A natural bacterial colonization
The problem is, yes it does provide nitrogen but it takes plant energy to capture the nitrogen, nothing is free . But it is better than no bacteria so there is a net gain. After the first few years we stopped using it because we were told there was enough bacteria in the soil and we didn’t need to use it every year.
The problem is it WILL NOT provide the large yields we are used to. It will NOT replace the current amount of N needed for our large yields.
Another one of those, “sounds good until you think about it.”
Maybe the new version is more efficient.