Federal clean air policies are potentially having an impact on Pennsylvania Farms. Soil test data showing a downward trend in sulfur soil test levels and deficiencies are indeed possible.
Are your cornfields off color in higher parts of the corn field and better in the lower lying areas? Some of our corn plants have yellow striping though out the corn leaves. Often the striping is found on younger leaves. One issue could be sulfur. For the past decades Pennsylvania has had adequate levels of Sulfur to grow agronomic crops. However, with the cleanup of acid rain we are starting to see more sulfur deficiencies in corn.
Sulfur is not readily remobilized from older plant parts to younger plant parts. Often sulfur deficiency is characterized by a yellowing of the younger leaves at the top of the corn plant. Typically, sulfur deficiency symptoms are not expressed uniformly across the field, but rather the symptoms are present in spots or streaks across the field. In this case where we had a sandy type soil the symptoms where located in areas where the least amount of organic matter was present. With this year’s heavy spring rain Sulfur could be easily leached from the root zone.
The plant nutrients taken up by crops during the growing season may come from many sources, including soil reserves, added fertilizer or manure, and crop residues. Sulfur deficiency is most likely on sandy, low organic matter soils and on soils that do not receive manure. Manure is a good source of sulfur, so even with reduced atmospheric sulfur, most crops on farms with manure are not likely to be sulfur deficient.
Often the striping is found on younger leaves. This particular corn field soil sulfur level was 9.2 ppm. The plant tissue was low with .18 %. Ammonium sulfate, or Ammonium thiosulfate are additives that can be used to increase you sulfur levels.
Source : psu.edu