Interaction of salinity and rhizobial strain on growth and N2-fixation by Acacia ampliceps

The growth, nodulation and N content of Acacia ampliceps inoculated with salt-tolerant Rhizobium PMA63/1 and salt-sensitive Bradyrhizobium PMA37 were compared at salinity levels of 0, 100 and 200 mm NaCl in sand culture. Salinity treatments were imposed 6 wk after sowing. Harvests were at 4, 6, 8, 10 and 12 wk after sowing. A. ampliceps inoculated with PMA63/1 was less affected in growth, nodule number and N content per plant by 200 mm NaCl than plants inoculated with PMA37. Inoculation with a salt-tolerant Rhizobium strain may improve biological N2-fixation under saline conditions.