Several common chemical fertilizer identification methods

Simple ways to identify chemical fertilizers: 1. Physical methods: (1) Visual inspection: Liquid fertilizers are usually in liquid form, while off-white powders are often phosphate fertilizers. (2) Smell test: A strong ammonia smell indicates ammonium bicarbonate. (3) Solubility test: Potash and nitrogen fertilizers are generally water-soluble, while most phosphorus fertilizers are either insoluble or only partially soluble.

2. Chemical methods: (4) Burning test: Potash does not burn and may crack or make a cracking sound when heated. Nitrogen-based fertilizers can melt, foam, or produce smoke when burned. (5) Lime reaction: When mixed with slaked lime, ammonium-based fertilizers release a pungent gas.

For fruit trees, it's better to use organic manure instead of chemical fertilizers whenever possible. Organic manure such as dried chicken or duck manure should be properly fermented before use. Depending on the growth stage, you can choose high-nitrogen or high-potassium fertilizers, or mix your own using urea, superphosphate, and potassium fertilizer. It’s recommended to use potassium sulfate for fruits and vegetables rather than potassium chloride, as the latter can negatively affect quality. For vegetables, especially those grown in greenhouses, water-soluble fertilizers are highly effective. Although they may cost more, their performance is excellent. For crops like wheat and corn, farmers typically rely on compound fertilizers that are high in nitrogen and potassium.