Identification of single element fertilizer. There are two kinds of counterfeit nitrogen fertilizers, such as fake urea, which appear most frequently in the market: First, the composition of the whole bag is inconsistent. If the top of the packaging bag has good fluidity, the lower part will not flow or even agglomerate, and a strong smell of volatile ammonia can be smelled. Basically, it can be judged that urea is above and ammonium bicarbonate is below. If the upper and lower fluidity is good, but the particle color and particle size are inconsistent, it may be fake ammonium nitrate; In another case, the whole bag of fertilizer has the same composition. Common counterfeits are: Jihua granular ammonium nitrate, Russian granular ammonium nitrate, and some macromolecular organic substances, such as polyols. Although the particles, colors and solubility of the above substances are similar to those of urea, they can still be identified by the following methods: 1. Appearance: urea is a white translucent particle with no reflecting surface; The surface of ammonium nitrate particles has obvious color and reflection; Polyols are opaque milky white particles, colorless and non-reflective. 2, feel: urea is smooth, loose, and has no wet feeling; Although ammonium nitrate is smooth, it feels wet; Although polyol is loose and moist, it is not very smooth. 3. Combustion: Put the three substances on red-hot charcoal or iron plate respectively, and urea will melt, giving off white smoke with the smell of ammonia; Ammonium nitrate burns violently, emitting strong light and white smoke, mixed with "before" sound; Although polyol decomposes and burns, it has no ammonia smell. The variety of simple phosphate fertilizer circulating in the market is mainly superphosphate, and the counterfeit products have been found: phosphogypsum, calcium magnesium phosphate, waste cement slag and brick powder. The main identification methods are: 1. Appearance: calcium superphosphate is a gray loose powder with sour taste; Phosphogypsum is gray hexagonal columnar crystal or crystalline powder, without sour taste; The color of calcium magnesium phosphate fertilizer is grayish green or grayish brown, without sour taste; In the form of very dry glassy particles or fine powder; The waste cement slag is dark gray powder, hard and rough, and has no sour taste; Brick and tile powder is blue in color, with coarse powder particles and no sour taste. 2, feel: generally, the calcareous ground is heavier and feels greasy; Phosphogypsum is light, cotton in hand, frivolous; Calcium-magnesium-phosphate fertilizer has a heavy texture and a dry hand. Waste cement slag is heavy in texture, not dry, and has hard cement slag; Brick powder feels very astringent, not dry and has brick residue. 3. Water solubility: calcium superphosphate is partially soluble in water; Phosphogypsum is completely soluble in water; Calcium magnesium phosphate is insoluble in water; Waste cement powder and brick slurry are precipitated under the condition of much water. 4. In the identification of phosphate fertilizer, if the following phenomena occur: there are obvious impurities such as clods, stones and cinders in calcium superphosphate, which can be judged as inferior products; If the sour taste is too strong and the moisture is high, it is an unqualified semi-finished product that has not matured; If it is found that the color is black and the hand feels astringent and prickly, it is not a fake fly ash. Second, the identification of compound fertilizer The counterfeit compound fertilizer appearing on the market is diammonium phosphate. Counterfeits have been found: nitrophosphate, superphosphate and granular superphosphate. Although they are similar to diammonium phosphate in color, particle size and compressive strength, they are quite different in nutrient composition, type, content and price. The nutrient contents of diammonium phosphate are P2O546-48%% and N16-18%; The nutrient contents of nitrophosphate are P2O511-13% and N25-27%; The nutrient content of superphosphate is P2O542-46%; The nutrient content of granular superphosphate is P2O5 14- 18%. The difference between them is as follows: 1. Appearance: Diammonium phosphate (made in America) is an irregular particle without wetting, with dark brown center, slightly yellow edge and slightly translucent outer edge. After wetting, the particles are dark brown and deepened, without yellow transparent edges, and a very small amount of powder white appears on the surface after wetting. Nitrophosphate is also irregular particles with dark brown color and smooth surface. The particles of superphosphate are dark gray. Calcium superphosphate particles are light gray in color and have poor surface finish. 2. Water solubility: Diammonium phosphate, nitrophosphate and superphosphate are all soluble in water; Granular calcium superphosphate is only partially soluble in water. 3. Combustion: Diammonium phosphate and nitrophosphate can quickly melt on red-hot charcoal or iron plate, and release ammonia gas; Calcium superphosphate (three materials) has no ammonia smell on red-hot charcoal or iron plate; Calcium superphosphate has no ammonia smell on red-hot charcoal or iron plate, and its particle shape has not changed. 4, when necessary, through the laboratory for quantitative analysis. Third, the identification of mixed fertilizers Mixed fertilizers are also called compound fertilizers, and fertilizers with total ternary (N+P2O5+K2O) nutrients greater than or equal to 40.0% are called high-concentration compound fertilizers. At present, the vast majority of fertilizers called ternary (multi-element) compound fertilizers on the market are not compound fertilizers, but mixed (compound) fertilizers. False mixed (mixed) fertilizers are mostly particles such as sludge, garbage, soil and coal ash powder, and generally do not contain nitrogen fertilizer. The difference method is 1. Appearance: nitrogenous fertilizer, especially mixed fertilizer containing more urea or ammonium nitrate, has good melting state and smooth surface due to suitable furnace temperature in the production process; However, the surface of fake mixed fertilizer particles is rough and dull, and there is no residue of urea and other fertilizers. 2. Combustion method: Combustion method is the main method to distinguish the true and false mixed (mixed) fertilizer and its concentration. Red-hot charcoal or compound fertilizer on iron plate will melt (the more nitrogen, the faster it melts), smoke, give off ammonia smell, and the particle deformation will become smaller (the higher the concentration, the less residue). Of course, the most accurate thing is to take samples for quantitative analysis. Iv. identification of foliar fertilizer generally inferior foliar fertilizer is characterized by simple packaging, incomplete quantity of three certificates (qualified quality, production license and fertilizer registration certificate) and unknown composition. Some concentrations are very low, the liquid is bright, and some deposits are obvious. The identification method is as follows: 1 Packaging: check whether the goods are registered by the agricultural department, whether there is a fertilizer use registration certificate number, whether the product trademark (registration), main components, scope of use, factory name and address are consistent with the document notice of the agricultural department, and if there are obvious differences, they are counterfeit products; If there is no fertilizer registration number, it is an illegally produced and sold product and cannot be promoted. 2. Appearance: For liquid fertilizer, the product description indicates that liquid fertilizer containing ferrous sulfate should be green; Liquid fertilizer containing fulvic acid should be brown; The liquid fertilizer containing sodium and potassium humate should be dark brown. If it has been marked that it contains the above ingredients alone, but it does not match the above color, it is a fake; If the colors are matched, but there is too much precipitation, it is inferior. Solid foliar fertilizer is mainly composed of urea, potassium dihydrogen phosphate and trace elements. Through the intuitive color and crystal shape, it can be identified by the above-mentioned identification method of single element fertilizer and compound fertilizer. 3. Look at the field effect: after spraying according to the instructions, the leaf color and growth of crops should change obviously after 3-5 days; The change of leaf color of zinc-containing fertilizer products should be more obvious; According to the above method, what remains unchanged for about a week is fake and shoddy products.