In this paper some of the criteria that have been used in the State of São Paulo in soil test interpretation were studied, correlating soil test parameters with corn response to applied nitrogen, phosphorus or potassium in 25 field experiments. Exchangeable potassium and phosphorus soluble in 0.05N H2SO, correlated well with responses of the crop to the applied nutrients. Nitrogen responses could not be correlated to soil test values. Response curves and fertilizer efficiencies are presented for nitrogen, phosphorus and potassium. For the two last nutrients, the average curves are given for very low, low, medium and high soil test values.