The Effect of Multiple Small Applications of Nitrogen on Yield and Uptake Efficiency in Corn.

The Effect of Multiple Small Applications of Nitrogen on Yield and Uptake Efficiency in Corn Carl R. Snyder1, John Benjamin1, and Dr. Natasha E.Macnack1 1University of Wisconsin River Falls ABSTRACT Increased nitrogen (N) uptake in corn may be accomplished by applying smaller applications of fertilizer throughout the growing season. An increase in N use efficiency would save the grower valuable dollars and prevent excess N from entering into local water supply. The purpose of this field experiment is to evaluate the effect of N application frequency on yield and N use efficiency in corn. The experiment will be conducted at the University of Wisconsin River Falls (UWRF) Mann Valley Laboratory Farm. Treatments will be laid out in a randomized complete block design with three replications. Urea-N fertilizer will be applied to five treatments at a rate of 210 lbs. N/acre applied at different growth stages and in different portions and one treatment will receive no N fertilizer (control). Treatment 2 will have two applications, one pre-plant and one at V5, with each application being half of the recommended rate. Treatment 3 will have a first application of 1/3 the recommended rate applied preplant and a second application of 2/3 the recommended rate applied at V5. Treatment 4 will have two applications, the first at preplant will be 1/4 of the recommended rate and the second will be 3/4 of the recommended applied at V5. Treatment 5 will have three applications of 1/3 the recommended rate applied at preplant, V5, and V8. Treatment 6 will have four applications of 1/4 the recommended rate of N applied at preplant, V5, V8 and V10. An application of Potassium Chloride will be applied to the entire trial area at a recommended rate of 20 lbs K2O/acre. Results will show that increased N use efficiency and yield can be achieved when multiple small applications of N fertilizer are issued to the crop versus the conventional method of applying a larger single rate of fertilizer.