Similar magnitudes of biological nitrogen fixation have
been found in grazed pasture swards of white
and rye grass. Recent
studies in the tropics have shown large yield increases in
common bean as a result of selecting native
Rhizobium strains with high N fixation rates, good competitive
ability, and tolerance to high soil temperatures, soil acidity, and
water stress . Brazilian bean cultivars in
nitrogen-limited soils inoculated with best performing native
strain PRF81 produced about 2500 kg ha−1which corresponds to
more than four times the national bean production average.
This example shows that exploring the variability in genetic
capacity to fix Neven within closely related organisms can be of
benefit to the ecosystemservice of N supply.