Land occupation and transformation impacts of soybean production in Southern Amazonia, Brazil

Abstract

Since 2000, soybean production has gained increasing importance in Brazil, particularly in Southern Amazonia and the state of Mato Grosso, the largest producer in the country. This expansion has taken place through cropland extensification into natural ecosystems in the Amazon (tropical forest) and Cerrado (savanna) biomes with land transformation and occupation activity well documented by remote sensing. Guidelines from the UNEP/SETAC Life Cycle Initiative now allow for impact assessment of land transformation and occupation within a Life Cycle Assessment (LCA) to estimate potential impacts to biodiversity and ecosystem services. In this study, we apply these guidelines to soybean produced in 2010 in order to complement more traditional soybean LCAs with mid- and end-point impact assessment on biodiversity, erosion potential, water purification, groundwater recharge, biotic production and climate regulation potential in each of the Amazon and Cerrado biomes. In addition to providing regionalized characterization factors of land transformation and occupation in both Mato Grosso biomes, we estimate that one tonne of soybean produced in 2010 in the Amazon had greater impacts than when produced in the Cerrado. For the Amazon, total land transformation and occupation damage was estimated at $ 532 ton−1 and $ 260 ton−1 respectively, with estimates of $ 231 ton−1 and $ 153 ton−1 for the Cerrado. The largest contributors to these damage estimates came from the change in mechanical filtration properties of the soil followed by the land's climate regulation and biotic production potentials. The impact allocation to pasture as a transitional landscape in the establishment of cropland onto natural ecosystems diminished the soybean contribution through allocation of pasture to the beef production system, further adding to the land sparing argument for future cropland expansion in the region.