Which problem may occur if farmers apply too much $\text{NH}_4\text{NO}_3$ to crops?
- ANot all the $\text{NH}_4\text{NO}_3$ is used by plants and the excess makes the soil alkaline.
- BRain washes some of the $\text{NH}_4\text{NO}_3$ into rivers where it forms a precipitate.
- CSome of the $\text{NH}_4\text{NO}_3$ dissolves in groundwater which may eventually be used for drinking.
- DAmmonia is produced; this lowers the pH of the soil.