The Grass Doctor

Liquid fertilizer that contains a mix of NH4 and P2O5 creates crystals when it drys. What is that?

Vinegar dissolves it into a white powder.

Public Comments

1. It depends on the type of fertilizer that is used! Liquid fertilizer is just a solution of water-soluble compounds. Many compounds can be used for fertilizer. Common nitrogen-containing compounds used are urea, ammonium nitrate, and ammonium phosphate. Some farmers directly apply ammonia to the soil; this is fairly cheap on a per-pound basis, but ammonia tends to evaporate rapidly. You are probably referring to someone who has used ammonia (NH3) and P2O5 (which reacts with water to form phosphates). If evaporated the resulting solid you would get would be ammonium phosphate: 3NH3(aq) + H3PO4(aq) --> (NH4)3PO4(s) (+ H2O(l))