Initial Growth of Pinus taeda by Fertilization Response at Planting

ABSTRACT The objective of this study was to evaluate how the fertilizer composition, type and application method contribute to the initial growth of Pinus taeda applied at planting. Seedlings from an open-pollinated seed orchard of Pinus taeda were planted on a Humic Dystrudepts soil containing 15 treatments of fertilizer application at planting. Basal diameter (immediately above ground – about 5 cm) and total height were measured on all live plants after six, 12 and 42 months. The basal diameter at six and 12 months ranged from 0.49 to 0.63 cm and 1.64 to 2.15 cm, respectively. The height at six and 12 months ranged from 0.49 to 0.64 m and 0.77 to 1.01 m, respectively, indicating that fertilizing improved this characteristics in ~30%. Fertilizer composition, type and application method contributed to the first year of growth of Pinus taeda. Nevertheless, fertilization response disappeared after 42 months.