PRECISION SIDEDRESS UAN APPLICATION FOR CORN PRODUCTION

1. PRECISION SIDEDRESS UAN APPLICATION FOR CORN PRODUCTION Kefyalew Girma Oklahoma State University O k l a h o m a S t a t e U n i v e r s i t y

2. Introduction O k l a h o m a S t a t e U n i v e r s i t y NitrogenLeak

3. Introduction O k l a h o m a S t a t e U n i v e r s i t y Coulter UAN application in corn (Ames, IA). UAN surface application is made within the center of the row, 15 inches away from the base of each stalk. The common use of UAN for sidedress N application in corn is to apply this liquid fertilizer in the middle of rows using either dribble surface bands, or rolling coulter injection.

4. Introduction O k l a h o m a S t a t e U n i v e r s i t y Excavated corn plants showing no overlapping of nodal root systems when corn plants were more than 10” apart, at silking growth stage

5. Objective • to compare three sidedress N placement methods on corn grain yield/where • Evaluate sidedress N rates O k l a h o m a S t a t e U n i v e r s i t y Sense by plant and treat based on yield potential

6. Treatment structure of precision sidedress UAN experiment, Haskell and Lake Carl Blackwell, 2005-2006. O k l a h o m a S t a t e U n i v e r s i t y

7. By-row By-plant O k l a h o m a S t a t e U n i v e r s i t y Between rows

8. Directed Stream Applicator O k l a h o m a S t a t e U n i v e r s i t y Directed stream application of UAN in corn applied at the base of stalk of the plant

9. N W E S 13 5 10 4 15 12 8 9 7 2 3 6 14 11 1 1 14 15 6 5 7 13 9 4 3 8 10 11 2 12 4 5 2 9 10 15 7 8 3 13 12 11 14 6 1 Design and Field Layout Location: Haskell-2005 III II O k l a h o m a S t a t e U n i v e r s i t y I • Plot size 10’ x 20’ with 5’ alley • By plant N rate was determined as: • Calculate UAN/row • Divide the above by number of plants/row

10. Between row and within row by plant corn grain weight variability at Haskell (Hask) and Lake Carl Blackwell (LC), OK, 2005. O k l a h o m a S t a t e U n i v e r s i t y

11. Between row and within row by plant corn grain weight variability at Haskell (Hask) and Lake Carl Blackwell (LC), OK, 2006. O k l a h o m a S t a t e U n i v e r s i t y

12. Martin et al. (2005) Agron. J. 97:1603-1611 Regardless of yield level, plant-to-plant variability in corn grain yield can be expected and averaged more than 2765 kg ha-1 (44 bu/ac) over 46 sites (Ohio, Iowa, Nebraska, Virginia, Mexico, Argentina)

13. Effect of UAN sidedress placement method on corn grain yield O k l a h o m a S t a t e U n i v e r s i t y

14. Effect of sidedress N rates on corn grain yield O k l a h o m a S t a t e U n i v e r s i t y

15. Summary • Within row variability in grain yield was very high • By plant sidedress application of N according to individual plant yield potential would result in improved efficiency and reduced cost to producers • The gain in yields from the three methods ranged from 7 to 25% more than the broadcast treatment in three location-years O k l a h o m a S t a t e U n i v e r s i t y

16. Summary • Under normal growing conditions, N should be sidedressed by plant at a rate of 20-40 lb/A to maintain yield level and decrease loss in fertilizer N concurrent with within row plant to plant variability • Results are not conclusive as the 2006 corn growing season was extremely dry/hot • The experiment will be continued for 1 more year O k l a h o m a S t a t e U n i v e r s i t y

17. Summary • Additional measurements such as ears per plant, 100-seed weight, ear size, plant spacing, and grain N concentration O k l a h o m a S t a t e U n i v e r s i t y

18. THANK YOU! O k l a h o m a S t a t e U n i v e r s i t y