CARBON-BASED MICROBIAL COMPOUND FERTILIZER AND PREPARATION METHOD THEREOF
Technical field The invention relates to the technical field of compound fertilizers, in particular to a carbon-based microbial compound fertilizer and a preparation method thereof.
Technical background China's total fertilizer application rate and unit area application rate are already at a high level in the world, but the fertilizer utilization rate is low. Although the application of chemical fertilizer can increase the content of available nutrients in soil and improve soil fertility, it will also bring many adverse effects to the environment. Long-term application of chemical fertilizer will cause soil acidification and hardening; Excessive application of chemical fertilizer will make the soil prone to salinization and secondary salinization; In addition, unreasonable fertilization will bring harmful substances into the soil, causing soil pollution, and then affecting the quality of agricultural products. Nitrogen fertilizer is widely used in agricultural production, which has obvious effect of increasing production, but it also has the greatest environmental risk. A large amount of nitrogen fertilizer applied in farmland will pollute groundwater, and excessive fertilizer flowing into water body with runoff will also cause eutrophication of water body and destroy ecological balance. Excessive application of nitrogen fertilizer will aggravate the emission of greenhouse gases such as nitrogen oxides, aggravate the greenhouse effect and affect global climate change. Therefore, on the basis of ensuring the yield and benefit of agricultural products, it is a key problem to be solved urgently in agricultural production by developing new fertilizers and adjusting fertilization structure to solve the problems of excessive fertilization, low utilization rate of fertilizers, and degradation of agricultural products and environmental quality.
Summary of the invention In order to solve the above problems, the invention provides a carbon-based microbial compound fertilizer which can not only improve soil fertility and crop yield and quality, but also avoid the problems of soil acidification, hardening, salinization, water eutrophication and the like.
The invention also provides a preparation method of the carbon-based microbial compound fertilizer, which has simple process steps and is easy to be produced by the existing equipment. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: A carbon-based microbial compound fertilizer is prepared from microbial compound fertilizer, coating agent, biochar and zeolite in a weight ratio of 100: (10 15): (10-30): (5-15). The microbial compound fertilizer consists of nitrogen fertilizer, phosphate fertilizer, potassium fertilizer and nitrogen-fixing microorganisms, wherein the weight percentage of each component in the microbial compound fertilizer is 45 50wt% of nitrogen fertilizer, 23.5-24wt% of phosphate fertilizer, 23.5-24wt% of potassium fertilizer and the balance of nitrogen-fixing microorganisms; The coating agent consists of attapulgite and polyvinyl alcohol aqueous solution, wherein the weight percentage of polyvinyl alcohol aqueous solution in the coating agent is 50 75wt%, and the balance is attapulgite. According to the invention, innovation is carried out on the basis of research on carbon-based fertilizers and microbial fertilizers, and biochar is compounded with common nitrogen, phosphorus and potassium fertilizers and microorganisms with nitrogen fixation function, so that the fertilizer has the advantages of both carbon based fertilizers and microbial fertilizers. In the coating agent, attapulgite has the function of adjusting pH value, polyvinyl alcohol has the function of coating and slow release, and all raw materials are polymerized together. Preferably, the nitrogen fertilizer is one of urea, ammonium nitrate or ammonium bicarbonate, the phosphate fertilizer is one of superphosphate or superphosphate, and the potassium fertilizer is one of potassium chloride, potassium sulfate or potassium nitrate. Preferably, the nitrogen-fixing microorganism is Bacillus subtilis. Preferably, the polyvinyl alcohol aqueous solution is a 3-6 wt% polyvinyl alcohol aqueous solution. Preferably, the biochar is rice hull charcoal, which is prepared by the following method: firstly, washing and drying rice hulls, then treating the washed and dried rice hulls at 200-300 °C for 20-30 minutes in an air atmosphere, then heating at 400-600 °C for 70-110 minutes in isolation from oxygen, cooling and crushing, sieving with a 30 50 mesh sieve, and then drying for 20-26 hours at 60-80 °C. Preferably, the attapulgite is 100-120 mesh sieve and the zeolite is 50-60 mesh sieve. A preparation method of a carbon-based microbial compound fertilizer comprises the following steps: Putting the microbial compound fertilizer into a coating machine, then adding a coating agent, biochar and zeolite, stirring for 20-60 minutes at a rotating speed of 60 70 rpm, and then drying at 30-40 °C to prepare the carbon-based microbial compound fertilizer. Preferably, before adding zeolite, the zeolite is washed with water, then the washed zeolite is soaked in hydrochloric acid solution for 20-40 minutes, the hydrochloric acid solution on the surface of zeolite is dried, then it is calcined at 600 750°C for 30-40 minutes and cooled, then the zeolite is soaked in sodium bicarbonate solution for 1-2 hours, and finally washed with water, dried and set aside. Preferably, the concentration of hydrochloric acid solution is 1.0-1.5 mol/L, and the concentration of sodium bicarbonate solution is 0.5-1.0 mol/L. Therefore, the invention has the following beneficial effects: (1) The content of nitrogen, phosphorus and potassium fertilizers and nitrogen fixing microorganisms in the carbon-based microbial compound fertilizer of the invention is higher, and the activity of nitrogen-fixing microorganisms is stronger; (2) The carbon-based microbial compound fertilizer in the invention is acidic or nearly neutral, and has potential application prospect in areas which are endangered by salinization and lack of phosphorus; (3) The carbon-based microbial compound fertilizer in the invention contains rich organic elements such as carbon and nitrogen, and the pH values are all acidic or close to neutral, and the total nutrient content meets the requirements of the national standard for compound fertilizer concentration in fertilizer; (4) The carbon-based microbial compound fertilizer has a certain slow release effect on nitrogen; (5) The preparation method of the carbon-based microbial compound fertilizer in the invention has simple process steps and is easy to produce by adopting existing equipment.
Detailed description of the invention The technical scheme of the present invention will be further explained with reference to specific embodiments. Example 1 A carbon-based microbial compound fertilizer is prepared from microbial compound fertilizer, coating agent, biochar and zeolite in a weight ratio of 100: 10: 10: 5. The microbial compound fertilizer consists of nitrogen fertilizer, phosphate fertilizer, potassium fertilizer and nitrogen-fixing microorganisms, wherein the weight percentage of each component in the microbial compound fertilizer is 45wt% of nitrogen fertilizer, 23.5wt% of phosphate fertilizer, 23.5wt% of potassium fertilizer and 7% of nitrogen-fixing microorganisms; The coating agent consists of attapulgite and polyvinyl alcohol aqueous solution, wherein the weight percentage of polyvinyl alcohol aqueous solution in the coating agent is 50wt%, and the weight percentage of attapulgite is 50wt%; The nitrogen fertilizer is ammonium nitrate, the phosphate fertilizer is calcium superphosphate, and the potassium fertilizer is potassium sulfate. The nitrogen-fixing microorganism is Bacillus subtilis, here Bacillus subtilis spore powder; The polyvinyl alcohol aqueous solution is 3 wt% polyvinyl alcohol aqueous solution; Attapulgite is attapulgite sieved by 100 meshes, and zeolite is zeolite sieved by 50 meshes. The biochar is rice hull charcoal, which is prepared by the following method: firstly, washing and drying rice hulls, then treating the washed and dried rice hulls in air atmosphere at 200°C for 20 minutes, then heating at 400°C for 70 minutes without oxygen, cooling and crushing, sieving with a 30-mesh sieve, and then drying at 60°C for 20 hours to prepare rice hull charcoal. A preparation method of a carbon-based microbial compound fertilizer comprises the following steps: Putting the microbial compound fertilizer into a coating machine, adding a coating agent, biochar and zeolite, stirring for 20 minutes at a rotating speed of 60rpm, and drying at 30 °C to prepare the carbon-based microbial compound fertilizer; The zeolite was washed with water before adding, then soaked in hydrochloric acid solution with concentration of 1.Omol/L for 20 minutes. After absorbing the hydrochloric acid solution on the surface of zeolite, it was calcined at 600°C for 30 minutes and cooled, then soaked in sodium bicarbonate solution with concentration of 0.5mol/L for 1 hour, finally washed with water and dried for later use. Example 2 A carbon-based microbial compound fertilizer is prepared from microbial compound fertilizer, coating agent, biochar and zeolite in a weight ratio of 100: 12: 20: 15. The microbial compound fertilizer consists of nitrogen fertilizer, phosphate fertilizer, potassium fertilizer and nitrogen-fixing microorganisms, wherein the weight percentage of each component in the microbial compound fertilizer is 50wt% of nitrogen fertilizer, 24wt% of phosphate fertilizer, 24wt% of potassium fertilizer and 2wt% of nitrogen-fixing microorganisms; The coating agent consists of attapulgite and polyvinyl alcohol aqueous solution, the weight percentage of which is 75wt%, and the weight percentage of attapulgite is 25wt%. Nitrogen fertilizer is ammonium bicarbonate, phosphate fertilizer is calcium superphosphate, and potassium fertilizer is potassium nitrate. The nitrogen-fixing microorganism is Bacillus subtilis, here Bacillus subtilis spore powder; The polyvinyl alcohol aqueous solution is 6 wt% polyvinyl alcohol aqueous solution; Attapulgite is attapulgite sieved by 120 meshes, and zeolite is zeolite sieved by 60 meshes. The biochar is rice hull charcoal, which is prepared by the following method: firstly, washing and drying rice hulls, then treating the washed and dried rice hulls in air atmosphere at 300°C for 30 minutes, then heating at 600°C for 110 minutes without oxygen, cooling and crushing, sieving with 50 mesh sieve, and then drying at 80°C for 26 hours to prepare rice hull charcoal. A preparation method of a carbon-based microbial compound fertilizer comprises the following steps: Putting the microbial compound fertilizer into a coating machine, adding a coating agent, biochar and zeolite, stirring for 60 minutes at a rotating speed of 70rpm, and drying at 40 °C to prepare the carbon-based microbial compound fertilizer; The zeolite is washed with water before being added, then the washed zeolite is soaked in hydrochloric acid solution with a concentration of 1.5mol/L for 40 minutes, the hydrochloric acid solution on the surface of the zeolite is dried, calcined at 750°C for 40 minutes and cooled, then the zeolite is soaked in sodium bicarbonate solution with a concentration of 1.Omol/L for 2 hours, and finally washed with water and dried for later use.
Example 3 A carbon-based microbial compound fertilizer is prepared from microbial compound fertilizer, coating agent, biochar and zeolite in a weight ratio of 100: 15: 30: 10. The microbial compound fertilizer consists of nitrogen fertilizer, phosphate fertilizer, potassium fertilizer and nitrogen-fixing microorganisms, wherein the weight percentage of each component in the microbial compound fertilizer is 47.5wt% of nitrogen fertilizer, 23.75 wt% of phosphate fertilizer, 23.75 wt% of potassium fertilizer and 5 wt% of nitrogen-fixing microorganisms; The coating agent consists of attapulgite and polyvinyl alcohol aqueous solution, wherein the weight percentage of polyvinyl alcohol aqueous solution in the coating agent is 60wt%, and the weight percentage of attapulgite is 40 wt%; The nitrogen fertilizer is urea, the phosphate fertilizer is superphosphate, and the potassium fertilizer is potassium chloride. The nitrogen-fixing microorganism is Bacillus subtilis, here Bacillus subtilis spore powder; The polyvinyl alcohol aqueous solution is 4wt% polyvinyl alcohol aqueous solution; Attapulgite is attapulgite sieved by 110 meshes, and zeolite is zeolite sieved by 55 meshes. The biochar is rice hull charcoal, which is prepared by the following method: firstly, washing and drying rice hulls, then treating the washed and dried rice hulls in air atmosphere at 250°C for 25 minutes, then heating at 500°C without oxygen for 90 minutes, cooling and crushing, sieving with a 40-mesh sieve, and then drying at 70°C for 24 hours to prepare rice hull charcoal. A preparation method of a carbon-based microbial compound fertilizer comprises the following steps: Putting the microbial compound fertilizer into a coating machine, adding a coating agent, biochar and zeolite, stirring for 30 minutes at a rotating speed of 65rpm, and drying at 35 °C to prepare the carbon-based microbial compound fertilizer; The zeolite is washed with water before adding, then soaked in hydrochloric acid solution with concentration of 1.2mol/L for 30 minutes, dried up the hydrochloric acid solution on the surface of zeolite, calcined at 700°C for 35 minutes and cooled, then soaked in sodium bicarbonate solution with concentration of 0.75mol/L for 1.5 hours, finally washed with water, dried and set aside.