If you've ever loaded up any decent city sim you would of probably noticed the combination of sand-brick or the similar to create something that would act as a more realistic ground i.e. Crumbling when destroyed and losing its solid form. Such as this thing I've been making in my spare time:
Whilst it does work well enough it still leaves these parts of the 'ground' after an explosion:
I chose this combination over the sand-brick one as if you get one small hole underground it ruins everything on top.
but, with what Tuttut said about the water and growing plants we should have two elements: Earth- The solid form of ground that would crumble into soil when under moderate pressure and melt then cool as sand or dust under quite high tempreture. Soil- The 'powder' form of ground, grows and forms plants slowly when it absorbs water, should absorb around 2-3px of water to form 1px of plant, it also melts and cools as dust.
Well damn, it's just ground, what other uses could it have.