to every 1 kg of enzymatic hydrolysate; The weight ratio of photosynthetic bacteria powder to fermentation substrate is 70:1000; the number of effective live bacteria in the photosynthetic bacteria powder is 5 billion / g; Intermittent light control is: 3 hours on, 3 hours off, repeated; S4, drying the fermentation liquid to obtain plant straw fermentation solid; The preparation method of the carbon increasing, stabilizing and storing agent for sandy soil is specifically to mix the carbon increasing, stabilizing and storing agent before adding it into the sandy soil, and the process is as follows: (1) Place the fermented plant straw solids in a stirring container, control the stirring speed to 30 r / min, and stir for 20 min; (2) While stirring, spray water into the stirring container in the form of water mist. Continue stirring for 10 minutes after spraying to obtain a carbon-increasing and carbon-stabilizing agent.

[0029] Example 3 A carbon-increasing, stabilizing and storing agent for sandy soil, comprising plant straw fermentation solids and water, wherein the weight ratio of the plant straw fermentation solids to the water is 95:5; The preparation method of plant straw fermentation solid is as follows: S1, crushing the wheat straw, adding a 0.3% sodium hydroxide solution until the solution covers the wheat straw, and soaking at room temperature for 20 hours; then adding water thereto, stirring, and obtaining a slurry; During the soaking process, the plant straw was turned over every 3 hours; the weight ratio of wheat straw to water was 1:5; S2, adjusting the pH of the slurry to 6.2, and then adding pectin methylesterase, xylanase, α-amylase and α-glucosidase to the slurry; the amount of pectin methylesterase added is 2.2u / g, the amount of xylanase added is 3.0u / g, the amount of α-amylase added is 2.5u / g, the amount of α-glucosidase added is 4.7u / g, the enzymolysis temperature is 45°C, the enzymolysis time is 4.5 hours, the enzyme is inactivated, and an enzymolysis solution is obtained; S3, adding sterilized magnesium sulfate, disodium hydrogen phosphate, disodium hydrogen carbonate, and ammonium sulfate to the enzymatic hydrolyzate to obtain a fermentation matrix; adding photosynthetic bacterial powder to the fermentation matrix, controlling the wavelength of the light source to 720nm, the light intensity to 2000lux, and intermittent illumination; then performing anaerobically fermentation at 35±0.5℃ for 5 days, sterilizing, and obtaining a fermentation liquid; Add 0.7 g of magnesium sulfate, 1.0 g of disodium hydrogen phosphate, 1.5 g of disodium hydrogen carbonate, and 2.0 g of ammonium sulfate to every 1 kg of enzymatic hydrolysate; The weight ratio of photosynthetic bacteria powder to fermentation substrate is 50:1000; the number of effective live bacteria in the photosynthetic bacteria powder is 8 billion / g; Intermittent light control is: 3 hours on, 3 hours off, repeated; S4, drying the fermentation liquid to obtain plant straw fermentation solid; The preparation method of the carbon increasing, stabilizing and storing agent for sandy soil is specifically to mix the carbon increasing, stabilizing and storing agent before adding it into the sandy soil, and the process is as follows: (1) Place the fermented plant straw solids in a stirring container, control the stirring speed to 50 r / min, and stir for 30 min; (2) While stirring, spray water into the stirring container in the form of water mist. Continue stirring for 15 minutes after spraying to obtain a carbon-increasing, carbon-stabilizing and storage agent.

[0030] Example 4 The difference from Example 1 is that the plant straw is corn straw.

[0031] Example 5 The difference from Example 1 is that the plant straw is peanut straw.

[0032] Example 6 The difference from Example 1 is that the plant straw is rice straw.

[0033] Field trials 1. Experimental land The experiment was carried out at the Qing'e Town Experimental Base in Cao County, Shandong Province. The plots with flat and even terrain and average soil fertility were selected as the experimental sites. The soil cultivation layer (0-50cm) in the experimental area is sandy soil (sandy loam). The soil is loose and easy to cultivate, but the soil has weak water and fertilizer retention capacity, low nutrient content, and no stamina. Small seedlings are produced, old seedlings are not produced, and crops grow poorly and have low yields. The basic physical and chemical properties of the soil are shown in Table 1 below: Table 1 Basic physical and chemical characteristics of soil

[0034] 2. Test items 2.1 Water holding capacity The water holding capacity is determined as follows: ① Dry the sample and remove impurities such as stones; then load the sample with a ring cutter and control the loading amount of the ring cutter to be consistent each time by weighing; ② Immerse the ring knife containing the sample in water, with the water surface level with the top of the ring knife, and soak for 12 hours; take out the ring knife, wipe off the water on the surface of the ring knife, and then soak it again, repeating the above steps until the ring knife containing the sample no longer increases in weight; ③ Take out the ring knife, drain the water naturally at room temperature until no more water flows out, take out the sample, weigh it, and record it as m1; ④ Dry the sample at 105℃ to constant weight and record the weight in m2; Water holding capacity of soil (%) = (m1-m2) / m2×100.

[0035] 2.2 Breathability Air permeability, using the soil density test method, is as follows: ① Use tools to remove the surface soil at the test point to a depth of 10 cm; ②Press the ring knife vertically into the soil, and make sure that the inside is filled with a complete soil column when taking it out; ③Take out the soil column, weigh it, and record it as m1; ④ Dry the soil at 105℃ to constant weight and record the weight in m2; Calculate the bulk density = m2 / ring volume.

[0036] 2.3 Soil organic matter The loss on ignition method was used to determine the soil organic matter content.

[0037] 3. Experimental design Experimental plots: each plot is 10m×10m; The experiment adopted a single-factor randomized block design with 11 treatments as follows: In the experimental group, 15 kg of the accumulator provided in Examples 1-6 was evenly sprinkled on the surface of the test plot (the accumulator was put into the field at 100 kg / mu), and the soil was tilled to 30-40 cm to mix the accumulator with the soil. For the control group, 15 kg of the accumulator provided in Comparative Examples 1-4 was evenly sprinkled on the surface of the test plot (the accumulator was put into the field at 100 kg / mu), and the soil was tilled to 30-40 cm to mix the accumulator with the soil. Control group (CK), soil without storage agent; Three replicates were set for each treatment; Planting crops: The tested crops were Jimai 23; One week before planting, apply organic fertilizer as base fertilizer. The organic fertilizer is fully decomposed farmyard manure, and the amount per mu is 2 tons; Use a seeder for row sowing, with a sowing rate of 10-15kg per mu and a soil covering depth of 3-5cm; Management was carried out in accordance with local conventional agronomic measures and farmers’ habits, and soil sampling and wheat yield calculation were completed on June 10, 2024; Soil sampling points: sampling before applying base fertilizer, sampling before wheat planting, sampling when wheat seedlings emerge; Wherein, the samples were taken before applying the base fertilizer, and the samples in the experimental group contained the storage agent provided in Examples 1-6, and the samples in the comparative group contained the storage agent provided in Comparative Examples 1-4; Sampling was performed before wheat planting. The samples in the experimental group contained the storage agent and base fertilizer provided in Examples 1-6, and the samples in the comparative group contained the storage agent and base fertilizer provided in Comparative Examples 1-4; Sampling was performed when wheat seedlings emerged. The samples in the experimental group contained the accumulator and basal fertilizer provided in Examples 1-6, and the samples in the comparative group contained the accumulator and basal fertilizer provided in Comparative Examples 1-4; The soil test results are shown in Tables 2-4 as follows: Table 2 Basic physical and chemical characteristics of soil before applying base fertilizer

[0038] Table 3 Basic physical and chemical characteristics of soil before wheat planting

[0039] Table 4 Basic physical and chemical characteristics of soil at wheat emergence

[0040] It can be seen from Table 2 that, compared with the comparison group and the control group, the storage agent obtained by the preparation method provided by the present invention, after being mixed with sandy soil, increases the bulk density, water holding capacity and organic matter content of the soil; indicating that the storage agent of the present invention can effectively improve the performance of sandy soil, and improve the water holding capacity of sandy soil while maintaining the air permeability of sandy soil; It can be seen from Table 3 that after the application of the base fertilizer, the sandy soil containing the storage agent provided by Examples 1-6 has a higher degree of retention of organic matter, indicating that the storage agent of the present invention can improve the fertilizer retention performance of the sandy soil; It can be seen from Table 4 that as wheat seedlings emerge, the contents of organic matter, nitrogen, phosphorus, potassium, etc. in the soil gradually decrease, but compared with the comparison group and the control group, the decrease in the sandy soil of the present invention is the lowest, which shows that in addition to the nutrients required for wheat growth, the sandy soil of the present invention can slow down the loss of organic matter, etc., further indicating that the storage agent of the present invention has good fertilizer retention performance; The wheat yield results are shown in Table 5, as follows: Table 5 Wheat production

[0041] From Table 5, it can be seen that after using the storage agent of the present invention, the wheat yield is significantly increased compared with the control group; although the control group also has different degrees of yield increase, the effect is lower than that of the invention group; it can be seen that although sandy soil has many problems that are not conducive to agricultural production, such as poor water retention and poor fertilizer retention, by improving the sandy soil, it can form a tillage layer that is conducive to crop growth.

[0042] Although the present invention has been described in detail by reference to the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A carbon-increasing, stabilizing and storing agent for sandy soil, characterized in that: It comprises plant straw fermentation solids and water, wherein the preparation method of the plant straw fermentation solids is as follows: S1, crushing the plant straw, adding a 0.3% sodium hydroxide solution until the solution covers the plant straw, and soaking at room temperature for 10-20 hours; then adding water thereto, stirring, and obtaining a slurry; S2, adjusting the pH of the slurry to 5.7-6.2, and then adding pectin methylesterase, xylanase, α-amylase and α-glucosidase to the slurry; the amount of pectin methylesterase added is 1.7-2.2u / g, the amount of xylanase added is 2.5-3.0u / g, the amount of α-amylase added is 2.1-2.5u / g, and the amount of α-glucosidase added is 4.3-4.7u / g, the enzymolysis temperature is 40-45°C, the enzymolysis time is 3.5-4.5 hours, the enzymes are inactivated, and an enzymolysis solution is obtained; S3, adding sterilized magnesium sulfate, disodium hydrogen phosphate, disodium hydrogen carbonate, and ammonium sulfate to the enzymatic hydrolyzate to obtain a fermentation matrix; adding photosynthetic bacterial powder to the fermentation matrix, controlling the wavelength of the light source to 700-720nm, the light intensity to 1800-2000lux, and intermittent illumination; then performing anaerobically fermentation at 35±0.5℃ for 5-7 days, sterilizing, and obtaining a fermentation liquid; S4, drying the fermentation liquid to obtain plant straw fermentation solid.

2. The carbon-increasing, stabilizing and storing agent for sandy soil according to claim 1, characterized in that: In step S1, the plant straw includes one of wheat straw, corn straw, peanut straw and rice straw.

3. The carbon-increasing, stabilizing and storing agent for sandy soil according to claim 1, characterized in that: In step S1, during the soaking process, the plant straw is turned over once every 3 hours; the weight ratio of the plant straw to water is 1:3-5.

4. The carbon-increasing, carbon-stabilizing and storage agent for sandy soil according to claim 1, characterized in that: In step S2, the intermittent lighting control is: lighting for 3 hours, off for 3 hours, and repeating.

5. The carbon-increasing, stabilizing and storing agent for sandy soil according to claim 1, characterized in that: In step S3, 0.5-0.7 g of magnesium sulfate, 0.5-1.0 g of disodium hydrogen phosphate, 0.7-1.5 g of disodium hydrogen carbonate, and 1.0-2.0 g of ammonium sulfate are added to every 1 kg of the enzymatic hydrolyzate.

6. The carbon-increasing, stabilizing and storing agent for sandy soil according to claim 1, characterized in that: In step S3, the weight ratio of photosynthetic bacteria powder to fermentation substrate is 50-70:1000; the number of effective live bacteria in the photosynthetic bacteria powder is ≥5 billion / g.

7. The carbon-increasing, stabilizing and storing agent for sandy soil according to claim 1, characterized in that: The weight ratio of plant straw fermentation solids to water is 90-95:5-10.

8. The method for preparing the carbon-increasing, carbon-stabilizing and storage agent for sandy soil according to claim 1, characterized in that: Before adding the carbon increasing, stabilizing and storing agent into the sandy soil, mix it. The process is as follows: (1) Place the fermented plant straw solids in a stirring container, control the stirring speed to 30-50 r / min, and stir for 20-30 min; (2) While stirring, spray water into the stirring container in the form of water mist. Continue stirring for 10-15 minutes after spraying to obtain a carbon-increasing, carbon-stabilizing and storage agent.

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