Which amendment raises soil pH?

• A. Lime
• B. Sulfur
• C. Perlite
• D. Vermiculite

Answer: (A)

Raising soil pH happens when you add something that neutralizes acidity in the soil. Lime provides calcium carbonate, which acts as a base. It neutralizes hydrogen ions and acidic aluminum on the soil particles, forming water and carbon dioxide and releasing calcium ions to improve the soil’s balance. This neutralization raises the pH, making nutrients more available to plants. Sulfur lowers pH because soil microbes convert it into sulfuric acid, increasing acidity. Perlite and vermiculite are inert minerals that mainly improve texture and moisture; they don’t meaningfully raise soil pH. So lime is the amendment that raises soil pH.