If you can chip the creosote off, what's left can be used to fill gullies or potholes, then covered with soil and planted.
Or make small part-sunken / part-raieed berms or ridges with them (erosion control), add some soil, and plant on tops and sides.
They will subside as they rot, but for a few years you have a spongy underground water reservoir that decays and puts organic matter into the soil.
Apparently, leaving the wood log-sized and partly below the root zone reduces the effect of "nitrogen deficit".
I recently learned a fancy name for "buried pile of rotting logs": hugelculture.
http://garden.org/ideas/view/d...
http://www.richsoil.com/hugelk...
