In this paper the authors presents some theoretic considerations and experimental researches concerning the use of the combined machines for seedbed preparation and sowing(MCLSS), using two passes or a single pass of the aggregates across the land. This modern technology, whose performances in practice are demonstrated by many agricultural machinery manufacturers and by farmers is the one which could conduct romarian farmers to make more rapidly the pass from the Convenţional Agriculture to Sustainable Agriculture. The qualitative indices of the working process, the reduced fuel consumption, the conservation of soil properties avoiding soil compaction and conserving soil biotope, the reduced costs of the labor due to high productivity are the main advantages these new technologies brings along.