Ammonium Nitrate

Ammonium nitrate makes a great fertilizer that can be directly applied to the soil. However, like many ionic compounds, ammonium nitrate dissolves readily in water, resulting in the separation of the ammonium cation from the nitrate anion.

Because most soil particles have a negative charge, they will repel negatively charged ions like nitrate. Therefore there is a limited amount of time for the nitrate to be absorbed by the plant before it leaches from the soil.