Nutrient–Growth Relationships in the Grand'Mère White Spruce Plantations before and after Fertilization
Relationships were studied between the concentrations of N, P, K, and Mg in the needles and the growth of planted white spruce (Piceaglauca (Moench) Voss) on sandy marine and associated soils at Grand'Mère, Quebec. Multiple correlation analysis indicated a positive and highly significant relationship between K concentrations and growth expressed in terms of basal area and total volume. Foliar N was positively and significantly correlated with basal area and Mg with total volume. There was a negative relationship between P concentrations and both basal area and total volume. However, the coefficients of partial correlation for N, Mg, and P were low.Significant increases in increments of basal area and total volume were obtained with 50 and 100 kg/ha K, 5 and 10 years after application. There was a moderate response in total basal area to rates of 57.5 and 115 kg/ha N in the first 5 years only. No growth response was obtained with 45 kg/ha Mg for either period of observation. K, N, and Mg were applied as K2SO4, urea, and MgSO4 respectively. No significant residual effects of N or K on foliar levels of N, K, and Mg could be established 10 years after treatment, although a marked and significant residual effect of Mg on foliar Mg concentrations could still be detected in the fertilized plots. Thus, K appeared to be the main element that limited growth of white spruce in these plantations.