Fertilizer trials were established on 8 sites in TFL 5 and TFL 52 for West Fraser Mills Ltd. These sites were identified as having nutrient deficiencies based on foliar sampling conducted in 2006 at 41 sites. The 8 trials were established in 2007 to compare the effects of fertilization on white or hybrid spruce and Douglas-fir. Nitrogen and boron ("Nitrogen Alone"), and a blend of macro and micro nutrients ("Blend") were the two fertilizer mixes used. The fertilized sites were sampled in the fall of 2008 and needle weights and foliar nutrient concentrations were analysed to determine treatment effects. Samples were analysed for concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), boron (B), total sulfur (S) and inorganic sulfate (SO4).
Control levels of N across all 8 sites ranged from very severely deficient (sites 2 and 14) to severely deficient (sites 5, 13, 23, 25, 29 and 41). The foliar levels of P, Ca, K, Cu, Zn and Mn were all adequate or above acceptable levels for spruce and Douglas-fir across the 8 control sites. Magnesium control levels ranged from adequate (sites 2, 5, 23) to a possible slight to moderate deficiency (sites 13, 15, 25, 29, 41). All of the control sites were considered deficient in S and were lower than 0.12%, which, in combination with the levels of SO4 (<.01%), suggest that a deficiency inducible by N fertilization is possible. The control foliar levels of Cu, Zn, and Mn were considered adequate in samples collected from all 8 sites. The levels of B were deficient on sites 13 and14, possibly deficient on 2, 5, 23, 25, and 13 and probably not deficient on site 29 where the recorded level of B was 15 ppm. The foliar control levels of SO4 were considered deficient on sites 2, 14, 25. For sites 5, 13, 23, 29, and 41 the SO4 control levels were not deficient but the concentrations indicated that an N induced deficiency is possible.
Analysis of variance results showed that treatment effects were significant for each treatment for N, needle weight, B and SO4. No other foliar nutrients showed any significant change as a result of fertilization. The Nitrogen Alone and Blend fertilizer treatments resulted in increased foliar nutrient concentrations and needle mass for these same measures.
Increases in needle weight were significantly greater for the Blend treatment, but 2 sites (2 and 13) showed higher needle weights for the N alone treatment when compared to the Blend treatment.
The Nitrogen Alone and Blend treatments resulted in higher but variable N concentration increases when compared to controls, with sites (14, 23, 29, 41) highest for Nitrogen Alone and sites (2, 5, 13, 25) highest for Blend. These differences were not significant between N Alone and Blend.
Similar to N concentrations, fertilization induced increases in B were variable for the Nitrogen Alone and Blend treatments and these increases were not significantly different between N Alone and Blend.
Fertilization resulted in a significant decrease in the concentration of SO4. With the exception of sites 2 and 5, the Nitrogen Alone treatment resulted in the greatest decrease when compared to the Blend treatment. The results of the Nitrogen Alone treatment for SO4 concentrations indicate that there is likely an actual or inducible S deficiency caused by the fertilization treatment.
The foliar nutrient and mass results suggest that operational fertilization of white spruce and Douglas-fir should focus on sites with similar nutrient deficiencies and that fertilization treatments should include N, B and S (as ammonium sulfate) to avoid induced nutrient deficiencies.
B. A. Blackwell and Associates Ltd.. 2009. West Fraser Mills - Fertilization Screening Trials. Forest Investment Account (FIA) - Land Base Investment Program. Forest Investment Account Report
Topic: FLNRORD Research Program
Keywords: Forest, Investment, Account, (FIA), British, Columbia
To copy the URL of a document, Right Click on the document title, select "Copy Shortcut/Copy Link", then paste as needed. Only documents available to the public have this feature enabled.