ABSTRACT
Forest species differ in the absorption capacity, translocation, accumulation and use of nutrients. These differences occur between species, provenances, progenies, and even clones of specific species with influence in their growth. This study has as objective to evaluate the effect of phosphorus addition to the soil on the initial growth and nutritional efficiency of seedlings of Eucalyptus dunnii and Eucalyptus benthamii clones cultivated in pots. The experiment was conducted in a greenhouse for three months. Treatments consisted in a factorial design (2 x 5) with two species and five rates of P (0, 50, 100, 200 e 400 mg dm-3). The soil is a Humic Haplumbrept collected from a 0-20 cm layer under a pine plantation, which had 4.6 mg dm-3 P. Ninety days after planting, shoots and roots biomass were harvested, dried at 65 oC, weighed and analyzed for P. Subsequently, the absorption of P, the use efficiency of P and the percentage of P applied recovered by the biomass were calculated. The clones of Eucalyptus dunnii and Eucalyptus benthamii showed a quadratic increase in total dry mass yield and in the use of P as the rate of P applied increased. Eucalyptus dunnii was more efficient in terms of dry matter yield and use and recovery of P in relation to Eucalyptus benthamii, in all levels of added P.
Keywords:
eucalypt; phosphate fertilization; forest nutrition