USE OF BIOFERTILIZERS TO ENHANCE RICE YIELD, NITROGEN UPTAKE AND FERTILIZER-N USE EFFICIENCY IN SALINE SOILS

Azolla, plant growth promoting rhizobacteria (PGPR) and chemical ferti lizer alone and in different combinations were used to study the effec t of nitrogen biofertilizers on rice biomass, nitrogen uptake and fert ilizer-N use efficiency. N-15 labelled ammonium sulphate was used to t race its uptake into rice plant and compute fertilizer-N recovery. Max imum rice biomass (straw+grain), its N yield and fertilizer-N recovery were obtained in the treatment where PGPR inoculum with 30 KgN/ha was used followed by treatment where in addition to PGPR and fertilizer-N , Azolla cover was also present. Use of biofertilizers alongwith it lo w input of chemical fertilizer-N soils was useful for increasing rice biomass, N uptake and fertilizer-N recovery in rice grown in saline so ils.