Approach to predict nutrient status and growth response of fertilized jack pine by foliar diagnosis

Abstract

A factorial experiment testing N, P and K fertilizers, and a series of simpler, two-treatment (control and NPK) fertilizer trials were established in a range of jack pine stands to determine the application of a foliar analysis technique for predicting potential growth response of stands to fertilization. The technique was based on a foliar diagnostic system, and involved the simultaneous comparisons of first season responses in dry weight, nutrient concentration and nutrient content of foliage in a single graphical display. Preliminary diagnosis revealed that N was the major growth limiting nutrient on the majority of the sites. The technique was therefore tested with foliar N response data, and individual stands were ranked according to potential responsiveness to fertilizer additions. It is recommended that actual (longterm) growth responses be compared with predicted responses to test the accuracy of the technique.