Research Branch

See below to download.

Douglas-fir Fertilization with Biosolids: Five-year Results at Whistler, B.C.

Author(s) or contact(s): L. de Montigny and S.C. Stearns-Smith
Source: Research Branch
Subject: Fertilization
Series: Extension Note
Other details:  Published 2001. Hardcopy is available.


Biosolids at 750, 1000, and 1500 kg-n/ha and conventional fertilizer at 225 kg-n/ha were applied in each of three seasons (spring, summer, and fall) to a 15-year-old coastal Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) plantation that had recently been precommercially thinned and pruned. Five-year results showed that rate and timing effects were independent. No height-growth response was evident, but annual diameter growth for all biosolids treatments averaged three times higher than for conventional fertilizer. Seasonal application differences were small but statistically significant. All plots, including the controls, experienced extensive top damage from snow and ice. Similar to growth, damage was greatest with biosolids fertilization. The study shows promise for biosolids fertilization as a viable alternative to conventional fertilization, but application in locations prone to snow and ice damage should be avoided.

Download Extension Note 50 PDF file (72 KB)

To view this document you need the current version of
Adobe Acrobat Reader, available free from the Adobe Web Site.

Updated April 19, 2007