I fully support avoiding herbicides and tillage. I do think there are contexts where tillage is appropriate.
We have heavy clay soil. Most places there is nothing loamy about it, and there’s little to nothing I would describe as topsoil. I suspect in many places you could use it straight out of the ground to make pottery. Frankly I am sometimes amazed anything grows in it, let alone well.
I have suspicions of how it got into this state but I’ll leave them for another time.
Basically we are in a similar situation trying to make heavy clay soil full of lawn grass more amenable to growing food. We also acted similarly last season and this season by just planting into the grass. We’ve really only just started this year with converting maybe a sixth of an acre of tree-ringed lawn grass and wild ground covers into space for food growing. So we have a similar goal and are at a similar point - - I can’t say “oh we tried this and it worked great”.
About the only thing I can say for certain is that six years (since getting the house) of not using herbicides and planting very little new lawngrass (which we will not do again) has made a difference. Violet, clover, and dandelion have become much larger components of the lawn. We just had to stop the poison use and wait.
Last fall we planted a lot of rye, radish, and vetch around the property, though not in the area we’re converting. I let most of the rye complete its lifecycle as I’d rather have more of a locally adapted weedy cover crop. Most people will likely argue this defeats the purpose of a cover crop, but Fukuoka’s cover crops were his main crops in a temperate clay soil context. He planted into a perennial ground cover of white clover.
@MarkReed has had awesome results using root crops as soil builders in clay soil. He has inspired me to step up my root crop game.
The fall crops you mentioned sound great I just wonder if you’ll have enough time for the tender ones to make good root mass or biomass.
I would not recommend planting crown vetch (which I’m sure you’re not). I can’t recommend hairy vetch either. Like crown vetch it is non-native and very aggressive. It is inedible by most reports, the seed pods shatter easily, and I believe the seeds are of interest to wildlife and therefore likely to spread.
Skip next paragraph if further detail on hairy vetch is uninteresting:
Earlier this year I observed a small and beautiful riparian ecosystem with a history of heavy disturbance (but minimal ongoing) in Cincinnati Ohio. As I had planted hairy vetch as cover last year and am very fond of the pretty flowers, I recognized its presence. Shortly after I realized that it was everywhere, followed by multiflora rose. Granted the native vining legumes that should have filled the same niche were absent, but it seems to me hairy vetch does not behave well when growing conditions are good and adjacent ecosystems are vulnerable.
I support rye being a great option for the cold season. I planted a lot in September this year and will plant still more mid-October or later.
Barley and non-green revolution wheat seem like good choices too. I’ve grown barley in or adjacent to lawn grasses and am trying wheat.
I’m not sure any cover is going to displace fescue, bermuda, violets, dandelions, etc. if that’s an aim. If Fukuoka’s methods are interesting to you, you might consider introducing or tolerating some native perennial legumes to cover the soil in the off season and serve as living mulch during the growing season
Hope to hear how it goes!