Alan Sundermeier, Extension Agriculture and Natural Resources Agent
To evaluate corn response to N-serve stabilized nitrogen and soil nitrogen availability with N-serve.
| Cooperator: | Carlton Meyer | Variety: | Wellman 1560 |
| County: | Henry | Seeding Rate: | 32,000 seeds/A |
| Soil Type: | Hoytville clay loam | Planting Date: | May 10, 2001 |
| Tillage: | Fall strip tillage | Harvest Date: | November 5, 2001 |
| Previous Crop: | Soybeans | Herbicide: | Dual |
A field was set up to compare fall-applied NH3 with N-serve to fall-applied NH3 with no N-serve in three replications with a randomized complete block design. All other inputs were the same. Treatment plots were 800 feet long and 12 rows wide. Anhydrous ammonia was applied in the fall at a rate of 180 lb/A of actual N with N-serve plus dry fertilizer of 20-48-85 (N-P-K) with strip tillage in a single pass on November 5, 2000.
Soil samples were taken on March 30, May 4, and May 29 of 2001. Samples were taken at depths of 0 to 12 inches and 12 to 24 inches in areas with and without N-serve. A&L Laboratories, Fort Wayne, Ind., conducted the analysis. At corn maturity (black layer), corn stalk nitrate samples were taken and analysis conducted by A&L Lab. Eight inches of stalk segment located six inches above ground were taken from three random sites in each plot. The data reported here is the average of multiple replications. Yield data was based on the center six rows along the full length of each plot being combined using a yield monitor. Corn yields were adjusted to 15.5% moisture.
| Table 1. Soil Nitrate and Ammonium Levels at Two Soil Depths on Three Sampling Dates. | ||||||||
| Nitrate (ppm NO3-N) | Ammonium (ppm NH4-N) | |||||||
| Sample Dates |
0- to 12-inch depth | 12- to 24-inch depth | 0- to 12-inch depth | 12- to 24-inch depth | ||||
| N-serve | No N-serve | N-serve | No N-serve | N-serve | No N-serve | N-serve | No N-serve | |
| 3/30/01 | 24.0 | 23.5 | 10.0 | 7.5 | 44.0 | 69.5 | 6.0 | 9.0 |
| 5/4/01 | 62.7 | 69.7 | 22.7 | 15.3 | 36.0 | 55.0 | 4.0 | 5.0 |
| 5/29/01 | 20.0 | 24.0 | 15.3 | 12.3 | 11.0 | 23.0 | 2.7 | 4.0 |
| Average | 35.6 | 39.1 | 16.0 | 11.7 | 30.3 | 49.2 | 4.2 | 6.0 |
| LSD (0.05) | 9.4 | 6.7 | 16.8 | 2.7 | ||||
| CV (%) | 7.1 | 13.7 | 12.1 | 14.9 | ||||
All of the above data were averages of multiple samplings of the replicates. There were wide variations of soil readings within many soil sample sites.
| Table 2. Corn Stalk Nitrate and Yield. | ||
| Stalk Nitrate | Yield | |
| ppm | bu/A | |
| N-serve | 200 | 128.5 |
| No N-serve | 100 | 116.6 |
| LSD (0.05) | 430 | 17.6 |
| CV (%) | 81.6 | 4.1 |
Soil nitrogen testing was inconclusive because of wide variation within specific sample sites. Average ammonium levels were significantly higher for the No N-serve treatment in the top 12 inches. This does not follow the expected nitrification inhibiting benefits of N-serve. By inhibiting nitrification one would expect a reduction in the microbial conversion of ammonium to nitrate.
Excessive rainfall in mid-May resulted in less than adequate soil nitrogen levels on May 29. Lack of rainfall in August may have caused corn plants to cannibalize stalk nitrate nutrients, resulting in very low corn stalk nitrate levels by maturity. Corn yields were not significantly different with or without N-serve nitrogen stabilizer.
For additional information contact:
Alan Sundermeier
Ohio State University Extension, Henry County
104 E. Washingston St., Ste 107
Napoleon, OH 43545
419-592-0806
sundermeier.5@osu.edu