130-1 Uptake Efficiency and Transport of Applied Nitrogen Fertilizers within Douglas-Fir Forests of the Pacific Northwest.

See more from this Division: SSSA Division: Forest, Range & Wildland Soils
See more from this Session: Forest, Range & Wildland Soils: I
Monday, November 3, 2014: 1:35 PM
Long Beach Convention Center, Seaside Ballroom B
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Stephani Michelsen-Correa, School of Environmental and Forest Science, University of Washington, Seattle, WA and Rob Harrison, University of Washington, Seattle, WA
Nitrogen (N) is known to be a limiting nutrient in Pacific Northwest forests, particularly in Douglas-fir ecosystems.  Theoretically, N fertilization should ameliorate these deficiencies and increase tree growth.  However, previous studies have shown that of the total N applied, the surrounding trees absorb only between 12-43%.  This study is composed of 10 sites along the western Douglas-fir region of Oregon and Washington.  These sites were selected to include the range of parent materials and latitudes of plantation forests in the region.  A complete randomized block design was used where each installation is a replicate that includes five treatment plots.   The plots were treated with 15N-enriched Urea, Agrium ESN, Urea + NBPT, or Urea + CUF type fertilizers.  The remaining plot was an unfertilized control.  The fertilizers were enriched to 0.5AP 15N (~370 0/00 15N).  Using a fertilizer enriched with 15N, the nitrogen is traced as it moves between pools within the study area.
See more from this Division: SSSA Division: Forest, Range & Wildland Soils
See more from this Session: Forest, Range & Wildland Soils: I