Land Transformation and Occupation Impacts of Farming Practices for the Production of Soybean in Mato Grosso, Brazil, Using Life Cycle Impact Assessment

Abstract:

The state of Mato Grosso is the largest producer of soybean in Brazil with production continuously increasing since 2000 through a near tripling of cropland area under soybean cultivation. This increase in production has occurred by land cover transformation (extensification into natural ecosystems, e.g. forest to crop) and land use intensification (increase in area by conversion of already cleared land, e.g. pasture to crop), largely to satisfy international demand. In this study, we assess cradle-to-farm gate impacts of soybean production in Mato Grosso using life cycle impact assessment applied to data collected from 110 farms. We combine 21 impact indicators of land transformation and occupation (i.e. land use and land cover change) to show impacts of life cycle stages of production to land, air, water, resource use, biodiversity and ecosystem services. The greatest damage to human health and ecosystem quality came from land transformation which primarily takes place in the tropical forest (Amazon) and savanna (Cerrado/Cerradão) biomes. Soybean production in tropical forest landscapes has greater impacts on climate regulation, biotic production and groundwater recharge compared to production in native savanna areas, while impacts on biodiversity, erosion and soil water purification are roughly equivalent for tropical forest vs. savanna transformation and occupation. Soybean production practices showed hot spots of damage to environmental quality and resources from phosphorous fertilizer application and diesel consumption in machinery through impact pathways such as terrestrial and aquatic acidification and the use of non-renewable energy. Life cycle impact assessment modeling can provide further information into the production process to enlighten decision making with respect to impacts occurring along the soybean product supply chain.