This paper reports and discusses the first results from a field experiment designed to determine the effects of irrigation and other soil management practices on coffee yield. The soil type was a Latosol Roxo, at Experiment Station in Ribeirão Preto. Soil samples for moisture determination were taken from every plot at approximately two weeks intervals at the depths of 0-25, 25-50, 50-75, 75-100, 100-125 and 125-150 cm. Since most of the coffee tree roots are located in the upper 50-100 cm layer, it was observed that sprinkler irrigation should be carried out when 70% of available water in the range had been used by evapotranspiration, which corresponds to volume of 70 mm of water stored in the above mentioned layers. Except for some years the analysis of variance showed significant differences in coffee yields for the irrigated treatments under the previously mentioned conditions as compared to those for the control treatments. Similar effects were observed in plots tested with plowed-in legumes and with barn manure at rate of 15/kg/hill/year (one hill = 3 - 4 plants).