Which soil test parameter helps determine lime or sulfur needs to adjust soil pH?

• A. Soil texture
• B. Soil pH and lime requirement (buffer pH)
• C. Organic matter content
• D. Electrical conductivity

Answer: (B)

To figure out how much lime or sulfur to apply to adjust soil pH, you need to know both where the pH stands now and how strongly the soil resists pH change. The lime requirement, often reported as buffer pH, provides that second piece by indicating how much lime is needed to raise the pH to the target level. In other words, the buffer pH test measures the soil’s buffering capacity and translates it into the amount of lime required to reach the desired pH, making it the best guide for lime applications and for planning sulfur use if you’re aiming to lower pH as well.

Soil texture can influence how quickly pH shifts and how lime or sulfur moves through the soil, but it doesn’t tell you how much to apply. Organic matter affects buffering and nutrient availability indirectly, but it isn’t a direct guide to lime or sulfur rates. Electrical conductivity measures salinity, not pH adjustment. The key is pairing the current pH with the lime requirement from the buffer test to determine proper adjustments.