Sulfuric acid generated on leaves and in thatch can damage foliage and destroy crowns. Contact with the soil buffers the decrease in soil pH around the S particle so this damage is limited. Faster reaction of incorporated S in comparison to surface applied S occurs because of higher soil moisture levels. Sulfur oxidation requires good moisture which is more prevalent in the soil than in the thatch or on the leaf surface. Plenty of irrigation water should be applied to wash the S from the turfgrass leaves after any method of application.
Incorporated applications acidify a larger portion of the root zone than surface applications.
Elemental S is immobile in the soil so surface applications remain on the soil surface. Even after the S is oxidized the acidity produced is slow to move into the root zone. Consequently severe decreases in pH may occur in the thatch layer and immediate soil surface with little impact on the remainder of the root zone. Using S on soils of lower pH is usually not necessary and can be dangerous due to over-acidification. Calcium should be added to soils dominated by sodium at the same time soil pH is lowered with S. Sulfur rates should be low to avoid damage to the crowns of the turfgrass plant.