A Central Illinois agronomist has observed potassium deficiency in corn.
This was especially noticeable earlier in the season when the outside edge of a leaf turned yellow with an occasional red band. Corn plants take up 90 percent of potassium from the knee-high growth stage to tassel.
“That deficiency, because of those tight dry soils back in that time period, has not limited the amount of potassium in that plant and now we are seeing nitrogen deficiency show up in those same trials, plots and fields,” explains Ed Corrigan, a technical agronomist with Brandt in Springfield.
Potassium is an element which actually makes nitrogen more efficient, Corrigan notes. You will likely notice more deficiencies during the next month or so.
“Zinc has some of those same characteristics of stopping disease that potassium does but it also assists with nitrogen efficiency,” added Corrigan.
Many Central Illinois growers have become more aware of the need to put down potassium. It can be applied in the fall and does not hurt the environment, actually stopping diseases in both soybeans and corn. Corrigan recommends applying at least 100 pounds per acre every year.
“Our soil tests are continuing to go lower in potassium in most situations because we are pulling off these huge crops.”
Corrigan believes a majority of the corn and soybean crops look good throughout our area, which leads to the likelihood of strong yields come harvest. Those developing crops need decent sunshine to finish out over the next 30 days.