氮磷钾化肥种类的定性鉴别首先可以从外观和溶解度上区别磷肥与氮、钾肥。常用的氮肥和钾肥一般呈白色晶体（进口氯化钾常带红色，石灰氮黑色），且溶于水，常用磷肥呈灰色粉状，不溶或部分溶于水。如要进一步区分氮、钾化肥则可将肥料磨成粉未，取少量放在小铁片上灼烧，若能 Qualitative identification of nitrogen, phosphorus and potassium fertilizers First of all, from the appearance and solubility of phosphorus and nitrogen and potassium fertilizer differentiation. Commonly used nitrogen and potassium fertilizer is generally white crystals (potassium chloride imports often red, lime nitrogen black), and soluble in water, commonly used phosphate fertilizer was gray powder, insoluble or partially soluble in water. If you want to further distinguish between nitrogen and potassium fertilizers can be ground into a powder fertilizer, take a small amount of iron on the burning, if