In rainfed agro-ecosystems, where resources are scarce and irrigation is unreliable, the productivity of crops is being chronically imperiled by water deficit stress, particularly during the critical reproductive phases. Use of rhizobacteria to improve crop productivity is a promising strategy under stressed environments, due to their ameliorative effect on plants. However, there is paucity of bioformulations targeting crops grown in drought-prone regions. To address this issue, different recipes of bioformulations were developed, using a combination of emulsifiers, thickening agents, oils and stabilizer; and evaluated in vitro for shelf-life and maintenance of plant growth promoting (PGP) traits. Out of eighteen different recipes, two bioformulations having shelf-life of one year, along with maintaining the PGP traits were selected for field evaluation in Indian mustard (Brassica juncea L.), an important oil seed crop majorly cultivated in arid and semi-arid regions and often exposed to drought stress. Two successive field trials (2019-20 & 2020-21), were conducted in split plot design, in the drought-prone region to assess the impact of rhizobacterial bioformulations of Bacillus sp. MRD-17 (B1 and B2) and bioformulation of a consortium of rhizobacterial strains Bacillus sp. MRD-17 and Bacillus casamancensis MKS-6 (B3) on mustard growth, yield and soil health, under different irrigation regimes (rainfed, one irrigation and two irrigations). Under both the field trials, increase in irrigation levels and application of all the rhizobacterial bioformulations improved relative water content and plant photosynthetic pigments content; and reduced proline content and superoxide dismutase activity. In both the trials, significant increase in seed and stover yield ranging between 17.4-27 % and 7.6-11.5 %, respectively, and soil biological properties viz. dehydrogenase, fluorescein diacetate hydrolase, and alkaline phosphatase activity, microbial biomass carbon was noted with the application of bioformulations, especially under limited soil moisture conditions. Hence, these bioformulations showed potential for mitigating waterdeficit stress in mustard in drought-prone areas. (c) 2025 SAAB. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.