[en] During photosynthesis, plants fix carbon dioxide from the atmosphere and transform it into bioavailable molecules like primary sugars and more complex molecules like cellulose. A significant fraction of these molecules is transferred to the soil in the plant root zone, where organic carbon compounds serve as food source for soil microorganisms and thus direct their metabolic activity. Increased microbial activity can lead to higher turnover rates of native soil organic matter (positive priming), while microbes can also shift their energy and nutrient acquisition from soil materials to fresh organic inputs, which reduces rates of soil organic matter mineralisation (negative priming). Here, an ecological perspective integrates both positive and negative rhizosphere priming effects as ubiquitous processes in vegetated terrestrial ecosystems linking carbon, nutrient and water cycles. It is suggested that in the mid- to long-term rhizosphere priming effects contribute to synchronising carbon and nutrient supply and demand between plants, soils and microbes, with a neutral carbon balance. Future research could address these rhizosphere plant-soil-microbe interactions in an agronomical context, for example by implementing exudation patterns and rhizosphere priming potential as specific plant-traits to provide new levers for land management strategies that reduce nutrient losses and the need for mineral fertiliser, while also increasing the potential for soil carbon storage.
