Canadian Forest Service Publications
Essai d'un dosage d'azote dans trois sapinières de 60 ans au Québec : résultats de 10 ans. 1980. Roberge, M.R.; Gagnon, J.D.; Ung, C.-H. Canadian Journal of Forest Research 10 : 470-475.
Available from: Laurentian Forestry Centre
Catalog ID: 14721
Net merchantable volume and diameter growth and changes in various properties of the humus horizon of three natural balsam fir stands have been observed during 10 years following the addition of 112, 224, and 336 kg/ha of nitrogen urea. The net growth in merchantable volume as a result of fertilization was 21 m3/ha with 112 kg/ha of nitrogen, and slightly more with 336 kg/ha of nitrogen. Diameter growth due to fertilization was maximum with 112 kg/ha of nitrogen then reaching 0.5 cm more than in the control. The chemical and microbiological properties of the humus horizon were more and more improved with an increase in the amount of nitrogen added, and this improvement was still easily observec 10 years after fertilization. Sample plots smaller than 0.04 ha did not allow us to determine ferlization effects with a satisfactory accuracy. According to the results obtained, the optimum amount of nitrogen to add as urea for a maximum growth would be less than 224 kg/ha. For an optimum improvement in the humus properties, the amount should probably not be over 336 kg/ha.