[Jedd]

> But how do you kill the cover crop so you can grow wheat again? How do you kill the weeds? ... The only viable answer today is...Roundup (glyphosate).

I don't agree, and I note that you also answered your question differently later in your post with the note about 'mixed farming' (grazing it off).

There are, of course, other answers than herbicides. Seasonal crops, harvesting and then seed-sowing amongst the stubble (provides some mulch & eroson protection), intensive strip-grazing (bovine, ovine, caprine, or fowl, all effective options), or even a cycle or two of fallow.

[jimnotgym]

But how do you kill the black grass before you plant wheat again. Grazing it will just keep it down until you plant wheat again. Then it will grow up through the wheat

[Jedd]

I had to look up black grass, as we don't have that particular weed in AU. I don't have any answers, of course, but a search on 'permaculture response in europe to black grass' gives some fairly unsurprising responses.

Broadscale monoculture invites its own range of problems, and herbicide-resistant highly-competitive (when in a single-other-species ecosystem) weeds are one such.

If the starting position is 'we must grow the same variety of wheat in the same field every year', then indeed, you're going to have some challenges.

[KaiserPro]

Yeah thats the killer, modern wheat is a wimp compared to various grasses.

I don't really think its possible yet, (or it might not be possible with the current breeds of wheat)