Water quality of the Canchim's creek watershed in Sao Carlos, SP, Brazil, occupied by beef and dairy cattle activities

The Canchim's creek watershed in Sao Carlos, SP, Brazil, was chosen to evaluate water quality affected by dairy and beef cattle production systems based on tropical pasture. The water samples were collected monthly, during three years, at six sampling points: spring in a tropical forest, spring in an intensive dairy production system, two dam springs, and stream water upward and at the delta. Results showed differences (P<0.01) among sampling points for the mean parameters. True color, hardness, turbidity, electric conductivity, alkalinity, pH, chemical oxygen demand and consumed oxygen explained well differences among sampling points. According to current legislation standards, water quality fitted with most of the established parameters for class 2, with exception of phosphate and iron. The high levels of total phosphorus, except in the forest spring, classified this water in an eutrophic class, even where soil and water conservation practices were considered adequate.