Expansion of Mechanized Agriculture and Land-Cover Change in Southern Rondonia, Brazil

region-wide soybean production and deforestation rates to suggest that soybean farmers are the next destroyers or "relentless foes" of the Amazon (Branford and Freris 2000; Fearnside 2001; Rohter 2003). It is argued that soybean cultivation will spread into fron tier forests, resulting in deforestation and consolidation of landholdings. In turn, this consolidation is feared to create a rural exodus of peasants, leading to even further ad vancement of forest destruction (Fearnside 2001; Bickel and Dros 2003; WWF et al. 2003). Agro-industrialists, however, describe mechanized farming as a uwin-win" sce nario for development and conservation, arguing that it increases land-use intensification which reduces the need for clearing new land while allowing for economic development (EMBRAPA 2002; Mueller and Bustamante 2002). No published empirical study has used spatially explicit data, human or physical, to measure or explain the mechanisms of forest change due to mechanized cultivation. Our current project engages this debate by seeking answers to three main ques tions: (1) To what extent are forests converted for mechanized annual cropping?; (2) What are the key human variables that explain land change patterns? (3) What is the relationship between land-use intensification and forest conversion? Our study area is a modern agricultural frontier in southern Rondonia, an area at the humid Amazon forest savanna transition that is poised to become another major soybean-producing region.