1. Scarification and Fertilization of Western Redcedar
and Western Hemlock
R.W. Negrave
Coast Forest Region

2. Scarification and Fertilization Treatments at SCHIRP
Study Design
Findings
Application to management

3. Treatments Two sites: CH and HA Two species: Cw and Hw
Fertilized and un-fertilized treatments:
225 kg/ha as urea
100 kg/ ha as triple superphosphate
NPK at planting
Scarified and un-scarified treatments:
Hoe-raking treatment to remove salal

4. Plots and Measurements
Treatments replicated 4X: 64 plots total
Measurement trees per plot: 64
Established in 1988, analyzed from 2002 data: 15 growing seasons
High planting density: sph

9. Findings Fertilization greatly increased growth Scarification:
Increased growth but less than fertilization
Fertilization-only treatment best on HA sites
Enhanced fertilizer response on CH sites
Tree nutrition was not enhanced by either fertilization or scarification*

19. Applications to Management
Fertilization gives greater effect than light scarification
Heavier mechanical treatment* plus fertilization may give greater response on CH
Planting density appears critical on CH sites