Soil Buffer PH.pdf

Concern is being expressed about soil buffer pH, particularly for sand-based golf putting greens and tees. Soil pH is measured by immersing a hydrogen ion sensitive glass electrode in a soil-liquid suspension, and the reading depends on the ratio of soil to liquid and the composition of the liquid. Different soil testing labs use different soil to liquid ratios, which can lead to conflicting results. Soil pH measured in a dilute salt solution is referred to as "salt" pH, which is lower than soil pH in pure water.

Soil pH buffering is the ability of soil to resist changes in pH, and it is determined by the amount of organic matter present. Sand has virtually no pH buffering capacity, making its pH uncontrollable and prone to fluctuation. Soil buffer pH is an estimate of the amount of acidity in soil, which depends on the existing pH and the amount and nature of organic matter present. It is not a measure of actual soil pH, and two soils with the same pH can have different buffer pH values. The author questions the recent concern about soil buffer pH, stating that salt pH is a better estimate of the actual pH of the soil.