An interesting article by Andrew Rice on the potential for agro-imperialism. Here is the permalink: http://www.nytimes.com/2009/11/22/magazine/22land-t.html
This idea of buying land for a type of guaranteed production is, of course, not sustainable. Currently, farmland occupies the equivalent of South America and uses upwards of 70% of available fresh water resources. As populations continue to grow so will demands on and for crop, lands and water.
Knowing, as we do, that traditional farming has to be changed to meet demands, what we are seeing in these land-grabbing attempts is, perhaps, a realization that the old ways of thinking need to be put aside. Where agriculture is concerned, it is a time for big ideas.

