Below- and above-ground growth of Eucalyptus nitens in a young plantation II. Nitrogen and phosphorus

Accumulation of nitrogen (N) and phosphorus (P) in below- and above-ground components of Eucalyptus nitens was studied in a plantation for two fertilizer treatments (T1, unfertilized; and T5, in which 600 and 300 kg ha-1 of N and P, respectively was applied at 2 and 26 months after planting). Variation of N-concentration in roots of various diameters 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 and P fertilizers at 26 months increased the concentrations of N in roots 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 accumulated 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.