The identification of chemical fertilizer can be quickly judged by watching, burning, touching, testing and other methods. The fake and inferior identification methods of several main types of chemical fertilizers are introduced as follows for reference only.

——There are two kinds of fake urea in the nitrogen fertilizer Market:

1. Urea and ammonium bicarbonate are mixed. The fertilizer bag is filled with urea above and ammonium bicarbonate below. It is characterized by good flow performance above, no flow or even agglomeration below, and can smell pungent ammonia. In this case, urea can be judged as fake urea mixed with ammonium bicarbonate.

2. Urea and ammonium nitrate are mixed. Both fertilizers are white, tasteless, good fluidity and white smoke. The difference is that urea particles are large, translucent, loose, non reflective and humid. They melt quickly on red burning charcoal or iron plate, and there is pungent and eye fuming ammonia release. Ammonium nitrate particles are small, shiny on the surface, with obvious reflection and humidity. When placed on red charcoal or iron plate, it will burn violently, emit strong light and produce "stabbing" sound. In this case, it can be judged that ammonium nitrate is mixed in urea.

——The main counterfeit superphosphate in the phosphate fertilizer market are phosphogypsum, waste cement slag, etc. The identification method is as follows:

1. Appearance. Calcium daphosphate is dark gray and gray white, light gray loose powder with sour taste. Phosphogypsum is grayish white hexagonal granular crystal or crystalline powder without sour taste. Calcium magnesium phosphate fertilizer has no sour taste and is very dry glassy fine grain or fine powder. The waste cement slag is gray powder particles, without luster and sour taste, and there are many hard particles.

2. Feel. Calcium superphosphate is heavy and feels soft but not frivolous. Phosphogypsum is light in texture, feels soft and dry. The texture of waste cement slag is heavier than that of calcium superphosphate. It does not feel greasy, spongy or dry, and there are hard cement particles.

3. Water soluble. The calcium superphosphate is partially dissolved in water, and the waste cement slag is added with water to form a slurry, which is solidified again. In identification, if there are obvious impurities such as clods, stones and cinders in superphosphate, it is inferior superphosphate; If it is found that the sour taste is too strong and there is more water, it is unqualified non-finished calcium superphosphate that has not been matured.

——In the market of compound fertilizer, granular calcium superphosphate is often used as phosphate nitrate and heavy calcium, and calcium superphosphate and phosphate nitrate are also used as diammonium phosphate. They have similar colors, particles and compressive strength, but there are great differences in composition, content and price. It can be identified from the following methods.

1. Appearance. Without moisture, diammonium phosphate is dark brown in the middle, slightly yellow and translucent around, and the surface is slightly smooth. It is irregular particles. After moisture, the color of the particles becomes darker, and the periphery loses the sense of yellow and transparency. The particles soaked in water behave the same as the wetted particles, and a very small amount of pink white appears on the surface. Nitrophosphate fertilizer has no obvious transparency, smooth surface and irregular black brown particles. Heavy calcium is dark gray particles, the color of superphosphate is gray or light gray, and the surface smoothness is poor.

2. Water soluble. Nitrophosphate fertilizer, diammonium phosphate and heavy calcium are soluble in water, while calcium superphosphate is not completely soluble in water.

3. Burn with fire. Diammonium phosphate and phosphate nitrate are burned on red carbon, which will soon melt and give off ammonia smell; Heavy calcium has no ammonia taste, while the shape of superphosphate has no change at all.

According to the inherent characteristics of the above fertilizers, the true and false fertilizers can be distinguished.