Both elements tend to leach downward and accumulate with the clay in the sub-soil. Medium to high levels of these elements in the top-soil should be adequate for the corn crop. Both magnesium and the sulfate form of sulfur are added from irrigation water supplied by most wells. Soil tests for sulfur are not very useful in predicting plant needs. Most S in soils is in unavailable forms associated with organic matter and clay.
Sulfur is released in small amounts as sulfates at various times throughout the year.
Sulfate-S may be either taken up by plants or leached downward, especially in sandy soils. Total nutrient analysis of the leaves is useful in evaluating the S status of plants. Low levels of s may exist in plants early in the growing season but be adequate later on. Dolomatic lime 2. Potassium magnesium sulfate 3.