Special silicon-containing compound fertilizer for rice and preparation method of special silicon-containing compound fertilizer

Abstract

The invention discloses a special silicon-containing compound fertilizer for rice and a preparation method thereof, and belongs to the technical field of silicon-containing compound fertilizers, the special silicon-containing compound fertilizer for rice comprises the following raw materials by mass: 15-25 parts of a nitrogen fertilizer, 15-20 parts of a phosphate fertilizer, 10-15 parts of potassium sulfate, 8-12 parts of a modified diatomite / nanocellulose nested compound and 10-20 parts of humic acid, the raw materials of the modified diatomite comprise diatomite and an inorganic modifier in a mass ratio of 1: (1.2-1.8), and the inorganic modifier comprises one or a combination of calcium chloride and zinc sulfate. The diatomite subjected to modification treatment can form a nested structure with the nanocellulose, the mesoporosity of the diatomite is effectively improved, more micropores and mesopores are formed in the diatomite, the immobilization amount of nutrients is increased, and the nanocellulose can also provide mechanical support and more adsorption sites for the pore structure of the diatomite, so that the adsorption efficiency of the diatomite is improved. A stable pore network is effectively maintained, and the fertilizer efficiency of the compound fertilizer is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of silicon-containing compound fertilizers, and in particular relates to a silicon-containing compound fertilizer special for rice and a preparation method thereof. Background Art

[0002] As one of the main food crops, the yield and quality of rice are crucial to ensuring food security. With the development of modern agricultural technology, people are constantly optimizing fertilizer formulas to further improve the growth efficiency and stress resistance of rice.

[0003] Rice is a silicon-loving crop. Silicon is an indispensable nutrient in the growth process of rice. As an important component of plant cell walls, applying silicon fertilizer to rice can thicken the epidermal cell walls and thicken the vascular bundles, which can significantly enhance the rice's stress resistance, ability to fight diseases and pests, and waterlogging resistance, thereby increasing rice yield and quality.

[0004] The main sources of silicon fertilizers are mostly ores, mainly silicate ores, including zeolite, quartz, feldspar, pyroxene, etc., as well as some industrial by-products, such as calcium silicate (gypsum), sodium silicate (alkali residue), etc. These silicon fertilizers can significantly improve the quality of rice to a certain extent, but there are also some problems. For example, silicon fertilizers made from industrial by-products may have the hidden danger of excessive heavy metals, which will damage soil properties and pollute the environment when applied to the soil. Silicon fertilizers and silicon-containing compound fertilizers made from general ores have low effective silicon content, making it difficult to highlight the role of silicon fertilizers.

[0005] Diatomaceous earth is a siliceous sedimentary rock formed by the consolidation of diatom remains and soft mud. People have found that using diatomaceous earth to make silicon fertilizer has a good yield-increasing effect, the fertilizer cost is appropriate, and the effective silicon content is high, and it will not cause environmental pollution. However, diatomaceous earth-based silicon fertilizers still have some problems, such as the poor mesoporous properties of diatomaceous earth, which will lead to the diatomaceous earth as one of the raw materials of compound fertilizers. The ability to adsorb nutrients and modify additives is reduced. The effective ingredients of the fertilizer cannot be fully fixed on the carrier and are easily lost with water. The sustained-release effect is poor, resulting in the release of nutrients too quickly or too slowly, affecting the nutrient supply process of crops. Summary of the invention

[0006] The purpose of the present invention is to provide a silicon-containing compound fertilizer for rice and a preparation method thereof, so as to solve the problems that the effective silicon content of silicon fertilizer is low, nutrients are easily lost when diatomaceous earth is used as a raw material for compound fertilizer, and the slow-release effect is poor.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] In a first aspect, the present invention provides a silicon-containing compound fertilizer for rice, comprising the following raw materials in parts by weight:

[0009] 15-25 parts of nitrogen fertilizer;

[0010] Phosphate fertilizer 15-20 parts;

[0011] 10-15 parts of potassium sulfate;

[0012] 8-12 parts of modified diatomaceous earth / nanocellulose nested compound;

[0013] Humic acid 10-20 parts;

[0014] The raw materials of modified diatomaceous earth include diatomaceous earth and inorganic modifier in a mass ratio of 1: (1.2-1.8); the inorganic modifier includes one or a combination of calcium chloride and zinc sulfate.

[0015] Preferably, the inorganic modifier is a combination of calcium chloride and zinc sulfate in a mass ratio of 1: (0.5-0.7).

[0016] Preferably, the content of silicon dioxide in diatomaceous earth is 85-90%.

[0017] Preferably, the nitrogen fertilizer includes a combination of one or more of urea, ammonium chloride, diammonium phosphate and monoammonium phosphate; the phosphate fertilizer includes a combination of one or more of diammonium phosphate, monoammonium phosphate and superphosphate.

[0018] By adopting the above technical solution, diatomaceous earth-based silicon fertilizer is applied in combination with nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer, which can provide rice with various nutrients required for growth, thereby improving the quality and yield of the final rice. In addition, combined with humic acid, the diatomaceous earth-based silicon fertilizer can be well combined to prevent the granular diatomaceous earth from being washed away by rainwater, thereby causing nutrient loss.

[0019] The diatomite-based silicon fertilizer of the present invention adopts a modified diatomite / nanocellulose nested compound. Diatomite itself is a porous material, but its pore size distribution is mainly concentrated between micropores and a small amount of mesopores. The number of mesopores is extremely limited and the pore size distribution is uneven. The pore structure is also prone to collapse or dissolution during the natural aging process, which further limits the performance of its mesoporosity. The mesoporous properties of diatomite can be well improved by forming a nested structure with nanocellulose, and more micropores and mesopores are formed inside the diatomite. Nanocellulose also provides mechanical support and more adsorption sites for the pore structure of diatomite, which can effectively enhance the fixation capacity of nutrient elements in the compound fertilizer, thereby increasing the mechanical strength and stability of diatomite, and improving the durability and effect of the obtained compound fertilizer.

[0020] Moreover, the nested structure helps to improve the porosity, making it easier for water to penetrate into the interior, thereby promoting the slow release of nutrients and extending the fertilizer effect period.

[0021] In order to form a stable nested structure compound, the diatomaceous earth is first modified, mainly by pre-treating the diatomaceous earth with an inorganic modifier. The inorganic modifier is evenly dispersed between the pores of the diatomaceous earth, and can form a columnar layered association structure, thereby dredging and expanding the original diatomaceous earth pores to form a larger space. Nanocellulose can therefore enter the diatomaceous earth pores well, forming nested compounds and playing a role in supporting the pores.

[0022] Moreover, the preferred inorganic modifiers of the present invention are calcium chloride and zinc sulfate. While improving the pore structure of diatomite, calcium and zinc elements required for rice growth are also introduced into the diatomite. After fertilization, calcium, zinc or a combination of calcium and zinc have the functions of maintaining the cell wall structure of rice, preventing fruit rot or cracking during heading, promoting auxin synthesis, and improving plant stress resistance. It can not only improve the slow-release effect of diatomite, but also provide additional nutrients, thereby improving the quality and yield of rice.

[0023] Preferably, the raw materials of the modified diatomaceous earth / nanocellulose nested compound include modified diatomaceous earth and cellulose nanocrystals in a mass ratio of 1:(0.2-0.3).

[0024] Preferably, the diameter of the cellulose nanocrystals is 10 to 50 nm and the length is 200 to 500 nm.

[0025] Preferably, the modified diatomaceous earth / nanocellulose nested compound is prepared according to the following method:

[0026] Preparation of modified diatomaceous earth: diatomaceous earth is crushed and sieved, dispersed in an aqueous solution containing an inorganic modifier, the temperature is raised to 30-40° C., stirred and mixed for 2-3 hours, and finally filtered, washed, dried and heat-treated to obtain modified diatomaceous earth;

[0027] Preparation of modified diatomaceous earth / nanocellulose nested compound: Disperse modified diatomaceous earth in anhydrous ethanol and disperse cellulose nanocrystals in water, mix the two solutions, stir at 50-60° C. for 15-20 h, filter and wash, and vacuum freeze-dry for 2-3 h to obtain the product.

[0028] By adopting the above technical scheme, after the diatomite is modified, the pore structure contained in the diatomite is unblocked and improved, and new cations are introduced to increase the attraction of the diatomite to the cellulose nanocrystals, which can produce strong electrostatic attraction and provide effective interface interaction, thereby promoting the attachment of the cellulose nanocrystals to the diatomite. Moreover, when a solution containing cellulose nanocrystals is introduced into the pores of the diatomite, the capillary force will push the liquid into the unblocked pore structure, helping the cellulose nanocrystals to be evenly distributed inside the diatomite to form a nested compound.

[0029] If the diatomaceous earth is not pre-treated with inorganic modifiers, it is difficult for cellulose nanocrystals to enter the complex pore structure of diatomaceous earth, and the binding force between cellulose nanocrystals and diatomaceous earth is not strong, so they are easily washed away by water during use. On the other hand, the original pore structure of diatomaceous earth has few mesoporous structures, and directly mixing cellulose nanocrystals can easily cause mesopore blockage. Not only can it fail to form nested structure compounds to further improve the pore structure of diatomaceous earth, but it will also block the mesopores, which is not conducive to the attachment and storage of nutrients.

[0030] Modified diatomaceous earth and cellulose nanocrystals form nested compounds. The addition of nanocellulose can not only act as a natural barrier to prevent the rapid loss of nutrients in fertilizers, but also promote soil microbial activity, which is beneficial to maintaining a healthy soil ecosystem. Cellulose nanocrystals are distributed inside the diatomaceous earth and shrink during the drying process, leaving regular channels inside, creating more micropores and mesopores for the diatomaceous earth, optimizing the pore size distribution, and being able to accommodate more nutrients into the pores stored in the diatomaceous earth, increasing the solid loading capacity of the diatomaceous earth, and being able to well control the release rate of nutrients.

[0031] Nanocellulose also provides an additional support framework for diatomaceous earth, helps disperse external forces, enhances the mechanical strength of modified diatomaceous earth, helps maintain a stable pore network, always maintains good air permeability and water permeability, and is conducive to the healthy growth of plant roots. Moreover, the addition of cellulose nanocrystals can automatically adjust the nutrient release efficiency according to the changes in soil moisture surface to meet the growth needs of crops.

[0032] Preferably, the cellulose nanocrystals are surface-modified; the raw materials of the surface-modified cellulose nanocrystals include cellulose nanocrystals and sodium ethylenediaminetetraacetate in a mass ratio of 1:(0.5-0.6).

[0033] Preferably, the cellulose nanocrystals are surface-modified by the following method: dispersing the cellulose nanocrystals in water, adding ethylenediaminetetraacetic acid, stirring at room temperature for 20 to 30 hours, and finally filtering, washing and drying to obtain surface-modified cellulose nanocrystals.

[0034] By adopting the above technical scheme, in the process of forming nested compounds between cellulose nanocrystals and modified diatomaceous earth, although the pore structure of diatomaceous earth is unblocked and expanded after modification with an inorganic modifier, the efficiency of the nested compound finally formed is not high, and the composite obtained by direct mixing has a poor effect on improving the mesoporous structure of diatomaceous earth and it is difficult to create more mesoporous structures. Therefore, the effect on plant growth is reduced, and the growth needs of crops and the attachment of nutrients cannot be well met.

[0035] In order to further solve this problem, cellulose nanocrystals are subjected to surface modification treatment, and ethylenediaminetetraacetic acid can be attached to the surface of nanocellulose by physical adsorption, and can also form chemical bonds such as covalent bonds or hydrogen bonds with the hydroxyl groups on the surface of cellulose nanocrystals. The modified cellulose nanocrystals can enhance their negative charge characteristics, thereby enhancing the electrostatic attraction between diatomite. In addition, ethylenediaminetetraacetic acid is a compound with a strong metal ion complexing ability, which can be complexed with the metal cations introduced in the modified diatomite, improve the uniform distribution and attraction of cellulose nanocrystals inside the modified diatomite, and the interface bonding force, thereby effectively obtaining a tightly combined nested compound, improving the internal pore structure of the diatomite, allowing nutrients to better adhere to and be stored in the diatomite and slowly released, thereby improving the promotion effect of fertilizer on rice growth.

[0036] In a second aspect, the present invention provides a method for preparing a silicon-containing compound fertilizer for rice, comprising the following process steps:

[0037] Relevant raw materials are weighed according to corresponding mass parts, mixed evenly and then conveyed to an agglomeration granulator for granulation, and after screening and aging, a silicon-containing compound fertilizer specially used for rice is obtained.

[0038] Beneficial effects of the present invention:

[0039] 1. The diatomite-based silicon fertilizer of the present invention adopts a modified diatomite / nanocellulose nested compound, and the formed nested structure can well improve the mesoporous properties of diatomite, and form more micropores and mesopores inside the diatomite, thereby effectively enhancing the fixation capacity and storage capacity of nutrient elements in the compound fertilizer. The addition of nanocellulose can also help regulate the release efficiency of nutrients, prevent the nutrients in the fertilizer from being lost too quickly, and provide mechanical support and more adsorption sites for the pore structure of diatomite, which helps to maintain a stable pore network and improve the fertilizer efficiency of the compound fertilizer.

[0040] 2. In the modified diatomaceous earth / nanocellulose nested compound of the present invention, the diatomaceous earth is first pretreated with an inorganic modifier, and after modification, a columnar layered association structure is formed, thereby clearing and expanding the original diatomaceous earth pores, which is beneficial to the penetration of cellulose nanocrystals and facilitates the formation of a nested structure compound; on the other hand, the inorganic modifier also provides additional nutrients for the compound fertilizer, promotes rice growth, and improves rice yield and quality. DETAILED DESCRIPTION

[0041] 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.

[0042] Preparation Example

[0043] Preparation Example 1: A modified diatomaceous earth / nanocellulose nested compound is prepared according to the following method:

[0044] Preparation of modified diatomite: 10g of diatomite (the average content of silicon dioxide in diatomite is 86%) is crushed through a 120-mesh sieve and dispersed in an inorganic modifier aqueous solution with a mass fraction of 20%, wherein the amount of the inorganic modifier added is 15g, and the inorganic modifier is a composition of calcium chloride and zinc sulfate with a mass ratio of 1:0.6, the temperature is raised to 35°C, stirred and mixed for 2h, and finally filtered, washed, dried and heat-treated to obtain modified diatomite, wherein the heat treatment temperature is 210°C and the heat treatment time is 2h;

[0045] Preparation of modified diatomaceous earth / nanocellulose nested compounds: 10 g of the modified diatomaceous earth obtained above was dispersed in 100 mL of anhydrous ethanol, and 2.5 g of cellulose nanocrystals (average diameter of 20 nm, average length of 300 nm) were dispersed in 50 mL of water. The two solutions were mixed with each other, stirred at 60°C for 20 h, and finally filtered and washed, and vacuum freeze-dried for 3 h.

[0046] Preparation Example 2, a modified diatomaceous earth / nanocellulose nested compound, differs from Preparation Example 1 only in that the amount of inorganic modifier added is 12 g, and the inorganic modifier is a composition of calcium chloride and zinc sulfate in a mass ratio of 1:0.5; the amount of cellulose nanocrystals added is 2 g.

[0047] Preparation Example 3, a modified diatomaceous earth / nanocellulose nested compound, differs from Preparation Example 1 only in that the amount of inorganic modifier added is 18 g, and the inorganic modifier is a composition of calcium chloride and zinc sulfate in a mass ratio of 1:0.7; the amount of cellulose nanocrystals added is 3 g.

[0048] Preparation Example 4, a modified diatomaceous earth / nanocellulose nested compound, is different from Preparation Example 1 only in that an equal amount of calcium chloride is used to replace the composition of calcium chloride and zinc sulfate in a mass ratio of 1:0.6.

[0049] Preparation Example 5, a modified diatomaceous earth / nanocellulose nested compound, is different from Preparation Example 1 only in that an equal amount of zinc sulfate is used to replace the composition of calcium chloride and zinc sulfate in a mass ratio of 1:0.6.

[0050] Preparation Example 6, a modified diatomaceous earth / nanocellulose nested compound, is different from Preparation Example 1 only in that the amount of inorganic modifier added is 10 g.

[0051] Preparation Example 7, a modified diatomaceous earth / nanocellulose nested compound, is different from Preparation Example 1 only in that the amount of inorganic modifier added is 20 g.

[0052] Preparation Example 8, a modified diatomaceous earth / nanocellulose nested compound, is different from Preparation Example 1 only in that the added amount of cellulose nanocrystals is 1 g.

[0053] Preparation Example 9, a modified diatomaceous earth / nanocellulose nested compound, is different from Preparation Example 1 only in that the added amount of cellulose nanocrystals is 4 g.

[0054] Preparation Example 10, a modified diatomaceous earth / nanocellulose nested compound, prepared according to the following method:

[0055] Preparation of modified diatomite: 10g of diatomite (the average content of silicon dioxide in diatomite is 86%) is crushed through a 120-mesh sieve and dispersed in an inorganic modifier aqueous solution with a mass fraction of 20%, wherein the amount of the inorganic modifier added is 15g, and the inorganic modifier is a composition of calcium chloride and zinc sulfate with a mass ratio of 1:0.6, the temperature is raised to 35°C, stirred and mixed for 2h, and finally filtered, washed, dried and heat-treated to obtain modified diatomite, wherein the heat treatment temperature is 210°C and the heat treatment time is 2h;

[0056] Preparation of surface-modified cellulose nanocrystals: 10 g of cellulose nanocrystals (average diameter of 20 nm, average length of 300 nm) were dispersed in 100 mL of water, 5 g of ethylenediaminetetraacetic acid was added, and stirred at room temperature for 24 h. Finally, surface-modified cellulose nanocrystals were obtained by filtration, washing and drying.

[0057] Preparation of modified diatomaceous earth / nanocellulose nested compound: 10 g of the modified diatomaceous earth obtained above was dispersed in 100 mL of anhydrous ethanol, 2.5 g of the surface-modified cellulose nanocrystals obtained above was dispersed in 50 mL of water, the two solutions were mixed with each other, stirred at 60°C for 20 h, and finally filtered and washed, and vacuum freeze-dried for 3 h to obtain the compound.

[0058] Preparation Example 11, a modified diatomaceous earth / nanocellulose nested compound, is different from Preparation Example 10 only in that the amount of ethylenediaminetetraacetic acid added is 6 g.

[0059] Preparation Example 12: A diatomaceous earth / nanocellulose composite was prepared according to the following method:

[0060] Preparation of diatomaceous earth / nanocellulose composite: 10 g of diatomaceous earth (the average content of silicon dioxide in diatomaceous earth is 86%) was crushed through a 120-mesh sieve and dispersed in 100 mL of anhydrous ethanol; 2.5 g of cellulose nanocrystals (average diameter of 20 nm, average length of 300 nm) were dispersed in 50 mL of water; the two solutions were mixed, stirred at 60°C for 20 h, filtered and washed, and vacuum freeze-dried for 3 h.

[0061] Preparation Example 13, a modified diatomaceous earth, prepared according to the following method:

[0062] Preparation of modified diatomaceous earth: Take 10g of diatomaceous earth (the average content of silicon dioxide in diatomaceous earth is 86%), crush it through a 120-mesh sieve, and then disperse it in a 20% aqueous solution of an inorganic modifier by mass, wherein the amount of the inorganic modifier added is 15g, and the inorganic modifier is a composition of calcium chloride and zinc sulfate in a mass ratio of 1:0.6. Raise the temperature to 35°C, stir and mix for 2h, and finally obtain modified diatomaceous earth by filtration, washing, drying and heat treatment, wherein the heat treatment temperature is 210°C and the heat treatment time is 2h.

[0063] Example

[0064] Example 1, a silicon-containing compound fertilizer for rice, is prepared according to the following process steps:

[0065] Weigh 200 g of urea, 180 g of ammonium dihydrogen phosphate, 120 g of potassium sulfate, 100 g of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 and 150 g of humic acid, mix them evenly and then convey them to an agglomeration granulator for granulation, and obtain a silicon-containing compound fertilizer for rice after screening and aging.

[0066] Embodiment 2 and Embodiment 3 are silicon-containing compound fertilizers for rice. The difference from Embodiment 1 is that the ratio of raw materials is adjusted, as shown in Table 1:

[0067] Table 1 Formula table of Example 1 to Example 3

[0068]

[0069] The modified diatomaceous earth / nanocellulose nested compounds used are all the modified diatomaceous earth / nanocellulose nested compounds prepared in Preparation Example 1.

[0070] Example 4, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 2.

[0071] Example 5, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 3.

[0072] Example 6, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 4.

[0073] Example 7, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 5.

[0074] Example 8, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 8.

[0075] Example 9, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 9.

[0076] Example 10, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 10.

[0077] Example 11, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 11.

[0078] Comparative Example

[0079] Comparative Example 1, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 6.

[0080] Comparative Example 2, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 7.

[0081] Comparative Example 3, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the added amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is 50 g.

[0082] Comparative Example 4, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the added amount of the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is 150 g.

[0083] Comparative Example 5, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of the diatomaceous earth / nanocellulose composite prepared in Preparation Example 12.

[0084] Comparative Example 6, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of modified diatomaceous earth prepared in Preparation Example 13.

[0085] Comparative Example 7, a silicon-containing compound fertilizer for rice, is different from Example 1 only in that the modified diatomaceous earth / nanocellulose nested compound prepared in Preparation Example 1 is replaced by an equal amount of diatomaceous earth.

[0086] Performance testing

[0087] The silicon-containing compound fertilizer for rice obtained in the examples and comparative examples was measured in different plots. The experimental crop variety was rice Liangyou 8106. Each plot had a single row and single irrigation. The mature plant height, number of grains per ear and actual yield of rice were recorded. The details are shown in Table 2:

[0088] Table 2 Performance test results

[0089]

[0090] According to Table 2, in combination with Example 1, Example 6 and Example 7, it can be seen that the quality and yield of rice in Example 6 and Example 7 are slightly reduced. The reason is that compared with Example 1, in the preparation process of modified diatomaceous earth, the inorganic modifier added in Example 6 and Example 7 is calcium chloride or zinc sulfate, while Example 1 uses a combination of the two. The inorganic modifier obtained by the combination can better provide and make up for the missing nutrients in the growth process of rice, thereby improving the quality and yield of rice.

[0091] Combining Example 1 and Example 10, it can be seen that the quality and yield of rice in Example 10 are increased compared with Example 1. The reason is that the cellulose nanocrystals in Example 10 are surface-modified by ethylenediaminetetraacetic acid before being nested in the composite modified diatomaceous earth. The modified cellulose nanocrystals can better form a nested structure compound with the modified diatomaceous earth, and can also enhance the binding force between the two, thereby better improving the mesoporous properties of the diatomaceous earth and the stability of the pore structure, thereby improving the storage and release efficiency of nutrients, which helps to improve the quality and yield of rice.

[0092] Combined with Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 5, it can be seen that the rice quality and yield of Comparative Example 1, Comparative Example 2 and Comparative Example 5 are reduced compared with Example 1, and the reduction of Comparative Example 5 is more obvious. The reason is that Comparative Example 1, Comparative Example 2 and Comparative Example 5 adjust the addition amount of inorganic modifier in modified diatomite compared with Example 1, and Comparative Example 1 reduces the addition amount of inorganic modifier, resulting in some micropores or mesopores in diatomite that have not been dredged and expanded, which will affect the mesoporous properties of diatomite itself on the one hand, and on the other hand, it is not conducive to the nesting and compounding of cellulose nanocrystals, and the binding force of nanocellulose crystals is also reduced. In Comparative Example 5, there is no inorganic modifier modification treatment, and cellulose nanocrystals are difficult to penetrate into the interior of diatomite to form nested compounds, and this composite obtained by direct mixing will significantly affect the mesoporosity of diatomite, not only the mesoporous properties cannot be improved, but the mesopores will be blocked due to uneven distribution, which is not conducive to the attachment and storage of nutrients, and the fertilizer nutrients obtained are easy to lose, and the quality and yield of rice are significantly reduced. In Comparative Example 2, the amount of inorganic modifier added is increased, which will cause the active sites inside the diatomaceous earth to be largely occupied by the inorganic modifier, which is not conducive to the binding of cellulose nanocrystals, resulting in a decrease in the overall stability of the compound fertilizer.

[0093] Combining Example 1, Comparative Example 6 and Comparative Example 7, it can be seen that the quality and yield of rice in Comparative Example 6 and Comparative Example 7 are significantly reduced compared to Example 1. The reason is that, compared to Example 1, Comparative Example 6 does not add cellulose nanocrystals to form nested compounds. On the one hand, the pore structure of the modified diatomite cannot be effectively supported, and the pore structure is prone to collapse or dissolution during use, thereby causing nutrient loss. On the other hand, the improvement effect of the mesoporosity of diatomite is significantly reduced, nutrients are easily lost, and it is difficult to regulate the release efficiency of nutrients, resulting in a decrease in the final rice yield and quality. Comparative Example 7 uses diatomite that has not been modified and nested, which not only lacks the supplement of additional nutrients, but also lacks the nested composite effect of cellulose nanocrystals, poor mesoporosity, and rapid nutrient loss, resulting in a significant decrease in rice quality and yield.

[0094] 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.

[0095] 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 silicon-containing compound fertilizer for rice, characterized in that: Including the following raw materials by mass: 15-25 parts of nitrogen fertilizer; Phosphate fertilizer 15-20 parts; 10-15 parts of potassium sulfate; 8-12 parts of modified diatomaceous earth / nanocellulose nested compound; Humic acid 10-20 parts; The raw materials of the modified diatomaceous earth include diatomaceous earth and an inorganic modifier in a mass ratio of 1:(1.2-1.8); the inorganic modifier includes one or a combination of calcium chloride and zinc sulfate.

2. The silicon-containing compound fertilizer for rice according to claim 1, characterized in that: The inorganic modifier is a combination of calcium chloride and zinc sulfate in a mass ratio of 1: (0.5-0.7).

3. The silicon-containing compound fertilizer for rice according to claim 1, characterized in that: The content of silicon dioxide in the diatomaceous earth is 85-90%.

4. The silicon-containing compound fertilizer for rice according to claim 1, characterized in that: The raw materials of the modified diatomaceous earth / nanocellulose nested compound include modified diatomaceous earth and cellulose nanocrystals in a mass ratio of 1:(0.2-0.3).

5. The silicon-containing compound fertilizer for rice according to claim 4, characterized in that: The cellulose nanocrystals have a diameter of 10 to 50 nm and a length of 200 to 500 nm.

6. The silicon-containing compound fertilizer for rice according to claim 4, characterized in that: The modified diatomaceous earth / nanocellulose nested compound is prepared according to the following method: Preparation of modified diatomaceous earth: diatomaceous earth is crushed and sieved, dispersed in an aqueous solution containing an inorganic modifier, the temperature is raised to 30-40° C., stirred and mixed for 2-3 hours, and finally filtered, washed, dried and heat-treated to obtain modified diatomaceous earth; Preparation of modified diatomaceous earth / nanocellulose nested compound: Disperse modified diatomaceous earth in anhydrous ethanol and disperse cellulose nanocrystals in water, mix the two solutions, stir at 50-60° C. for 15-20 h, filter and wash, and vacuum freeze-dry for 2-3 h to obtain the product.

7. The silicon-containing compound fertilizer for rice according to claim 4, characterized in that: The cellulose nanocrystals are surface-modified; the raw materials of the surface-modified cellulose nanocrystals include cellulose nanocrystals and sodium ethylenediaminetetraacetate in a mass ratio of 1:(0.5-0.6).

8. The silicon-containing compound fertilizer for rice according to claim 7, characterized in that: The cellulose nanocrystals are surface modified according to the following method: the cellulose nanocrystals are dispersed in water, ethylenediaminetetraacetic acid is added, stirred at room temperature for 20 to 30 hours, and finally filtered, washed and dried to obtain the surface modified cellulose nanocrystals.

9. The silicon-containing compound fertilizer for rice according to claim 1, characterized in that: The nitrogen fertilizer includes one or more combinations of urea, ammonium chloride, diammonium phosphate and monoammonium phosphate; the phosphate fertilizer includes one or more combinations of diammonium phosphate, monoammonium phosphate and superphosphate.

10. A method for preparing a silicon-containing compound fertilizer for rice according to any one of claims 1 to 9, characterized in that: The process steps include: Relevant raw materials are weighed according to corresponding mass parts, mixed evenly and then conveyed to an agglomeration granulator for granulation, and after screening and aging, a silicon-containing compound fertilizer specially used for rice is obtained.

Images