Resumo. The objective of this research was to evaluate the nutritional and moisture conditions of a soil cultivated with Eucalyptus benthamii, in which it was used biochar coming from the fast pyrolysis of a mixture of native species of Mixed Ombrophilous Forest in the preparation of the pre-planting. The study was developed in an experimental area of the State University of the Center-West located in Irati, Paraná state. Four doses of biochar, 0, 10, 20 and 40 Mg ha-1, with and without mineral fertilization of 340 Kg ha-1 of NPK with 14 Kg N, 48 Kg P2O5, 28 Kg K2O in formulation 4-14-8, in a randomized complete block design with four replicates. Eucalyptus benthamii seedlings were planted in spacing 3 x 2 meters and, after 60 and 180 days, the following soil attributes were evaluated: pH, organic carbon, P, K, Ca, Mg, Al contents and soil moisture. The application of 40 Mg ha-1 biochar with and without basic fertilization, caused an increase of pH and nutrients due to the ash content in the constitution of the conditioner, and an increase of the soil moisture. The application of biochar may become a positive practice in order to provide nutrients for the initial development of the crop. However, it is necessary to evaluate the effect of fertility according to the dose applied, since the availability of nutrients may decrease over time, leading to the need for cover fertilization, however in smaller amounts.