human feces can be used as fertilizer, and still is, with a little processing. In fact, I've seen a prison that made the inmates do the processing. All they needed to do was spread it flat out in the sun for awhile. Not really an expert either, but I feel like this might lower it's quality as fertilizer as it probably kills off the nitrogen fixing bacteria as well. Well, they could probably get away with reintroducing the bacteria from another source.