“You can’t manage what you can’t measure”: Regenerative agriculture, farming by numbers, and calculability in soil microbiopolitics

Microbes are increasingly central to visions of sustainable and healthy futures, including in farming movements such as regenerative agriculture. In social science and environmental humanities scholarship, (re)connecting with microbes is seen as a way to challenge, conceptually and practically, the very ontology of human-nature separation which underpins the destruction and violence in human relations with other living beings and with environments. The crux of this onto-ethical potential is a shift towards relational modes of knowing microbes, rooted in localised, proximate, and sensuous practice, and expressed in embodied expertise. This paper engages critically with this promise by calling attention to persistence of calculability to people's self-governance within current microbiopolitics. Through a case study of regenerative agriculture in the United Kingdom, I argue that while embodied expertise of soil microbes is seen as crucial to soil health-oriented farming, it is also dismissed as an insufficient in guiding farmers and shaping future practice, including by farmers themselves. Regenerative agriculture continues to function within “farming by numbers”, an agri-biopolitical regime in which farmers’ and advisors’ subjectivity is that of calculating managers situated in calculable environments. As a result, calculability acts as a ‘break’ on the development of alternative microbial onto-ethics, and regenerative agriculture practitioners look for ways to bring soil microbes into the realm of calculability (e.g., through metagenomics). Consequently, the way microbes are being incorporated into future agri-environmental relations reinforces rather than threatens existing structures of biopolitical power. Overall, I argue that human-microbe research, potentially due to its empirical focus on alternative practices, has underplayed the importance of calculability to people's self-governance in relations with microbes. The struggle for a new microbiopolitics, especially in agriculture and environmental management, will require addressing the continued importance of calculability, and a creative and socially relevant experimentation with alternative forms of expertise.