Non herbicide buttercup control

Here in northern Vermont, virtually all the hay land has been invaded with buttercups. We have had a couple of wet spells, and I do understand that buttercups thrive in poorly drained, compacted soil which has been overgrazed.  However, it is affecting everybody and almost all grass stands.  Having said that, my previous control methods haven't done a thing this year. I do a small rotational grazed beef operation. Normally, I lime, cut the buttercups after the cattle leave a paddock (mower set about 4") and try not to overgraze, but this year is terrible--honestly more buttercups than grass and where I have clipped, they are growing faster than the grass.  I sell hay to an organic producer and the land is certified, so I can't use herbicides.

What I am trying this year on a test plot was to harrow the field, seed with buckwheat to produce a green manure which I hope will shade out the buttercups as they try to come back and then graze it off in Sept. and seed to a pasture mix.  In another field, I am going to bush hog it down, do some subsoiling and plant some tillage radishes in the most compacted part.  I don't know how this is going to go.  The only part of the farm that doesn't look like a stand of buttercups is hayfield which get 2-3 cuts and only minimal grazing.

Any useful experience would be great to hear about.  Thanks

Non herbicide buttercup control