Areas of tropical vegetation are rapidly disappearing due to agricultural expansion, posing significant threats to biodiversity and climate stability. To address this issue, companies and governments have adopted supply-chain sustainability policies and zero-deforestation commitments. However, challenges persist in their implementation and there is resistance to conservation regulations. The Brazilian Cerrado, a biodiverse savanna, experiences rising deforestation driven by soy production. Understanding soy farmers' decision-making is key to overcoming this issue, as most of deforestation occurs on private properties and in compliance with legal conservation requirements. Yet, little knowledge on soy farmers land use decision-making in the Cerrado exists. This thesis investigates soy farmers' land-use decision-making processes in the Cerrado to contribute to the zero-deforestation debate and propose effective conservation strategies. The study's objectives are as follow: (1) To emphasize the urgency of including the Cerrado biome in conservation policies and propose effective deforestation mitigation measures, (2) To assess the current state of agricultural literature regarding mental models, identifying patterns in their use, (3) To explore and analyze the perspectives, attitudes, and behavior of Brazilian soy farmers regarding land-use decisions, and (4) To investigate farmers' acceptability of interventions that aim to reduce the rates of deforestation. [...]