Organic solid waste biochar fertilizer and preparation method thereof

Abstract

The invention provides an organic solid waste biochar fertilizer and a preparation method thereof, and belongs to the technical field of fertilizers. Comprising the following steps: S1, taking fresh chicken manure, airing in advance, naturally airing, grinding into a crushed state, and sieving to obtain organic solid waste; s2, dissolving a carbon source, a nitrogen source, a phosphorus source and a magnesium source in water to obtain a nutrient solution; s3, the organic solid waste is soaked in the nutrient solution and dried, and the organic solid waste biochar fertilizer is prepared. The organic solid waste biochar fertilizer not only contains rich carbon, but also contains a large amount of inorganic mineral components such as N, P and Mg, is stable in property and large in specific surface area, and can exist in soil for a long time to provide a sufficient space for nutrient adsorption and microorganism survival, and the absorbed nutrients can be directly utilized by root systems, so that the growth of crops is promoted, and the yield of the crops is increased. And the yield is improved.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to an organic solid waste biochar fertilizer and a preparation method thereof. Background Art

[0002] With the rapid development of agricultural production and the change of people's lifestyle and consumption, the amount of agricultural waste has been increasing year by year. Now the breeding industry has also begun to change, from the original small-scale individual breeding to large-scale and collective forms. This can not only bring good economic income to the majority of breeders, but also bring considerable economic benefits to the society. However, large-scale breeding also inevitably produces a large amount of livestock and poultry manure. Unlike other pollutants, livestock and poultry manure is rich in fertilizer sources. Applying it to the soil can improve the fertility of the soil.

[0003] Biochar can increase soil porosity, improve soil pH, increase organic matter content, soil nutrient content and reduce nutrient loss, so it can also be used as a soil conditioner, and after application, it can affect the transformation process of "four waters" in the soil. Biochar not only changes the physical and chemical properties of the soil, but also has a strong carbon fixation and fertilizer saving effect. The internal structure of biochar is very stable, with rich functional groups, large specific surface area and developed pore structure, so it can be used as a high-quality adsorption and slow-release material. Applying it to soil can not only increase the soil carbon pool, but also increase the role of increasing carbon sinks and reducing emissions in agriculture. Biochar is a loose, porous and low-density material. By returning it to the field, it can not only significantly increase the porosity and surface area of ​​the soil, but also effectively increase the water holding rate of soil water. Returning biochar to the field can reduce soil bulk density, on the one hand because it has a loose and porous nature, and on the other hand because the activity of microorganisms can be increased after returning biochar to the field, thereby promoting soil cohesion and improving the internal structure of the soil. In addition, biochar is rich in ash, which can significantly improve soil pH after being applied to the soil. The porous structure of biochar and the active functional groups on its surface can also accelerate the absorption of nutrients by the soil. Applying biochar can improve the acidity and alkalinity of the soil, increase fertility, improve physical and chemical properties, reduce nutrient leaching and greenhouse gas emissions. For this reason, the application prospects of biochar in agriculture are very bright. Summary of the invention

[0004] The purpose of the present invention is to provide an organic solid waste biochar fertilizer and a preparation method thereof, which not only contains rich carbon content, but also contains a large amount of inorganic mineral components such as N, P, Mg, etc., has stable properties and a large specific surface area, can exist in the soil for a long time to provide sufficient space for the adsorption of nutrients and the survival of microorganisms, and the absorbed nutrients can be directly used by the root system, thereby promoting the growth of crops and increasing yields.

[0005] The technical solution of the present invention is achieved in this way: The present invention provides a method for preparing organic solid waste biochar fertilizer, comprising the following steps: S1. Take fresh chicken manure and dry it in advance, then grind it into powder, sieve it, and obtain organic solid waste; S2. dissolving a carbon source, a nitrogen source, a phosphorus source, and a magnesium source in water to obtain a nutrient solution; S3. Soaking the organic solid waste in a nutrient solution and drying it to obtain an organic solid waste biochar fertilizer.

[0006] As a further improvement of the present invention, the mesh number of the sieving screen is 20-40 meshes.

[0007] As a further improvement of the present invention, the carbon source is selected from at least one of glucose, sucrose and fructose.

[0008] As a further improvement of the present invention, the nitrogen source is selected from at least one of ammonium chloride, ammonium sulfate and ammonium nitrate.

[0009] As a further improvement of the present invention, the phosphorus source is selected from at least one of sodium phosphate, sodium monohydrogen phosphate, and sodium dihydrogen phosphate.

[0010] As a further improvement of the present invention, the magnesium source is selected from at least one of magnesium chloride, magnesium sulfate and magnesium nitrate.

[0011] As a further improvement of the present invention, the mass ratio of the carbon source, nitrogen source, phosphorus source, magnesium source and water is 10-12:4-7:2-3:0.5-1:200.

[0012] As a further improvement of the present invention, the solid-to-liquid ratio of the organic solid waste to the nutrient solution is 1:5-7 g / mL.

[0013] The present invention further protects an organic solid waste biochar fertilizer prepared by the above preparation method.

[0014] The present invention has the following beneficial effects: The organic solid waste biochar fertilizer of the present invention not only contains rich carbon content, but also contains a large amount of inorganic mineral components such as N, P, Mg, etc. It has stable properties and a large specific surface area. It can exist in the soil for a long time to provide sufficient space for nutrient adsorption and the survival of microorganisms. The absorbed nutrients can be directly used by the root system, thereby promoting the growth of crops and increasing yields. It not only plays a role in the growth stage of crops, but also affects the germination process of seeds, promoting the growth of crops. The unstable substances and components with high C / N content contained in the biochar can fix the available N in the plant in a certain way, reduce the migration rate of ions in the soil, reduce the amount of nutrient leakage available in the soil, fix the soil nutrients, and better promote the growth of crops. In addition, biochar also has an effect on NH4 + It has good adsorption properties, can effectively reduce the volatilization of ammonia content in the soil, and also has a strong adsorption capacity for P existing in the soil in the form of anions. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0016] Example 1 This embodiment provides a method for preparing organic solid waste biochar fertilizer, comprising the following steps: S1. Take fresh chicken manure in advance and air-dry it naturally, grind it into powder, pass it through a 20-mesh sieve, and obtain organic solid waste; S2. Dissolve 10 g of fructose, 4 g of ammonium chloride, 2 g of sodium phosphate, and 0.5 g of magnesium chloride in 200 mL of water to obtain a nutrient solution; S3. Soak the organic solid waste in a nutrient solution with a solid-liquid ratio of 1:5 g / mL, and dry it to obtain an organic solid waste biochar fertilizer.

[0017] Example 2 This embodiment provides a method for preparing organic solid waste biochar fertilizer, comprising the following steps: S1. Take fresh chicken manure in advance and air-dry it naturally, grind it into powder, pass it through a 40-mesh sieve, and obtain organic solid waste; S2. Dissolve 12 g of fructose, 7 g of ammonium sulfate, 3 g of sodium monohydrogen phosphate, and 1 g of magnesium sulfate in 200 mL of water to obtain a nutrient solution; S3. Soak the organic solid waste in a nutrient solution with a solid-liquid ratio of 1:7 g / mL, and dry it to obtain an organic solid waste biochar fertilizer.

[0018] Example 3 This embodiment provides a method for preparing organic solid waste biochar fertilizer, comprising the following steps: S1. Take fresh chicken manure in advance and air-dry it naturally, grind it into powder, pass it through a 40-mesh sieve, and obtain organic solid waste; S2. Dissolve 11 g of glucose, 5.5 g of ammonium nitrate, 2.5 g of sodium dihydrogen phosphate, and 0.7 g of magnesium nitrate in 200 mL of water to obtain a nutrient solution; S3. Soak the organic solid waste in a nutrient solution with a solid-liquid ratio of 1:6 g / mL, and dry it to obtain an organic solid waste biochar fertilizer.

[0019] Test Example 1 The crops used for planting were white stem water spinach purchased from Shicheng Seed Co., Ltd. The soil was taken from the surface cultivated soil of the vacant land near Beier Road, Wenhui Street, Dongying District, Dongying City (Table 1). The biochar was prepared in the laboratory from fresh chicken manure taken from a chicken farm near Dongying District, Dongying City, and was sealed in a glass jar before the experiment. The potted plant experiment used a flower pot with a size of 18*17*12 cm.

[0020] Table 1 Initial physical and chemical properties of test soil pH Conductivity Alkaline nitrogen content Available phosphorus content Organic matter content 7.6 220 μs 21.7 mg / kg 11.4 mg / kg 13.3 g / kg 1. Processing and methods The surface cultivated soil of Dongying District, Dongying City, after natural air drying was taken as the test soil, and the soil sample with a 2 mm aperture sieve was selected for potted plant test. The preparation of biochar was consistent with the germination test. Three treatments were set up: control group (CK), and each treatment of Example 1-3 was repeated 3 times, with a total of 9 pots. 2.5 kg of the test soil was added with the organic solid waste biochar fertilizer (10 g) prepared in Example 1-3, mixed, placed in a flower pot, and allowed to stand for a period of time before conducting a potted plant test.

[0021] The seeds of water spinach were sterilized by soaking in a H2O2 solution with a concentration of about 2% for 10 min, then repeatedly rinsed under tap water and then rinsed with distilled water. Healthy and plump seeds were selected for potted experiments, and 10 seeds were sown in each pot. The potted experiment cycle was 30 days. During the experiment, water was replenished by weighing at a water content of 20%. After the potted experiment was completed, the growth of water spinach was observed, and the physical and chemical properties of the soil were measured and compared with the initial values ​​of the soil.

[0022] 2. Measurement indicators and methods (1) Determination of alkaline nitrogen - alkaline diffusion method First, pass the air-dried soil sample through a 18-mesh sieve (1 mm), then weigh 2.00 g and pour it into the clean outer chamber of the diffusion dish, then gently rotate the diffusion dish to spread the soil sample. Use a syringe to suck 2 mL of H3BO3 solution and carefully inject it into the inner chamber of the diffusion dish (this process must ensure that the inner chamber is clean and dry, otherwise the H3BO3 indicator solution will change color and affect the test results). Then use a cotton swab to apply alkaline glue on the edge of the outer chamber of the diffusion dish, then cover it with frosted glass and turn it several times until it is fully bonded to the diffusion dish. Then open a small gap, then use a syringe to suck 10.0 mL of NaOH solution and inject it into the outer chamber, immediately cover the frosted glass, and then let the diffusion dish rotate slowly so that the NaOH solution immerses all the soil samples. Then use two rubber bands to tighten the diffusion dish and frosted glass. After all samples are ready, place the diffusion dish flat in a constant temperature box set at 40°C and diffuse for 24 hours. Take it out after the time is up, and the H3BO3 indicator solution in the inner chamber should turn blue. Carefully remove the frosted glass, then use the prepared H2SO4 standard solution to titrate the NH3 in the inner chamber absorption liquid. The inner chamber solution will turn from blue to purple, and after standing for a period of time, the solution will no longer turn blue.

[0023] A blank test is also performed to correct for reagent and titration errors.

[0024] Calculation results: Alkaline nitrogen (N) content (mg·kg -1 )=

[0025] (2) Determination of available phosphorus—0.5 mol·L -1 NaHCO3 method The air-dried soil sample was passed through a 20-mesh sieve, and 2.50 g was weighed and placed in a 150 mL triangular flask. Then 50 mL of NaHCO3 solution was added, and finally about 10 g of phosphorus-free activated carbon was added, and the flask was sealed with a sealing film. Then, the flask was shaken on an oscillator for half an hour. After the shaking was completed, the filtrate was filtered into a 100 mL triangular flask with a phosphorus-free filter paper, and 10 mL of the filtrate was pipetted into a 150 mL triangular flask. Then, 35 mL of water and 5 mL of molybdenum antimony reagent were injected into the flask, and the mixture was shaken and placed for half an hour. At the same time, the UV-visible spectrophotometer was turned on and the wavelength was adjusted to preheat for half an hour. After the time was up, the colorimetry was performed at a wavelength of 880 nm. The absorption value of the blank solution was set to 0, and the absorption value (A) of the test solution was read respectively.

[0026] (3) Determination of organic matter - potassium dichromate volumetric method Weigh 0.5000 g of soil sample into a 500 mL conical flask and add 1 mol·L -1Take 10 mL of K2Cr2O7 solution, rotate the conical flask to mix the solution and soil sample, then add 20 mL of concentrated H2SO4 and rotate slowly for 1 min (the bottle wall is hot at this time, be careful when handling) to ensure that the two are mixed and fully exert their effects. After laying flat for half an hour, dilute with water to 250 mL, finally add 3-4 drops of o-phenanthroline indicator, shake well and titrate with FeSO4 standard solution. When the solution changes from green to dark green, start adding FeSO4 drop by drop, and shake while adding, until the solution turns brick red, at which time the titration end point is reached.

[0027] At the same time as the test, a blank sample is measured (the soil sample is replaced by an equal amount of SiO2, and everything else remains unchanged).

[0028] Calculation results: Organic carbon content (g kg -1 )= Organic matter content (g kg -1 ) = organic carbon content (g kg -1 ) ×1.724 The results are shown in Table 2.

[0029] Table 2 Group Average germination rate in 2 days (%) Alkaline nitrogen content (mg / kg) Available phosphorus content (mg / kg) Organic matter content (g / kg) Control group 26 17 7.5 12.5 Example 1 57 69 18.9 22.7 Example 2 61 72 19.4 23.1 Example 3 62 74 20.2 23.5 It can be seen from the above table that the organic solid waste biochar fertilizers prepared in Examples 1-3 of the present invention can significantly increase the germination rate and have a significant effect on improving soil fertility.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing organic solid waste biochar fertilizer, characterized in that: The following steps are involved: S1. Take fresh chicken manure and dry it in advance, then grind it into powder, sieve it, and obtain organic solid waste; S2. dissolving a carbon source, a nitrogen source, a phosphorus source, and a magnesium source in water to obtain a nutrient solution; S3. Soaking the organic solid waste in a nutrient solution and drying it to obtain an organic solid waste biochar fertilizer.

2. The preparation method according to claim 1, characterized in that: The mesh number of the sieve is 20-40 meshes.

3. The preparation method according to claim 1, characterized in that: The carbon source is selected from at least one of glucose, sucrose and fructose.

4. The preparation method according to claim 1, characterized in that: The nitrogen source is selected from at least one of ammonium chloride, ammonium sulfate and ammonium nitrate.

5. The preparation method according to claim 1, characterized in that: The phosphorus source is selected from at least one of sodium phosphate, sodium monohydrogen phosphate and sodium dihydrogen phosphate.

6. The preparation method according to claim 1, characterized in that: The magnesium source is selected from at least one of magnesium chloride, magnesium sulfate and magnesium nitrate.

7. The preparation method according to claim 1, characterized in that: The mass ratio of the carbon source, the nitrogen source, the phosphorus source, the magnesium source and water is 10-12:4-7:2-3:0.5-1:

200.

8. The preparation method according to claim 1, characterized in that: The solid-to-liquid ratio of the organic solid waste to the nutrient solution is 1:5-7 g / mL.

9. An organic solid waste biochar fertilizer obtained by the preparation method according to any one of claims 1 to 8.