Canadian Forest Service Publications

Response of a 50-year-old Douglas-fir stand to urea fertilization. 1970. Mitchell, K.J.; Kellogg, R.M. Government of Canada, Department of Fisheries and Forestry, Forest Research Laboratory, Victoria, BC. Information Report BC-X-045. 20 p.

Year: 1970

Issued by: Pacific Forestry Centre

Catalog ID: 26478

Language: English

Series: Information Report (PFC - Victoria)

Availability: Order paper copy (free), PDF (download)

Mark record


Stem analyses were carried out on 96 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees, five years after treatment with LOO and 200 lb of nitrogen per acre. A small growth response in ring-width, lasting four years and possibly longer, was evident the year after treatment in trees of the 8- to 16-inch d.b.h, class. The response was small and quite variable over the length of the bole in the 16- to 20-inch d.b,h, class and was undetectable in the 4- to 8-inch d,b.h, class.

In the five years after fertilization, the total volume of the treated trees in the 8- to 16-inch d,b,h, class increased by 22% , only 1.5% more than the volume added by control trees in the same period. The average volume response of trees in the other d.b,h. classes was negligible. The treatment did not affect the proportion of latewood.