In a couple of different contexts, I've run into the idea that soil reclaimed from rain forests is bad for farming. Jeffrey Sachs makes the idea prominent in some of his recent arguments for why African economic history developed differently over the longue duree. And recently it showed up in an article on Colombia, about how farmers in the recently sprayed Putamayo district would likely be planting coca there again, even if the government made good on its offer to provide $2000 worth of fertilizer to each peasant that joined the voluntary eradication program (originally it was supposed to $5000, in cash), because the fragile jungle soils that had no tree cover couldn't support intensive agriculture.
For a bio-ignoramus like myself, it seems puzzling how soil that can support the luxuriant growth of a rain forest can't support farming. But maybe it's not a matter of fertility but of proneness to washing away, or of a negative interaction with fertilizer? At any rate, if someone could explain why jungle soil won't sustain intensive farming as well as temparate climate soil will, I'd be much obliged. URLS or citations would also be great.
Michael
__________________________________________________________________________ Michael Pollak................New York City..............mpollak at panix.com