Ailanthus vigor on nutrient poor soils may result from an ability to induce increased rates of nitrogen-fixation
by neighboring free-living soil bacteria such as Azotobacter vinelandii.
Seasonal changes in rates of nitrogen-fixation
(AR) and numbers of potential nitrogen-fixing bacteria associated with excised roots of aquatic angiosperms.
Russelle doesn't suggest that farmers apply manure to all fields of legumes--just those fields with the highest nitrogen-fixation
rates, because those plants are hungry for an easy supply of nitrogen.
May BM, Attiwill PM (2003) Nitrogen-fixation
by Acacia dealbata and changes in soil properties 5 years after mechanical disturbance or slash-burning following timber harvest.
Although Azolla does not require any nitrogen in the medium, the level of nitrogen in the water does affect its growth and nitrogen-fixation