What is the purpose of using a pH meter or soil test kit?

• A. To measure soil temperature
• B. To determine soil pH and guide nutrient availability and amendments
• C. To detect pests
• D. To measure rainfall

Answer: (B)

Understanding how soil pH affects nutrient availability is the key idea. A pH meter or soil test kit tells you how acidic or basic the soil is, and that pH level determines how nutrients dissolve and are taken up by plant roots. When the soil pH is outside the optimal range for a crop, essential nutrients can become less available or locked up in minerals, leading to deficiencies even if you add fertilizers. Knowing the pH lets you decide on lime to raise pH or sulfur to lower it, and to select fertilizers that supply nutrients in the forms plants can actually use. It also helps predict how active soil microbes will be, which influences nutrient cycling. So the purpose is to determine soil pH and guide nutrient availability and amendments. This tool isn’t used for measuring soil temperature, detecting pests, or measuring rainfall, which require different instruments.