A long-term field experiment was established in 1967 and continued through 1983 to evaluate the response of corn (Zea mays L.) and the loading capacity of a Davidson clay loam soil (clayey, kaolinitic, thermic Rhodic Paleudult) to yearly additions of Cu and Zn sulfates. By 1983, the 17 annual additions of Cu and Zn resulted in cumulative totals up to 280 kg Cu and 560 kg Zn ha−1. These Cu and Zn additions, either alone or together, did not cause any grain or stalk yield decreases. The DTPA extractant separated most of the soil treatment levels for both Cu and Zn. The sevenfold increase in DTPA extractable Cu and eighteenfold increase in DTPA extractable Zn followed linear relationships to treatment levels. Copper concentrations in the blades and grain were not related to soil additions of Cu or Zn. However, Zn concentrations in blades and grain were directly related to each other, to soil Zn treatment levels and to DTPA Zn. Increasing blade Zn concentrations were accompanied by decreasing blade Mn concentrations.