Recent history of the agriculture of the Brazilian Amazon Basin : prospects for sustainable development and a first look at the biogeochemical consequences of pasture reformation

Land-use change for human settlement and agricultural purposes, especially pasture establishment, has caused major impacts on the Amazon Basin's environment. Development of strategies for reformation and restoration of already degraded pastures constitutes the main goal of the authors' research work. For some of this work, a homogeneous area of land in terms of soil characteristics was selected at Nova Vida ranch in Rondônia state to conduct a multidisciplinary experiment, which included agronomic, environmental and economic analyses. Since July 2001, the authors have monitored five treatments: control, herbicide, tillage, no-till rice and no-till soybean, arranged in four blocks. Early results on carbon and nitrogen stocks, nitrogen mineralization, trace-gas fluxes, dissolved organic carbon and microbial biomass are briefly presented