Those sad, shriveled Christmas trees heaped in piles by the roadside will actually help keep Carson Valley green next year. That's because the Bently Ranch in Minden is working with Douglas County Parks and Recreation to recycle the trees. "We'll compost them and use them on our agricultural fields," Jim Usher, Bently Ranch manager, said Wednesday. "We've been doing this for at least 10 years through the Bently Agrowdynamics site, but this is the first year we're doing it in conjunction with the county."In previous years, Douglas County collected trees, chipped them, and used the mulch in public parks. With …