Ever wonder what it means when a plant is a nitrogen fixer?
Nitrogen fixing plants, such as clover, peas and goumi, take nitrogen from the air (atmosphere) and convert it into a plant usable form. These are presented as nitrogen nodules on the roots.
Here is a picture I just took of the roots from aslike clover. The nodules are nitrogen.
Fix the soil, fix the world.
#permaculture #soilhealth 
The Soil Food Web School taught me that the bacteria which form these nodules don't actually fix nitrogen until the nodules get big enough. At that point the center becomes anaerobic and the bacteria changes the way it functions to start fixing nitrogen. You can tell it's happening when the center of the nodule is red.
Thanks for the info.
One of the cool parts of all this is that the red in the root nodules (leghaemoglobulin) a very similar structure to that which carries oxygen in our blood. Except in this instance oxygen slows the N fixation process and the leghaemoglobulin removes the oxygen thereby allowing other enzymes to work their magic.
I made this video of pea nodules growng a few years back. So much fun. https://youtu.be/BEmb82qEiIA?si=_puWbEE6Pq-DmYbV
