105-9 No-till Corn Response to Shallow Placement of Anhydrous Ammonia.

See more from this Division: S04 Soil Fertility & Plant Nutrition
See more from this Session: Nitrogen and Crop Production: I
Monday, November 1, 2010: 10:40 AM
Long Beach Convention Center, Room 201B, Second Floor
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Fabian Fernandez, 1102 South Goodwin Avenue, University of Illinois, Urbana, IL, John E. Sawyer, Iowa State University, Ames, IA, David B. Mengel, Kansas State University, Manhattan, KS and Joshua Stamper, Syngenta Seed, Waterloo, NE
Anhydrous ammonia (AA) is used extensively in the Midwest USA as a source of nitrogen (N) for corn (Zea mays L.) production. As farm size increases there is a need to enhance speed of N application without sacrificing efficiency. The objective of this study was to compare a traditional AA knife injection system (TRAD) and a prototype high-speed, low-draft AA opener system (HSLD). This study was conducted in no-till fields following soybean (Glycine max. L. Merr.) during 2007- 2009 in Illinois, Iowa, and Kansas. A factorial arrangement of the two AA systems (TRAD and HSLD), three application times [fall (FA) only in 2008-09, spring pre-plant (SP), and sidedress (SD)], and five N rates (0, 90, 135, 180, and 225 kg N ha-1) was replicated four times in a split-plot arrangement with time of application as the main plot in a randomized complete block design. FA and SP applications were in-row (future corn row), while SD was between every other row. The TRAD application was at 18-cm depth and 10 km hr-1 and the HSLD at 10-cm depth and 13 to 16 km hr-1. Corn yield increased with increasing N rate. Yield with the FA application was 11.1 Mg ha-1, 3.7 and 3.5% lower than SD and SP applications, respectively.  Across N rates, yield with the TRAD was 3.4% higher compared to the HSLD with SP application (5.5% higher, 665 kg ha-1, with the highest N rate), but no difference with other application times. This reduction was likely caused by N loss and/or seedling injury with the shallow AA positioned spring preplant in-row. In-season plant measurements produced similar results to those with grain yield. The HSLD is a viable alternative to TRAD when soil conditions are adequate for proper operation of the HSLD and application is not near the seed-row.
See more from this Division: S04 Soil Fertility & Plant Nutrition
See more from this Session: Nitrogen and Crop Production: I