Fourteen-year growth response of young lodgepole pine to repeated fertilization

Abstract

Four rates of N (0, 50, 100, and 150 kg·ha -1 ) with and without a fertilizer mix containing P, K, S, Ca, Mg, and micronutrients were applied to a stand of 8-year-old lodgepole pine (Pinus contorta var. latifolia Engelm.) in four applications during 7 years. Fourteen years after the first fertilization, mean tree basal area and volume were significantly increased in the treatments containing the two highest rates of N plus the fertilizer mix. Mean tree basal area was 38% greater and mean tree volume was 42% greater in the highest N (525 kg·ha -1 ) plus mix treatment than in the control treatment. Stand basal area increased 48% over the control in the highest N plus mix treatment. Mean tree basal area and volume were 27 and 25% greater than the control under the intermediate N rate (350 kg·ha -1 ) with mix, respectively. Height growth was not significantly increased by fertilization. Both higher rates of N (four applications of >100 kg·ha -1 ) and the fertilizer mix were required for significant growth responses to occur. Addition of N alone or mix alone had a negative effect on mean tree basal area and volume. Addition of higher N rates without the mix decreased foliar total S and SO 4 -S concentration and increased the N/S ratio. Addition of the higher rates of N without the mix aggravated slight K deficiencies. The responses to the higher N rates in combination with the fertilizer mix are mainly attributable to S.Résumé : Quatre taux de N (0, 50, 100 et 150 kg·ha -1 ) avec ou sans un mélange d'engrais contenant P, K, S, Ca, Mg et des micro-éléments ont été appliqués dans un peuplement de pin lodgepole (Pinus contorta var. latifolia Engelm.) quatre fois sur une période de sept ans. Quatorze ans après la première application, la surface terrière et le volume moyens étaient significativement plus élevés dans les traitements contenant les deux taux de N les plus élevés avec le mélange d'engrais. La surface terrière et le volume moyens des arbres étaient respectivement 38 et 42% plus élevés dans le traitement avec le plus haut taux de N (525 kg·ha -1 ) combiné au mélange d'engrais que dans le traitement té-moin. La surface terrière et le volume moyens des arbres étaient respectivement 27 et 25% plus élevés dans le traitement avec le taux intermédiaire de N (350 kg·ha -1 ) combiné au mélange de fertilisant que dans le traitement témoin. La fertilisation n'a pas significativement augmenté la croissance en hauteur. La croissance en hauteur n'a pas été significativement affectée par la fertilisation. Les deux plus hauts taux de N (quatre applications de plus 100 kg N·ha -1 ) combinés au mélange d'engrais étaient nécessaires pour obtenir une augmentation significative de croissance. L'ajout de N seul ou du mélange d'engrais seul avait un effet négatif sur la surface terrière et le volume moyens des arbres. L'ajout des plus hauts taux de N sans le mélange d'engrais a causé une diminution de la concentration de S total et de S sous forme de SO 4 et a augmenté le rapport N/S. L'ajout des plus hauts taux de N sans...

Long-term effects of intensive silvicultural practices on productivity, composition, and structure of northern temperate and boreal plantations in Ontario, Canada

“…Results of fertilization trials vary greatly from improved yields, little or no benefit, to negative effects on plantation yield (Neilsen and Lynch, 1998;Hangs et al, 2003Hangs et al, , 2004. The success of fertilization depends on the fertilizer formulation, rate and application method of fertilizer, stock type, site characteristics, and associated silvicultural treatments (Kishchuk et al, 2002). A plausible explanation for a null fertilization response in jack pine, black spruce, and white spruce of this study may be related to site characteristics.…”

“…Short-term responses (<5 years post-treatment) of www.elsevier.com/locate/foreco Forest Ecology and Management 241 (2007) [115][116][117][118][119][120][121][122][123][124][125][126] planted conifers to intensive silvicultural activities abound in the literature (Thompson and Pitt, 2003), but few report the long-term (>10 years) results of intensifying management in the northern temperate and boreal forests (e.g. Kishchuk et al, 2002;Chen et al, 2006). Furthermore, few studies have examined the possible interactive effects of multiple treatments on conifer growth.…”

Does inorganic nitrogen limit plant growth 3–5 years after fire in a Wyoming, USA, lodgepole pine forest?

“…A considerable amount of research has focused on nutrient limitation in young and mature lodgepole pine trees, often within a silvicultural context, with different results reported in different settings (e.g., Yang, 1998 and references cited therein;Brockley, 2000Brockley, , 2003Startsev et al, 2007). Although N has often been found to be limiting, growth also may be limited primarily by other nutrients such as sulfur or boron (e.g., Brockley, 2000Brockley, , 2003Kishchuk et al, 2002;Blevins et al, 2005;Sanborn et al, 2005).…”

“…First, we experimentally augmented the supply of only one nutrient, inorganic N. Additional experiments are needed to test the hypothesis of P limitation in L. argenteus and in C. rubescens when this latter species' N needs are met. Moreover, lodgepole pine may be limited by P or by trace elements, notably sulfur or boron (Brockley, 2000(Brockley, , 2003Kishchuk et al, 2002;Blevins et al, 2005;Sanborn et al, 2005), none of which was tested in this study. Second, our sample sizes were small (n = 6 for each speciestreatment combination) and our statistical analyses relatively simple.…”

Comparison of potential non-timber forest products in intensively managed young stands and mature/old-growth forests in south-central British Columbia

“…The fertilization treatments were designed as large-scale applications of previously established ''optimum nutrition'' fertilization field experiments in Sweden (Tamm et al, 1999) and BC (Kishchuk et al, 2002;Brockley, 2005). Fertilizer was applied at 2-year intervals for 10 years (total of 5 applications), using multinutrient fertilizer formulations developed from annual nutrient diagnosis of lodgepole pine foliage samples.…”