Quantifying Foliar and Soil Uptake of Granular 15 N-Labeled Urea by Corn

Core Ideas Foliar uptake of nitrogen from granular urea placed in the corn whorl can be significant over short time periods. Foliar nitrogen applications cannot provide season total corn nitrogen requirements. Nitrogen recovery efficiency of whorl‐applied urea can be as high as 16.6% in the 11 d following application. Corn ( Zea mays L.) “green‐up” in the absence of rainfall or irrigation following broadcast applications of urea led to the...