A field experiment was conducted during kharif 2017-18 to investigate the impacts of azolla (Azolla pinnata) bio-fertilizer and urea on rice (Oryza sativa L.) yield, temporal soil P availability and improvement in soil acidity indices under low land acidic soil of Meghalaya. Six treatments viz., control (T1), fresh azolla incorporation @ 16000 kg ha-1 (T2), 30 kg N ha-1 through urea (T3), 60 kg N ha-1 through urea (T4), 30 kg N ha-1 through urea + azolla incorporation @ 16000 kg ha-1 (T5) and 60 kg N ha-1 through urea with azolla incorporation @ 16000 kg ha-1 (T6) were tested in Randomized Block Design with four replications. Application of 60 kg N ha-1 through urea along with azolla incorporation @ 16000 kg ha-1 (T6) produced highest grain yield (4.2 t ha-1) followed by T5 and T4. It had significantly greater available phosphorus at 30 DAT (24.13 P2O5 kg ha-1) and at maturity (20.63 P2O5 kg ha-1) followed by 30 kg N ha-1 through urea + azolla incorporation @ 16000 kg ha-1 (T5), compared to control and other treatment plots. Available phosphorus in T6 was statistically significant over T4 (60 kg N ha-1 through urea) whereas T5 was significant over T3 (30 kg N ha-1 through urea) with respect to advancement in crop age. The soil acidity indices reflected highest improvement with azolla bio-fertilizer incorporation @ 16000 kg ha-1 (T2) over all other treatments indicating that azolla bio-fertilizer can be an alternative option for acid soil management.