Growth and nutrition of three Salix clones in low conductivity solutions

Abstract

The ability of Salix aquatica Smith, S. fragilis L. and S. vlminalis L. to grow in low conductivity solutions was investigated. The effects of four different relative nutrient addition rates on the N, K, P, Ca, and Mg contents of the plants, on concentrations in the media, and on dry matter distribution between roots, stems, and leaves, were measured. No significant and persistent increase of concentration of any element resulting from the daily nutrient additions was measured in the media. Practically all nutrients were consumed by the plants at the same rate and in about the same proportions at which they were supplied. Linear regressions were found between any two of the three factors: relative rate of nutrient supply, nitrogen status, and relative growth rate. High nutrient addition rates favoured leaf development while low nutrient addition rates stimulated root growth. It is concluded that the decisive factor governing the mineral uptake rate in Salix is the rate of nutrient supply and that these clones are well suited for short rotation energy forestry in so far as their ability to absorb the mineral elements efficiently is concerned.