Greg La Barge, Extension Agent, Agriculture and Natural Resources
To observe yield response when 28% UAN and 82% anhydrous ammonia are supplied at different rates on lakebed soils. Observe yield response to corn-corn and soybean-corn rotations.
| Cooperator: | Hoytville Branch, | Fertilizer: | See Treatments |
| OARDC | Planting Date: | June 1, 2002 | |
| County: | Wood | Planting Rate: | 30,000 seeds/A |
| Nearest Town: | Hoytville | Row Width: | 30-inch |
| Drainage: | Tiled | Herbicides: | |
| Soil type: | Hoytville clay | Soybean-Corn: | Degree Extra 3qt A, |
| Tillage: | Conventional till | Atrazine 1 pt/A, Sterling | |
| Previous Crop: | See treatments | 6oz/A, Crop oil 9.6 oz/A | |
| Variety: | Pioneer 34B24 | Corn-Corn: | 2,4-D Ester 1pt/A, |
| Soil test: | Harness 2.75 pt/A, | ||
| Soybean-Corn: | Princep 1qt/A, | ||
| pH 6.5, P 87 ppm, | Roundup 32 oz/A, | ||
| K 370 ppm | POST application-Accent | ||
| Corn-Corn: | 14g/A | ||
| pH 6.5, P 95 ppm, | Harvest Date: | October 31, 2001 | |
| K 379 ppm |
This is the fifth-year result of a multi-year nitrogen study on corn at OARDC, Hoytville. Starter nitrogen at the rate of 40 lbs. actual nitrogen per acre was applied in a 2 x 2 placement to all plots. Plot design was a randomized split block design with four replications. Main plots were the rates of nitrogen applied. Subplots were the two sources of sidedress nitrogen. Each subplot consisted of four rows 70 feet long in which the center two were harvested for grain yield.
At V5-V6 stage of corn growth, 28% urea ammonium nitrate (UAN) and 82% anhydrous ammonia was applied at 0, 20, 80, 140, and 200 pounds of N per acre to make a total nitrogen application of 40, 60, 120, 180, and 240 pounds of actual N per acre. The 28% UAN was applied with a solid stream injector behind a no-till coulter.
In 2000, a second series of plots following corn were added to the experiment to separate out the nitrogen contribution from soybeans as a previous crop. This is the second year of this addition.
Table 1. 2001 Corn Yields Resulting from Nitrogen Rates by Crop Rotation.
| Total Nitrogen | Yield | Yield |
| Rate(lbs/A) | (bu/A) | (bu/A) |
| Soybeans-Corn | Corn-Corn | |
| 40 | 81.2 | 82.8 |
| 60 | 82.7 | 89.9 |
| 120 | 95.9 | 86.0 |
| 180 | 87.7 | 92.8 |
| 240 | 87.7 | 96.8 |
| LSD (0.05) | NS | NS |
| F test | 1.2 | 1.3 |
Table 2. Comparison in Yield from the Two Sources of Nitrogen by Crop Rotation.
| Yield | Yield | |
| Source | (bu/A) | (bu/A) |
| Soybeans-Corn | Corn-Corn | |
| Anhydrous Ammonia | 86.4 | 91.9 |
| 28% UAN | 87.6 | 87.4 |
| LSD (0.05) | NS | NS |
| F test | 3.6 | 1.9 |
The drought of 2002 had a significant impact on the nitrogen plot and overshadowed any treatment effects of the nitrogen. The four-year yield average on these plots was 173 bushels for 1998-2001. The average yield this year is 87 bu/A. Stalk nitrogen tests were taken on two replications, and the results showed very little residual N in the base of the stalk. The harvest height of the corn was less than four feet. In addition to the drought, the planting date of June 1 is a month later than normal due to wet soil conditions that occurred up to that time.
No significant differences in yield were noted with the two sources of nitrogen fertilizer in the soybean-corn plot or the corn-corn in 2002. There was no significant interaction effect for nitrogen source by nitrogen rate for either rotation.
A big thank you goes to Matt Davis and the crew at the Custer OARDC Branch for their assistance on this project. Thanks also go to Phil Rzewnicki for providing the statistical analysis and Ed Lentz for providing input into this project.
For additional information, contact:
Greg La Barge
Ohio State University Extension, Fulton County
135 Courthouse Plaza
Wauseon, OH 43567
419-337-9210
labarge.1@osu.edu