Field experiment was carried out at Norman E. Borlaug Crop Research Centre, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Udham Singh Nagar, Uttarakhand, India during Rabi season of 2015-16 to study the effect of biofertilizers on productivity of berseem (Trifolium alexandrinum ) in Tarai region of Western Himalayas. The experiment site was sandy loam in texture with soil pH (7.6), medium in organic carbon (0.848), nitrogen (278.48 kg/ha), phosphorus (27.7) and potassium (232.8 kg/ ha). The experiment consisted of 7 treatments i.e. T 1-Control, T2-Seed treatment with Azotobacter @2ml/ kg seed, T3-Seed treatment with Phosophobacter @ 2ml /kg seed, T4-Seed treatment with Azotobacter @3ml/kg seed, T5-Seed treatment with Phosphobacter @ 3m/kg seed, T6-Seed treatment with mixture of Azotobacter @ 2ml + Phosphorbacter @ 2ml /kg seed and T 7- Seed treatment with mixture of Azotobactor @3ml + Phosphorbacter @ 3ml /kg seed and replicated thrice in randomized block design. All treatments were fertilized with 30 kg N, 60kg P205 and 40 kg K20/ha before drilling of seed. Significantly higher plant height of berseem was recorded under seed treatment with mixture of Azotobacter and Phosphobacter @ 2ml/kg seed of each biofertiliser. Maximum number of plants per meter row length was recorded under seed treatment with mixture of Azotobacter @ 2ml + Phosphorbacter @ 2ml/kg seed. The green, dry fodder yield, gross returns, net return and B:C ratio were not affected significantly by biofertilisers, however the highest values were recorded under seed treatment with mixture of Azotobacter @ 2ml + Phosphorbacter @ 2ml/kg seed followed seed treatment with Azotobacter @ 3ml/kg seed. The seed treatment with mixture of Azotobacter @ 2ml + Phosphorbacter @ 2ml/kg seed gave 12.1, 12.4 and 13.4% higher green fodder yield, gross return and net return, respectively than control. Therefore it may be concluded that seed treatment with mixture of Azotobacter @ 2ml+ Phosphobacter @ 2ml/kg seed may be recommended for boosting the productivity and profitability of berseem in Tarai region of Western Himalayas.

Key Words: Bio-fertilizers; Berseem; Azotobacter; Phosphobacter; Productivity; Profitability.