RESPONSE OF A SCOTS PINE (PINUS-SYLVESTRIS) STAND TO APPLICATION OF PHOSPHORUS, POTASSIUM, MAGNESIUM AND LIME .3. FOLIAR NUTRIENT CONCENTRATIONS AND STAND DEVELOPMENT

The effects of liming and P, K and Mg fertilization in 1985-1988 on so il nutrient concentrations in the forest floor and mineral soil of a S cots pine stand were discussed in two previous papers. The present pap er addresses the effects of these treatments on foliar nutrient concen trations and tree growth. Stem volume increments of individual trees w ere measured. Average volume growth was estimated to amount to approx. 16 m3 ha-1 y-1, which may be a slight underestimation. P and K showed increased foliar concentrations instantly after fertilization and wer e the only elements that significantly increased volume growth in the period 1988-1991. Additional volume growth of individual trees brought about by P and K corresponded with 0.9 and 2.2 m3 ha-1 y-1, respectiv ely. Foliar Mg and Ca were increased later and insignificantly reduced and increased volume growth, respectively. Lime and Mg applications t ended to lower foliar N. When absolute foliar concentrations and eleme nt ratios were compared to Dutch and German standards, it appeared tha t the application of some of these standards in present research would not always have given a fully correct prediction of growth responses to nutrient additions.