EFFICIENCY OF SLOW RELEASE FERTILIZERS IN THE PRODUCTION OF Eucalyptus grandis SEEDLINGS
forest nutrition; controlled fertilization; fertilizer leaching
Fertilization in the seedling production phase is essential to form quality seedlings. Thus, the aim of this study was to evaluate the appropriate doses of two slow-release fertilizers (SRF1 and SRF2) and their nutrient leaching behavior. For this, five different doses of fertilizers were tested. 0, 2, 4, 6, and 8 kg m-³. The height, stem diameter, leaf area, shoot dry mass, root system dry mass, total dry mass, and the Dickson Quality Index were measured, and for each variable the maximum dose of technical efficiency was determined. In addition, was evaluated the electrical conductivity, over time, for determinate the leaching of the nutrients. All the variables had satisfactory growth for field planting. However, the SRF2 resulted in greater seedling growth and also experienced less nutrient loss by leaching, when compared with the SRF1. The both fertilizers could be utilized to seedlings production, at doses of 4.00 kg m-³.