Six introduced and one native nitrogen fixing tree species were grown in a potted non-sterilized Inceptisol inoculated with: species-specific rhizobia
strain TAL 1145, a leucaena
isolate; Bradyrhizobium japonicum
strain TAL 169, and without inoculation. Twelve weeks later, significant species differences in dry matter yield, total N yield and nitrogen derived from the atmosphere (Ndfa) were obtained. Unlike earlier reports, Acacia albido and Acacia Senegal were better N2 fixers than Leucaena leucocephala
. Two species did not respond to any of the inoculation treatments and none responded to inoculation with TAL 169. In species belonging to one cross-inoculation group, TAL 1145 had similar Ndfa values as those of species-specific rhizobia, implying that it is sufficient as the inoculum for this group.