Three crop production systems (namely conventional, reduced tillage and no-till) were compared as to yields, fuel consumption, and number of machine hours per hectare in a five-year experiment (1979/80 to 1982/83) carried out at the Experiment Station in Jundiaí, State of São Paulo, Brazil. No significant differences among treatments were detected in the yields, althought they came up in fuel consumption and number of machine hours. The performance of a disc cultivator was also evaluated. The no-till system showed the least values for fuel consumption and number of machine hours, while the reduced tillage showed intermediate results and the conventional system the highest values. The dísc cultivator in the no-till system demonstrated the possibility of eliminating the use of herbicides in the inter-row cultivation. Once the three systems showed significant differences in fuel consumption and number of machine hours per hectare but not in the yields, both factors could be taken in consideration in the adoption of one of the systems evaluated.
soil management systems; corn crop