In this paper are reported the results obtained in ten fertilizer experiments three of which repeated in the same plots during five, seven or eight seasons - to study the effect, on the corn crop, of cottonseed meal used alone or combined with bone meal or coffee bean ash. These trials were conducted between 1943-44 and 1951-52 and located at seven different agricultural experiment stations of the State of São Paulo. As a whole, the study indicates that, at the rate of about 500 kilograms to the hectare and supplemented where needed with other fertilizers, cottonseed meal is a good source of nutrients for corn, but results are erratic if it is applied just before planting and slightly mixed with the soil under the seed.