Which method is most commonly used to lower soil pH?

Elemental sulfur is widely recognized as the most effective method for lowering soil pH. When elemental sulfur is applied to the soil, it undergoes a biological oxidation process facilitated by specific bacteria. This process converts the sulfur into sulfate ions, which then interact with water molecules to produce sulfuric acid. The formation of this acid is what leads to a decrease in soil pH.

Lowering soil pH is often necessary in agricultural practices when the soil is too alkaline for certain crops to thrive. An ideal pH range allows for optimal nutrient availability and microbial activity in the soil. Consequently, the application of elemental sulfur is a common agronomic practice to help achieve this desired pH level.

Other options, such as ammonium nitrate and urea, are primarily nitrogen sources and do not have the same effect on soil pH. While they may contribute to soil fertility, they do not effectively acidify the soil. Compost can improve soil structure and add nutrients, but it alone is not a reliable method for significantly lowering soil pH.