OTOH as I've pointed out before, much of the enormous productivity of Brazil's sugar cane fields is the result of a one-time accelerated liquidation of centuries of topsoil deposition from the original forest cover.  Dust Bowl redux.

Sugar cane at a near-equatorial location with adequate rainfall is bound to yield more energy than corn in the temperate North, but there's still a physical limit to how much energy you can harvest from a hectare of biomass w/o liquidating the soil.  And so-called "modern, improved" Western methods of farming are all about liquidating topsoil for fast, "cheap," temporary returns.

more later...

The difference between theory and practise in practise ...