Abstract
dc:description.abstractIncreased nitrogen (N) costs and environmental concerns have created a need to reevaluate current sidedress N application recommendations for corn. Injection of Urea Ammonium-Nitrate (UAN) may reduce N-loss via ammonia (NH?) volatilization compared to current surface application methods. This study evaluated injection and surface-banding application techniques of UAN in two ways: (1) by conducting a laboratory experiment where NH?-N loss was measured from UAN applied by both techniques across varying residue covers; and (2) by performing a field study where the application methods were compared by their effect on corn grain yield, ear leaf tissue N content, and stalk nitrate (NO3). The laboratory system used to compare the NH?-N loss from the UAN application methods was evaluated and found to be capable of providing rapid, accurate, and precise measurements of N loss throughout a range of N rates and conditions. In the laboratory study, injection of UAN reduced NH?-N losses to <1% of applied N. Surface-banding of UAN resulted in NH?-N losses between 15.3 and 32.5% of applied N. Results from the field study suggest that differences between application methods were commonly seen in ear leaf tissue N, where injection of UAN was often found to increase tissue N compared to surface-banding. Also, injection of UAN reduced the optimal N rate by 25 kg N ha?? compared to surface-banding. The results suggest that injection of UAN reduces the potential of NH?-N losses and is a practice worth considering in developing an efficient N fertilizer program.
Degree
thesis:*- Name thesis:degree_name
- Master of Science
- Level thesis:degree_level
- masters
- Discipline thesis:degree_discipline
- Crop and Soil Environmental Sciences
- Department dc:contributor.department
- Crop and Soil Environmental Sciences
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 2011
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Woodward, Timothy Ryan
- Chair dc:contributor.committeechair
-
- Alley, Marcus M.
- Committee members dc:contributor.committeemember
-
- Thomason, Wade E.
- Reiter, Mark S.
- Davis, Paul H.
Subjects
dc:subject × 5Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
- Language dc:language.iso
- en_US
Identifiers
dc:identifier.*- Dc Identifier Other
- etd-06162011-093454
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/76800