A slow-release nitrogen fertilizer based on straw polymerization and its preparation method and application

A straw and slow-release technology is applied in the field of slow-release nitrogen fertilizer and preparation based on the polymerization of straw, which can solve the problems of low nitrogen utilization rate and difficult utilization of cellulose, and achieves long nutrient release cycle, good slow-release effect, and improved The effect of agglomerate structure

CN106565376BActive Publication Date: 2022-05-13INST OF ENVIRONMENT & SUSTAINABLE DEV IN AGRI CHINESE ACADEMY OF AGRI SCI
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2022-05-13

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Abstract

The invention belongs to the technical field of environment-friendly slow-release nitrogen fertilizer, and in particular relates to a slow-release nitrogen fertilizer formed based on straw polymerization, a preparation method and application thereof. The structural formula of the main active ingredient of the slow-release nitrogen fertilizer is shown in the following formula (I): wherein, n is an integer of 2-51. The slow-release nitrogen fertilizer preparation method includes adding sulfuric acid solution and straw powder into a reactor, stirring and reacting at normal temperature until the straw is completely liquefied, adding sodium hydroxide solution to obtain a low-viscosity straw solution; adding urea and formaldehyde solution to another reactor, Stir evenly, keep the temperature at 45°C to 47°C, add the prepared low-viscosity straw solution, and react; dry, pulverize, and obtain. The release period of the slow-release nitrogen fertilizer of the invention can reach 28 days to 148 days, effectively reduces the solubility of urea, and can effectively improve the slow-release performance of nitrogen. The slow-release nitrogen fertilizer can be decomposed by the action of microorganisms, and the decomposed nitrogen is released through the colloidal network structure, so as to realize the slow release of nitrogen and effectively improve the physical and chemical properties of soil.
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Description

technical field

[0001] The invention belongs to the technical field of environment-friendly slow-release nitrogen fertilizer, and in particular relates to a slow-release nitrogen fertilizer formed based on straw polymerization, a preparation method and application thereof. Background technique

[0002] Straw is the main waste in crop production. With the development of society and economy, the utilization of straw is getting lower and lower. Especially in rural areas, the process of electrification has exacerbated the low recovery rate of straw. It has caused a waste of resources and also caused great harm to the environment, such as air pollution, low visibility, and aggravated smog. Every year, grassroots units invest a lot of manpower and material resources in straw management, mainly including law enforcement to stop straw burning, straw collection and so on. Although straw returning to the field is now advocated, it has also brought a series of problems, mainly includi...

Examples

Embodiment 1

[0049] A method for preparing slow-release nitrogen fertilizer based on straw polymerization, comprising the following steps:

[0050] (1) Add 1kg of sulfuric acid solution with a molar concentration of 2mol / L and 10kg of straw powder (a mixture of rice straw, wheat straw, etc.) 10kg of sodium solution was used to obtain a low-viscosity straw solution for subsequent use.

[0051] (2) Add 4.5 kg of formaldehyde solution with a mass fraction of 37% and 3.3 kg of urea to another reactor, keep the temperature at about 45° C., stir for 10 min, then add the low-viscosity straw solution prepared in step (1), and react for 10 min; After the reaction, dry at 90°C and pulverize to obtain slow-release nitrogen fertilizer.

[0052]After testing, the nitrogen content of the slow-release nitrogen fertilizer is 9.8%, and the nitrogen release cycle is 28 days.

Embodiment 2

[0054] A method for preparing slow-release nitrogen fertilizer based on straw polymerization, comprising the following steps:

[0055] (1) Add 1 kg of sulfuric acid solution with a molar concentration of 2 mol / L and 20 kg of straw powder (a mixture of rice straw, wheat straw, etc.) 10kg of sodium solution was used to obtain a low-viscosity straw solution for subsequent use.

[0056] (2) Add 4.5 kg of formaldehyde solution with a mass fraction of 37% and 3.3 kg of urea to another reactor, keep the temperature at about 45° C., stir for 40 min, then add the low-viscosity straw solution prepared in step (1), and react for 10 min; After the reaction, dry at 90°C and pulverize to obtain slow-release nitrogen fertilizer.

[0057] After testing, the nitrogen content of the slow-release nitrogen fertilizer is 9.2%, and the nitrogen release cycle is 128 days.

Embodiment 3

[0059] A method for preparing slow-release nitrogen fertilizer based on straw polymerization, comprising the following steps:

[0060] (1) Add 1 kg of sulfuric acid solution with a molar concentration of 2 mol / L and 30 kg of straw powder (a mixture of rice straw, wheat straw and other weights) into the reactor, stir for 40 minutes at room temperature to completely liquefy, and then add 40% mass fraction of hydrogen 10kg of sodium solution was used to obtain a low-viscosity straw solution for subsequent use.

[0061] (2) Add 4.5kg of formaldehyde solution and 3.3kg of urea with a mass fraction of 37% in another reactor, keep about 45°C, stir for 40min, then add the low-viscosity straw solution prepared in step (1), and react for 10min; After the end, it is dried at 90°C and crushed to obtain a slow-release nitrogen fertilizer.

[0062] After testing, the nitrogen content of the slow-release nitrogen fertilizer is 8.7%, and the nitrogen release cycle is 88 days.