Preparation method and application of multifunctional rice carbon-based fertilizer

Abstract

The invention discloses a preparation method and application of a multifunctional rice carbon-based fertilizer, relates to the technical field of fertilizer manufacturing, and has the technical key points that the multifunctional rice carbon-based fertilizer is prepared according to nutritional requirements of rice, soil fertility characteristics of southern acidic rice fields and nutrient release characteristics of the carbon-based fertilizer; fermented organic fertilizer, biomass charcoal and chemical fertilizer containing nitrogen, phosphorus and potassium are mixed according to a specific proportion, a pyroligneous granulation and cross-linking modification coating technology is adopted to prepare the fertilizer, and the nutrient content control indexes are as follows: N + P2O5 + K2O is greater than or equal to 25%, and SOC is greater than or equal to 9%. The fertilizer has multiple improvement functions, and can effectively improve the physicochemical properties of soil, reduce the fertilization frequency, improve the fertilizer utilization rate, promote the growth of rice and increase the yield. Meanwhile, soil acidity adjustment, carbon sequestration and pollution reduction are facilitated, and the lodging resistance of the rice is enhanced, so that the goals of high yield, efficiency improvement and quality improvement are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizer manufacturing, and in particular to a preparation method and application of a multifunctional rice charcoal-based fertilizer. Background Art

[0002] The quality of cultivated land is the basic guarantee for food security. Rice is one of the three major grain crops in my country, and the area of ​​rice fields in the south accounts for about 69% of the country. In recent decades, there have been problems such as a decline in cultivated land area, serious soil acidification, lack of soil organic matter and some trace elements, and aggravated heavy metal pollution in southern my country, resulting in prominent regional imbalances in food supply, and the "transportation of grain from the south to the north" has been replaced by the "transportation of grain from the north to the south". This is related to the general excessive use of chemical fertilizers and insufficient input of organic fertilizers in southern agricultural areas of China. The fundamental reason is the low income from grain production, the loss of rural labor, and the relatively extensive management of rice production. There are abundant organic waste resources in southern my country, such as straw, pig manure, chicken manure, etc., but organic fertilizers produced solely from organic waste have low nitrogen content, large fertilizer dosage, slow fertilizer effect, and low cost performance. Although chemical fertilizers are effective quickly, the fertilizer utilization rate is low, resulting in serious non-point source pollution. In addition, there are many typhoons in the southern rice-growing areas, and rice is prone to lodging.

[0003] Therefore, fertilizer management in southern rice-growing areas needs to take into account soil acidification, carbon fixation effects, and the ability of rice production to resist lodging, while reducing heavy metal pollution, and improving fertilizer utilization and rice quality. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problems and provide a preparation method and application of a multifunctional rice charcoal-based fertilizer. According to the characteristics of agricultural and forestry wastes in the red-yellow soil area in the south, targeting key problems such as soil acidification and lack of soil organic matter in medium and low-yield fields in the area, combined with the soil fertility characteristics of medium and low-yield fields in red-yellow soil and the fertilizer requirements of rice, a multifunctional rice charcoal-based fertilizer is developed to achieve the purposes of acidification, carbon fixation, pollution reduction, efficiency increase, and improving the ability of rice to resist lodging.

[0005] In order to achieve the above object, the technical scheme of the present invention is as follows: a method for preparing a multifunctional rice charcoal-based fertilizer, wherein the multifunctional rice charcoal-based fertilizer is prepared by mixing fermented organic fertilizer, biochar and fertilizer containing nitrogen, phosphorus and potassium in a specific proportion according to the nutritional requirements of rice, the fertility characteristics of southern acidic paddy field soil and the nutrient release characteristics of charcoal-based fertilizer, and by wood vinegar granulation and cross-linking modification coating process;

[0006] The control indicators of nutrient content are: N+P2O5+K2O≥25%, SOC≥9%.

[0007] Preferably, based on the sum of weight percentages being 100%, the multifunctional rice charcoal-based fertilizer comprises the following raw materials in parts by weight: 20-26% urea, 8-12% phosphate fertilizer, 15-20% potassium sulfate, 10-20% biochar, 10-20% organic fertilizer, 4-6% calcium magnesium phosphate fertilizer, 0.5-2% crop growth promoter and 4-7% binder; the mass ratio of N, P2O5 and K2O in the nitrogen, phosphorus and potassium-containing charcoal-based fertilizer is 10:4:7.

[0008] Preferably, the binder is one or a mixture of attapulgite, bentonite and modified starch.

[0009] Preferably, the organic fertilizer is obtained by composting livestock and poultry manure such as pig manure or chicken manure that has not been separated into dry and wet parts, drying it, and passing it through a 20-mesh sieve.

[0010] Composting: organic materials such as pig manure are piled up and covered with plastic sheets. After high-temperature fermentation, the temperature of the pile drops below 40 degrees. The powdery materials become dark brown, loose, and have no odor. When they have a slight organic acid aroma, the fermentation is complete. The organic carbon content of the composted pig manure reaches 8% to 20%, and the humic acid content reaches more than 8%.

[0011] Preferably, the biochar is rice, wheat or rape straw, which is pyrolyzed at 550°C-600°C under anaerobic high temperature pyrolysis process and crushed through a 60 mesh sieve. Wood vinegar is a by-product of biochar production.

[0012] Preferably, the cross-linked modified coating film is a starch / PVA film, and its preparation process is as follows: a certain amount of starch and PVA (starch: PVA = 2:3) are weighed respectively, and the starch is first added to a certain amount of tap water (starch: water = 4:150), and stirred at a constant speed at 100°C to gelatinize the starch. Then PVA is added in proportion and stirred at 100°C for 1 hour until it is completely dissolved. The temperature is lowered to 80°C, and then 1% of the cross-linking agent wood vinegar and 30% of the plasticizer glycerol are added in sequence, and the cross-linking reaction is carried out for more than 2 hours for coating.

[0013] The present invention also provides an application of the multifunctional rice charcoal-based fertilizer, which is applied at a rate of 70-100 kg / mu, 100% of which is used as base fertilizer for side deep fertilization, and shallow water application is maintained. In the later stage, no fertilizer is required or 2-3 times of amino acid water-soluble foliar fertilizer is sprayed. The fertilizer can also be used as a special fertilizer during the rice seedling raising period, which can increase the germination rate of rice seeds, promote rice growth, and achieve the purpose of strengthening rice seedlings.

[0014] Compared with the prior art, this solution has the following beneficial effects:

[0015] 1) The formula design is highly targeted and fully functional. According to the nutritional requirements of rice, the fertility characteristics of southern rice fields, and the nutrient release characteristics of organic and inorganic fertilizers, the present invention sets a special fertilizer-nutrient ratio for rice, adopts biochar, chemical fertilizers and organic fertilizers as raw materials, and utilizes the functional groups of biochar and fermented organic fertilizers as carriers of chelated inorganic fertilizers. Combined with modified coating technology, the product has the advantages of taking advantage of each other, comprehensive nutrients, carbon and nitrogen are suitable, and the effect of combining speed and slowness can be avoided. Rapid loss and volatilization of fertilizer nutrients can be avoided, fertilizer utilization rate can be improved, the number of topdressing times can be reduced, and soil properties can be improved at the same time to meet the nutrient requirements of rice throughout the growth period. The product can be used as a special fertilizer for raising rice seedlings, and can also be used as a supporting fertilizer for side deep fertilization technology (compared to commercially available compound fertilizers, this product does not absorb moisture) to promote its use. The research and development product has multiple functions such as acid adjustment, carbon fixation, pollution reduction, high yield, efficiency increase, and improving the ability of rice to resist lodging.

[0016] 2) Turn waste into treasure, and achieve a win-win situation for green agricultural development and effective utilization of solid waste. The present invention comprehensively utilizes agricultural solid waste resources such as pig manure and straw, reduces environmental pollution problems caused by their abandonment and incineration, and resources can be recycled. At the same time, the byproduct wood vinegar during the production of biochar is fully combined with the charcoal-based fertilizer granulation process, and the advantages of wood vinegar are brought into play to modify the biochar, thereby reducing the problem of large ammonia losses caused by the alkalinity of biochar during the production of charcoal-based fertilizers. Compared with the simple use of biochar or organic fertilizer, charcoal-based fertilizers are used less frequently, are applied once and are convenient to apply, and have increased fertilizer efficiency, thereby achieving the goals of increased production, increased efficiency, and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the finished product of carbon-based fertilizer in an embodiment of the present invention (where a is uncoated and b is coated);

[0018] Figure 2 Schematic diagram of the change of nitrogen release rate after coating in an embodiment of the present invention;

[0019] Figure 3 Schematic diagram of rice pot test results in the embodiment of the present invention (where a is Hubei soil, b is Hunan soil);

[0020] Figure 4 Schematic diagram of rice germination experiment results in an embodiment of the present invention;

[0021] Figure 5 Schematic diagram of fertilizer treatment effect at rice seedling stage according to an embodiment of the present invention;

[0022] Figure 6 Schematic diagram of the results of different treatment experiments at the rice soil culture seedling stage according to the embodiment of the present invention;

[0023] Figure 7 This is a real picture of the rice maturity period in the field test in the embodiment of the present invention;

[0024] Figure 8 It is a schematic diagram of the test results of different treatments in rice fields in the embodiments of the present invention. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solution of the present invention will be further described in detail below in conjunction with the embodiments of the present invention and the accompanying drawings. 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 should fall within the scope of protection of the present invention.

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0027] Embodiment 1:

[0028] A multifunctional carbon-based fertilizer (BBOF) for rice planting includes the following raw materials in parts by weight: 50% compound fertilizer, 10% urea, 5% potassium sulfate, 4.7% attapulgite, 10% biochar, 10% organic fertilizer, 10% calcium magnesium phosphate fertilizer, and 0.3% crop growth promoter. Except for the compound fertilizer, the other raw materials are crushed and sieved through 60 meshes, and the compound fertilizer is sprayed with water, coated, and dried. The nutrient content of the final product is: N 12.2%, P2O5 9.2%, K2O 10.7%, and organic matter 10.0%. At the same time, a reference fertilizer (BBF) without pig manure is prepared by the same production process as above, which is 50% compound fertilizer, 10% urea, 5% potassium sulfate, 4.7% attapulgite, 20% biochar, 10% calcium magnesium phosphate fertilizer, and 0.3% crop growth promoter. The nutrient content of the final product is: N12.1%, P2O59.0%, K2O 11.0%, and organic matter 12.6%.

[0029] Pot experiment: Paddy field soil was collected from the tillage layer (0–20 cm) in Hunan (N) and Hubei (B), and the soil physical and chemical properties are shown in Table 1. The soil was naturally air-dried and passed through a 5 mm stainless steel sieve, and 5 kg of air-dried soil was dispensed into each pot. Potted test treatments: conventional fertilizer treatment (CF: 250kgN / ha-138kgP2O5 / ha-138kgK2O / ha, calculated in terms of nitrogen, 40% of basal fertilizer was applied with only compound fertilizer, 30% of tillering fertilizer was applied with only urea, 30% of ear fertilizer was applied with 15% urea and 15% of compound fertilizer as topdressing), charcoal-based inorganic fertilizer formula treatment (BBF: the same N dosage as CF, calculated in terms of nitrogen, 60% of basal fertilizer was applied with only BBF, 20% of tillering fertilizer was applied with only urea, 20% of ear fertilizer was applied with 10% urea and 10% BBF as topdressing), charcoal-based inorganic-organic compound fertilizer formula treatment (BBOF: the same N dosage as CF, calculated in terms of nitrogen, 60% of basal fertilizer was applied with only BBOF, 20% of tillering fertilizer was applied with only urea, 20% of ear fertilizer was applied with 10% urea and 10% BBOF as topdressing). There were 3 treatments in total, with 3 replicates for each treatment. The rice variety was Jinxiangyu No. 1. Other rice management was consistent with the conventional management of Jinxiangyu No. 1 "Technical Regulations for Machine Transplantation Production of Excellent Tasting Japonica Rice Jinxiangyu No. 1" DB3210 / T11242022.

[0030] The effect of application is shown in Figure 3 .from Figure 3 It can be seen that the carbon-based fertilizer prepared only by the unmodified biomass carbon-coated compound fertilizer process has certain effects on acid adjustment (increasing pH), carbon fixation (increasing soil organic carbon) and reducing heavy metal Cd pollution, but no obvious promoting effect was observed on rice growth.

[0031] Table 1 Basic physical and chemical properties of the test soil

[0032]

[0033] Embodiment 2:

[0034] A multifunctional carbon-based fertilizer for rice planting includes the following raw materials in parts by weight: 25% urea, 7% diammonium phosphate, 9% potassium sulfate, 5% bentonite, 2% modified starch, 25% biochar, 20% organic fertilizer, 6.5% calcium magnesium phosphate fertilizer, and 0.5% crop growth promoter. All raw materials are crushed and sieved through 60 meshes, mixed, sprayed with wood vinegar to granulate, dried, sieved, and produced by using wood vinegar cross-linked modified starch / PVA coating, etc. The nutrient content of the final finished product is: N 13.3%, P2O5 5.5%, K2O9.1%, and organic matter 15.5% (BBOF). At the same time, a reference fertilizer (BBF) without pig manure is prepared by the same production process as above, the biochar is increased to 35%, the nitrogen, phosphorus and potassium content is increased, and the nutrient content of the finished product is: N 16.5%, P2O5 6.6%, K2O10.5%, and organic matter 16.3%.

[0035] 1. Germination experiment: Compound fertilizer (CF: 15-15-15) and carbon-based fertilizer samples (BBOF, BBF) were mixed with ultrapure water at 1:100 (W / V), extracted by shaking for 2 hours, and filtered. 10 mL of filtrate was added to a culture dish covered with two layers of filter paper. 30 sterilized rice seeds (Xinliangyou 2172, indica hybrid rice) of uniform size and strong vitality were placed in each culture dish. The rice seeds had been soaked in 3% hydrogen peroxide for 30 minutes, and then soaked and rinsed with deionized water for 5 to 7 times. With compound fertilizer (CF) as a reference, each treatment was repeated 3 times. The culture dish was placed in a 25°C light incubator (light 12 hours, dark 12 hours) for 7 days, and the number of rice seeds germinating was recorded regularly every day (germination was considered when the young sprout reached 1 / 2 of the seed length). At the end of the culture, 10 representative seedlings were randomly selected from each culture dish, and the length and dry weight of their radicle and plumule were measured.

[0036] Results Figure 4 .from Figure 4 It can be seen that the carbon-based fertilizer products produced by the improved process, especially BBOF, have obvious advantages in improving the germination rate of rice seeds, increasing biomass and radicle length.

[0037] 2. Soil culture test: The test soil is the soil with code B in Table 1, collected from Dafa Temple Town, Wuxue City, Hubei Province. The soil was naturally air-dried and passed through a 5mm stainless steel sieve, and 200g of air-dried soil was dispensed into each pot. The disinfection and washing of rice seeds were the same as the germination test. After 5 days of rice cultivation, the rice was transferred to the soil culture device for outdoor natural light soil cultivation test. A total of 3 treatments were set up, including conventional compound fertilizer treatment (CF: 35mg / kg dry soil ≈ 84kgN / ha), carbon-based inorganic fertilizer formula treatment (BBF: the same N dosage as CF), and carbon-based inorganic-organic compound fertilizer formula treatment (BBOF: the same N dosage as CF). Each treatment was repeated 3 times. The rice variety was Xinliangyou 2172. When the hydroponic rice seedlings grew to four leaves and one heart (35d), the relevant indicators were measured.

[0038] Seedling stage effect Figure 5 , see Figure 6 .from Figure 6 It can be seen that the cross-linked modified coating product BBOF significantly increases the leaf area of ​​the fourth leaf of rice and the above-ground and underground biomass, and has a significant positive growth-promoting effect on rice growth.

[0039] Embodiment 3:

[0040] A multifunctional carbon-based fertilizer for rice planting, comprising the following raw materials in parts by weight: 22% urea, 8% diammonium phosphate, 16% potassium sulfate, 5% bentonite, 2% modified starch, 20% biochar, 20% organic fertilizer, 6.5% calcium magnesium phosphate fertilizer, and 0.5% crop growth promoter. The fertilizer is produced by crushing and screening 60 meshes, granulating wood vinegar, drying, cross-linking modified starch / PVA coating of wood vinegar, and the nutrient content of the final product is: N 12.1%, P2O56.0%, K2O 9.6%, and organic matter 15.0%.

[0041] Field test: A field test was conducted in Shanggui Village, Dafa Temple Town, Wuxue City, Hubei Province, to compare the field application effects of carbon-based fertilizer products. The rice variety used was Taoyuan Xiangsi Miao, a local conventional indica rice variety. Three treatments were set, each with three replicates, and each plot had an area of ​​30m 2 , a total of 9 plots, arranged in random blocks, treatments included:

[0042] ① Blank control (CK: no fertilizer), ② Conventional fertilizer treatment (CF, 100% conventional NPK dosage, determined according to local fertilization habits, N: P2O5: K2O = 1: 0.5: 0.8, that is, base fertilizer: compound fertilizer (15-15-15), 1.5 kg / plot; tillering fertilizer: urea 0.49 kg / plot; ear fertilizer: potassium chloride 0.23 kg / plot, equivalent to N: P2O5: K2O = 150: 75: 1 per hectare 20kg. ③ Carbon-based organic fertilizer treatment (BBOF: N dosage equal to CF), only used as base fertilizer: carbon-based organic fertilizer 4.13kg / plot; equivalent to N: P2O5: K2O = 150: 69: 124kg per hectare. Each plot is equipped with a separate water inlet and drainage outlet, and a 40cm wide and 40cm high ridge is built between the plots. The ridge is covered with film to prevent water and fertilizer from leaking, and protective rows are set up around it. Other management measures during the whole growth period are carried out according to local production habits.

[0043] The effect of BBOF in field trials is shown in Figure 7 , see Figure 8 .from Figure 8 It can be seen that the wood vinegar cross-linked modified coating product BBOF significantly increased the number of effective panicles in the three elements of rice yield (compared with CF, an average increase of 8.1%), thereby increasing the yield, with an average increase of 12.4%, which has certain advantages for rice yield. In addition, BBOF has obvious effects in acid adjustment and carbon fixation, especially significantly increasing the organic carbon content of 20-40cm soil and the resistance of rice to lodging, and the resistance coefficient of rice to lodging has increased significantly ( Figure 8 ).

[0044] The above specific embodiments are merely explanations of the present invention and are not limitations of the present invention. After reading this specification, those skilled in the art may make modifications to the embodiments without any creative contribution as needed. However, such modifications are protected by the patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing a multifunctional rice charcoal-based fertilizer, characterized in that: The multifunctional rice charcoal-based fertilizer is prepared by mixing fermented organic fertilizer, biochar and fertilizer containing nitrogen, phosphorus and potassium in a specific proportion according to the nutritional requirements of rice, the fertility characteristics of southern acidic paddy field soil and the nutrient release characteristics of charcoal-based fertilizer, and by wood vinegar granulation and cross-linking modification coating process; The control indexes of the nutrient content of the multifunctional rice charcoal-based fertilizer are: N+P2O5+K2O≥25%, SOC≥9%.

2. The method for preparing a multifunctional rice charcoal-based fertilizer according to claim 1, characterized in that: The multifunctional rice charcoal-based fertilizer is composed of the following raw materials in parts by weight: 20-26% urea, 8-12% phosphate fertilizer, 15-20% potassium sulfate, 10-20% biochar, 10-20% organic fertilizer, 4-6% calcium magnesium phosphate fertilizer, 0.5-2% crop growth promoter and 4-7% binder.

3. The method for preparing a multifunctional rice charcoal-based fertilizer according to claim 2, characterized in that: The binder is one or a mixture of attapulgite, bentonite and modified starch.

4. The method for preparing a multifunctional rice charcoal-based fertilizer according to claim 1 or 2, characterized in that: The organic fertilizer is prepared by composting livestock and poultry manure that has not been separated into dry and wet parts and then screening it through a 20-mesh screen; The composted livestock and poultry manure has an organic carbon content of 8% to 20% and a humic acid content of more than 8%.

5. The method for preparing a multifunctional rice charcoal-based fertilizer according to claim 1 or 2, characterized in that: The biochar is produced through the pyrolysis process of rice, wheat or rape straw; the wood vinegar is a by-product produced in the production process of the biochar.

6. The method for preparing a multifunctional rice charcoal-based fertilizer according to claim 1, characterized in that: The cross-linked modified coating adopts starch / PVA film, and the film material is prepared by the cross-linked modification reaction of wood vinegar, starch and PVA.

7. The method for preparing a multifunctional rice charcoal-based fertilizer according to claim 6, characterized in that: The preparation method of the starch / PVA film comprises the following steps: S1. Raw material preparation: according to the mass ratio of starch to PVA of 2:3, weigh the required amount of starch and PVA respectively, wherein starch is added into tap water, and the ratio of water to starch is 4:150; S2, gelatinizing starch: dissolving starch in water and stirring at a constant speed at 100°C until the starch is completely gelatinized; S3, adding PVA: adding PVA in proportion to the gelatinized starch solution, and continuing to stir at 100°C for 1 hour until the PVA is completely dissolved; S4, adding a cross-linking agent and a plasticizer: lowering the temperature of the mixed solution to 80° C., and sequentially adding 1% of a cross-linking agent, wood vinegar, and 30% of a plasticizer, glycerol; S5, cross-linking reaction: continue stirring and cross-linking reaction at 80°C for no less than 2 hours until a membrane material is formed; S6. Film preparation: After the cross-linking reaction is completed, the solution is used for film coating to obtain the desired starch / PVA film.

8. An application of the multifunctional rice charcoal-based fertilizer according to claim 1, characterized in that: The application method of the multifunctional rice charcoal-based fertilizer comprises: Application of base fertilizer: Apply 70-100 kg of multifunctional rice charcoal base fertilizer per mu as 100% base fertilizer for side deep fertilization, and keep shallow water during fertilization; Late management: In the late stage of rice growth, you can choose not to apply fertilizer, or spray amino acid water-soluble foliar fertilizer 2-3 times during tillering, booting, and grain filling to meet the nutritional needs of rice; Application during the rice seedling raising period: This charcoal-based fertilizer can also be used as a special fertilizer during the rice seedling raising period to increase the germination rate of rice seeds and promote the growth of seedlings.

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