In the Thunder River drainage, north of Blue River, the initial results of a fertilization trial on Thuja plicata (western redcedar) and Picea glauca x engelmannii (hybrid spruce) have been completed. The study was established in the spring of 2003. Two hundred planted seedlings of each species in the trial were fertilized with a teabag fertilizer; an additional two hundred seedlings of each species were identified as controls. One hundred of each of the fertilized and control seedlings, by species, were planted on the site in broadcast burned ground; the same density was planted 'as is' in ground that had no site preparation. The purpose of the trial is to determine if fertilization at the time of planting will both increase seedling height and caliper, and result in the reduction or elimination of broadcast burning and, or brushing, and promote the achievement of minimum free-growing heights at an earlier date. The trial is also set-up to evaluate the efficacies of broadcast burning and fertilization with respect to each other. The initial results of the trial indicate that both species present a moderate response to fertilization. Fertilized hybrid spruce planted 'as is' and on broadcast burned ground display notable height growth increases of 7 and 6 percent over their respective controls. Western redcedar have not responded as greatly to fertilization where stock on plant 'as is' ground has an increase in height of 3 percent and stock planted on burned ground has an increase of 1 percent over their respective controls. Fertilized spruce also has the biggest increase in caliper on both planting mediums over the controls; this finding is statistically significant. Trees on plant 'as is' ground are 12 percent larger, and trees on burned ground are 11 percent larger. Fertilized cedar also displays gains over its controls. Trees on plant 'as is' ground are 2 percent larger, and trees on burned ground are 3 percent larger. Overall fertilized stock on plant 'as is' ground has yielded the greatest height and caliper gains in the first growing season. When broadcast burning without fertilizer was compared to planting 'as is' with fertilizer, it was found that heights were lower for both species, however calipers were increased. The results of Foliar Analysis indicate that both of the species have benefited from fertilization with increased levels of macro and micronutrients over the controls. By species, hybrid spruce shows the greatest initial response. By treatment, seedlings planted in the broadcast burned area without fertilizer had higher nutrient concentrations than the fertilized seedlings planted 'as is'. Initial results indicate that greater tree growth can be expected from fertilizer treatments. Results from future growing seasons are expected to confirm that fertilization at crop establishment results in more robust crop trees that are better suited to compete with vegetation and have the potential to achieve free-growing at an earlier date than would otherwise be expected. How planting 'as is' with fertilizer compares to broadcast burning without fertilizer is unknown and will continue to be assessed following future growing seasons Second Growth Consulting Ltd.
Second Growth Consulting Ltd.. 2004. Teabag Fertilization at Planting on Thuja Plicata, and Picea glauca x engelmannii: first growing season results - Thunder River. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2004MR123