GEOPHYSICAL MONOGRAPH SERIES, VOL. 186, PP. 61-81, 2009
The expansion of intensive agriculture and ranching in Brazilian Amazonia
Agriculture in Amazonia has often provoked controversy, given the tremendous ecological value of the region's environment.
First with ranching, and now with the soybean boom, tractors and cattle have marched across lands that for millennia supported
only closed moist forest, resident ecosystems, and dispersed indigenous peoples. The present chapter considers this expansion,
focusing on the Brazilian portion of the basin. Its premise is that effective Amazonian policy must be grounded on an understanding
of the region's agriculture. The chapter pursues its objectives by first addressing the development initiatives that created
the preconditions for Amazonia's current agricultural economy. The region is remote and has therefore required sustained government
intervention to release its potential. The policy discussion is followed by descriptions of cattle ranching and soy farming.
For each, market settings and trajectories of expansion are presented. Although these sectoral descriptions are data rich,
they do not provide a conceptual framework for analyzing the environmental impacts of evolving market conditions. To accomplish
this, the chapter invokes the classical land use model of von Thünen to explain Amazonian land cover dynamics in relation
to soy-cattle linkages. It addresses these dynamics with remote sensing data from Mato Grosso, Pará, and Rondônia, and then
discusses scenarios of agricultural advances on the forest. Conclusions follow, considering possible policy responses to deforestation,
and the social context of agricultural intensification, with special attention to the issues of land tenure security and distributional
Citation: Walker, R.,