Bingol, N.T., Karsli, M.A., Bolat, D. and Akca, I. 2006. Effect of molasses and sulphuric acid addition to barley/Hungarian vetch bi-crop silages. J. Appl. Anim. Res., 30: 29–32. To determine the effects of sulphuric acid (H2SO4 and molasses (M) on silage quality and in vitro dry matter digestibility, barley (157/37 Tokak) and Hungarian vetch (Vicia pannonica Crantz) were planted together at the rate of 3:1 and harvested at the milk stage of barley and conserved in 1 kg jar, laboratory silos. Silages were treated with no additive (control silage), 6% M, 0.3% 2N H2SO4, 0.3% 4N H2SO4, 0.3% 2N H2SO4 + 6% M and 0.3% 4N H2SO4 + 6% M. Dry matter was significantly higher in silages treated with molasses and with 4N H2SO4 + M (P<0.05). Ash, organic matter, crude protein, neutral detergent fiber and acid detergent fiber concentrations were not affected by additives. ThepH values were significantly lower in silages treated with 2N H2SO4 and 4N H2SO4 (P<0.05). Silages treated with molasses, 2N H2SO4 and 2N H2SO4 + M had significantly higher lactic acid concentrations (P<0.05). The addition of 2N H2SO4 + M and 4N H2SO4 + M into silages increased silage propionic acid levels (P<0.05). In vitro dry matter digestibility of silages with additives, except 4N H2SO4 + M, were significantly higher compared with control (P<0.05). Addition of molasses and 2N H2SO4 may be considered to improve quality of barley + Hungarian vetch bi crop silage.