Canadian Forest Service Publications
Response of young Douglas-fir to urea fertilizer applied on and off snow. 1994. Marshall, V.G.; Barclay, H.J. The Forestry Chronicle 70(3): 294-298.
Issued by: Pacific Forestry Centre
Catalog ID: 3425
Availability: Not available through the CFS (click for more information).
The effects of 200 kg N ha-1 applied as urea fertilizer on 50 cm of snow or on bare ground were studied in an 11-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantation on Vancouver Island. Analysis was done on all trees per plot and on 20 selected dominant trees per plot. Up to 2 years after fertilization, urea significantly increased absolute DBH increments over controls in all trees and the 20 selected trees per plot; response to fertilization on snow was equal to that on bare ground. Between the 3rd and 9th year following fertilization, mean DBH increments were not significantly different for any treatment. Four-year absolute volume increments were 63 and 87% greater than the controls for bare-ground and on-snow applications, respectively. A positive and quantitatively similar response is expected in wetter coastal Douglas-fir stands whether urea is applied on snow or under better conditions during other seasons.