In the fields, in the shadow of giant billboards giving motivational advice or productivity targets, women in headscarves bend over crops of maize, corn and rice.
Also in Germany, there are aerobic digesters which are fed by maize(corn) rather than waste and so the same argument would arise over growing crops for fuel or for food as applies to biodiesel production and must ring an eventual death-knell for both biodiesel and biogas, if the latter is made from food too.