In order to evaluate the effect of increasing biosolid rates (0, 5, 10, 15, 20 and 40 t ha-1, dry base) on some chemical soil attributes, and macro and micronutrient growth and uptake in Eucalyptus grandis stands, an experiment was established at the Experimental Station of Itatinga of ESALQ/USP, Itatinga (SP). Some treatments had additional application of K and P, and, as reference, only mineral fertilization was applied in one of them as practiced in some high technology forest companies in the region. The soil of the area was characterized as a Red-Yellow Latosol dystrophic, medium texture (Oxisol). Six months after the biosolid application, no pH, P, Mg, Zn, Cu and B changes in the soil were observed. Increasing of K, Ca and S, and reduction of Al, Fe and Mn concentrations were verified. Thirteen months after application, increasing of pH and P, and Ca, K and S concentrations were verified only in the 0-5 cm layer. For the two samplings, increasing biosolid rates caused the reduction of organic matter content only at 0-5 cm soil layer. Accordingly, the leaf N and S concentration increased. Available P (resin) increased considerably with biosolid-soil contact time, resulting in a higher uptake of P and plant growth. The application of P fertilizer in the furrow or in the planting hole, simultaneously with biosolid on soil, was found to be necessary to elevate the initial growth of the plants. No K response was observed. For medium exchangeable K, K fertilizer application in young eucalypt plantations may be no necessary for biosolid rates larger than 10 t ha-1. Increasing biosolid rates from 0 to 40 t ha-1 resulted in a quadratic response of wood production. The response to biosolid application increased with age, mainly due to the beneficial effects of increasing nutrient availability for the trees.
eucalypt; plantation; organic fertilization; nutrient availability