Reduced in bulk and which can be safely returned to the environment. It is, in effect, a low-moisture, solid-substrate fermentation process, as previ-ously discussed (chaoter 4). To be totally effective, it should only use as substrates readily decomposable solid organic wastes, the final product is mostly used for soil improvement, but in more spcialised operations using specific organic raw substrates(straw, animal manures, etc.),