Field evaluation of native Azotobacter and Azospirillum spp. formulations for rice productivity in laterite soil

Effects of indigenous biofertilizer formulations of six native isolates each of Azotobacter (Az.) and Azospirillum (As.) spp. of rice (var. Khandagiri and Pooja) rhizosphere, commercial formulations one each of Azotobacter and Azospirillum spp. in combination with N0 (without N), N30 (30 kg ha⁻¹) i.e. half (N/2) of recommended N and N60 (60 kg ha⁻¹) i.e. recommended N dose, and vermicompost (5 t ha⁻¹) were assessed on productivity of the drought tolerant rice var. Khandagiri in laterite soil fields of OUAT, Odisha. Compared to untreated control, rice production was increased by about 45% for N60 and 29% for N30; 52–120% and 43–109% for N60 and N30 with experimental biofertilizers combinations, respectively, whereas, 43–75% and 49–84% for commercial formulations with N30 and N60 combinations, respectively. Productivity for combined biofertilizers with N30 or N60 did not differ significantly. The experimental formulations performed better than the commercial formulations. Productivity was enhanced by about 23–92%, 21–65% and 27% by individual experimental and commercial formulations, and vermicompost, respectively. Combination of N/2 dose with the biofertilizers could reduce about half N requirement. Among different biofertilizers, the Az. vinelandii SRIAz3 and As. lipoferum CRRI1As6 formulations were most effective. Combination of these two organisms resulted in about 109% but with N/2 dose effected optimum (139–177%) rice production.