It also gets me thinking more about the way that energy supply and food production inter-relate. When I posted about a solar farm/photovoltaic array being planned near us, a couple of people made the point that farmers actually farm sunlight (as well as managing the landscape), and that whether the direct outputs go to the shelf or the grid is a secondary concern. In a sense, the use of animal waste for biodiesel adds to the argument of farmers playing an important role in energy production as well as food production. And once you grok that, you start to see how energy and food prices might start to influence farmer behaviour, particularly as agricultural producers become ever bigger concerns (and presumably start to engage in financial engineering, where the concern is not so much the industry the company is nominally a part of, but the servicing of debt).