On Wed, 17 Jul 2013 11:49:38 +0100, Janet wrote:

Green manures are normally dug into the soil, what are you going to
do with the top crop yours produce?

Either cover them with black plastic for a while or hoe them off and
leave them as a mulch, I thought. Field beans will be cut off and
composted leaving the roots (and nodules) in.

I'm in Jersey so light is less of a problem