The Effects of Levels and Times of Fertilizer Application on the Growth of White Spruce Seedlings

Abstract

AbstractFour levels of nitrogen and phosphorus were added in combination on three different time schedules to white spruce seedlings during their second growing season. The three time schedules were: (1) “Periodic,” in which fertilizer was applied in five dressings from May to September; (2) “Normal,” in which fertilizer was applied in May, June, and July; and (3) “Summer and Fall,” in which fertilizer was applied in May, June, and September.Seedling dry weight increased with increasing level of fertilizer application but was not significantly affected by time of application. Seedling height showed a general increase with increase in amount of fertilizer. Shoot/root ratios increased with increasing level of fertilizer, however, by using a “Periodic” time schedule the increase was minimized. Nitrogen concentrations and contents in the foliage increased with increase in fertilizer level and “Periodic” and “Summer and Fall” applications resulted in larger concentrations than did those under the “Normal” time schedule. Foliage concentrations of phosphorus were not affected by any of the treatments.