Out in the field, plants don’t so much earn their stripes, they dread them. And this year is raising more alarms than others because yellow striping has been cropping up more often than in the past. In a publication released this month, Purdue Extension soil fertility specialist Jim Camberato points to a likely culprit: sulfur deficiency.
“We used to get quite a bit of sulfur from rainfall. The power plants would burn coal that had sulfur in it, so sulfur would be deposited in rainfall or absorbed directly from the air by the soil,” Camberato said in a document posted on Purdue’s website. “But over the last 20 to 25 years, these emissions have been reduced, so perhaps now the amounts in rainfall and atmosphere deposition are low enough that plants are not getting enough that way anymore.”
Weather and temperature also play a role in the availability of soil sulfur. Purdue explains that usable inorganic sulfur is mineralized, or released from organic matter, by microorganisms in warm, moist soil, so if weather is cold and dry, this process will be inhibited. Purdue has done extensive research on the subject.
While testing shows sulfur levels are a good possibility for the yellow, or yellow-white striping on the leaves of corn plants that farmers are currently seeing, it isn’t always the culprit — a variety of nutrient deficiencies can cause damage.
When yellow striping occurs on corn leaves, it is best to send soil and tissue samples to a private lab for nutrient analysis, Camberato said on Purdue’s website. Samples should be taken from both healthy and affected areas of the field for comparison, and it’s prudent to also test for deficiencies in magnesium, zinc, manganese and iron.
There are several fertilizers available to correct deficiencies.