UPTAKE OF NUTRIENTS FOLLOWING FERTILISATION OF SITKA SPRUCE ON DEEP PEAT IN NORTHERN IRELAND

The effects are described of broadcast application of mineral phosphate at rates from 0–400 units† P2O5per acre and top‐dressing treatments with nitrogen and potassium at rates up to 30 units N and 180 units K2O per acre on the growth and nutrient uptake of newly planted Sitka spruce on deep oligotrophic peat in western Northern Ireland. Rate of tree growth and P uptake increased progressively over four years with increasing phosphate application. Applied K appreciably increased rate of growth, length of growing season and K uptake, but tree response decreased in the fifth season after application. Nitrogen application has had little effect except in the year of planting. Levels of N and K in Sitka foliage at the end of the first growing season were very much higher than in subsequent years. Copyright © 1969 John Wiley & Sons, Ltd