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  • Utility of in situ ion‐exchange membranes to assess nutrient availability, productivity, and fertilizer response of coastal Douglas‐fir of the Pacific Northwest
Title: Utility of in situ ion‐exchange membranes to assess nutrient availability, productivity, and fertilizer response of coastal Douglas‐fir of the Pacific Northwest
Abstract Douglas‐fir [Pseudotsuga menziesii(Mirb.) Franco] is the predominant forest plantation species in the Pacific Northwest (PNW), with site productivity and fertilizer response influenced by climate and soil variations. This study investigates the utility of in situ 12‐week supply measurements of nitrogen (N), calcium (Ca), and phosphorus (P) to ion‐exchange resins (specifically Plant Root Simulator [PRS] probes) to estimate carbon (C):N ratios, soil nutrient contents (0–1 m), foliar nutrient concentrations, Douglas‐fir productivity (site index and basal area mean annual increment), and fertilizer volume response. PRS nutrient supply rates were correlated with N, Ca, and P soil nutrient contents (0–1 m), C:N ratios, and foliar nutrient concentrations. Low PRS NO3supply rates (<25 mg N·m−2·burial period−1) were correlated with lower Douglas‐fir productivity and greater fertilizer volume response. PRS NO3supply rates performed as well as total soil N contents and foliar N concentrations at estimating volume growth response to fertilizer. Twelve weeks after fertilization, PRS NO3, NH4, and Ca supply rates were significantly elevated compared to the unfertilized treatment. This research found that PRS probes were an effective in situ tool and are recommended for understanding N, Ca, and P nutrient availabilities, site productivity, and fertilizer response in Douglas‐fir plantations and for developing fertilizer prescriptions.  more » « less
Award ID(s):
1916155
PAR ID:
10585232
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Wiley
Date Published:
Journal Name:
Soil Science Society of America Journal
Volume:
88
Issue:
3
ISSN:
0361-5995
Page Range / eLocation ID:
565 to 583
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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