BELOW-AND ABOVEGROUND GROWTH OF EUCALYPTUS-NITENS IN A YOUNG PLANTATION - II - NITROGEN AND PHOSPHORUS

Accumulation of nitrogen (N) and phosphorus (P) in below-and above-gro und components of Eucalyptus nitens was studied in a plantation for tw o fertilizer treatments (T1, unfertilized; and T5, in which 600 and 30 0 kg ha(-1) of N and P, respectively was applied at 2 and 26 months af ter planting). Variation of N-concentration in roots of various diamet ers was small. The concentration of N in roots was similar to that for leaves, but the concentration of P was higher in roots compared with leaves and other above-ground components of trees. Application of N an d P fertilizers at 26 months increased the concentrations of N in root s and P in leaves and stems following fertilizer application. Temporal variation of N- and P-concentrations in roots did not match with that for the above-ground components of trees. Leaves and coarse roots acc umulated higher proportion of total N and P than other components. By 34 months, total accumulated N and P in trees was 290 and 31 kg ha(-1) , respectively. The ratio of below-ground to above-ground P decreased with addition of P but a similar ratio for N remained unaffected by N- fertilization. (C) 1998 Elsevier Science B.V.