Land-use transitions between 2000 and 2006 in the Legal Amazon. In the municipalities where deforestation occurred over this period (green and orange), we separated those in which pasture increased from those where soy increased. (In municipalities where both soy and pasture increased, we labeled it using the dominant change.) Also, we identified municipalities where soy expanded while pasture decreased (and the decrease in pasture exceeds deforestation). Captions / images copyright Barona et. al. (2010)

By Rhett A. Butler, www.mongabay.com
April 28, 2010 Industrial soy expansion in the Brazilian Amazon has contributed to deforestation by pushing cattle ranchers further north into rainforest zones, reports a new study published the journal Environmental Research Letters. The authors — including Elizabeth Barona, Navin Ramankutty, Glenn Hyman and Oliver Coomes — analyzed annual census data on deforestation, crop harvest area, livestock population, and pasture area between 2000 and 2006 from municipalities in the Brazilian Legal Amazon. Their analysis found that deforestation shifted 39 km to the northeast during the period, while pasture shifted 87 km to the northwest, from northeastern Mato Grosso to southwestern Para, and soybeans moved 82 km to the northeast, from southern to northeastern Mato Grosso. The researchers also noted that soybean expansion was accompanied by a decline in pasture area in many municipalities in Mato Grosso, lending support to the argument that “decreases in pasture in Mato Grosso owing to soybean expansion may have been compensated by increases in pasture elsewhere in northern Mato Grosso, Para and Rondônia causing some deforestation indirectly, i.e., ‘displacement deforestation.'” … Soy production in the Amazon exploded in the early 1990s following the development of a new variety of soybean suitable to the soils and climate of the region. Most expansion occurred in the cerrado, a wooded grassland ecosystem, and the transition forests in the southern fringes in the Amazon basin, especially in states of Mato Grosso and Pará — direct conversion of rainforests for soy has been relatively limited. Instead, the impact of soy on rainforests — as suggested by the Environmental Research Letters study — is generally seen to be indirect. Soy expansion has driven up land prices, created impetus for infrastructure improvements that promote forest clearing, and displaced cattle ranchers to frontier areas, spurring deforestation.  …

Large-scale soy farming in Brazil pushes ranchers into the Amazon rainforest