Researchers from Kansas State and Purdue universities say that it takes more than just high nitrogen uptake levels for corn to hit its maximum yield potential. This news release from Kansas State says the work found that nitrogen, potassium, and phosphorus uptake needs to be in the proper ratio.
This is one of the main findings of a comprehensive review of corn research in the United States and worldwide over the past 100 years by cropping systems specialists, Ignacio Ciampitti of Kansas State University, and Tony Vyn of Purdue University.
“The highest corn yields, if there are no other limiting factors, are when nitrogen and potassium uptake is in a 1-to-1 ratio and nitrogen and phosphorus uptake is in a 5-to-1 ratio,” Ciampitti said. “Having the right nutrient balance within the plants is more important to increasing yields than just applying extra nitrogen.”
Those nutrient uptake ratios are measured in aboveground portions of the corn plant soon after physiological maturity is reached, he added. The ratios will be different at other stages of growth.
Corn takes up a higher percentage of its potassium (K) earlier in its life than nitrogen (N). By the flowering stage of development, corn has absorbed about 80 to 90 percent of its total seasonal K amount, but only 50 to 60 percent of its total seasonal N uptake, Ciampitti said.
As a result, as the season progresses, the N:K ratio in the plant gradually gets larger. At maturity, high-yielding corn has a ratio of about 1-to-1.
The research also found that the nitrogen:phosphorus (P) ratio was also an important factor to consider, as is an integrated approach to improving corn yields.