Abstract To test the effects of late nursery fertilization on outplanted 2-0 Douglas-fir, seedling lots from five seed sources, half of each fertilized with 50 pounds of nitrogen per acre and half unfertilized, were outplanted at the University of Washington's Pack Forest. Survival and leader growth were recorded for five years (1957-1961), total height measured in 1961, and the data analyzed statistically. Application of nitrogen fertilizer in the nursery late in the growing season significantly increased field survival. Survival varied with seed source, but was influenced by planting blocks. Fertilized trees grew faster than unfertilized trees as measured by leader growth. Fertilized trees were taller than unfertilized trees at th end of five years, but height was influenced by planting blocks. Effects of fertilization were more pronounced in the slowest growing block.
Anderson et al. (Tue,) studied this question.