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The low efficiency of applied P fertilizers is major concern for economic production of Indian mustard in calcareous semi-arid tracts of the sub-continent. It is believed that the trend could be reversed through use of phosphate solubilizing and mobilizing micro-organisms (PSMM) and foliar application of P at grand growth stage of the crop. The hypothesis was tested during 2008-09 and 2009-10 at Bharatpur, India. The mean seed yield of Indian mustard was increased by 5.5% due to PSB seed inoculation and by 10.8% due to combined PSB+VAM application over non-inoculated treatment since PSB solubilizing the native or fixed P and VAM mobilizing it to plant rhizosphere. Similarly, the basal application of 17.6 kg P/ha significantly increased the average seed yield by 14.2% over no P-fertilization. And splitting P level to 15.4 kg P basal+2.2 kg P foliar spray at 35 DAS increased the seed yield by 26.3% over basal P application and by 44.2% over no P-fertilization indicating better synchrony between P requirement and availability. The increase in seed yield due to treatments corresponded with respective significant increase in growth and yield attributes viz., primary branches per plant, siliquae per plant, siliqua length, seeds per siliqua and straw yield. The supplementary application of PSSM over P fertilization revealed their additive effect on seed yield on diminishing return. The maximum incremental benefit : cost ratio values of 13.80-17.60 due to PSB inoculation among PSMM treatments and 3.60-6.37 to split P application among fertilization practices were estimated. The findings confirm the economic viability of the tested practices for Indian mustard under semi-arid conditions.