Bio-based submerged plant fiber planting blanket and preparation method thereof

Abstract

The invention discloses a bio-based submerged plant fiber planting blanket and a preparation method thereof, and belongs to the technical field of fiber planting blankets, the bio-based submerged plant fiber planting blanket comprises a bearing layer and a matrix layer, the matrix layer comprises the following raw materials by mass fraction: 90-95% of a biomass matrix, 4-8% of urea slow-release particles and 1-3% of minerals; the urea sustained-release particle is of a core-shell structure, a core material is a gel particle loaded with urea, and a wall material is a beta-cyclodextrin and sodium hyaluronate compound. The main raw material of the substrate layer is a biomass substrate, the substrate layer has good air permeability and water-retaining property, nutrients contained in the substrate layer can nourish the growth of the cultivated submerged plants, and a good supporting structure is provided for the substrate layer. The urea slow-release particles are added, so that nutrient elements beneficial to growth can be slowly released in the growth process of the submerged plants, the problems of excessive absorption in the initial stage and lack in the later stage caused by a traditional quick-acting chemical fertilizer are solved, the survival rate of the submerged plants is increased, and the effect of quickly repairing the ecological system of a water body is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of fiber planting blankets, and in particular relates to a bio-based submerged plant fiber planting blanket and a preparation method thereof. Background Art

[0002] With the acceleration of industrialization and urbanization, water pollution has become increasingly serious and has become one of the key factors affecting the sustainable development of the economy. In order to improve water quality and restore aquatic ecosystems, people have used many methods. Among them, submerged plants are widely used in ecological restoration projects in lakes, rivers and other waters due to their strong self-purification ability and good landscape effects. Submerged plants can not only absorb nutrients such as nitrogen and phosphorus in the water to reduce the occurrence of eutrophication, but also oxygenate the water through underwater photosynthesis, promote the development of microbial communities in the water, and form a virtuous cycle ecosystem.

[0003] Traditional submerged plant planting usually adopts the method of directly sowing seeds or cuttings. However, these methods lack effective fixation measures, which can easily cause seedlings to drift under the long-term impact of water flow, thereby reducing the survival rate. In addition, the surviving seedlings grow slowly in the early stage, making it difficult to quickly establish a stable vegetation cover layer, affecting the effect of ecological restoration.

[0004] At present, there are methods of using additional devices to increase the gravity of submerged plants to achieve the fixation of submerged plants, or using substrates to cultivate submerged plants, but these materials mostly rely on artificial synthetic fibers or non-woven fabrics with low natural organic matter content, which are not conducive to the environment and also limit the material exchange between the roots of submerged plants and the soil. Therefore, it is of great significance to obtain a green and environmentally friendly material that can be used as an excellent substrate for submerged plant cultivation or repair of damaged ecosystems. Summary of the invention

[0005] The object of the present invention is to provide a bio-based submerged plant fiber planting blanket and a preparation method thereof, so as to solve the problems of submerged plants being difficult to fix, having low survival rate and slow growth.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a bio-based submerged plant fiber planting blanket, comprising a bearing layer and a matrix layer, wherein the matrix layer comprises the following raw materials in mass fractions:

[0008] Biomass matrix 90-95%;

[0009] Urea slow-release particles 4-8%;

[0010] Minerals 1-3%;

[0011] The urea sustained-release particles are of a core-shell structure, wherein the core material is gel particles loaded with urea, and the wall material is a complex of β-cyclodextrin and sodium hyaluronate.

[0012] Preferably, the mass ratio of the core material to the wall material is 1:(1.5-2).

[0013] Preferably, the mass ratio of β-cyclodextrin to sodium hyaluronate is (2-3):1.

[0014] Preferably, the biomass substrate comprises a combination of one or more of peat soil, garden waste, wine slop, crop straw and humus.

[0015] More preferably, the biomass matrix is ​​peat soil, crop straw and humus in a mass ratio of (0.6-0.8):(0.1-0.3):(0.1-0.2).

[0016] Preferably, the supporting layer is a dense mesh of plant fibers.

[0017] By adopting the above technical scheme, the bio-based submerged plant fiber planting blanket in the present invention uses a dense plant fiber mesh as a bearing layer, which can fix the matrix layer. The plant fiber as a raw material is biodegradable, and its pore structure also facilitates the exchange of substances between the roots of submerged plants and the soil, which is beneficial to the growth of submerged plants.

[0018] The main raw material of the matrix layer is the biomass matrix, and the biomass materials used are all secondary utilization materials, which are not only green and environmentally friendly but also realize recycling; and the nutrients contained in the biomass matrix itself will also nourish the growth of cultivated submerged plants. After the submerged plants grow up, these biomass materials will gradually degrade and become part of the water body soil. Moreover, the biomass matrix has good air permeability and water retention, and the root system will not be hindered from passing through the pores of the biomass matrix, which is conducive to the smooth growth of submerged plants. More preferably, the biomass matrix is ​​a composition of peat soil, crop straw and humus. The crop straw can provide a good support structure for the matrix layer, improve the mechanical properties of the matrix layer, and peat soil and humus are conducive to the rooting and growth of submerged plants, provide a certain support for the root system, improve the fixation of the obtained fiber planting blanket to submerged plants, and also help to improve the survival rate of submerged plants.

[0019] Urea slow-release particles are also added to the matrix layer. Nitrogen atoms are an important component in the process of plant growth, and their participation provides sufficient growth nutrients for submerged plants. However, if urea is directly doped in the biomass matrix, submerged plant seedlings are prone to seedling burns due to their fragile root systems, affecting the survival rate and growth of submerged plants. Therefore, the present invention provides a urea slow-release particle that can slowly release nutrient elements that are beneficial to growth during the growth of submerged plants, ensuring sufficient nutrients required for the growth of submerged plants, and also ensuring that during the submerged plant seedling period, there will be no problems such as seedling burns due to excessive nutrients, solving the problems of excessive absorption in the early stage and lack in the later stage caused by traditional quick-acting fertilizers. It ensures the rapid growth of submerged plants, improves the survival rate of submerged plants, and achieves the effect of quickly repairing the water ecosystem.

[0020] Specifically, the urea slow-release particles of the present invention are core-shell structures, which can better protect the urea inside, reduce the direct contact between the root system and the urea, and ensure that the urea can be slowly released from the gel particles, which is conducive to the growth of submerged plants. The wall material mainly adopts a complex of cyclodextrin and sodium hyaluronate. Cyclodextrin can provide certain structural support for the wall material, and the large number of polar groups contained in sodium hyaluronate can improve the hydrophilicity and water retention of the urea slow-release particles, so that the inside of the matrix layer can always maintain full water, providing a good growth environment for the growth of submerged plants, and the hydrophilicity is also more conducive to the growth of microorganisms, achieving a good ecological cycle balance, and at the same time contributing to the effective degradation of the subsequent urea slow-release particles.

[0021] Preferably, the urea-loaded gel particles are prepared according to the following method:

[0022] Sodium carboxymethyl cellulose is dissolved in a sodium hydroxide aqueous solution with a mass fraction of 15-20%, an emulsifier is added, and the mixture is stirred and emulsified for 20-30 minutes. The temperature is adjusted to 40-45° C., an organic cross-linking agent and a sodium hydroxide aqueous solution with a mass fraction of 30-40% are added, and the mixture is kept warm for reaction for 5-6 hours. Gel particles are obtained after washing and dialyzing. The gel particles are immersed in a urea aqueous solution with a concentration of 5-15 g / L for 6-8 hours, and urea-loaded gel particles are obtained after freeze-drying.

[0023] Preferably, the mass volume ratio of the gel particles to the urea aqueous solution is 1 g: (4-6) mL.

[0024] Preferably, the organic crosslinking agent includes one or more of epichlorohydrin, 1,4-butanediol diglycidyl ether, sodium tripolyphosphate and N,N'-methylenebisacrylamide; the added amount of the organic crosslinking agent is 0.5-1.5% of the mass of sodium carboxymethyl cellulose.

[0025] By adopting the above technical scheme, in the present invention, urea is first loaded on gel particles composed of carboxymethyl cellulose. On the one hand, the formed gel particles have many internal pores, which can increase the storage capacity of urea and further control the release rate of urea, so that it is slowly and continuously released into the environment, reducing urea loss and improving the utilization rate of nitrogen fertilizer; on the other hand, by loading urea on carboxymethyl cellulose gel particles, urea loss can be greatly reduced, thereby reducing the problem of eutrophication of water bodies caused by ammonia volatilization or runoff. At the same time, carboxymethyl cellulose, as a natural polymer material, will not pollute the water body after subsequent decomposition, which is green and environmentally friendly.

[0026] Preferably, the sodium hyaluronate is a composition of cross-linked sodium hyaluronate and acetylated sodium hyaluronate in a mass ratio of (0.7-0.8):(0.2-0.3).

[0027] By adopting the above technical solution, the wall material of the urea slow-release particles contains sodium hyaluronate, which can improve the water retention of the matrix, help maintain the moisture content of the matrix layer, provide a continuous and stable water supply for the roots of submerged plants, and help regulate the release efficiency of urea to support the growth of submerged plants. Furthermore, the sodium hyaluronate is a composition of cross-linked sodium hyaluronate and acetylated sodium hyaluronate.

[0028] Cross-linked sodium hyaluronate can improve the mechanical strength of the wall material. When combined with cyclodextrin, it can significantly improve the structural stability of urea sustained-release particles, and to a certain extent can resist the influence of external environmental factors. In addition, the cross-linked network structure of cross-linked sodium hyaluronate has greater steric hindrance, which can better control the release of urea and lock in moisture more effectively. The addition of acetylated sodium hyaluronate will reduce the hydrophilicity of sodium hyaluronate, which can strengthen the physical barrier effect of the wall material, prevent moisture from penetrating too quickly, slow down the speed of water absorption and expansion, and improve the overall stability.

[0029] Preferably, the urea slow-release particles are prepared according to the following method:

[0030] β-cyclodextrin and sodium hyaluronate are added to deionized water respectively, the temperature is increased to 65-75°C, and an aqueous solution with a mass fraction of 5-10% is prepared. The mixture is mixed and stirred for 2-3 hours according to the mass ratio, and gel particles loaded with urea are added. The mixture is stirred for 6-8 hours at room temperature, and finally urea sustained-release particles are obtained by centrifugation, washing and drying.

[0031] By adopting the above technical solution, the core-shell structured urea sustained-release particles obtained with urea-loaded gel particles as the core material and β-cyclodextrin and sodium hyaluronate as the wall material can effectively slow down the release rate of uric acid from the carboxymethyl cellulose gel particles. The dense but permeable film formed by β-cyclodextrin and sodium hyaluronate can reduce the direct contact between the roots of submerged plants and nitrogen fertilizers, and reduce the impact of the outside world on internal nitrogen fertilizers. Through the dual protection mechanism, it can ensure that nitrogen elements can be absorbed by submerged plants in a more controllable and uniform manner, providing a continuous and stable nitrogen source for submerged plants, effectively avoiding the problem of excessive absorption at one time and insufficient nutrition in the later stage, thereby improving the survival rate and growth efficiency of submerged plants.

[0032] In a second aspect, the present invention provides a method for preparing a bio-based submerged plant fiber planting blanket, comprising the following process steps:

[0033] S1. mixing the biomass matrix, urea slow-release particles and minerals in a corresponding mass ratio and compressing them to obtain a matrix layer;

[0034] S2. Laying the obtained matrix layer on the bearing layer to obtain a bio-based submerged plant fiber planting blanket.

[0035] Beneficial effects of the present invention:

[0036] 1. The raw materials used in the bio-based submerged plant fiber planting blanket provided by the present invention are green and environmentally friendly materials, which can provide a good living environment while achieving green and environmental protection requirements. The main raw material of the matrix layer in the fiber planting blanket is the biomass matrix, which can provide certain support and nutrients for submerged plants, help submerged plants grow, and also help submerged plants take root, providing certain support for the root system, thereby improving the fixation effect of the fiber planting blanket on submerged plants and improving the survival rate.

[0037] 2. The matrix layer of the fiber planting blanket of this aspect also contains urea slow-release particles, which can greatly reduce the direct contact between nitrogen fertilizer and the roots of submerged plants, thereby reducing damage to the roots of submerged plants and the occurrence of problems such as seedling burn. The slow release of urea can effectively solve the problems of excessive absorption in the early stage and deficiency in the later stage caused by traditional quick-acting fertilizers, continuously and stably provide nitrogen sources for submerged plants, and improve the survival rate and growth rate of submerged plants; the sodium hyaluronate in its wall material can improve the water retention and hydrophilicity of the urea slow-release particles, so that the inside of the matrix layer can always maintain full moisture, providing a good growth environment for the growth of submerged plants. DETAILED DESCRIPTION

[0038] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in 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 are within the scope of protection of the present invention.

[0039] Preparation Example

[0040] Preparation Example 1: A urea sustained-release particle is prepared according to the following method:

[0041] Dissolve 10g of sodium carboxymethyl cellulose (viscosity of 800-1200mpa·s) in 250mL of 15% sodium hydroxide aqueous solution, add 0.5g of octylphenol polyoxyethylene ether, stir and emulsify for 30min, adjust the temperature to 40°C, add 0.1g of epichlorohydrin and 50mL of 35% sodium hydroxide aqueous solution, keep warm for 5h, and obtain gel particles after washing and dialyzing; take 10g of gel particles and immerse them in 50g of 10g / L urea aqueous solution for 7h, and obtain gel particles loaded with urea after freeze-drying.

[0042] 18 g of β-cyclodextrin and sodium hyaluronate in a mass ratio of 2.5:1 were added to deionized water respectively, wherein the sodium hyaluronate was a composition of cross-linked sodium hyaluronate and acetylated sodium hyaluronate in a mass ratio of 0.8:0.2, the temperature was raised to 70°C, and an aqueous solution with a mass fraction of 10% was prepared, mixed and stirred for 2 hours, 10 g of the above-mentioned urea-loaded gel particles were added, and stirring was continued at room temperature for 6 hours. Finally, urea sustained-release particles were obtained by centrifugation, washing and drying.

[0043] Preparation Example 2, a urea sustained-release particle, is different from Preparation Example 1 only in that the added amount of 10 g / L urea aqueous solution is 40 g; the total added amount of β-cyclodextrin and sodium hyaluronate is 15 g.

[0044] Preparation Example 3, a urea sustained-release particle, is different from Preparation Example 1 only in that the added amount of 10 g / L urea aqueous solution is 60 g; the total added amount of β-cyclodextrin and sodium hyaluronate is 20 g.

[0045] Preparation Example 4, a urea sustained-release particle, is different from Preparation Example 1 only in that the mass ratio of β-cyclodextrin to sodium hyaluronate is 2:1; wherein the sodium hyaluronate is a composition of cross-linked sodium hyaluronate and acetylated sodium hyaluronate in a mass ratio of 0.7:0.3.

[0046] Preparation Example 5, a urea sustained-release particle, is different from Preparation Example 1 only in that the mass ratio of β-cyclodextrin to sodium hyaluronate is 3:1.

[0047] Preparation Example 6, a urea sustained-release particle, is different from Preparation Example 1 only in that an equal amount of β-cyclodextrin is used to replace the composition of β-cyclodextrin and sodium hyaluronate.

[0048] Preparation Example 7, a urea sustained-release particle, is different from Preparation Example 1 only in that an equal amount of cross-linked sodium hyaluronate is used to replace the composition of cross-linked sodium hyaluronate and acetylated sodium hyaluronate in a mass ratio of 0.7:0.3.

[0049] Preparation Example 8, a urea sustained-release particle, is different from Preparation Example 1 only in that an equal amount of acetylated sodium hyaluronate is used to replace the composition of cross-linked sodium hyaluronate and acetylated sodium hyaluronate in a mass ratio of 0.7:0.3.

[0050] Preparation Example 9, a urea sustained-release particle, is different from Preparation Example 1 only in that an equal amount of ordinary sodium hyaluronate is used to replace the composition of cross-linked sodium hyaluronate and acetylated sodium hyaluronate in a mass ratio of 0.7:0.3.

[0051] Preparation Example 10, a urea sustained-release particle, prepared according to the following method:

[0052] Dissolve 10g of sodium carboxymethyl cellulose (viscosity of 800-1200mpa·s) in 250mL of 15% sodium hydroxide aqueous solution, add 0.5g of octylphenol polyoxyethylene ether, stir and emulsify for 30min, adjust the temperature to 40°C, add 0.1g of epichlorohydrin and 50mL of 35% sodium hydroxide aqueous solution, keep warm for 5h, and obtain gel particles after washing and dialyzing; take 10g of gel particles and immerse them in 50g of 10g / L urea aqueous solution for 7h, and obtain gel particles loaded with urea after freeze-drying, which are urea sustained-release particles.

[0053] Preparation Example 11, a urea sustained-release particle, prepared according to the following method:

[0054] 18 g of β-cyclodextrin and sodium hyaluronate in a mass ratio of 2.5:1 were added to deionized water respectively, wherein the sodium hyaluronate was a composition of cross-linked sodium hyaluronate and acetylated sodium hyaluronate in a mass ratio of 0.8:0.2, the temperature was raised to 70°C, and an aqueous solution with a mass fraction of 10% was prepared, mixed and stirred for 2 hours, 10 g of urea was added, and stirring was continued at room temperature for 6 hours. Finally, urea sustained-release particles were obtained by centrifugation, washing and drying.

[0055] Example

[0056] Example 1, a bio-based submerged plant fiber planting blanket is prepared according to the following process steps:

[0057] S1. Mix 92% of biomass matrix, 6% of urea slow-release particles prepared in Preparation Example 1 and 2% of minerals (phosphate mineral powder), and compress them to obtain a matrix layer; wherein the biomass matrix is ​​peat soil, crop straw and humus in a mass ratio of 0.7:0.2:0.1.

[0058] S2. Laying the obtained matrix layer on the plant fiber dense net to obtain a bio-based submerged plant fiber planting blanket.

[0059] Example 2, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the matrix layer includes 95% of biomass matrix, 4% of urea slow-release particles prepared in Preparation Example 1 and 1% of minerals.

[0060] Example 3, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the matrix layer includes 90% of biomass matrix, 8% of urea slow-release particles prepared in Preparation Example 1 and 2% of minerals.

[0061] Example 4, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced by an equal amount of urea slow-release particles prepared in Preparation Example 2.

[0062] Example 5, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced with an equal amount of urea slow-release particles prepared in Preparation Example 3.

[0063] Example 6, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced by an equal amount of urea slow-release particles prepared in Preparation Example 4.

[0064] Example 7, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced with an equal amount of urea slow-release particles prepared in Preparation Example 5.

[0065] Example 8, a bio-based submerged plant fiber planting blanket, differs from Example 1 only in that an equal amount of peat soil is used to replace the biomass matrix obtained by combining peat soil, crop straw and humus in a mass ratio of 0.7:0.2:0.1.

[0066] Example 9, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced with an equal amount of urea slow-release particles prepared in Preparation Example 7.

[0067] Example 10, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced with an equal amount of urea slow-release particles prepared in Preparation Example 8.

[0068] Example 11, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced by an equal amount of urea slow-release particles prepared in Preparation Example 9.

[0069] Comparative Example

[0070] Comparative Example 1, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced by an equal amount of urea slow-release particles prepared in Preparation Example 6.

[0071] Comparative Example 2, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced by an equal amount of urea slow-release particles prepared in Preparation Example 10.

[0072] Comparative Example 3, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced by an equal amount of urea slow-release particles prepared in Preparation Example 11.

[0073] Comparative Example 4 is a bio-based submerged plant fiber planting blanket, which is different from Example 1 only in that the matrix layer includes 96% of biomass matrix, 2% of urea slow-release particles prepared in Preparation Example 1 and 2% of minerals.

[0074] Comparative Example 5, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the matrix layer includes 88% of biomass matrix, 10% of urea slow-release particles prepared in Preparation Example 1 and 2% of minerals.

[0075] Comparative Example 6, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the urea slow-release particles prepared in Preparation Example 1 are replaced with an equal amount of urea.

[0076] Comparative Example 7, a bio-based submerged plant fiber planting blanket, is different from Example 1 only in that the matrix layer includes 98% of biomass matrix and 2% of minerals.

[0077] Performance testing:

[0078] Three submerged plants (dead grass, black algae and elodea) were planted in the fiber planting blankets obtained in the examples and comparative examples, respectively, and placed in a river for testing, wherein the river flow rate was 2.5-4 m / s. After three months of testing, the survival rate was calculated.

[0079] The above test results are shown in Table 1:

[0080] Table 1 Survival rate test results

[0081]

[0082]

[0083] According to Table 1, in combination with Example 1 and Example 9 to Example 11, it can be seen that the plant survival rate of Example 9 to Example 11 is lower than that of Example 1. The reason is that the type of sodium hyaluronate used as the surface wall material of the urea sustained-release particles of Example 9 to Example 11 is adjusted, wherein acetylated sodium hyaluronate is not added in Example 9, and the physical barrier effect of the wall material is reduced, which will affect the water absorption of the urea sustained-release particles, resulting in the release efficiency of over-expanded urea being affected. In Example 10, cross-linked sodium hyaluronate is not added, which will affect the structural stability of the urea sustained-release particles and affect the controlled release of urea. In Example 11, ordinary sodium hyaluronate is used, which does not have the good water-locking property of cross-linked sodium hyaluronate, nor the good barrier effect of acetylated sodium hyaluronate, thereby affecting the sustained-release efficiency of urea and affecting the absorption of nutrients by the plant.

[0084] Combining Example 1 and Comparative Examples 1 to 3, it can be seen that the plant survival rate of Comparative Examples 1 to 3 is lower than that of Example 1. The reason is that the wall material in Comparative Example 1 does not add sodium hyaluronate, so the water retention of the urea slow-release particles is significantly reduced, and the moisture content of the matrix layer is difficult to maintain and stabilize, and it is impossible to provide a stable water supply to the roots of submerged plants, affecting plant growth; in Comparative Example 2, the gel particles loaded with urea are directly used, and the release rate of urea is greatly increased, and the plant roots will directly contact with the urea gel particles, and the phenomenon of burning seedlings will still occur, affecting the survival rate of the plants. In Comparative Example 3, urea is not first loaded on the gel particles, which will affect the slow-release efficiency of urea, and will also cause additional loss of urea, resulting in the plant not absorbing the proper nutrients and the survival rate decreasing.

[0085] Combining Example 1, Comparative Example 4, Comparative Example 5 and Comparative Example 7, it can be seen that the survival rate of the plants in Comparative Example 4, Comparative Example 5 and Comparative Example 7 is lower than that in Example 1. The reason is that the amount of urea slow-release particles added in Comparative Example 4 is reduced, which reduces the nutrient supply to the plants and reduces the water retention, which affects the growth of the plants and leads to a decrease in the survival rate of the plants. In Comparative Example 7, no urea is added, and the survival rate decreases more significantly. In Comparative Example 5, the amount of urea slow-release particles added is increased, and excessive urea content is not conducive to plant growth, which can cause problems such as seedling burning in plants, and the survival rate will also decrease.

[0086] Combining Example 1 and Comparative Example 6, it can be seen that the plant survival rate of Comparative Example 6 is lower than that of Example 1. The reason is that in Comparative Example 6, urea is directly mixed into the fiber planting blanket, and a large amount of urea directly contacts the plant root system, which will damage the fragile seedling root system, and will cause problems of excessive absorption in the early stage and deficiency in the later stage, which is not conducive to plant growth and reduces the survival rate.

[0087] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0088] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A bio-based submerged plant fiber planting blanket, comprising a bearing layer and a matrix layer, characterized in that: The matrix layer includes the following raw materials by mass fraction: Biomass matrix 90-95%; Urea slow-release particles 4-8%; Minerals 1-3%; The urea sustained-release particles are of a core-shell structure, wherein the core material is gel particles loaded with urea, and the wall material is a complex of β-cyclodextrin and sodium hyaluronate.

2. The bio-based submerged plant fiber planting blanket according to claim 1, characterized in that: The mass ratio of the core material to the wall material is 1:(1.5-2).

3. The bio-based submerged plant fiber planting blanket according to claim 1, characterized in that: The urea-loaded gel particles are prepared according to the following method: Sodium carboxymethyl cellulose is dissolved in a sodium hydroxide aqueous solution with a mass fraction of 15-20%, an emulsifier is added, and the mixture is stirred and emulsified for 20-30 minutes. The temperature is adjusted to 40-45° C., an organic cross-linking agent and a sodium hydroxide aqueous solution with a mass fraction of 30-40% are added, and the mixture is kept warm for reaction for 5-6 hours. Gel particles are obtained after washing and dialyzing. The gel particles are immersed in a urea aqueous solution with a concentration of 5-15 g / L for 6-8 hours, and urea-loaded gel particles are obtained after freeze-drying.

4. The bio-based submerged plant fiber planting blanket according to claim 3, characterized in that: The mass volume ratio of the gel particles to the urea aqueous solution is 1 g: (4-6) mL.

5. The bio-based submerged plant fiber planting blanket according to claim 1, characterized in that: The mass ratio of the β-cyclodextrin to sodium hyaluronate is (2-3):

1.

6. The bio-based submerged plant fiber planting blanket according to claim 1, characterized in that: The sodium hyaluronate is a composition of cross-linked sodium hyaluronate and acetylated sodium hyaluronate in a mass ratio of (0.7-0.8):(0.2-0.3).

7. The bio-based submerged plant fiber planting blanket according to claim 1, characterized in that: The urea slow-release particles are prepared according to the following method: β-cyclodextrin and sodium hyaluronate are added to deionized water respectively, the temperature is increased to 65-75°C, and an aqueous solution with a mass fraction of 5-10% is prepared. The mixture is mixed and stirred for 2-3 hours according to the mass ratio, and gel particles loaded with urea are added. The mixture is stirred for 6-8 hours at room temperature, and finally urea sustained-release particles are obtained by centrifugation, washing and drying.

8. The bio-based submerged plant fiber planting blanket according to claim 1, characterized in that: The biomass matrix includes one or more combinations of peat soil, garden waste, wine slop, crop straw and humus.

9. The bio-based submerged plant fiber planting blanket according to claim 1, characterized in that: The bearing layer is a dense mesh of plant fibers.

10. A method for preparing a bio-based submerged plant fiber planting blanket according to any one of claims 1 to 9, characterized in that: The process steps include: S1. mixing the biomass matrix, urea slow-release particles and minerals in a corresponding mass ratio and compressing them to obtain a matrix layer; S2. Laying the obtained matrix layer on the bearing layer to obtain a bio-based submerged plant fiber planting blanket.

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