Selection and application method of urea formaldehyde fertilizer
Urea formaldehyde slow-release nitrogen fertilizer is only suitable as base fertilizer. In addition to lawn and garden, if it is applied to rice, wheat and cotton and other field crops, it should be properly equipped with quick acting water-soluble nitrogen fertilizer. If there is no available nitrogen fertilizer, the phenomenon of insufficient nitrogen supply will appear in the early stage of crops, and it is difficult to achieve the goal of high yield, which will increase the cost of fertilization in vain. In some cases, ammonium sulfate and urea should be applied as appropriate. Of course, in any case, the base fertilizer can not ignore the matching of phosphorus and potassium fertilizer, such as single superphosphate and potassium chloride.
Since urea formaldehyde contains less cold water-soluble nitrogen, when applied to annual crops, some quick-acting nitrogen fertilizers must be applied together to avoid poor growth of crops due to insufficient nitrogen supply in the early stage. Therefore, the compound fertilizer processed by the NPK fertilizer manufacturing process can better meet the needs of crops.
The common varieties of urea formaldehyde fertilizers are urea formaldehyde slow-release nitrogen fertilizer, urea formaldehyde slow-release compound fertilizer, part of urea formaldehyde slow-release mixed fertilizer and so on. They are both granular and powdery, and liquid fertilizer can be prepared for application.
Advantages of NPK compound fertilizer
1. Urea formaldehyde compound fertilizer can dissolve quickly after being applied into the soil, which is convenient to fertilize with water, but the insoluble nitrogen in cold water can be firmly absorbed by the soil, so as to ensure no loss of nutrients.
2. A small amount of urea in urea formaldehyde can be rapidly converted into nitrogen that can be directly absorbed by crops under the condition of microbial decomposition, which is the available nitrogen in urea formaldehyde fertilizer;
3. The hydroxyl urea, methylene biurea and dimethyltrimethyl urea in urea formaldehyde must be decomposed by microorganism for a period of time, and then transformed into inorganic nitrogen which can be directly absorbed by crops;
4. The higher polymerization degree of methylene urea in urea formaldehyde, such as trimethyl tetraurea and tetramethyl pentaurea, must be decomposed by microorganisms for a long time and many times before it can be transformed into inorganic nitrogen which can be absorbed by crops. Therefore, long-term nitrogen in urea formaldehyde fertilizer is formed.
The NPK fertilizer production process includes ingredients, granulation, drying, cooling, screening, coating, packaging, etc. Basic fertilizer equipment: batching system, crusher, mixer, rotary drum granulator, screening machine, drum dryer, cooler, fertilizer coating machine, packaging machine, etc.
Urea-formaldehyde compound fertilizer is directly processed by using urea-formaldehyde powder as an intermediate raw material to avoid the occurrence of non-long-lasting nitrogen in the fertilizer due to the lack of long-acting nitrogen in the urea-formaldehyde liquid, resulting in high water content in the urea-formaldehyde solution and low particle hardness. There are problems such as formaldehyde emissions. The urea-formaldehyde powder is a slow-release nitrogen fertilizer manufactured by an automated process. After the urea-formaldehyde powder is used, the urea-formaldehyde slow-release nitrogen of the product can reach more than 4 unprecedented. At the same time, the process of synthesizing urea-formaldehyde compound fertilizer can also increase the reaction chain of methylene urea. The methylene urea in urea formaldehyde has an adsorption effect, which can promote the combination of fertilizer and soil particles to form a colloidal chelate, thereby reducing nutrient loss and allowing The crop is fully absorbed and the fertilizer utilization rate is improved.
Compared with common compound fertilizer, urea formaldehyde slow-release compound fertilizer has the advantages of low moisture, high particle strength and light caking. It is simple and easy to transform the existing drum steam granulation or disc granulation NPK fertilizer production device to produce urea formaldehyde slow-release compound fertilizer. The project has the advantages of simple process, low investment, short construction period, convenient configuration, lower production cost than slow-release long-term or coated controlled-release fertilizer. Urea formaldehyde fertilizer has the functions of quick acting, slow effect and long-term effect, which can fully meet the demand of farmers for slow-release function of fertilizer, which is more promising in the industry.