All soil has a rating on the pH scale from 1 to 10. If soil is balanced, its pH rating is 7.0. Soils with a lower rating are said to be acid, while soils with a higher rating are more alkaline. Each plant has a pH rating as well. Plants that are planted in soil that is optimal for their pH range can take up nutrients from the soil more effectively. Limestone soils are more alkaline in nature, and tend to be rated with a pH higher than 7.0. Gardeners must typically adjust the pH so that it is less alkaline in limestone soils.
Test your soil with a pH testing kit. pH testing kits are available in many garden centers. By combining a soil sample with the included testing fluid, your soil's pH will cause the fluid to change colors. Match the soil color with the kit's color key to determine your soil's pH.
Loosen your alkaline soil with a rototiller.
Spread powdered sulfur or ammonium sulfate over your soil to lower the soil's pH. It typically takes 1 pound of ammonium sulfate per 10 square feet, or ¼ pound of powdered sulfur per 10 square feet to lower the pH of soil by 1.
Mix amendments into the soil with the rototiller.