Fertilization of Hw and Cw

Roderick Negrave PhD, RPF, PAgResearch Section Head, Coast Area

FLNRO, Nanaimo

Topics:

Introduction to results from transitional-site fertilization

Urea-only fertilization of mixed stands

Height, 2000 sph

CW HW CW HW CW HW CW HW0

100

200

300

400

500

600

700

800

900

1000

F0

F1

Heig

ht,

cm

Monoculture

Mixed

Growth Effects:

Fertilizer effect with increased growth appears evident for both species

Hemlock may have increased height growth in mixed-species plantations

Density unanalyzed at this point

Fertilization of Mixed Cw-Hw Stands with

Urea to Promote Cw

New Experiment

Mixed-Species Stands:

Cw and Hw may occur together in juvenile stands

Hw typically grows faster than Cw in these stands

Hw usually dominates the canopy and relegates Cw to a sub-canopy position

Variable Response to Fertilization:

Cw shows good response to urea fertilization

Hw shows variable to no response when fertilized with urea alone

Hw has shown good response to combined applications of urea an P

The Investigation: Paired fertilized and un-fertilized

stands Beginning with 15 pairs Plan to increase this to 60 pairs over 4 years North and west Vancouver Island

Design 0.03 ha plots plus 5 m buffer Randomized block... Post free-growing 250 kg/ha of N as urea (elevated) Focus on height and diameter growth Foliar analysis : P anticipated as a covariate