Consequences of different pesticide emissions modelling: case study for soybean crop in Brazil

The impacts of pesticide use are one of the main environmental problems in agriculture and a threat to as much environment as human beings. Even Life Cycle Assessment (LCA) methodologies, one of the main ones to evaluate production systems, have encountered difficulties in determining the (eco)toxicity impacts of pesticides. The lack of understanding in the relationship between the production system and the environmental emission compartment is one of the problems. Thus, this study aimed to evaluate two modeling methods – and two definitions of environmental emission compartments, ecosphere and technosphere – for pesticides: 100% of emissions to soil and PestLCI. Two soybean production techniques were considered, integrated pest and disease management (IPM-IDM) and scheduled application. To assess the impacts, two methods were adopted: USEtox and ReCiPe. In the evaluation by USEtox, we observed the human toxicity category, which suffered few changes, different of the freshwater ecotoxicity category. For ReCiPe that most impact categories have undergone few changes, except for ecotoxicity categories, terrestrial and freshwater. Therefore, despite the difference in modeling and emission compartments, no consensus has been reached on the framing of compartments between ecosphere and technosphere. However, we observe that the combination of different models together with different impact assessment methods mainly influence the (eco)toxicity impact categories, of which the definition of emission compartments is more sensitive