Not sure if this is the correct place to post, please direct if I am
wrong.

We have well rotted horse manure (straw based not shavings), that anyone
is welcome to help themselves to by the bag or trailer load. This would
have to by appointment for the security of the yard. We are based in
Bolton, Lancashire. It has been well maintained to maximise the rotting
down process.

Or if anyone could advise me of the best place to offer this?

No one ever want`s ours unless we bag it and take it to them, blow that, we
don't do that sort of thing any more, I keep a smallish heap near the
stables and the rest I dump in the corner of the paddock, it is surprising
how quickly it rots down

kate