Following a period of intense interest in the use of human excrement as fertilizer in nineteenth-century Europe, this type of manure was largely sidelined by the rise of synthetic fertilizers. However, interest in human excreta as manure has seen a resurgence in recent decades thanks to the growing use of composting toilets at the domestic level, particularly in France. In this chapter, we explore how the practice of returning human excrement to the soil relates to agricultural production at different points in recent history. Specifically, we examine how these practices provide a basis for a political and economic critique of the prevailing extractive model and serve as a means of inquiry into the (re)production of soil fertility.