Nitrogen fertilizer that can slowly release nitrogen for a period of time for continuous absorption and utilization by plants, is also known as slow-acting nitrogen fertilizer or long-acting nitrogen fertilizer. It is different from the general water-soluble fertilizer, which is characterized by high nitrogen utilization. After application, the nitrogen loss is small and the fertilizer efficiency is long. Moreover, the adverse effects of excessive local soil fertilizer concentration on crop growth in a short period of time can be avoided. Reducing the number of fertilizations not only improves economic efficiency, but also reduces pollution and helps protect the ecological environment.

Slow release nitrogen fertilizers are often manufactured using two processes.

1. Preparation of slow release nitrogen fertilizer by chemical method. It includes urea formaldehyde, oxalic acid amide and the like.

2. Using a physical method such as encapsulation and granulation to prepare a slow release nitrogen fertilizer. Control the release rate of water-soluble nitrogen fertilizer, such as sulfur-coated urea, granulated ammonium bicarbonate, and the like. Urea formaldehyde is the earliest slow release nitrogen fertilizer developed and sold.

In 1946, the US Department of Agriculture published a research report. A series of field trials and process studies were then carried out. Then they started to product and sell in 1955. Japan sold this fertilizer in 1963. The development and application of coated fertilizer began in the United States in 1960 to sell resin coated fertilizer. In 1961, the United States developed sulfur-coated urea (SCU). In the same year, Japan developed a coated high-efficiency fertilizer (C.S.R, Coated Slow-release). China began to study and apply slow-release nitrogen fertilizers such as asphalt, paraffin granular ammonium bicarbonate and ammonium magnesium phosphate coated granular ammonium bicarbonate around 1970.

Slow release nitrogen fertilizers can be roughly divided into three categories:

One is a poorly water-soluble substance, such as ammonium magnesium phosphate; 

One is water-soluble. However, it can be the effective nitrogen by chemical action or microbial decomposition, etc., such asisobutylidene diurea and urea formaldehyde; 

Another one is easily soluble in water. It slowly decomposes in the soil and gradually becomes effective, such as urea-based hydrazine. 

The application techniques and methods of slow release nitrogen fertilizer are similar to those of general nitrogen fertilizer. Pay attention to the following points:

Slow release nitrogen fertilizer is generally used as base fertilizer. For example, when it is used for topdressing of long-growing crops or perennial gardens and grassland plants, the application time should be such that the fertilizer release period is consistent with the crop fertilizer requirement period. 

The depth of fertilization should not only enable the crop to absorb nitrogen, but also reduce the loss. 

Rationally apply quick-acting nitrogen fertilizer and coordinate nitrogen supply. 

Lianyungang JM Bioscience NBPT Manufacturer supplies a variety of slow release nitrogen fertilizer. If you need, please contact us.