EFFECT OF NPK FERTILIZATIONS ON KALMIA-ANGUSTIFOLIA - IMPLICATIONS FOR FOREST DISTURBANCE AND CONIFER REGENERATION

Growth response and NPK concentrations of sprouts, current year's twig s and rhizomes of Kalmia angustifolia were determined in a factorial g reenhouse experiment where N, P and K fertilizations were added on pot ted Kalmia. Growth of above and belowground components of Kalmia and t he N, P and K concentrations of leaves were significantly altered due to treatments. Results are in contrast to the effect of fertilization on growth of other ericaceous shrubs. Involvement of special physiolog ical processes, mycorrhizal relationships and open grown conditions we re argued as probable causes for the observed better growth of Kalmia after fertilization. Enhanced growth of Kalmia contributes to its comp etitive ability and allelopathic interference, which play a significan t role in its spread and interference to conifer regeneration.