Harris, Jim A.Evans, Daniel L.Mooney, Sacha J.2022-08-162022-08-162022-07-26Harris JA, Evans DL, Mooney SJ. (2022) A new theory for soil health [Opinion], European Journal of Soil Science, Volume 73, Issue 4, July-August 2022, Article number e13291351-0754https://doi.org/10.1111/ejss.13292https://dspace.lib.cranfield.ac.uk/handle/1826/18322The term “soil health” has captured the interest of government, and land managers, whilst the academic community has struggled to rationalise its use and wider benefit. It has proved a powerful tool in conveying best practice to a lay audience. However, the widespread adoption of the “metaphor” has resulted in calls for tools that facilitate the measurement of soil health, preferably quantitatively, and often as a single figure, for ease of use/communication and cost of monitoring. The insurmountable problem is that soil health is neither a readily quantifiable nor measurable object. Only organisms can have ‘health’, which manifests as characteristics of a living system—true of complex systems exhibiting “emergent” properties such as resilience in the face of perturbation. We pose the key question: is soil really a system capable of exhibiting “health”, or any other property emerging from a complex, connected, self-regulating system? We argue that if you cannot detect emergent properties, you are: (i) looking at the wrong dynamic parameter; (ii) not considering the entire system; or (iii) not evaluating at a system at all. We suggest that our focus should instead be on the relationships between components, complexity, and function. Using this as a basis for a new framework will allow us to assemble and align disparate threads of soil science into a cogent and coherent “new theory of soil health”, which is an essential and practical step forward for the sustainable management of global soil resources, across all land uses.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/Soil healthemergent propertiesresiliencesystemsscaledynamic propertiesArticle1365-2389