The last article shared four common chemical fertilizer identification methods. This edition will continue to share common chemical fertilizer identification methods for everyone. Let's go on
1. Ammonium bicarbonate for agricultural use is white or slightly gray crystal, with ammonia smell, strong hygroscopicity, easily soluble in water, and the aqueous solution is weakly acidic. During identification, a small amount of samples can be rubbed with fingers to smell strong ammonia gas. The agricultural nitrogen content is 17%.
2. The appearance of superphosphate is dark gray, gray white, light yellow and other loose powder, slightly sour. It is an acid fertilizer, sensitive to alkali, and easy to lose its fertilizer effect. Some can be dissolved in water, and the aqueous solution is acidic. Generally, the hygroscopicity is relatively small. For example, when the air humidity reaches 80% or more, there is hygroscopicity, which forms a hard lump. The effective phosphorus pentoxide content of super grade product is 20%, that of grade IV product A is 13%, and that of grade B is 12%.
3. The appearance of calcium magnesium phosphate fertilizer is grayish white, grayish green or grayish black powder. The powder is very fine. Under the sunlight, crushed objects similar to glass bodies can be seen, which are sparkling. It is insoluble in water, not easy to lose, non hygroscopic, non-toxic, and non corrosive. When heated on fire, there is no visible change. The melting point is about 135 ℃. The effective phosphorus pentoxide of super grade products is 20%, calcium oxide 40%, magnesium oxide 12%
4. The appearance of compound fertilizer is grayish brown or grayish white granular. Some compound fertilizers contain incomplete crushed white urea grain crystals, while some compound fertilizers contain complete urea grains alone. It is slightly hygroscopic, and the compound fertilizer particles are easy to be crushed after moisture absorption. It is non-toxic, tasteless and non corrosive. Nitrogen fertilizer, potassium fertilizer in compound fertilizer and water-soluble phosphorus in some phosphorus fertilizers can be dissolved in water. When heating on the fire, white smoke can be seen and ammonia smell can be smelled, which can not be completely melted.
5. Ammonia water is an aqueous solution of ammonia gas dissolved in water. It is colorless, transparent or yellowish liquid with strong irritating odor and toxicity. The aqueous solution is weakly alkaline. Ammonia content in agricultural ammonia water is generally 15%.
