I do not think that producing biofuel is such an disaster, of course depending on how you implement it. In Germany quite a few farmers already produce biogas using large fermenters on their farm, most often then to directly use it for electricity and heat production, as pressurizing it is too costly. But well, all you are doing is pumping some cubic metres of liquid manure and some other decomposable materials in a huge tank and let anaerobic digestion do their work. As it turns out this even improves the fertilizing properties of the leftovers, since you create an optimal environment for the bacteria involved in the rotting process, just like in a well structured composter.
Holding the soil in place can be done via in-between-cultures like mustard or spinache. Of course then one can not use only one crop specifically designed to withstand herbicides and kill off absolutely all other plants on the ground, as it is commonly practiced and doing a huge environmental damage, not only on the soil itself, but also on the surrounding ecosystem (bee colony collapse for example).
The real problem here is that bio fuel is often used as an incentive to further subventionize farmers and the malpractice of huge mono cultures, especially of corn. Mining stuff to undo a bit of the damage done by these is just another bad idea.