This chapter considers the relationship between biodiversity and modern commodity agriculture in Brazil and Australia. It provides an overview of the financial constraints on biodiversity protection and the development of public programmes to encourage more sustainable ways of farming, including by small-scale, family farmers. The chapter then focuses on the threats to biodiversity posed by agriculture, including from land clearing, contamination from agro-chemicals and invasive species. The chapter concludes with a discussion of socio-ecological issues and governance of agriculture.