What compound can neutralize ammonium fertilizers?

Calcium carbonate (CaCO3) is effective at neutralizing ammonium fertilizers due to its ability to react with acids. Ammonium fertilizers, when applied to soil, can lead to increased acidity as they convert to nitrate, releasing hydrogen ions (H+). This acidity can be detrimental to soil health and plant growth.

Calcium carbonate acts as a liming agent, which not only neutralizes the excess acidity but also raises the pH of the soil. By increasing the pH, calcium carbonate helps to create a more favorable environment for nutrient availability and microbial activity in the soil.

For the other compounds listed, sodium chloride (NaCl) mainly serves as a source of sodium and chloride ions, which do not play a role in neutralizing acidity. Magnesium sulfate (MgSO4) can provide magnesium and sulfur nutrients but also does not neutralize acidity. Potassium oxide (K2O) is a source of potassium, vital for plant growth, but similarly lacks the properties necessary to neutralize ammonium fertilizers or reduce soil acidity.