Sandy soil modifier as well as preparation method and application thereof

Abstract

The invention relates to the field of sandy soil improvement, in particular to a sandy soil improver which comprises the following raw materials in parts by mass: 1 part of nano clay, 5-10 parts of a plant polymer adhesive, 5-15 parts of soluble plant hemicellulose and 5-15 parts of charcoal. Comprising the following steps: adding sodium polycarboxylate into nano-clay according to 0.1-0.5% of the nano-clay, and mixing; the amylopectin is prepared by crushing glutinous rice or extracting from glutinous rice or corn starch, adding rice bran powder into the amylopectin according to 10-20% of the amylopectin, and mixing; the glucomannan is extracted from the konjak; the straw or the rice husk is pyrolyzed in a high-temperature oxygen-deficient closed container to prepare the biochar. The sandy soil improver and sandy soil or sand are applied to ecological restoration of the following application scenes according to the proportion of 1: 10000: tailing pond ecological restoration, ecological restoration after sand making of mine solid waste, desert gobi ecological restoration and stony desertification ecological restoration. By adopting the technical scheme, the physical characteristics of the sandy soil or the sand can be optimized, and the moisture and fertilizer retention and maintenance capabilities of the sandy soil or the sand are improved.

Description

Technical Field

[0001] This invention relates to the field of sand and soil improvement, specifically to a sand and soil conditioner, its preparation method, and its application. Background Technology

[0002] Soil conditioners are substances used to improve the physical, chemical, and biological properties of sandy soils (soils with a sand content greater than 70%) or deserts. Their aim is to enhance the water and fertilizer retention capacity of sandy soils to make them suitable for plant growth. Sandy soils and deserts are characterized by their loose structure, high porosity, and susceptibility to erosion. They have poor water and fertilizer retention, are prone to leaching, and suffer from severe water shortages during dry seasons or in areas with low organic matter content, low microbial activity, and low fertility.

[0003] Commonly used soil conditioners include organic (compost, straw, biochar, humic acid), inorganic (bentonite, pumice, diatomaceous earth), biological (microbial agents), and polymeric materials (polyacrylamide, PAM). The use of these materials can improve the physical and chemical properties and biological activity of sand and desert to some extent. However, due to the lack of systematic and comprehensive research, there is a lack of intrinsic correlation between the conditioners, and their sustainability needs to be improved. The water-stable aggregate content, non-capillary porosity, and soil bulk density of the improved sand or soil are not ideal, and the ability to retain water, fertilizer, and nutrients is poor. The actual application effect is not satisfactory, and large-scale promotion is restricted. Summary of the Invention

[0004] The present invention aims to provide a soil conditioner to optimize the physical properties of sand or gravel and improve its water retention, fertilizer retention and maintenance capabilities.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a sand and soil conditioner comprising the following raw materials in parts by weight: 1 part nano clay, 5-10 parts plant polymer binder, 5-15 parts soluble plant hemicellulose, and 5-15 parts biochar.

[0006] The beneficial effects of this plan are: 1. The properties of nano-clay greatly enhance its water, fertilizer, and nutrient retention capabilities. Nano-clay, with a single layer thickness of 1-100 nm, possesses an extremely large specific surface area (up to 800 m² / g) and high adsorption capacity. Its layered structure allows for the adsorption of water molecules and ions between layers. The surface is rich in hydroxyl groups (-OH) and negative charges, easily combining with sand or sand particles, organic matter, and nutrients. Nano-clay particles fill the sand with air, reducing permeability and water evaporation, increasing water retention capacity by 3-5 times. Through electrostatic interactions, it connects sand particles to form a granular structure, adsorbing water, ammonium nitrogen, potassium ions, etc., through ion exchange and hydrogen bonding, reducing nutrient loss. Simultaneously, the water and nutrients stored between layers are released slowly. The amount used is only 1 / 10 of that of traditional clay, significantly reducing usage. Furthermore, the controlled application of nano-clay effectively avoids the problem of sand or sand compaction.

[0007] 2. Plant-based polymer adhesives bind sand or sand particles through hydrogen bonds and van der Waals forces, forming stable micro-aggregates and reducing the risk of wind and water erosion. The adhesives combine with water molecules to form a gel-like structure, slowing down water evaporation. Their molecular structure can adsorb amino acids, nitrogen, and potassium ions, reducing nutrient loss. Plant polymers are naturally biodegradable, leave no residue, and are low in cost.

[0008] 3. Soluble plant hemicellulose materials have high water absorption, forming a gel-like structure. Molecules adhere to sand particles through hydrogen bonds and van der Waals forces, forming stable aggregates and a surface adhesive film, thus enhancing wind erosion resistance. The gel network locks in moisture, adsorbs nutrients from the sand, and combines with nano-clay to improve salt and alkali resistance.

[0009] 4. Due to its porous internal structure, biochar forms stable aggregates, which improves water retention capacity and can greatly enhance the durability of other materials. It also has the ability to adsorb water and nutrients and delay their release, thus slowing down the degradation rate of plant polymer materials and soluble plant hemicellulose.

[0010] 5. Nanoclay, plant polymers, and biochar are all natural materials. Through the synergistic effect of nanoclay's water retention, the adhesive force of plant polymers, the water absorption of soluble plant hemicellulose, and the stability of biochar, the water retention, fertilizer retention, and moisture retention capacity of sand or soil is improved, which is conducive to plant growth and the sustainable use of sand or soil, and facilitates the promotion of ecological restoration.

[0011] Furthermore, it also includes nano-clay dispersant and plant fiber, with the nano-clay dispersant being 0.1-0.5% of the nano-clay and the plant fiber being 10-20% of the plant polymer adhesive.

[0012] The beneficial effects of this solution are as follows: Nano clay is a natural mineral and is pollution-free. Adding nano clay dispersant and plant fiber can effectively solve the problems of nano clay agglomeration and prevent the self-coagulation of plant polymer adhesives.

[0013] Furthermore, the nano-clay dispersant is sodium polycarboxylate, the plant polymer binder is amylopectin, the plant fiber is rice bran powder, the soluble plant hemicellulose is glucomannan, and the biochar is pyrolyzed straw or rice husk.

[0014] The beneficial effects of this scheme are as follows: the primary degradation product of amylopectin is dextrin, which is still a water-retaining agent; the primary degradation product of glucomannan, mannose, also has strong water-retaining properties.

[0015] Another object of the present invention is to provide a method for preparing a sand amendment, comprising the preparation of the following raw materials: The clay is made into nano-sized nano-clay, and sodium polycarboxylate is added to the nano-clay at 0.1-0.5% of the nano-clay and mixed. Amylopectin is made by grinding glutinous rice grains, or by extracting amylopectin from glutinous rice or corn starch, by adding rice bran powder to amylopectin at 10-20% and mixing. Glucomannan is extracted from konjac; Straw or rice husks are pyrolyzed in a closed container at a high temperature and low oxygen level below 600℃ to produce biochar.

[0016] The beneficial effects of this solution are: it directly crushes glutinous rice, reducing the hulling process, and large-scale application can reduce production costs.

[0017] Furthermore, the prepared nano-clay and sodium polycarboxylate mixture is mixed with amylopectin obtained by pulverizing glutinous rice grains or a mixture of amylopectin and rice bran powder.

[0018] The beneficial effects of this solution are: first, mix raw materials in a certain proportion, and then adjust the ratio of glucomannan to biochar according to the different proportion requirements of different application scenarios.

[0019] Another objective of this invention is to provide an application of a sand amendment, which is used for ecological restoration in scenarios including but not limited to: tailings pond ecological restoration, ecological restoration after sand making from mine solid waste, desert and Gobi ecological restoration, and rocky desertification ecological restoration.

[0020] Furthermore, the mixing ratio of the soil conditioner to sand or gravel is 1:10000.

[0021] Furthermore, the raw materials in the soil conditioner can be applied separately or mixed together before being applied to the application site.

[0022] The beneficial effects of this scheme are: the raw materials are not mixed in advance, which makes it easy to adjust the dosage according to the basic conditions of various sands or soils. For example, in arid areas where water retention is required to be stronger, the dosage of glucomannan needs to be increased; in areas with coarse sand, the dosage of amylopectin needs to be increased; if there are many metal elements in the soil, the dosage of biochar needs to be increased. For example, when treating tailings sand, biochar has the function of adsorbing metal ions, which is more in line with the needs of environmental protection.

[0023] Furthermore, the application method includes the following steps: Step 1: Take samples from the application scenario for testing to understand the basic physicochemical conditions of the sand or soil. Step 2: Select different formulas of soil conditioner based on the basic physicochemical conditions of the application scenario, apply them to the sand or soil, and spray water thoroughly. Step 3: After 15-20 days of natural conditioning, take samples again for testing. The physical and chemical properties of the improved sand or gravel are close to or reach the standards of loam. Step 4: Regularly observe and sample the improved soil to maintain its physicochemical and biological stability.

[0024] Furthermore, step two involves conducting a small-sample experiment, and step four involves making large-scale improvements based on the results of the small-sample experiment. Attached Figure Description

[0025] Figure 1 This is a diagram showing the growth of wheat seedlings cultivated according to the present invention. Detailed Implementation

[0026] Example A soil conditioner comprises the following raw materials in parts by weight: 1 part nano-clay, 5-10 parts plant polymer binder, 5-15 parts soluble plant hemicellulose, and 5-15 parts biochar. It also includes a nano-clay dispersant and plant fiber, wherein the nano-clay dispersant is 0.1-0.5% of the nano-clay, and the plant fiber is 10-20% of the plant polymer binder. The nano-clay dispersant is sodium polycarboxylate, the plant polymer binder is amylopectin, the plant fiber is rice bran powder (specifically, rice husk powder or wheat bran powder), the soluble plant hemicellulose is glucomannan, and the biochar is pyrolyzed straw or rice husk.

[0027] In the specific implementation process, the most representative desert sand was selected as the experimental object to observe the changes in the physical and chemical properties of sand caused by different formulations of improvers and the growth of sown wheat seeds.

[0028] Example 1 A sand amendment comprises the following raw materials by weight: 1g of nano-clay, sodium polycarboxylate added to the nano-clay at 0.5% of the nano-clay and mixed, 5g of amylopectin, rice husk powder added to the amylopectin at 10% of the amylopectin and mixed, 5g of glucomannan, and 15g of biochar; the sand amendment is used to amend desert sand at a ratio of 1:10000. Example 2 A sand amendment comprises the following raw materials by weight: 1g of nano-clay, sodium polycarboxylate added to the nano-clay at 0.5% of the nano-clay and mixed, 5g of amylopectin, rice husk powder added to the amylopectin at 10% of the amylopectin and mixed, 10g of glucomannan, and 5g of biochar; the sand amendment is used to amend desert sand at a ratio of 1:10000.

[0029] Example 3 A sand amendment comprises the following raw materials by weight: 1g of nano-clay, sodium polycarboxylate added to the nano-clay at 0.5% of the nano-clay and mixed, 10g of amylopectin, rice husk powder added to the amylopectin at 10% of the amylopectin and mixed, 5g of glucomannan, and 10g of biochar; the sand amendment is used to amend desert sand at a ratio of 1:10000.

[0030] Example 4 A sand amendment comprises the following raw materials by weight: 1g of nano-clay, sodium polycarboxylate added to the nano-clay at 0.5% of the nano-clay and mixed, 5g of amylopectin, rice husk powder added to the amylopectin at 10% of the amylopectin and mixed, 15g of glucomannan, and 10g of biochar; the sand amendment is used to amend desert sand at a ratio of 1:10000.

[0031] Comparative Example The comparison sample is untreated desert sand.

[0032] The test results of the improved desert sand in Examples 1-4 and the unimproved desert sand in the comparative example are shown in the table below. The improved desert sand in Examples 1-4 corresponds to sample names XY-I to XY-Ⅳ, and the unimproved desert sand in the comparative example corresponds to sample name NULL.

[0033]

[0034]

[0035]

[0036] The test results in the table above show that the core physical properties of desert sand after improvement, such as the content of water-stable macroaggregates, non-capillary porosity, and soil bulk density, have been optimized. The content of water-stable macroaggregates and non-capillary porosity are positively correlated; the higher the index, the better the hydrophobicity and the less water-retaining. The sand conditioner effectively reduced the content of water-stable macroaggregates and non-capillary porosity, thus enhancing the water retention of sand. After improvement, both of these indicators fall within the loam range, which are soil physical properties suitable for planting.

[0037] In natural evolution, the content of water-stable macroaggregates, non-capillary porosity, and soil bulk density are negatively correlated. However, due to human intervention, the specific gravity of the amendments is lower than that of sand or gravel. Therefore, the actual bulk density of each embodiment is slightly lower than that of the comparative embodiment, which is reasonable.

[0038] Mechanical composition refers to the distribution and proportion of large, medium and small particles in the soil, indicating the properties of the soil. As shown in the table above, only the comparative example has clay particles smaller than 0.002 mm. In other examples, the clay particles were bonded together by the amendment into relatively large particles. The sand particles in the comparative example are smaller than those in the examples, and the silt (sand) particles in the comparative example are larger than those in the examples. The clay particles in the examples have disappeared and have been bonded together by the amendment into large particles, indicating that the improved sandy soil or sand has become loamy soil with good water retention and fertility.

[0039] Eluent loss refers to the amount of hydrochloric acid lost, which is related to pH value. Alkaline sand or soil has a low hydrochloric acid elution rate, while improved sand or soil has a higher elution rate. In all embodiments, the pH value and cation exchange capacity remained consistent and decreased. In the comparative example, the cation exchange capacity, larger particle content, and pH value all increased. Because the amendment is rich in hydroxyl groups, which neutralize cations in the sand or soil, the pH values ​​of all embodiments decreased to varying degrees compared to the comparative example, becoming closer to neutral soil. Therefore, the amendment helps to adjust the acidity and alkalinity of sandy soil. The cation exchange capacity is affected by several factors. In practical applications, the soil's fertility retention capacity may require the addition of colloids and organic matter, and the soil cultivation time must be considered. The desert sand samples were tested. Since no organic matter was added, the effects of pH value and particle size became more prominent, further demonstrating that the improved soil had enhanced water and fertilizer retention capacity. Specifically, due to the large number of hydroxyl groups in the amendment, which have a strong neutralizing and adhesive effect, they neutralize the free cations in desert sand and cause fine sand powder to aggregate into granules. The measured values ​​of cation exchange capacity and nitrogen, phosphorus, and potassium were lower than those of the control group. This does not mean that the fertilizer retention capacity has decreased. In fact, these ions still exist in the improved soil, but their form has changed. Hydroxyl groups and cations neutralize to form salts, so the measured conductivity is generally higher than that of the control group. In the specific implementation process, it is necessary to add organic fertilizer to enhance the overall fertility of the soil.

[0040] Furthermore, this invention uses the improvers from Examples 1-4 to improve desert sand, while using unimproved desert sand as a control. Wheat seeds of equivalent quality and quantity are sown in both cases, and wheat seedlings are cultivated under the same conditions for the same period of time. Figure 1 As shown, the wheat seedlings grown in the improved sand exhibited significantly better growth than the control group.

[0041] Example 5 This embodiment provides a method for preparing a sand amendment, including the preparation of the following raw materials: The clay was made into nano-sized nano-clay, and sodium polycarboxylate was added to the nano-clay at 0.1-0.5% of the nano-clay and mixed. In this example, 0.5% was used. Amylopectin is made by grinding glutinous rice, or it can be extracted from glutinous rice or corn starch. Rice bran powder is added to amylopectin at 10-20% and mixed. In this example, 10% is selected. The rice bran powder is rice husk powder or wheat bran powder. Glucomannan is extracted from konjac; Straw or rice husks are pyrolyzed in a closed container at a high temperature and low oxygen level below 600℃ to produce biochar.

[0042] The raw materials can be prepared in any order. Alternatively, the mixture of nano-clay and sodium polycarboxylate, as well as the amylopectin obtained from crushed glutinous rice or the mixture of amylopectin and rice bran powder, can be mixed separately with glucomannan and pyrolyzed straw or rice husks. Or, the mixture of nano-clay and sodium polycarboxylate, the amylopectin obtained from crushed glutinous rice or the mixture of amylopectin and rice bran powder, glucomannan, and pyrolyzed straw or rice husks can be mixed together.

[0043] Similarly, each raw material can be applied to the application site separately without any order; of course, the mixture of prepared nano-clay and sodium polycarboxylate, as well as the amylopectin obtained from crushed glutinous rice or the mixture of amylopectin and rice bran powder, can be mixed and then applied to the application site, and then glucomannan and pyrolyzed straw or rice husks can be applied to the application site separately; of course, the mixture of prepared nano-clay and sodium polycarboxylate, the amylopectin obtained from crushed glutinous rice or the mixture of amylopectin and rice bran powder, glucomannan, and pyrolyzed straw or rice husks can be mixed together and then applied to the application site.

[0044] Example 6 This embodiment provides an application of a sand amendment, which is used for ecological restoration in scenarios including but not limited to: tailings pond ecological restoration, ecological restoration after sand making from mine solid waste, desert and Gobi ecological restoration, and rocky desertification ecological restoration. The mixing ratio of the sand amendment to sand or gravel is 1:10000. Each raw material in the sand amendment is applied separately or mixed and then applied to the application scenario.

[0045] The specific application method includes the following steps: Step 1: Take samples from the application scenario for testing to understand the basic physicochemical conditions of the sand or soil. Step 2: Select different formulations of soil conditioners based on the basic physicochemical conditions of the application scenario, apply them to the sand or soil, and spray sufficient water. Step 3: After 15-20 days of natural conditioning, take samples again for testing. The physical and chemical properties of the improved sand or gravel are close to or reach the standards of loam. Step 4: Regularly observe and sample the improved soil, and perform follow-up management to maintain the physical, chemical, and biological stability of the improved soil.

[0046] Step two involves conducting small-sample experiments and adjusting the formula as needed to meet the soil conditions for plant growth. Step four involves large-scale soil improvement based on the results of the small-sample experiments, followed by regular observation, sampling and testing of the improved soil, and proper subsequent management.

[0047] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A soil conditioner, characterized in that: The raw materials include the following parts by weight: 1 part nano clay, 5-10 parts plant polymer binder, 5-15 parts soluble plant hemicellulose, and 5-15 parts biochar.

2. The sand amendment according to claim 1, characterized in that: It also includes nano-clay dispersant and plant fiber, with the nano-clay dispersant being 0.1-0.5% of the nano-clay and the plant fiber being 10-20% of the plant polymer adhesive.

3. The soil conditioner according to claim 2, characterized in that: The nano-clay dispersant is sodium polycarboxylate, the plant polymer binder is amylopectin, the plant fiber is rice bran powder, the soluble plant hemicellulose is glucomannan, and the biochar is pyrolyzed straw or rice husk.

4. A method for preparing a sand amendment, characterized in that: The preparation of the following raw materials includes: The clay is made into nano-sized nano-clay, and sodium polycarboxylate is added to the nano-clay at 0.1-0.5% of the nano-clay and mixed. Amylopectin is made by grinding glutinous rice grains, or by extracting amylopectin from glutinous rice or corn starch, by adding rice bran powder to amylopectin at 10-20% and mixing. Glucomannan is extracted from konjac; Straw or rice husks are pyrolyzed in a closed container at a high temperature and low oxygen level below 600℃ to produce biochar.

5. The method for preparing a sand amendment according to claim 4, characterized in that: The prepared nano-clay and sodium polycarboxylate mixture is mixed with amylopectin obtained by pulverizing glutinous rice grains or a mixture of amylopectin and rice bran powder.

6. The application of a sand and soil conditioner, characterized in that: The sand amendment prepared by the method of any one of claims 1-3 and any one of claims 4-5 is applicable to ecological restoration in scenarios including but not limited to: tailings pond ecological restoration, ecological restoration after sand making from mine solid waste, desert and Gobi ecological restoration, and rocky desertification ecological restoration.

7. The application of the sand and soil conditioner according to claim 6, characterized in that: The mixing ratio of the soil conditioner to sand or gravel is 1:10000.

8. The application of a sand amendment according to claim 7, characterized in that: Each ingredient in the soil conditioner is applied separately or mixed before being applied to the application site.

9. The application of a sand amendment according to claim 8, characterized in that: The application method includes the following steps: Step 1: Take samples from the application scenario for testing to understand the basic physicochemical conditions of the sand or soil. Step 2: Select different formulas of soil conditioner based on the basic physicochemical conditions of the application scenario, apply them to the sand or soil, and spray water thoroughly. Step 3: After 15-20 days of natural conditioning, take samples again for testing. The physical and chemical properties of the improved sand or gravel are close to or reach the standards of loam. Step 4: Regularly observe and sample the improved soil to maintain its physicochemical and biological stability.

10. The application of a sand amendment according to claim 9, characterized in that: Step two involves conducting a small-sample experiment, and step four involves making large-scale improvements based on the results of the small-sample experiment.

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