Drought and Potassium Deficiency in Corn and Soybean

Since potassium is mobile in plants, yellowing along leaf margins starts in the lower leaves and progress toward the top. In plants, potassium activates as many as 60 enzymatic and plant hormonal reactions, regulating many physiological and biochemical processes. Potassium also regulates the opening and closing of leaf stomates responsible for water and gas exchange. Therefore, adequate potassium levels are needed to keep plants from being susceptible to drought.

As it approaches time to plant corn and soybean or as corn is coming up, producers need to be able to properly identify potassium deficiency in corn and soybean. This extension bulletin from Michigan State University Extension gives a detailed description of physical deficiency symptoms, as well as, physiological stresses. This publication came out in July 2016, when most areas were experiencing drought. However, producers should still be aware of potassium deficiency symptoms.