1. Packaging identification method. ① Inspection marks: according to the regulations of relevant national departments, the product name, nutrient content, grade, trademark, net weight, standard code, factory name, address and production license number must be indicated on the chemical fertilizer packaging bag. If there is no such mark or the mark is incomplete, it may be fake or inferior fertilizer. ② Check the sealing of the packaging bag: pay special attention to the chemical fertilizer with obvious unpacking marks on the packaging seal, which may be adulterated.
2. Shape and color identification method. ① Urea is white or light yellow, granular, acicular or prismatic crystal, no powder or little powder; ② Ammonium sulfate is white crystal except by-products; ③ Ammonium chloride is white or light yellow crystal; ④ Ammonium bicarbonate is white granular crystal, and some manufacturers also produce large granular flat spherical ammonium bicarbonate; ⑤ Superphosphate is gray white or light gray powder; ⑥ Heavy superphosphate is dark gray, gray white particles or powder; ⑦ Potassium sulfate is white crystal or powder; ⑧ Potassium chloride is white or light red particles.
3. Odor identification method. If the liquid with strong pungent ammonia smell is ammonia; The particle with obvious pungent ammonia smell is ammonium bicarbonate; The fine powder with sour taste is heavy superphosphate. If superphosphate has a pungent sour taste, it indicates that waste sulfuric acid is likely to be used in the production process. This kind of chemical fertilizer has great toxicity and is easy to burn crops, especially rice seedlings. It should be reminded that although some chemical fertilizers are true, their content is very low. For example, the content of low-quality calcium superphosphate and effective phosphorus is less than 8% (the minimum standard should be 12%). These chemical fertilizers are low-quality chemical fertilizers with little fertilizer effect. Professionals should be invited to identify them when purchasing.
