Rhizodeposition-Mediated Soil Carbon Cycle: A Bibliometric Analysis

Rhizodeposition has a major impact on the soil carbon (C) cycle. However, a clear understanding of global rhizodeposition-related research directions and trends is still lacking. The present study aims to identify the most relevant publications, countries, topics, and authors involved in the field of soil C cycle-rhizodeposition (SCC-Rhizo) to promote the development of future research frameworks for ecologists, soil scientists, and phytologists. A bibliometric analysis of 2598 studies on SCC-Rhizo over the 1966-2023 period was performed in this study using R, VOSviewer, and CiteSpace software. The main findings obtained are as follows: (1) SCC-Rhizo research is still in its nascent stages and has great growth and development potential; (2) a temporal increase in annual publications on SCC-Rhizo was observed. In addition, the main contributing countries/regions have shifted from Europe and the United States of America to China during in the last decade; (3) SCC-Rhizo research has focused mainly on the impacts of rhizodeposition to soil organic matter decomposition, soil microorganisms, the priming effect, as well as their responses to climate change; (4) the focus of SCC-Rhizo research has shifted from small-scale rhizosphere studies to large-scale ecosystem studies, taking into account forests, grasslands, and wetlands. Therefore, future research on the mechanisms, dynamics, scaling effects, and cumulative impacts of rhizodeposition on soil C cycling using advanced measurement techniques, predictive models, and interdisciplinary collaboration is required to address this knowledge gap. This bibliometric meta-analysis identified hotspots and cutting-edge trends in SCC-Rhizo research over the past four decades, providing guidance for future related studies.