2021-06-02
Packaging inspection
1. Check the labeling.The archived article describes Chinese fertilizer labeling requirements, including product name, nutrients, grade, trademark, net weight, standard code, manufacturer, address and telephone, with registration or production-license information for relevant products. Missing or incomplete labeling may indicate a counterfeit or substandard product.
2. Check the bag seal.Pay particular attention to fertilizer packaging showing signs of having been opened, as it may have been adulterated.
Identification by shape and color
Urea is described as white or pale-yellow granules, needles or prisms with little powder; ammonium sulfate as white crystals; ammonium chloride as white or pale-yellow crystals; ammonium bicarbonate as powder, granules or sometimes larger flattened spheres; and superphosphate as gray-white powder.
The article describes strong ammonia-smelling liquid as ammonia solution, ammonia-smelling granules as ammonium bicarbonate and acidic fine powder as triple superphosphate. Strongly acidic superphosphate may contain harmful industrial residues and damage crops, particularly rice seedlings.
Some fertilizers are genuine but low-grade. For example, the original article describes superphosphate below 8% available phosphorus, against a stated minimum of 12%, as low-quality. Seek expert assessment when buying.
Identifying Compound Fertilizers
Compound fertilizers vary widely in quality. Their broad nutrient content, convenience and targeted effects are popular with growers, but counterfeit products also occur. The article introduces simple preliminary quality checks.
1. Visual inspection.Check for double-layer packaging, trademark, production license, fertilizer registration, standard code, total nutrient content, manufacturer's name and address, and a certificate inside. Missing identification may indicate a counterfeit or substandard product.
2. Touch test.The original article states a 5% moisture limit for low-concentration ternary compound fertilizer. Slightly wetter material feels sticky, while substantially wetter material can be pressed into a cake.
3. Burn test.The article describes heating a small sample of compound fertilizer on metal: an ammonia smell indicates nitrogen and a yellow flame indicates potassium; stronger signs are presented as a rough indication of higher content.
4. Smell test.Compound fertilizer generally has little odor except organic–inorganic blends. The article associates unusual smells with ammonium bicarbonate or harmful residues in phosphate materials, which can injure seedlings and persist to affect later crops.
5. Dissolution test.Good compound fertilizer is relatively soluble: most dissolves in water and any sediment is fine. Poor-quality fertilizer is difficult to dissolve and leaves coarse, hard residue.
Hubei Changyin Edible Fungi Machinery Co., Ltd. supplies bag filling machines, clipping machines, dryers and other mushroom equipment to customers across China, supported by after-sales service.