Biological fertilizer water retention agent, preparation method thereof and compound fertilizer

Abstract

The invention relates to the technical field of fertilizers, and particularly discloses a biological fertilizer water retention agent, a preparation method thereof and a compound fertilizer. The preparation method of the biofilm fertilizer water retention agent comprises the following steps: preparing loaded microorganisms; adding polyglutamic acid and glucan into water, uniformly stirring, adjusting the temperature of the system to 50-70 DEG C, cooling, adding the loaded microorganisms, and uniformly mixing to obtain a premix a; adding cross-linked carboxymethyl cellulose and silica fume into the premix a, and uniformly mixing to obtain a premix b; and uniformly mixing guar gum, polyvinyl alcohol and carboxymethyl cross-linked dextran gel, adjusting the water content of the system, stirring, cooling, adding into the premix b in a stirring state, stirring, and carrying out post-treatment to obtain the biofilm fertilizer water retention agent. The invention discloses a compound fertilizer and a preparation method thereof. Through the synergistic effect of various effective components, the water-retaining and fertilizer-retaining capacities of soil are improved, and the water-retaining and fertilizer-retaining agent is used for compound fertilizers, promotes plant growth and is suitable for large-scale popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to a biological fertilizer water retaining agent and a preparation method thereof and a compound fertilizer. Background Art

[0002] After fertilizers are applied to the soil, they cannot be completely absorbed and utilized by crops. A large part of them is converted into a form that cannot be absorbed by crops due to factors such as leaching, volatilization or fixation by the soil. Therefore, conventional fertilizers have low nutrient utilization rate and short fertilizer effect period, which cannot meet the needs of crop growth and development. Due to the low fertilizer utilization rate, it leads to serious resource consumption, reduced crop quality, and serious environmental pollution. In addition, the soil has poor water retention capacity under irregular rainfall. Conventional biofilm fertilizer and water retention agents have limited water and fertilizer retention effects. Summary of the invention

[0003] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a biological fertilizer water retaining agent and a preparation method thereof and a compound fertilizer.

[0004] A biofilm fertilizer and water retaining agent, whose raw materials include, by mass, 1-3 parts of sodium alginate, 5-10 parts of halloysite nanotubes, 1-2 parts of polyaspartic acid, 60-100 parts of microbial culture liquid, 400-500 parts of calcium chloride aqueous solution, 20-30 parts of polyglutamic acid, 5-15 parts of dextran, 1-3 parts of cross-linked carboxymethyl cellulose, 1-2 parts of microsilica powder, 1-2 parts of guar gum, 1-2 parts of polyvinyl alcohol and 1-2 parts of carboxymethyl cross-linked dextran gel.

[0005] Preferably, the mass fraction of the calcium chloride aqueous solution is 6-10%.

[0006] Preferably, the microbial solution includes rhizobia, phosphate-solubilizing bacteria, and lactic acid bacteria, and the number of viable rhizobia is 1-3×10 9 cfu / g, the number of viable phosphate-solubilizing bacteria is 1-3×10 9 cfu / g, the number of viable lactic acid bacteria is 1-3×10 9 cfu / g.

[0007] Preferably, the particle size of the microsilica powder is 1-10 μm, and more preferably, the particle size of the microsilica powder is 2 μm.

[0008] The preparation method of the biofilm fertilizer and water retaining agent comprises the following steps:

[0009] S1. Add sodium alginate to water and stir until dissolved, the dissolution temperature is 60-80°C, add halloysite nanotubes and stir evenly, cool to room temperature, add microbial solution and stir, the stirring speed is 500-1000r / min, the stirring time is 1-2h, use a syringe and squeeze it into a calcium chloride aqueous solution through a needle, let it stand, filter, and wash with water until neutral to obtain loaded microorganisms;

[0010] S2, adding polyglutamic acid and dextran to water and stirring evenly, adjusting the system temperature to 50-70°C, cooling to room temperature, adding loaded microorganisms and mixing evenly to obtain premix a;

[0011] S3, adding cross-linked carboxymethyl cellulose and microsilica powder to premix a and mixing evenly to obtain premix b;

[0012] S4. Evenly mix guar gum, polyvinyl alcohol and carboxymethyl cross-linked polysaccharide gel, add water to adjust the water content of the system to 1-2wt%, stir, cool to room temperature, add to premix b under stirring, and sequentially dry, cool, screen and anti-caking treatment to obtain a biofilm fertilizer and water retaining agent.

[0013] Preferably, in S1, the standing time is 2-5 hours. Further optimization, the dissolution temperature is 65°C. Further optimization, the dissolution temperature is 65°C and the standing time is 2 hours.

[0014] Preferably, in S2, the stirring temperature is 65°C

[0015] Preferably, in S4, water is added to adjust the water content of the system to 1-2 wt%, and the mixture is stirred at a temperature of 60-80°C for 20-40 min. Further optimization is performed, and the stirring temperature is 70°C.

[0016] A compound fertilizer, whose raw materials include, by weight: 20-30 parts of ammonium sulfate, 10-15 parts of potassium chloride, 15-30 parts of monoammonium phosphate, 5-10 parts of bentonite, 15-30 parts of straw and mushroom residue compost, 0.1-0.5 parts of zinc sulfate, 0.5-2 parts of borax, and 1-5 parts of the above-mentioned biofilm fertilizer and water retaining agent.

[0017] Preferably, the ratio of nitrogen, phosphorus and potassium is N: P2O5: K2O = 14-20: 4-10: 4-11; based on the total weight of the compound fertilizer, the organic matter content accounts for 12-14wt%.

[0018] Preferably, the straw mushroom residue compost includes colloidal Bacillus and Bacillus subtilis, and the number of live bacteria of colloidal Bacillus is 1-3×10 9 cfu / g, the number of viable Bacillus subtilis is 1-3×10 9 cfu / g.

[0019] Beneficial effects:

[0020] In order to solve the problem of soil moisture and fertilizer loss and low fertilizer utilization rate, the present application provides a biofilm fertilizer and water retaining agent, which is made of polyglutamic acid, glucan and microorganisms (including rhizobia, phosphate-solubilizing bacteria, and lactic acid bacteria) as biofilm, and then cross-linked carboxymethyl cellulose and microsilica powder are used as water absorption and structural materials. The present application uses the above biofilm fertilizer and water retaining agent in compound fertilizer, which has obvious advantages compared with the output and benefits of biofilm fertilizer and water retaining agents and compound fertilizer products on the market.

[0021] The present invention adopts sodium alginate and halloysite nanotubes to form a combination, which has high adsorption and bonding strength for microorganisms. The loaded microorganisms formed by calcium chloride solidification have high stability. On the basis of increasing the loading amount, it is not easy to break. Further, polyglutamic acid and glucan have good affinity with microbial cell membranes. On the basis of further enhancing the stability of the loaded microorganisms, the sustained-release effect of the microorganisms is enhanced.

[0022] The carboxyl group in cross-linked carboxymethyl cellulose reacts with the amino group in polyglutamic acid and the hydroxyl group on the sodium alginate loaded with microorganisms to play a fixing role, while the microsilica powder can directly pass through the cell membrane and protein, and has a good water absorption effect in combination with cross-linked carboxymethyl cellulose and sodium alginate.

[0023] In compound fertilizer, organic fertilizer partially replaces chemical fertilizer and reduces the amount of chemical fertilizer used, which is a green fertilizer. The organic part of compound fertilizer, straw mushroom residue compost, not only has a high nutrient dissolution rate and high utilization rate, but also contains rich colloidal Bacillus and Bacillus subtilis, which can produce cellulase, can degrade cross-linked carboxymethyl cellulose, promote its decomposition into small molecules, and facilitate the absorption and utilization of plants. After the cross-linked carboxymethyl cellulose is decomposed, microsilicon powder also absorbs water and releases slowly, continuing to provide water retention for plants. At the same time, its slow release process is coordinated with the fertilizer requirement of plants, effectively reducing the amount of chemical fertilizer used and the number of fertilizations. However, the large amount of cellulase produced by colloidal Bacillus and Bacillus subtilis will consume a large amount of nitrogen, resulting in soil nitrogen loss. This application further cooperates with rhizobia, phosphate-solubilizing bacteria and lactic acid bacteria, which can not only increase the nitrogen fixation rate and fertilizer utilization rate, but also provide a microbial environment for straw mushroom residue compost, repair and improve the soil, and effectively eliminate harmful chemicals in chemical fertilizers.

[0024] After the present invention is applied to the soil, as the slow-release process proceeds, the microorganisms are released and attached to the soil surface to form a biofilm to slowly release fertilizer and water. However, too many microorganisms fill the soil pores, resulting in insufficient aeration. Polyglutamic acid and glucan can form a three-dimensional network structure in the soil, effectively locking in water and nutrients, helping to reduce losses due to evaporation and leakage, and improving the soil's aeration and water permeability.

[0025] Since the introduction of a large number of microorganisms can easily cause plant diseases, silicon has a positive effect on plant growth and environmental protection. The microorganisms of the present invention combined with microsilicon powder can not only effectively prevent the harm of microorganisms to plants, but the structure formed by the combination of microsilicon powder with polyglutamic acid, glucan and microorganisms can significantly improve the air permeability and water permeability of the soil, increase the soil's water and fertilizer retention capacity, and have a good sustained release effect, which can provide a good growth environment for plant roots.

[0026] In summary, biofilm fertilizer and water retention agent improves the water and fertilizer retention capacity of soil through the synergistic effect of multiple effective ingredients. It is used in compound fertilizers to significantly improve the physical and chemical properties of soil and is suitable for large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a comparison chart of soil biomass before and after the test of Example 5, Comparative Examples 1-3 and a blank group.

[0028] Figure 2 It is a comparison chart of soil moisture evaporation rate of Example 5, Comparative Examples 1-3 and a blank group.

[0029] Figure 3 It is a comparison chart of soil nitrogen dissolution rate of Example 5, Comparative Examples 1-3 and a blank group.

[0030] Figure 4 It is a comparison chart of soil phosphorus dissolution rate of Example 5, Comparative Examples 1-3 and a blank group.

[0031] Figure 5 It is a comparison chart of soil potassium dissolution rate of Example 5, Comparative Examples 1-3 and a blank group.

[0032] Figure 6 It is a comparison chart of per mu yield of Example 5, Comparative Examples 1-3 and the blank group. DETAILED DESCRIPTION

[0033] The present invention will be further explained below in conjunction with specific embodiments.

[0034] The microsilica powder used below was purchased from Mouyuan (Xi'an) Microsilica Powder Co., Ltd.; the compound fertilizer used in the following comparative example 3 is Stanley compound fertilizer, purchased from Shimou Fertilizer Co., Ltd., and the effective ingredients include: N: P2O5: K2O = 14: 16: 15, and the organic matter content is 20%.

[0035] Example 1

[0036] A method for preparing a biofilm fertilizer and water retaining agent comprises the following steps:

[0037] S1. Add 0.1 kg sodium alginate to 80 kg water, stir until dissolved, the dissolution temperature is 65 ° C, add 0.5 kg halloysite nanotubes and stir evenly, cool to room temperature, add 6 kg microbial culture solution and stir, the stirring speed is 1000 r / min, the stirring time is 1 h, use a syringe and squeeze through a needle into 40 kg of 6% CaCl2 solution, let stand for 2 h, filter, rinse to neutral, and obtain loaded microorganisms;

[0038] The above-mentioned microbial liquid includes: the number of viable bacteria is 1×10 9 cfu / kg of rhizobia, the number of viable bacteria is 1×10 9 cfu / kg of phosphate-solubilizing bacteria, and the number of viable bacteria is 1×10 9 cfu / kg of lactic acid bacteria;

[0039] S2, add 2 kg of polyglutamic acid and 0.5 kg of dextran to 4 kg of water and stir evenly, adjust the system temperature to 65 ° C, cool to room temperature, add the loaded microorganism and mix evenly to obtain premix a;

[0040] S3, adding 0.1 kg of cross-linked carboxymethyl cellulose and 0.1 kg of microsilica powder with a particle size of 2 μm to the premix a and mixing evenly to obtain a premix b;

[0041] S4. Evenly mix 0.1 kg guar gum, 0.1 kg polyvinyl alcohol and 0.1 kg carboxymethyl cross-linked polysaccharide gel, add water to adjust the water content of the system to 1 wt %, and stir at 70°C for 40 min. Cool to room temperature, add to premix b with stirring, and sequentially dry, cool, screen and anti-caking treatment to obtain a biofilm fertilizer and water retaining agent.

[0042] A compound fertilizer, the raw materials of which include: 20kg of ammonium sulfate, 10kg of potassium chloride, 30kg of monoammonium phosphate, 5kg of bentonite, 15kg of straw and mushroom residue compost, 0.1kg of zinc sulfate, 0.5kg of borax, and 1kg of biological fertilizer water retaining agent;

[0043] The above straw mushroom residue compost includes: the number of viable bacteria is 1×10 9 cfu / kg of colloidal Bacillus, and the number of viable bacteria is 1×10 9 cfu / kg of Bacillus subtilis.

[0044] Example 2

[0045] A method for preparing a biofilm fertilizer and water retaining agent comprises the following steps:

[0046] S1. Add 0.3 kg sodium alginate to 12 kg water, stir until dissolved, the dissolution temperature is 65 ° C, add 1 kg halloysite nanotubes and stir evenly, cool to room temperature, add 10 kg microbial culture and stir, the stirring speed is 1000 r / min, the stirring time is 1 h, use a syringe and squeeze through a needle into 500 kg of 6% CaCl2 solution, let stand for 2 h, filter, rinse to neutral, and obtain loaded microorganisms;

[0047] The above-mentioned microbial liquid includes: the number of viable bacteria is 3×10 9 cfu / kg of rhizobia, and the number of viable bacteria is 3×10 9 cfu / kg of phosphate-solubilizing bacteria and 3×10 9 cfu / kg of lactic acid bacteria;

[0048] S2, add 3 kg of polyglutamic acid and 1.5 kg of dextran to 6 kg of water and stir evenly, adjust the system temperature to 65 ° C, cool to room temperature, add the loaded microorganism and mix evenly to obtain premix a;

[0049] S3, adding 0.3 kg of cross-linked carboxymethyl cellulose and 0.2 kg of microsilica powder with a particle size of 2 μm to the premix a and mixing evenly to obtain a premix b;

[0050] S4. Evenly mix 0.2 kg guar gum, 0.2 kg polyvinyl alcohol and 0.2 kg carboxymethyl cross-linked dextran gel, add water to adjust the water content of the system to 2 wt %, and stir at 65 ° C for 40 min. Cool to room temperature, add to premix b under stirring, and sequentially dry, cool, screen and anti-caking treatment to obtain a biofilm fertilizer and water retaining agent.

[0051] A compound fertilizer, the raw materials of which include: 30kg of ammonium sulfate, 15kg of potassium chloride, 20kg of monoammonium phosphate, 10kg of bentonite, 30kg of straw and mushroom residue compost, 0.5kg of zinc sulfate, 2kg of borax, and 5kg of biofilm fertilizer and water retention agent;

[0052] The above straw mushroom residue compost includes: the number of viable bacteria is 3×10 9 cfu / kg of colloidal Bacillus, and the number of viable bacteria is 3×10 9 cfu / kg of Bacillus subtilis.

[0053] Example 3

[0054] A method for preparing a biofilm fertilizer and water retaining agent comprises the following steps:

[0055] S1. Add 0.12 kg of sodium alginate to 9 kg of water, stir until dissolved, the dissolution temperature is 65 ° C, add 0.6 kg of halloysite nanotubes and stir evenly, cool to room temperature, add 6.5 kg of microbial culture solution and stir at a stirring speed of 1000 r / min for 1 h, use a syringe and squeeze through a needle into 42 kg of a 6% CaCl2 solution, let stand for 2 h, filter, and rinse to neutral to obtain loaded microorganisms;

[0056] The above-mentioned microbial liquid includes: the number of viable bacteria is 1.1×10 9 cfu / kg of rhizobia and the number of viable bacteria was 1.1×10 9 cfu / kg of phosphate-solubilizing bacteria and the number of viable bacteria was 1.1×10 9 cfu / kg of lactic acid bacteria;

[0057] S2, add 2.1 kg of polyglutamic acid and 0.6 kg of dextran to 4.2 kg of water and stir evenly, adjust the system temperature to 65°C, cool to room temperature, add the loaded microorganism and mix evenly to obtain premix a;

[0058] S3, adding 0.12 kg of cross-linked carboxymethyl cellulose and 0.11 kg of microsilica powder with a particle size of 2 μm to the premix a and mixing evenly to obtain a premix b;

[0059] S4. Evenly mix 0.11 kg guar gum, 0.11 kg polyvinyl alcohol and 0.11 kg carboxymethyl cross-linked polysaccharide gel, add water to adjust the water content of the system to 1.1 wt %, and stir at 70°C for 40 min. Cool to room temperature, add to premix b with stirring, and sequentially dry, cool, screen and anti-caking treatment to obtain a biofilm fertilizer and water retaining agent.

[0060] A compound fertilizer, the raw materials of which include: 21kg of ammonium sulfate, 11kg of potassium chloride, 16kg of monoammonium phosphate, 6kg of bentonite, 16kg of straw and mushroom residue compost, 0.18kg of zinc sulfate, 0.8kg of borax, and 2kg of biofilm fertilizer and water retention agent;

[0061] The straw mushroom residue compost includes: the number of viable bacteria is 1.1×10 9 cfu / kg of colloidal Bacillus, and the number of viable bacteria was 1.1×10 9 cfu / kg of Bacillus subtilis.

[0062] Example 4

[0063] A method for preparing a biofilm fertilizer and water retaining agent comprises the following steps:

[0064] S1. Add 0.29g sodium alginate to 11.5kg water, stir until dissolved, the dissolution temperature is 65°C, add 0.9kg halloysite nanotubes and stir evenly, cool to room temperature, add 9kg microbial solution and stir, the stirring speed is 1000r / min, the stirring time is 1h, use a syringe and squeeze through a needle into 49kg CaCl2 solution with a mass fraction of 6%, let stand for 2h, filter, rinse to neutrality, and obtain loaded microorganisms;

[0065] The above-mentioned microbial liquid includes: the number of viable bacteria is 2.9×10 9 cfu / kg of rhizobia and the number of viable bacteria was 2.9×10 9 cfu / kg of phosphate-solubilizing bacteria and the number of viable bacteria was 2.9×10 9 cfu / kg of lactic acid bacteria;

[0066] S2, add 2.9 kg of polyglutamic acid and 1.4 kg of dextran to 5.5 kg of water and stir evenly, adjust the system temperature to 65 ° C, cool to room temperature, add the loaded microorganism and mix evenly to obtain premix a;

[0067] S3, adding 0.29 kg of cross-linked carboxymethyl cellulose and 0.19 kg of microsilica powder with a particle size of 2 μm to the premix a and mixing evenly to obtain a premix b;

[0068] S4. Evenly mix 0.19 kg guar gum, 0.19 kg polyvinyl alcohol and 0.19 kg carboxymethyl cross-linked polysaccharide gel, add water to adjust the water content of the system to 1.9 wt %, and stir at 70 ° C for 40 min. Cool to room temperature and add to premix b under stirring. Dry, cool, screen and anti-caking treatment in sequence to obtain a biofilm fertilizer and water retaining agent.

[0069] A compound fertilizer, the raw materials of which include: 29kg of ammonium sulfate, 14kg of potassium chloride, 19kg of monoammonium phosphate, 9kg of bentonite, 29kg of straw and mushroom residue compost, 0.45kg of zinc sulfate, 1.8kg of borax, and 4.5g of a biofilm fertilizer and water retaining agent;

[0070] The above straw mushroom residue compost includes: the number of viable bacteria is 2.9×10 9 cfu / kg of colloidal Bacillus, and the number of viable bacteria was 2.9×10 9 cfu / kg of Bacillus subtilis.

[0071] Example 5

[0072] A method for preparing a biofilm fertilizer and water retaining agent comprises the following steps:

[0073] S1. Add 0.2 kg sodium alginate to 100 kg water, stir until dissolved, the dissolution temperature is 65 ° C, add 0.75 kg halloysite nanotubes and stir evenly, cool to room temperature, add 8 kg microbial culture solution and stir, the stirring speed is 1000 r / min, the stirring time is 1 h, use a syringe and squeeze through a needle into 450 kg of CaCl2 solution with a mass fraction of 6%, let it stand for 2 h, filter, and rinse to neutrality to obtain loaded microorganisms;

[0074] The above-mentioned microbial liquid includes: the number of viable bacteria is 2×10 9 cfu / kg of rhizobia, and the number of viable bacteria is 2×10 9 cfu / kg of phosphate-solubilizing bacteria and the number of viable bacteria is 2×10 9 cfu / kg of lactic acid bacteria;

[0075] S2, add 2.5 kg of polyglutamic acid and 1 kg of dextran to 5 kg of water and stir evenly, adjust the system temperature to 65 ° C, cool to room temperature, add the loaded microorganism and mix evenly to obtain premix a;

[0076] S3, adding 0.2 kg of cross-linked carboxymethyl cellulose and 0.15 kg of microsilica powder with a particle size of 2 μm to the premix a and mixing evenly to obtain a premix b;

[0077] S4. Evenly mix 0.15g guar gum, 0.15kg polyvinyl alcohol and 0.15kg carboxymethyl cross-linked polysaccharide gel, add water to adjust the water content of the system to 1.5wt%, and stir at 70°C for 40min. Cool to room temperature and add to premix b under stirring. Dry, cool, screen and anti-caking treatment in sequence to obtain a biofilm fertilizer and water retaining agent.

[0078] A compound fertilizer, the raw materials of which include: 25 kg of ammonium sulfate, 12.5 kg of potassium chloride, 17.5 kg of monoammonium phosphate, 7.5 kg of bentonite, 22.5 kg of straw and mushroom residue compost, 0.3 kg of zinc sulfate, 1.25 kg of borax, and 3 kg of the above-mentioned biofilm fertilizer and water retaining agent;

[0079] The above straw mushroom residue compost includes: the number of viable bacteria is 2×10 9 cfu / kg of colloidal Bacillus, and the number of viable bacteria is 2×10 9 cfu / kg of Bacillus subtilis.

[0080] Comparative Example 1

[0081] A method for preparing a biofilm fertilizer and water retaining agent comprises the following steps:

[0082] S1. Add 2.5 kg of polyglutamic acid and 1 kg of dextran into 5 kg of water and stir evenly, adjust the system temperature to 65° C., and cool to room temperature to obtain premix a;

[0083] S2, adding 0.2 kg of cross-linked carboxymethyl cellulose and 0.15 kg of microsilica powder with a particle size of 2 μm to the premix a and mixing evenly to obtain a premix b;

[0084] S3. Evenly mix 0.15g guar gum, 0.15kg polyvinyl alcohol and 0.15kg carboxymethyl cross-linked polysaccharide gel, add water to adjust the water content of the system to 1.5wt%, and stir at 70°C for 40min. Cool to room temperature and add to premix b with stirring. Dry, cool, screen and anti-caking treatment in sequence to obtain a biofilm fertilizer and water retaining agent.

[0085] A compound fertilizer, the raw materials of which include: 25 kg of ammonium sulfate, 12.5 kg of potassium chloride, 17.5 kg of monoammonium phosphate, 7.5 kg of bentonite, 22.5 kg of straw and mushroom residue compost, 0.3 kg of zinc sulfate, 1.25 kg of borax, and 3 kg of the above-mentioned biofilm fertilizer and water retaining agent;

[0086] The above straw mushroom residue compost includes: the number of viable bacteria is 2×10 9 cfu / kg of colloidal Bacillus, and the number of viable bacteria is 2×10 9 cfu / kg of Bacillus subtilis.

[0087] Comparative Example 2

[0088] A method for preparing a biofilm fertilizer and water retaining agent comprises the following steps:

[0089] S1. Add 0.2 kg sodium alginate to 100 kg water, stir until dissolved, the dissolution temperature is 65 ° C, add 0.75 kg halloysite nanotubes and stir evenly, cool to room temperature, add 8 kg microbial culture solution and stir, the stirring speed is 1000 r / min, the stirring time is 1 h, use a syringe and squeeze through a needle into 450 kg of CaCl2 solution with a mass fraction of 6%, let it stand for 2 h, filter, and rinse to neutrality to obtain loaded microorganisms;

[0090] The above straw mushroom residue compost includes: the number of viable bacteria is 2.9×10 9 cfu / kg of colloidal Bacillus, and the number of viable bacteria was 2.9×10 9 cfu / kg of Bacillus subtilis;

[0091] S2, add 2.5 kg of polyglutamic acid and 1 kg of dextran to 5 kg of water and stir evenly, adjust the system temperature to 65 ° C, cool to room temperature, add the loaded microorganism and mix evenly to obtain premix a;

[0092] S3, adding 0.2 kg of chitosan and 0.15 kg of microsilica powder with a particle size of 2 μm to the premix a and mixing evenly to obtain a premix b;

[0093] S4. Evenly mix 0.15g guar gum, 0.15kg polyvinyl alcohol and 0.15kg carboxymethyl cross-linked polysaccharide gel, add water to adjust the water content of the system to 1.5wt%, and stir at 70°C for 40min. Cool to room temperature and add to premix b under stirring. Dry, cool, screen and anti-caking treatment in sequence to obtain a biofilm fertilizer and water retaining agent.

[0094] A compound fertilizer, the raw materials of which include: 25 kg of ammonium sulfate, 12.5 kg of potassium chloride, 17.5 kg of monoammonium phosphate, 7.5 kg of bentonite, 22.5 kg of straw and mushroom residue compost, 0.3 kg of zinc sulfate, 1.25 kg of borax, and 3 kg of the above-mentioned biofilm fertilizer and water retaining agent;

[0095] The above straw mushroom residue compost includes: the number of viable bacteria is 2×10 9 cfu / kg of colloidal Bacillus, and the number of viable bacteria is 2×10 9 cfu / kg of Bacillus subtilis.

[0096] Comparative Example 3

[0097] A method for preparing a biofilm fertilizer and water retaining agent comprises the following steps:

[0098] S1. Add 0.2 kg sodium alginate to 100 kg water, stir until dissolved, the dissolution temperature is 65 ° C, add 0.75 kg halloysite nanotubes and stir evenly, cool to room temperature, add 8 kg microbial culture solution and stir, the stirring speed is 1000 r / min, the stirring time is 1 h, use a syringe and squeeze through a needle into 450 kg of CaCl2 solution with a mass fraction of 6%, let it stand for 2 h, filter, and rinse to neutrality to obtain loaded microorganisms;

[0099] The above-mentioned microbial liquid includes: the number of viable bacteria is 2×10 9 cfu / kg of rhizobia, and the number of viable bacteria is 2×10 9 cfu / kg of phosphate-solubilizing bacteria and the number of viable bacteria is 2×10 9 cfu / kg of lactic acid bacteria;

[0100] S2, add 2.5 kg of polyglutamic acid and 1 kg of dextran to 5 kg of water and stir evenly, adjust the system temperature to 65 ° C, cool to room temperature, add the loaded microorganism and mix evenly to obtain premix a;

[0101] S3, adding 0.2 kg of cross-linked carboxymethyl cellulose and 0.15 kg of microsilica powder with a particle size of 2 μm to the premix a and mixing evenly to obtain a premix b;

[0102] S4. Evenly mix 0.15g guar gum, 0.15kg polyvinyl alcohol and 0.15kg carboxymethyl cross-linked polysaccharide gel, add water to adjust the water content of the system to 1.5wt%, and stir at 70°C for 40min. Cool to room temperature and add to premix b under stirring. Dry, cool, screen and anti-caking treatment in sequence to obtain a biofilm fertilizer and water retaining agent.

[0103] A compound fertilizer, whose raw materials include: 87kg of purchased compound fertilizer and 3kg of the above-mentioned biological fertilizer water retaining agent.

[0104] Field trials

[0105] The test soil is sandy ginger black soil, clay loam, medium fertility, and the previous wheat crop, after mechanical harvesting, the straw was crushed and returned to the field, and rotary tillage was harrowed. Five fields were selected, and there was no significant difference in soil quality between them.

[0106] Wanmian 121 cotton was used as the test variety, and the fertilizer application rate of each group was 50 kg / mu. Among them, the compound fertilizer obtained in Example 5 was applied in the Example 5 group, the compound fertilizer obtained in the comparative example 1 group was applied in the comparative example 1 group, the compound fertilizer obtained in the comparative example 2 group was applied in the comparative example 2 group, the compound fertilizer obtained in the comparative example 3 group was applied in the comparative example 3 group, and the blank group was not subjected to any fertilization treatment. Other field management measures remained the same.

[0107] 1.1 Detect the microbial count of each test group before and after the test.

[0108] After the soil sample is dissolved, the number of microbial cells is counted by titration. The titration method mainly involves using Pseudomonas fluorescens as a reference bacterium, mixing the bacteria with the soil sample, and titrating after a series of dilutions. By observing the number of colonies in the titration solution, the biomass of the microorganisms in the original soil sample can be inferred. The results are as follows Figure 1 As shown, the biomass after the test of applying the compound fertilizer of Example 5 is the largest, which is better than that of the comparative examples 1-3, indicating that the compound fertilizer obtained by Example 5 can increase the biomass in the soil and improve the physical and chemical properties of the soil.

[0109] 1.2 Test the water and fertilizer retention capacity of the soil in each test group.

[0110] The soil water evaporation rate is one of the important indicators of the soil's water retention capacity. The determination of the soil water evaporation rate can directly reflect the water retention capacity of the fertilizer after it is applied to the soil. The method for determining the soil water evaporation rate of the present invention is as follows: 4g of different water retaining agent samples and 200g of air-dried soil (passed through a 26-mesh sieve) are mixed and placed in a beaker, 150g of tap water is added, weighed and recorded as Wi, placed at room temperature, the total weight of the beaker is weighed every 5 days and recorded as Wn, and observed continuously for 30 days, and a treatment without adding fertilizer is set as a control.

[0111] The soil moisture loss rate (W%) is calculated as follows:

[0112] W% = (Wi - Wn) × 100 / 150.

[0113] The results are as follows Figure 2 As shown, the soil moisture loss rate of the compound fertilizer of Example 5 is the slowest, which is better than that of the comparative examples 1-3, indicating that the compound fertilizer obtained by Example 5 can increase the soil water retention capacity.

[0114] 1.3 Testing the slow-release performance of fertilizers in each test group

[0115] The slow-release performance of the test fertilizer was tested by the intermittent leaching method of soil column. One end of a PVC tube with an inner diameter of 5 cm and a length of 35 cm was sealed with a 200-mesh nylon mesh. First, a small amount of fine sand (25 g) was added to the tube and then 100 g of soil was added as a buffer layer. Then, a uniform mixture of 400 g of air-dried soil and compound fertilizer was loaded on it according to the standard of 20:1 of air-dried soil and compound fertilizer with the same compactness. Finally, a small amount of fine sand (25 g) was covered on the soil column to avoid disturbing the soil layer during leaching. The 5th group of embodiment, the 1-3 groups of comparative examples and the blank group were treated in turn, and each treatment was repeated 5 times. After the soil column was filled, it was placed on a special leaching rack, a funnel was placed at the lower end of the soil column, and a 350 ml plastic bottle was placed under the funnel to collect the leaching solution. For the first time, add 170 ml of water to make the soil moisture close to saturation. After standing for 24 hours, pour 200 ml of water into the PCV tube and collect the leaching solution. When no more water drips out, take the leaching solution to determine its nitrogen, phosphorus and potassium content. After culturing at room temperature for 4 days, use 200 ml of water for the second leaching on the 5th day. After that, repeat the culturing and leaching according to the same operation on the 9th, 13th and 17th days, and collect the 3rd, 4th and 5th leaching solutions respectively. Analyze and calculate the dissolution rates of nitrogen, phosphorus and potassium in the leaching solutions. The results are as follows: Figure 3-5 As shown, the dissolution rate of nitrogen, phosphorus and potassium in the soil with the compound fertilizer of Example 5 was the slowest, which was better than that of the comparative examples 1-3, indicating that the compound fertilizer obtained by using Example 5 can increase the soil's fertilizer retention capacity and the soil's slow-release capacity.

[0116] 1.4 Test the yield per mu of each test group.

[0117] The results are as follows Figure 6As shown, the soil yield per mu with the compound fertilizer of Example 5 is the highest, which is better than that of the comparative examples 1-3, indicating that the compound fertilizer obtained in Example 5 can promote plant growth and increase the yield per mu.

[0118] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A biofilm fertilizer and water retaining agent, characterized in that: The raw materials include, by mass, 1-3 parts of sodium alginate, 5-10 parts of halloysite nanotubes, 1-2 parts of polyaspartic acid, 60-100 parts of microbial culture liquid, 400-500 parts of calcium chloride aqueous solution, 20-30 parts of polyglutamic acid, 5-15 parts of dextran, 1-3 parts of cross-linked carboxymethyl cellulose, 1-2 parts of microsilica powder, 1-2 parts of guar gum, 1-2 parts of polyvinyl alcohol and 1-2 parts of carboxymethyl cross-linked dextran gel.

2. The biofilm fertilizer and water conservation agent according to claim 1, characterized in that: The mass fraction of the calcium chloride aqueous solution is 6-10%.

3. The biofilm fertilizer and water conservation agent according to claim 1, characterized in that: The microbial solution includes rhizobia, phosphate-solubilizing bacteria, and lactic acid bacteria. The number of live rhizobia is 1-3× 10 9 cfu / g, the number of viable phosphate-solubilizing bacteria is 1-3×10 9 cfu / g, the number of viable lactic acid bacteria is 1-3× 10 9 cfu / g。 4. The biofilm fertilizer and water conservation agent according to claim 1, characterized in that: The particle size of microsilica powder is 1-10μm.

5. A method for preparing the biofilm fertilizer and water conservation agent according to any one of claims 1 to 4, characterized in that: The steps include: S1. Add sodium alginate to water and stir until dissolved, the dissolution temperature is 60-80°C, add halloysite nanotubes and stir evenly, cool to room temperature, add microbial solution and stir, the stirring speed is 500-1000r / min, the stirring time is 1-2h, use a syringe and squeeze it into a calcium chloride aqueous solution through a needle, let it stand, filter, and wash with water until neutral to obtain loaded microorganisms; S2, adding polyglutamic acid and dextran to water and stirring evenly, adjusting the system temperature to 50-70°C, cooling to room temperature, adding loaded microorganisms and mixing evenly to obtain premix a; S3, adding cross-linked carboxymethyl cellulose and microsilica powder to premix a and mixing evenly to obtain premix b; S4. Evenly mix guar gum, polyvinyl alcohol and carboxymethyl cross-linked polysaccharide gel, add water to adjust the water content of the system to 1-2wt%, stir, cool to room temperature, add to premix b under stirring, and sequentially dry, cool, screen and anti-caking treatment to obtain a biofilm fertilizer and water retaining agent.

6. The method for preparing the biofilm fertilizer and water conservation agent according to claim 5, characterized in that: In S1, the standing time is 2-5 h.

7. The method for preparing the biofilm fertilizer and water conservation agent according to claim 5, characterized in that: In S4, water is added to adjust the water content of the system to 1-2 wt%, and stirring is performed, wherein the stirring temperature is 60-80° C. and the stirring time is 20-40 min.

8. A compound fertilizer, characterized in that: The raw materials include, by weight: 20-30 parts of ammonium sulfate, 10-15 parts of potassium chloride, 15-30 parts of monoammonium phosphate, 5-10 parts of bentonite, 15-30 parts of straw and mushroom residue compost, 0.1-0.5 parts of zinc sulfate, 0.5-2 parts of borax, and 1-5 parts of the biofilm fertilizer and water retaining agent according to any one of claims 1-4.

9. The compound fertilizer according to claim 8, characterized in that: The ratio of nitrogen, phosphorus and potassium is N: P2O5: K2O = 14-20: 4-10: 4-11; based on the total weight of the compound fertilizer, the organic matter content accounts for 12-14wt%.

10. The compound fertilizer according to claim 8, characterized in that: The straw and mushroom residue compost contains colloidal Bacillus and Bacillus subtilis, and the number of live bacteria of colloidal Bacillus is 1-3×10 9 cfu / g, the number of viable Bacillus subtilis is 1-3×10 9 cfu / g.

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