Hi Jen,
Don't actually have a great answer for you, I can only offer my observations, which aren't so scientific.....
Started my gardens 11 years ago. Had a lot to learn. In the beginning there were some successes and lots of failures. By year 3 I had created 3 big beds and about 20 smaller ones all around the
yard. I was/am always amending beds. Some are in much better shape than others.
Every year I start or try to start 4-5 different varieties of peas and 4-5 different beans. And I always rotate my crops so they are always in different beds (some good, some not so great) every year. Year 2 I had some decent success with some of the peas and some of the beans. Maybe 3 out of 5 of each did better than the others. Was it the beds I put them in? But then I had an explosion of earwigs that ate everything. By the end of the summer I got them under control. Year 3 I decided to try using an inoculate. Got the same results.
But then I got an explosion of pill bugs that ate everything in sight. Pill bugs are hard to overcome. I had created a monster and I had “MILLIONS”of them. In the end it took me 5 long years to finally eradicate and control most of them. I had to use serious garden hygiene! I couldn't use any mulch at all, ever. I used lots of Spinosad. At the end of each season I had to remove every plant, all the debris and even the roots from the soil so they had nowhere to hide and nothing to eat. I figure it was kind of like chemotherapy for my garden. I had to destroy the good (bacteria and fungi) with the bad but it finally worked. I have slowly, the last 3 years started to garden more like normal people do.
So, fast forward.... 4 years ago I finally got decent crops of peas and beans again. Maybe 3 out of every 5 different kinds did well again. But I was still practicing my severe garden hygiene so I dug up all the plants and roots again. I noticed on one group of beans that had done really well that there were lots of little white nodules on all the roots. I figured that couldn't be good and I should look that up but I forgot. The next year I dug up the roots of some peas that had also done well that were in an adjacent bed and they had bigger pink nodules all over the roots. I did look it up that time and according to the internet experts that was the nitrogen that the plants were taking from the air, putting in the soil and hoarding! Really!! And you're supposed to leave them in the ground so they release the nitrogen! Why hadn't I heard of that before?? Still don't know how much truth there is to that. But, whatever.
So last year I decided to try inoculate again. I used it on all of them, 5
pea varieties and 5 bean varieties. And it still looks like I got the same results. 3 out of each 5 varieties did much better than the others. So, was it the inoculate or the different beds or the varieties? But I did, for one last time, (don't think I need to dig up the roots any more because my pill bug problem is manageable now) dig up the roots of all the plants. The ones that did great and the ones that did not so great. And I didn't find any nodules on any of them. Go figure! But I did get to pack my freezer full of beans!
So, my final takeaway is... Give it a try, it can't hurt. Happy
gardening.