This paper reports the results of an experiment conducted in "terra roxa misturada" soil at the Central Experiment Station, Campinas, to study mainly the effect of dried sewage sludge as a fertilizer for corn. The product contained approximately 10% water, 45% organic matter, 2.5% N, 0.7% P2O5, and 0.2% K2O and was used at the dosages of 2.5, 5 and 10 metric tons to the hectare, either alone or supplementd with phosphorus (bone meal), potassium (coffee beans ash), or both. All the fertilizers were applied only in the first year, 1943-44, but corn was planted in the same plots for three consecutive yars. The yield increase due to phosphorus was small, apparently because the area used for the experiment had been fertilized with phosphates in the previous crops. Potassium increased considerably the yield in the first year and showed excellent residual effect in the two succeeding years. In the absence of potash the sludge product acted poorly, but in the presence of that nutrient its effect increased appreciably. The 5 and 10 tons rates gave satisfactory results; however, they increased comparatively more the production of stover than the grain yield. The nitrogen of the sludge product acts fairly quickly, but apparently little of it remains in the soil for the succeeding crops. For better utilization of its nitrogen, the sludge product should be applied frequently (perhaps annually) and at moderate rates, supplemented with potash and phosphate, according to the soil.