Assessment [MA], 2005). Yet, the living components of soils and their multiple interactions above-and belowground still receive relatively little attention globally in agriculture.

Here, I enlarge the discussion of biodiversity in agricultural ecosystems from the current focus on soil parasites and pathogens to a broader overview of soil biodiversity; this is particularly needed when planning for long-term sustainability of ecosystems worldwide. Sustainability, a concept of treating the environment carefully so that the needs of future generations may be met, is not new and has been employed from the time of the earliest hunting and farming societies as resource limitation of one form or another affected the ability to catch prey or produce food. I begin with several examples of global environmental agreements and policies that have already focused attention on components of soil biodiversity, discuss the role of soil biodiversity in the provision of ecosystem services, and conclude with a discussion of biocontrol or disease regulation as a service. Ecosystem services here are deŸned according to the global analysis of the MA (2005) as beneŸts people obtain from ecosystems. These beneŸts were termed provisioning services (e.g., food, Ÿber, and clean water), regulating services (e.g., climate regulation, disease regulation), cultural services (e.g., aesthetic, recreation, spiritual values), and supporting services (e.g., primary production, decomposition, and soil formation).