Balanço geoquímico em plantações de eucalipto e caracterização de águas superficiais próximas a depósito de lixo: estudos de casos

Abstract

This work consists oftwo different chapters. The first aimed to quantify the geochemical balance ofnutrients in an experimental watershed catchment in Aracruz-ES, Brazil, at the Aracruz Celulose S.A. eucalyptus plantations. For obtaining the geochemical balance, it were measured nutrient inputs through fertilizers, soil amendments, and atmospheric depositions and the nutrient outputs were measured in the stream flowing out ofthe watershed and in the plants harvested from the área. The studied period ranged from Oct./1996 till Mar./2003. The total área ofthe catchments is 286 ha (189 ha under eucalyptus). The annual average precipitation was 1157mm and the average waterflow in the local stream was 3,1 L s"1. Three scenarios are discussed to compare different forest management strategies. From the geochemical balance standpoint, the current management now used is very suitable as there are not significant gains nor losses ofany nutrient, which points to a condition nearly ideal. The nutrient flows for this watershed are much lower than in similar watershed in other Brazilian regions as in the State of São Paulo. The second chapter is about monitoring program for water and sediment quality in streams affected by a nearby garbage deposit, in Nazareno-MG, Brazil. The water samplings were accomplished at five sites in the Engenho stream, one site in the Cala-a-Boca stream, and another at the Grande River, every two months during one year. The analyzed parameters were: temperature, pH, conductivity electrolytic, turbidity, solids in suspension, NHJ, NO;, NO;, PO;3, SO;2, dissolved 02, Ca, Mg, Zn, Cu, Fe, Mn, Pb, Ni, Cr, Al, Cd, K, and Na. There were also obtained river bottom sediments at the same sites of sampling for trace-elements. AH water samples complied the standards for Class 3 waters (CONAMA 020/86). There were not found evidences showing the garbage deposit is significantly hindering the quality ofthe surface waters.