Potassium Metaphosphate

a potassium salt of metaphosphoric acid, a white powder; a high-concentration potassium-phosphate fertilizer.

Potassium metaphosphate contains 55–60 percent P₂O₅ and 35–40 percent K₂O. It is nonhygroscopic and readily assimilated by plants (particularly those growing in acidic soils). It is most effective when applied to the soil under chlorine-sensitive crops(tobacco, tea, grapes, legumes).