Experimentations were conducted at the Experimental Field for Tobacco - Voicesti, Vilcea, in a crop rotation of long duration with Oriental tobacco (1982-1994), the fertilization being organic, mineral and mixed. From 1982-1985, the tests used cultivar Djebel 123, in a rotation: oats-tobacco-corn-bean; from 1986 -1989 cultivar Djebel M 83, in a rotation: oats- tobacco-corn-corn and from 1990-1994 cultivar Djebel 252 in a rotation: oats-tobacco-corn-corn. The fertilization of Oriental tobacco with well decomposed organic fertilizers (compost) at doses of 5-15 t/ha results in very high yields, even superior to those obtained by chemical fertilization at the optimum dose, compared with the non-fertilized check. The crop rotation of 4 years results in high yields for non-fertilized checks: 913 kg/ha cured tobacco for cultivar Djebel 123, 1115 kg/ha for cultivar Djebel M 83 and 1078 kg/ha for cultivar Djebel 252. Increasing doses of organic or mixed fertilizers does not deteriorate the quality of cured tobacco, the percentage of top grade being 23.8-30.1% for cultivar Djebel 123, 11.2-30.1% for cultivar Djebel M 83 and of 11.1-23.1% for cultivar Djebel 252 and the percentage of class I tobacco was 42.6-48.0% for Djebel 123, 42.6-60.8% for Djebel M 83 and 46.2-52.6% for Djebel 252. The 4 years rotation after 12 years of experimentation visibly contributed to the improvement of the alluvial soil at Voicesti, the non-fertilized variant producing high values of enzymatic activities. The chemical composition of the unfermented tobacco reveals the correlation between the small values of the analyzed reference points at small doses of fertilizers and the high values at high doses of fertilizers and at inferior classes of industrial quality; it is considered that the highest values do not represent a worsening of the chemical composition connected with organic or mixed fertilization. The Oriental tobacco gives very good results of yield and quality with organic fertilization at 5-15 t/ha of compost (simple dose or improved with PK), and at the same time the biotic activity of the soil is improved, also maintaining the fertility state, when the tobacco is included in a 4 years rotation.