阅读说明：本技术 一种设施栽培茄子专用水溶性缓释复合肥及其制备方法 (Special water-soluble slow-release compound fertilizer for facility-cultivated eggplants and preparation method thereof ) 是由 郭延乐 于 2019-10-29 设计创作，主要内容包括：本发明公开了一种设施栽培茄子专用水溶性缓释复合肥及其制备方法,将甲醛溶液和水混合,所得混合液升温至40～70℃,然后加入尿素,快速搅拌溶解后,加入胺类物质,缓慢升温至65～95℃,反应1～3h,反应结束后冷却至室温,调节溶液体系pH值至6～7即得。本发明方法利用一般合成设备即可完成,方法简单,便于推广；制得的缓释复合肥不仅具备速效,还兼具缓效,可以达到减少施肥次数,提高肥料利用率,具有广阔的应用前景。产品澄清透明,不需要添加悬浮剂等助剂,长期存放不沉淀,利于其市场推广应用,尤其是应用于水肥一体化设施。(The invention discloses a special water-soluble slow-release compound fertilizer for eggplant facility cultivation and a preparation method thereof, wherein a formaldehyde solution and water are mixed, the obtained mixed solution is heated to 40-70 ℃, then urea is added, after the urea is rapidly stirred and dissolved, an amine substance is added, the temperature is slowly raised to 65-95 ℃, the reaction is carried out for 1-3 h, after the reaction is finished, the temperature is cooled to room temperature, and the pH value of a solution system is adjusted to 6-7, so that the special water-soluble slow-release compound fertilizer is obtained. The method can be completed by using general synthesis equipment, is simple and is convenient to popularize; the prepared slow-release compound fertilizer not only has quick effect, but also has slow effect, can reduce the fertilizing times, improves the utilization rate of the fertilizer, and has wide application prospect. The product is clear and transparent, does not need to add auxiliary agents such as suspending agents and the like, does not precipitate after being stored for a long time, is beneficial to market popularization and application, and is particularly applied to water-fertilizer integrated facilities.)

1. A preparation method of a special water-soluble slow-release compound fertilizer for facility-cultivated eggplants is characterized by comprising the following steps:

(1) mixing a formaldehyde solution with water, and heating the obtained mixed solution to 40-70 ℃;

(2) adding urea into the mixed solution obtained in the step (1), rapidly stirring and dissolving, adding an amine substance, slowly heating to 65-95 ℃, and reacting for 1-3 hours;

(3) and cooling to room temperature after the reaction is finished, and adjusting the pH value of the solution system to 6-7 to obtain the catalyst.

2. The preparation method of the special water-soluble slow-release compound fertilizer for eggplant to be cultivated by facility as claimed in claim 1, wherein in the step (1), the concentration of the formaldehyde solution is 30-50 wt%, and the mixing mass ratio of the formaldehyde solution to water is 3-4: 1.

3. The preparation method of the special water-soluble slow-release compound fertilizer for eggplant cultivated by facility as claimed in claim 1, wherein in the step (2), the molar ratio of the added amount of the urea to the formaldehyde in the formaldehyde solution is 0.5-1.5: 1.

4. The method for preparing the water-soluble slow-release compound fertilizer special for eggplant to be cultivated by facility as claimed in claim 1, wherein in the step (2), the amine substance is one or a mixture of more than two of methylamine, cyclopentylamine, ammonia water and triethanolamine; the molar ratio of the urea to the amine substances is 0.5-3: 1.

5. The preparation method of the special water-soluble slow-release compound fertilizer for eggplant cultivated by facility as claimed in claim 1, wherein sodium hydroxide, potassium hydroxide or sodium bicarbonate is used to adjust the pH value of the solution to 7.5-8.5 in the reaction process in the step (2).

6. The preparation method of the water-soluble slow-release compound fertilizer special for eggplant cultivated by facility according to claim 1, wherein a catalyst is added in the reaction process in the step (2) for reaction, the catalyst is any one of ammonium phosphate, ammonium sulfate, ammonium chloride and ammonium borate, and the addition amount is 0.2-0.5% of the total amount of the raw materials.

7. The method for preparing the water-soluble slow-release compound fertilizer special for eggplant to be cultivated by facility as claimed in claim 1, wherein in the step (3), a phosphoric acid, sulfuric acid or hydrochloric acid solution is used for adjusting the pH value of the solution system.

8. The water-soluble slow-release compound fertilizer special for eggplant cultivated in a facility, which is prepared by any one of the preparation methods in the claims 1-7.

Technical Field

The invention belongs to the technical field of fertilizers, and particularly relates to a special water-soluble slow-release compound fertilizer for eggplant facility cultivation and a preparation method thereof.

Background

Nitrogen is an important mineral element for high yield of agriculture, and nitrogen fertilizer is an important source of nitrogen and is an important guarantee for improving crop yield. However, nitrogen fertilizer utilization is generally low worldwide. The low utilization rate of the nitrogen fertilizer is caused by various reasons, such as incorrect fertilizing method, surface runoff, leaching, volatilization and the like; these in turn lead to a number of environmental problems such as water eutrophication, ground water pollution and greenhouse gas emissions. The slow/controlled release nitrogen fertilizer has great advantages in improving the utilization rate of the nitrogen fertilizer and the economic and environmental protection performance.

As a non-renewable resource, water is an important factor affecting the development of national economy. However, the scarcity of water resources is a serious problem to be faced. Particularly, the problem of water resources is more and more prominent in agricultural production, the development of water-saving agriculture is the development trend of agriculture, and along with the popularization of water-fertilizer integrated facilities, the improvement of the process and the transformation of concept in China, the water-soluble fertilizer can play a great role in the fields of agricultural cost reduction and efficiency improvement and water saving and environmental protection, and the market space is huge. The water-soluble fertilizer can be applied to spraying, sprinkling irrigation and drip irrigation, so that water and fertilizer integration is realized, and water, fertilizer and labor are saved; the fertilizer has obvious advantages in the aspects of improving the utilization rate of the fertilizer, saving agricultural water, reducing ecological environment pollution, improving crop quality, reducing labor force and the like, and is an important direction for the development of the fertilizer in the future.

Although water-soluble fertilizers in China develop rapidly, some problems exist in the aspects of production technology, fertilizer application and the like, and the water-soluble fertilizers are far behind developed countries. Most factories adopt a simple mixing production mode, the production process is backward, and the product quality is poor. Many enterprises simply mix raw material fertilizers such as urea, potassium nitrate, potassium sulfate, ammonium phosphate and the like, a production workshop has no moisture absorption equipment, an anti-caking technology is not over-closed, and the produced fertilizer often has the phenomena of deliquescence, hardening, poor water solubility and the like, so that the production and the sale of the water-soluble fertilizer are seriously influenced. Some enterprises emphasize nutrient content and do not pay attention to nutrient form, efficacy, auxiliary agents and scientific configuration of organic nutrients, so that the utilization rate of active ingredients of the product is not high despite water solubility. The nitrogenous fertilizer selected by most enterprises is generally quick-acting nitrogenous fertilizer and does not have slow-release effect, so frequent irrigation and fertilization (generally once a week) are needed, the fertilization cost is correspondingly increased, and the popularization and application of water and fertilizer integration are restricted. Therefore, the research on the water-soluble slow-release compound fertilizer which has the anti-caking function and the nutrient slow-release performance has wide market and application prospect.

However, most of the slow/controlled release nitrogen fertilizers are slightly soluble in water (urea formaldehyde) and insoluble in water (resin coated urea), and are not suitable for drip irrigation and sprinkling irrigation. Therefore, the development of efficient and environment-friendly water-soluble slow-release compound fertilizers has become an important research direction under new potentials. Meanwhile, with the change of agricultural production patterns, the water-soluble fertilizer industry which is rapidly developed and has wide development prospect also meets new development opportunities.

In recent years, urea-formaldehyde-based liquid fertilizers containing triazinone structures have been proved to provide slow-release nitrogen, and the urea-formaldehyde-based liquid fertilizers prepared through organic synthesis reaction can be slowly decomposed into inorganic nitrogen by microorganisms.

Disclosure of Invention

The invention aims to solve the technical problem of providing a liquid fertilizer with quick and slow effects aiming at the defects of the prior art so as to reduce the price of the fertilizer and improve the utilization rate of the fertilizer.

In order to achieve the above object of the invention, the invention adopts the following technical scheme:

a preparation method of a special water-soluble slow-release compound fertilizer for facility-cultivated eggplants comprises the following steps:

(1) mixing a formaldehyde solution with water, and heating the obtained mixed solution to 40-70 ℃;

(2) adding urea into the mixed solution obtained in the step (1), rapidly stirring and dissolving, adding an amine substance, slowly heating to 65-95 ℃, and reacting for 1-3 hours;

(3) and cooling to room temperature after the reaction is finished, and adjusting the pH value of the solution system to 6-7 to obtain the catalyst.

Specifically, in the step (1), the concentration of the formaldehyde solution is 30-50 wt%, and the mixing mass ratio of the formaldehyde solution to water is 3-4: 1.

In the step (2), the molar ratio of the added urea to the formaldehyde in the formaldehyde solution is 0.5-1.5: 1.

In the step (2), the amine substance is one or a mixture of more than two of methylamine, cyclopentylamine, ammonia water and triethanolamine; the molar ratio of the urea to the amine substances is 0.5-3: 1.

Further, sodium hydroxide, potassium hydroxide or sodium bicarbonate is adopted in the reaction process in the step (2) to adjust the pH value of the solution to 7.5-8.5.

Furthermore, a catalyst can be added in the reaction process in the step (2) for catalytic reaction, wherein the catalyst is any one of ammonium phosphate, ammonium sulfate, ammonium chloride and ammonium borate, and the addition amount is 0.2-0.5% of the total amount of the raw materials.

In the step (3), phosphoric acid, sulfuric acid or hydrochloric acid is adopted for adjusting the pH value of the solution system.

The water-soluble slow-release compound fertilizer special for the eggplant cultivated in the greenhouse, which is prepared by the method, also belongs to the protection scope of the invention.

Has the advantages that:

the method can be completed by using general synthesis equipment, is simple and is convenient to popularize; the prepared slow-release compound fertilizer not only has quick effect, but also has slow effect, can reduce the fertilizing times, improves the utilization rate of the fertilizer, and has wide application prospect. The product is clear and transparent, does not need to add auxiliary agents such as suspending agents and the like, does not precipitate after being stored for a long time, is beneficial to market popularization and application, and is particularly applied to water-fertilizer integrated facilities.

Drawings

The foregoing and/or other advantages of the invention will become further apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

FIG. 1 is a process flow diagram of the preparation method of the present invention.

FIG. 2 is a nuclear magnetic resonance hydrogen spectrogram of the water-soluble slow-release compound fertilizer A prepared in example 1.

FIG. 3 is the nuclear magnetic resonance carbon spectrum of the water-soluble slow-release compound fertilizer A prepared in example 1.

FIG. 4 is a graph showing the nitrogen conversion rate of water-soluble controlled-release compound fertilizer A prepared in example 1 in soil.

Detailed Description

The invention will be better understood from the following examples.