Canadian Forest Service Publications
Containerized black spruce seedling development under exponential fertilizer additions. 1993. Burgess, D.M.; Hay, D.; Etheridge, P. Pages 54-58 in F.P. Donnelly and H.W. Lussenburg, Compilers. Proceedings of the 11th Annual Conference of the Forest Nursery Association of British Columbia, September 23-26, 1991, Prince George, BC. Forest Nursery Association of BC, Victoria, BC.
Issued by: Pacific Forestry Centre
Catalog ID: 4435
Availability: PDF (request by e-mail)
Black spruce second-crop seedlings are grown usually on a tight schedule and are not always of acceptable size for outplanting. Their nutrition is typically not closely controlled and therefore application of Ingestad's concept of relative addition rate was examined. Seedlings were fed twice weekly following two different rates (2.5 and 4% per day) of exponentially increasing fertilizer dosages and compared with normal production stock. Black spruce seedlings grew fastest and had significantly more root development when fertilized using exponentially increasing fertilizer dosages and nitrate was the main nitrogen source, but the 4% treatment seedlings also had higher shoot:root ratios. During the hardening phase, nitrate was more thoroughly leached from the growing medium and resulted in a greater decline in foliage nitrogen concentration in those seedlings that had been fed at exponential rates, suggesting that the fertilizing schedule normally used during their hardening phase may need modification.