77045 Efficacy of UAN Placement Distance On 15N Uptake and Recovery and Corn Grain Yield.

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Monday, February 4, 2013: 1:45 PM
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Jon M. Carson, Plant and Soil Science, Mississippi State University, Starkville, MS

Title: Efficacy of UAN Placement Distance on 15N Uptake and Recovery and Corn Grain Yield

Authors: Jon M. Carson

Abstract: Improving nitrogen (N) management in corn production has been the subject of considerable research in the past. Current recommendations suggest knifing fertilizer N in the center of the furrow to help prevent root pruning when N is split applied. However, such placement could potentially result in increased N loss, leading to reduced NUE and grain yield. The objective of this research was to evaluate crop N uptake and corn grain yield as influenced by urea-ammonium nitrate (UAN) fertilizer placement distance from the corn row. Treatments included 15N labeled fertilizer applied at 15, 30, and 45 cm distances from the corn row using both surface and subsurface banded application. Fertilizer N was split-applied at 180 kg ha-1, with 50% applied at V3/V4 followed by 50% applied at the V5/V6 growth stage. Data collection included ear leaf samples at vegetative tasseling, and whole plant and grain samples at physiological maturity for determination of 15N recovery, total N uptake, and grain yield. Results from 2011 and 2012 show increased NUE, 15N recovery, and grain yield as N fertilizer is placed in closer proximity to the planted row. In addition, results show that the average total 15N recovery increased 22% and grain yield increased 14% in both growing seasons as N fertilizer placement decreased from 45 to 15 cm from the row. Results from this study indicated an overall combination of fertilizer N placement distance at 15 cm and subsurface banding resulted in greater fertilizer 15N recovery, total N uptake, and corn grain yield both years. Data provided definitive documentation to further optimize in field placement of N fertilizer and maximize profitability.

See more from this Division: Submissions
See more from this Session: Graduate Student Oral Soils