I have planted acacias and tree Lucerne in the beginnings of my food forest as foundation species. Some of the acacias were from a nursery and some I purchased on line along with tagasaste on line. All purchased as seedlings. Some looked like they were propagated from cuttings especially the tagasaste, the ones from the nursery all look like they have been grown true. Will they all form rhizobium nodules on their roots as a matter of course, as this is part of the function that they are there for.
Were they inoculated with the appropriate bacteria? I've recently discovered that without the relevant bacteria either already in the ground where you're planting or applied by inoculant, there will be no nitrogen fixing going on.
https://forums.permaculturenews.org...-Tipu-Crotalaria&p=94337&viewfull=1#post94337 Yes, there can be with pre-existing bacteria. Just not as "potentially" efficient.
from my experience soil type is important: i have planted nitrogen fixers such as leucaena, acacia, casuarina with little nitrogen fixingas a result because the soil is extremely sandy (over 90%) here and the bacteria simply fall through the big sand particles.