Saline-alkali soil improvement and disease resistance double-effect controlled release fertilizer and preparation method thereof

Abstract

The invention discloses a saline-alkali soil improvement and disease resistance double-effect controlled release fertilizer and a preparation method thereof. The fertilizer comprises 18-22% of biochar, 12-18% of furfural residues, 8-12% of cow dung compost and 6-10% of potassium humate. 5-7% of aluminum sulfate, 4-6% of sulfur and 3-5% of zeolite; the microbial inoculum comprises the following components in percentage by weight: 1.5 to 2.5 percent of saline-alkaline bacillus, 0.8 to 1.2 percent of bacillus subtilis and 0.8 to 1.2 percent 8-12% of a sodium polyacrylate coating, 4-6% of a sulfur coating and 1-3% of polyglutamic acid; 0.8 to 1.2 percent of humic acid chelated iron, 0.8 to 1.2 percent of algal polysaccharide and 0.8 to 1.2 percent of urease inhibitor; 0.8 to 1.2 percent of zinc sulfate, 0.5 to 1.0 percent of manganese sulfate and 0.5 to 1.0 percent of borax. The fertilizer can reduce the pH and conductivity of soil, increase the organic matter content of the soil and effectively improve the physicochemical properties of the soil, meanwhile, by adding the microbial agent, the disease resistance of crops can be effectively improved, the morbidity and disease index of the crops can be reduced, and nutrient release of the fertilizer has a sustained and controlled release characteristic; the initial release rate and the cumulative release rate of nitrogen are both lower than those of common chemical fertilizers, and the cumulative release rate of nitrogen is moderate within 60 days, so that the nutrient requirements of crops in different growth stages can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of fertilizers, and in particular to a slow-release fertilizer with dual effects of saline-alkali land improvement and disease resistance and a preparation method thereof. Background Art

[0002] In agriculture, saline-alkali land, a unique soil type, has long been a bottleneck restricting crop growth and agricultural development due to its high salt content, high pH, ​​and poor physical and chemical properties. While traditional chemical fertilizers can replenish soil nutrients and promote crop growth to a certain extent, they are limited in their effectiveness in improving saline-alkali land and enhancing crop disease resistance. Furthermore, commonly used fertilizers release nutrients rapidly, which can easily lead to nutrient loss, excessive crop growth, and soil compaction, further compromising crop yield and quality. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a slow-release fertilizer with dual effects of saline-alkali land improvement and disease resistance and a preparation method thereof.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: The present invention provides a slow-release fertilizer for improving saline-alkali land and resisting diseases and a preparation method thereof, comprising the following components in percentage by weight: Biochar 18-22%, furfural residue 12-18%, cow dung compost 8-12%, potassium humate 6-10%; Aluminum sulfate 5-7%, sulfur 4-6%, zeolite 3-5%; Halophilic Bacillus 1.5-2.5%, Bacillus subtilis 0.8-1.2%, Trichoderma 0.8-1.2%; Sodium polyacrylate coating 8-12%, sulfur coating 4-6%, polyglutamic acid 1-3%; Humic acid chelated iron 0.8-1.2%, seaweed polysaccharide 0.8-1.2%, urease inhibitor 0.8-1.2%; Zinc sulfate 0.8-1.2%, manganese sulfate 0.5-1.0%, borax 0.5-1.0%.

[0005] As a preferred technical solution of the present invention, the biochar is prepared by pyrolyzing corn straw at 500-600°C under anoxic conditions for 2-4 hours, with a specific surface area of ​​≥300m² / g and a pH of 8.5-9.5.

[0006] As a preferred technical solution of the present invention, the salt tolerance concentration of the halophilic alkali Bacillus is ≥18 g / L NaCl, and the ratio of the viable counts of the Bacillus subtilis to the viable count of Trichoderma is (1.5-2.5):1.

[0007] As a preferred technical solution of the present invention, the sodium polyacrylate coating is formed by a fluidized bed spraying process, and the coating solution concentration is 7-9%; the particle size of the sulfur coated particles is 0.7-0.9 mm, and the coating thickness is 0.15-0.25 mm.

[0008] As a preferred technical solution of the present invention, the urease inhibitor is at least one of N-(n-butyl)thiophosphoric triamide or hydroquinone.

[0009] A method for preparing a slow-release fertilizer with dual effects of saline-alkali land improvement and disease resistance comprises the following steps: S1. Organic matrix pretreatment: Mix biochar, furfural residue, cow dung compost, and potassium humate in appropriate proportions, add a composite fermentation agent, pile up to 1.2-1.5m, ferment at 50-60°C for 7-10 days, turn the pile over once a day, and then grind it into a particle size of ≤2mm using a grinder. S2. Chemical modifier granulation: Aluminum sulfate, sulfur, and zeolite were mixed into an organic matrix according to weight percentage, premixed with the S1 product at a mass ratio of 3:7, and 2-3% carboxymethyl cellulose (binder) was added. The mixture was granulated into granules with a particle size of 1-2 mm using a disc granulator. S3. Microbial load: Compounding of microbial agents: The ratio of viable bacteria count of Bacillus halophilus: Bacillus subtilis: Trichoderma is 2:1.5:1; A seaweed extract solution (3% concentration, brown algae source) was mixed with the bacterial agent in a 1:1 volume ratio, and 0.05% xanthan gum (stabilizer) was added; The composite bacterial agent of halophilic Bacillus, Bacillus subtilis and Trichoderma was mixed with the seaweed extract solution at a bacterial agent concentration of 1×10 9 -5×10 9 CFU / mL, by high-pressure airless spraying onto the surface of S2 product, the spraying amount is 6-7% of the organic matrix mass, and pre-activated at 25℃ constant humidity for 24 hours; S4, double-layer coating: Using fluidized bed coating technology, with an inlet air temperature of 40-45°C, the S3 product is first sprayed with a sodium polyacrylate solution to form a water-retaining layer at a spraying rate of 10-12 ml / min, and then coated with a sulfur film to form a sustained-release layer with a thickness of 0.2 mm and a porosity of 15-20%. S5. Addition of synergist: Humic acid chelated iron, seaweed polysaccharide and urease inhibitor were premixed, evenly dispersed and mixed with S4 product through a pneumatic conveying system, and formed into a final product with a particle size of 3-5 mm through a drum granulator, and finally dried at 60°C for 20 minutes by a blower.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The present invention can reduce soil pH and electrical conductivity, increase soil organic matter content, effectively improve the physical and chemical properties of the soil, create a more favorable soil environment for crop growth, and simultaneously, by adding microbial agents, effectively improve the disease resistance of crops, reduce crop morbidity and disease index, and the nutrient release of the fertilizer has a slow-release property, with both the initial nitrogen release rate and cumulative release rate lower than those of conventional fertilizers, and a moderate cumulative nitrogen release rate within 60 days, which can meet the nutrient requirements of crops at different growth stages. This slow-release property helps reduce nutrient loss, prevent excessive crop growth, and improve nutrient utilization efficiency. DETAILED DESCRIPTION

[0011] Implementation location: Yellow River Delta saline-alkali land improvement experimental station in Dongying City, Shandong Province (soil pH 8.5-9.2, conductivity 3.5-4.8 mS / cm, organic matter content 8-12 g / kg) Crop variety: Cotton (Lumianyan No. 28) Experimental design: randomized block design, each example and comparative example was repeated 3 times, the plot area was 20 m², and the fertilizer application rate was 500 kg / ha.

[0012] Example 1 The present invention provides a slow-release fertilizer with dual effects of saline-alkali land improvement and disease resistance and a preparation method thereof, comprising the following components in percentage by weight: Biochar 22%, furfural residue 15%, cow dung compost 10%, potassium humate 8%; Aluminum sulfate 5%, sulfur 4%, zeolite 3%; Bacillus halophilus 2.5%, Bacillus subtilis 1.2%, Trichoderma 0.8%; Sodium polyacrylate coating 10%, sulfur coating 5%, polyglutamic acid 2%; Humic acid chelated iron 1%, seaweed polysaccharide 1%, urease inhibitor 1%; Zinc sulfate 1%, manganese sulfate 0.5%, borax 0.5%.

[0013] The preparation method of fertilizer in this embodiment: S1. Organic substrate pretreatment: biochar, furfural residue, cow dung compost, and potassium humate were mixed in proportion, composite fermentation agent was added, piled to a height of 1.2 m, fermented at 55°C for 8 days, turned over once a day, and then crushed to a particle size of ≤2 mm using a grinder.

[0014] S2. Chemical modifier granulation: After aluminum sulfate, sulfur, and zeolite are mixed into an organic matrix, they are premixed with the S1 product at a mass ratio of 3:7, 2.5% carboxymethyl cellulose (binder) is added, and granules with a particle size of 1-2 mm are formed using a disc granulator.

[0015] S3. Microbial load: A composite bacterial agent of halophilic Bacillus, Bacillus subtilis and Trichoderma (viable cell count ratio 2:1.5:1) was mixed with a seaweed extract solution (3% concentration, brown algae source) at a bacterial agent concentration of 3×10 9 CFU / mL, sprayed onto the surface of S2 product by high-pressure airless spraying, the spraying amount was 6.5% of the mass of the organic matrix, and pre-activated at 25℃ constant humidity for 24 hours.

[0016] S4, double-layer coating: using fluidized bed coating technology, the inlet air temperature is 42 ° C, the S3 product is first sprayed with sodium polyacrylate solution to form a water-retaining layer at a spraying rate of 11 ml / min, and then wrapped with sulfur coating to form a sustained-release layer with a thickness of 0.2 mm and a porosity of 18%.

[0017] S5. Addition of synergist: premix humic acid chelated iron, seaweed polysaccharide and urease inhibitor, evenly disperse and mix with S4 product through pneumatic conveying system, and form final product with particle size of 3-5mm through drum granulator, and finally dry at 60℃ for 20min through blower.

[0018] Example 2 The present invention provides a slow-release fertilizer with dual effects of saline-alkali land improvement and disease resistance and a preparation method thereof, comprising the following components in percentage by weight: Biochar 20%, furfural residue 12%, cow dung compost 8%, potassium humate 6%; Aluminum sulfate 7%, sulfur 6%, zeolite 5%; Bacillus halophilus 1.8%, Bacillus subtilis 1%, Trichoderma 0.6%; Sodium polyacrylate coating 12%, sulfur coating 6%, polyglutamic acid 3%; Humic acid chelated iron 0.8%, seaweed polysaccharide 0.8%, urease inhibitor 0.8%; Zinc sulfate 0.8%, manganese sulfate 0.8%, borax 0.6%.

[0019] The preparation method of fertilizer in this embodiment: S1. Organic substrate pretreatment: biochar, furfural residue, cow dung compost, and potassium humate were mixed in proportion, composite fermentation agent was added, piled to a height of 1.3 m, fermented at 50°C for 10 days, turned over once a day, and then crushed to a particle size of ≤2 mm using a grinder.

[0020] S2. Chemical modifier granulation: After aluminum sulfate, sulfur, and zeolite are mixed into an organic matrix, they are premixed with the S1 product at a mass ratio of 3:7, 2% carboxymethyl cellulose (binder) is added, and granules with a particle size of 1-2 mm are formed using a disc granulator.

[0021] S3. Microbial load: A composite bacterial agent of halophilic Bacillus, Bacillus subtilis and Trichoderma (viable cell count ratio 2:1.5:1) was mixed with a seaweed extract solution (3% concentration, brown algae source) at a bacterial agent concentration of 1×10 9 CFU / mL, sprayed onto the surface of S2 product by high-pressure airless spraying, the spraying amount was 6% of the mass of the organic matrix, and pre-activated at 25℃ constant humidity for 24 hours.

[0022] S4, using fluidized bed coating technology, with an inlet air temperature of 40 ° C, the S3 product is first sprayed with sodium polyacrylate solution to form a water-retaining layer at a spraying rate of 10 ml / min, and then wrapped with a sulfur film to form a sustained-release layer with a thickness of 0.2 mm and a porosity of 15%.

[0023] S5. Premix humic acid chelated iron, seaweed polysaccharide and urease inhibitor, evenly disperse and mix with the S4 product through a pneumatic conveying system, and form a final product with a particle size of 3-5 mm through a drum granulator. Finally, dry it at 60° C. for 20 minutes using a blower.

[0024] Example 3 The present invention provides a slow-release fertilizer with dual effects of saline-alkali land improvement and disease resistance and a preparation method thereof, comprising the following components in percentage by weight: Biochar 18%, furfural residue 18%, cow dung compost 12%, potassium humate 10%; Aluminum sulfate 5%, sulfur 4%, zeolite 3%; Halophilic Bacillus 1.5%, Bacillus subtilis 0.8%, Trichoderma 0.5%; Sodium polyacrylate coating 8%, sulfur coating 4%, polyglutamic acid 1%; Humic acid chelated iron 1.2%, seaweed polysaccharide 1.2%, urease inhibitor 1.2%; Zinc sulfate 1.2%, manganese sulfate 1%, borax 1%.

[0025] The preparation method of fertilizer in this embodiment: S1. Organic substrate pretreatment: biochar, furfural residue, cow dung compost, and potassium humate were mixed in proportion, composite fermentation agent was added, piled to a height of 1.5 m, fermented at 60°C for 7 days, turned over once a day, and then crushed to a particle size of ≤2 mm using a grinder.

[0026] S2. Chemical modifier granulation: After aluminum sulfate, sulfur, and zeolite are mixed into an organic matrix, they are premixed with the S1 product at a mass ratio of 3:7, 3% carboxymethyl cellulose (binder) is added, and granules with a particle size of 1-2 mm are formed using a disc granulator.

[0027] S3, a composite bacterial agent of halophilic Bacillus, Bacillus subtilis and Trichoderma (viable bacteria ratio 2:1.5:1) was mixed with a seaweed extract solution (3% concentration, brown algae source) at a bacterial agent concentration of 5×10 9 CFU / mL, sprayed onto the surface of S2 product by high-pressure airless spraying, the spraying amount was 7% of the organic matrix mass, and pre-activated at 25℃ constant humidity for 24 hours.

[0028] S4, double-layer coating: using fluidized bed coating technology, the inlet air temperature is 45 ° C, the S3 product is first sprayed with sodium polyacrylate solution to form a water-retaining layer at a spraying rate of 12 ml / min, and then wrapped with sulfur coating to form a sustained-release layer with a thickness of 0.2 mm and a porosity of 20%.

[0029] S5. Addition of synergist: premix humic acid chelated iron, seaweed polysaccharide and urease inhibitor, evenly disperse and mix with S4 product through pneumatic conveying system, and form final product with particle size of 3-5mm through drum granulator, and finally dry at 60℃ for 20min through blower.

[0030] Comparative Example Use a compound fertilizer with an NPK ratio of 15-15-15.

[0031] Test methods and standards 1. Test on the improvement effect of saline-alkali land Soil pH and conductivity: A five-point sampling method was used to collect soil samples from the 0-20 cm layer. After air-drying, the samples were passed through a 2 mm sieve and shaken for 30 min at a water-soil ratio of 1:5. The samples were then measured using a pH meter and a conductivity meter.

[0032] Standard: Refer to "Soil Testing Part 6: Determination of Soil Organic Matter" (NY / T 1121.6-2006) and "Determination of Soil Electrical Conductivity" (NY / T 1377-2007).

[0033] Soil organic matter: Potassium dichromate-external heating method to calculate the organic matter content.

[0034] 2. Crop disease resistance testing Incidence and disease index: Incidence rate: Investigate all plants in each plot and calculate the percentage of diseased plants.

[0035] Disease index: Grading standard (Grade 0: no disease; Grade 1: leaf spot area ≤5%; Grade 2: 5%-20%; Grade 3: 20%-50%; Grade 4: >50%), formula: Disease index = Σ (number of diseased plants × disease grade value) / (total number of plants × highest disease grade value) × 100%.

[0036] Standard: Refer to "Plant Disease Investigation Specification" (GB / T 17980.1-2000).

[0037] 3. Nutrient release characteristics test Nitrogen release rate: Initial release rate: Soak in water at 25℃ for 24 h and measure the dissolved nitrogen content.

[0038] Cumulative release rate: Dynamic water extraction method was used, with shaking in water at 25°C. Samples were taken regularly to determine the nitrogen content and calculate the cumulative release rate.

[0039] Standard: Refer to "Slow-release fertilizers Part 5: Determination of nitrogen release rate of controlled-release fertilizers" (GB / T 23348-2009).

[0040] 4. Crop yield and quality testing Yield: When harvesting, weigh the whole plant in the plot and calculate the yield increase rate.

[0041] Vitamin C and soluble sugars: Vitamin C: 2,6-dichlorophenol indophenol titration method.

[0042] Soluble sugar: anthrone colorimetric method.

[0043] Standard: Refer to "Determination of Vitamin C in Foods" (GB 5009.86-2016) and "Determination of Soluble Sugars in Plants" (NY / T 1278-2007).

[0044] Based on the above test methods and standards, the above three embodiments and one comparative example were tested, and the test results are as follows:

[0045] From the data in the table we can see that: 1. Effect on improving saline-alkali soil: All three examples of fertilizers significantly reduced soil pH and conductivity and increased soil organic matter content, achieving significantly better results than conventional fertilizers. The fertilizer in Example 3 performed best in reducing soil pH and conductivity, while the fertilizer in Example 1 was most effective in increasing soil organic matter content. This demonstrates that the fertilizers provided by the present invention have significant advantages in improving saline-alkali soil and can effectively improve soil physical and chemical properties.

[0046] 2. Crop Disease Resistance: The incidence and disease index of crops treated with the three example fertilizers were significantly lower than those treated with conventional fertilizers, demonstrating that the microbial agents in the fertilizers of this invention effectively improve crop disease resistance. The fertilizer of Example 3 was most effective in reducing both incidence and disease index, likely due to the viable bacterial count and formulation of the microbial agents.

[0047] 3. Nutrient Release Characteristics: The three examples of fertilizers exhibited slow- and controlled-release nutrient release. Both the initial and cumulative nitrogen release rates were lower than those of conventional fertilizers. The cumulative nitrogen release rate over 60 days was moderate, meeting the nutrient needs of crops at different growth stages. In contrast, conventional fertilizers release nutrients rapidly, which can easily lead to nutrient loss and excessive crop growth. The fertilizer in Example 1 exhibited a more balanced slow- and controlled-release effect.

[0048] 4. Crop Yield and Quality: The yield and quality indicators (vitamin C content and soluble sugar content) of crops using the three example fertilizers were significantly higher than those using conventional fertilizers, demonstrating that the fertilizers of the present invention can promote crop growth and improve both yield and quality. The fertilizer of Example 3 was the most effective in improving crop yield and quality, a result of the combined effects of its nutrient ratio and improved crop quality.

[0049] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A slow-release fertilizer with dual effects of saline-alkali land improvement and disease resistance, characterized in that: The composition comprises the following components in weight percentage: Biochar 18-22%, furfural residue 12-18%, cow dung compost 8-12%, potassium humate 6-10%; Aluminum sulfate 5-7%, sulfur 4-6%, zeolite 3-5%; Halophilic Bacillus 1.5-2.5%, Bacillus subtilis 0.8-1.2%, Trichoderma 0.8-1.2%; Sodium polyacrylate coating 8-12%, sulfur coating 4-6%, polyglutamic acid 1-3%; Humic acid chelated iron 0.8-1.2%, seaweed polysaccharide 0.8-1.2%, urease inhibitor 0.8-1.2%; Zinc sulfate 0.8-1.2%, manganese sulfate 0.5-1.0%, borax 0.5-1.0%.

2. The slow-release fertilizer for improving saline-alkali land and resisting diseases according to claim 1, characterized in that: The biochar is prepared by pyrolyzing corn straw at 500-600° C. under anoxic conditions for 2-4 hours, with a specific surface area of ​​300 m² / g or more and a pH of 8.5-9.

5.

3. The slow-release fertilizer for improving saline-alkali land and resisting diseases according to claim 1, characterized in that: The salt tolerance concentration of the halophilic alkali Bacillus is ≥18 g / L NaCl, and the ratio of the viable bacteria count of the Bacillus subtilis to that of the Trichoderma is (1.5-2.5):

1.

4. The slow-release fertilizer for improving saline-alkali land and resisting diseases according to claim 1, characterized in that: The sodium polyacrylate coating is formed by a fluidized bed spraying process, and the coating solution concentration is 7-9%; the particle size of the sulfur coated particles is 0.7-0.9 mm, and the coating thickness is 0.15-0.25 mm.

5. The slow-release fertilizer for improving saline-alkali land and resisting diseases according to claim 1, characterized in that: The urease inhibitor is at least one of N-(n-butyl)thiophosphoric triamide or hydroquinone.

6. The method for preparing a slow-release fertilizer for saline-alkali land improvement and disease resistance according to claim 1, characterized in that: The following steps are involved: S1. Organic matrix pretreatment: Mix biochar, furfural residue, cow dung compost, and potassium humate in appropriate proportions, add a composite fermentation agent, pile up to 1.2-1.5m, ferment at 50-60°C for 7-10 days, turn the pile over once a day, and then grind it into a particle size of ≤2mm using a grinder. S2. Chemical modifier granulation: Aluminum sulfate, sulfur, and zeolite were mixed into an organic matrix according to weight percentage, premixed with the S1 product at a mass ratio of 3:7, and 2-3% carboxymethyl cellulose (binder) was added. The mixture was granulated into granules with a particle size of 1-2 mm using a disc granulator. S3. Microbial load: Compounding of microbial agents: The ratio of viable bacteria count of Bacillus halophilus: Bacillus subtilis: Trichoderma is 2:1.5:1; A seaweed extract solution (3% concentration, brown algae source) was mixed with the bacterial agent in a 1:1 volume ratio, and 0.05% xanthan gum (stabilizer) was added; The composite bacterial agent of halophilic Bacillus, Bacillus subtilis and Trichoderma was mixed with the seaweed extract solution at a bacterial agent concentration of 1×10 9 -5×10 9 CFU / mL, by high-pressure airless spraying onto the surface of S2 product, the spraying amount is 6-7% of the organic matrix mass, and pre-activated at 25℃ constant humidity for 24 hours; S4, double-layer coating: Using fluidized bed coating technology, with an inlet air temperature of 40-45°C, the S3 product is first sprayed with a sodium polyacrylate solution to form a water-retaining layer at a spraying rate of 10-12 ml / min, and then coated with a sulfur film to form a sustained-release layer with a thickness of 0.2 mm and a porosity of 15-20%. S5. Addition of synergist: Humic acid chelated iron, seaweed polysaccharide and urease inhibitor were premixed, evenly dispersed and mixed with S4 product through a pneumatic conveying system, and formed into a final product with a particle size of 3-5 mm through a drum granulator, and finally dried at 60°C for 20 minutes by a blower.

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