Knowledge Map and Global Trends in Root Exudates Research from 2012 to 2021: a Bibliometric Analysis

The number of publications on root exudates has been increasing continuously, because root exudates play a key role in soil biochemical cycles and plant-soil feedbacks. However, global trend and research hotpots on root exudates research were still unclear. The study aims to identify leading publications, authors, countries, and topics in root exudates research to help ecologists and phytologists to adjust and radicate framework of future research. Five thousand eight hundred seventy-nine literatures on root exudates research in the Web of Science database from 2012 to 2021 were collected as the data source, and bibliometric analysis was performed by using CiteSpace software. The results show that (1) the number of publications on root exudates research increased year by year steadily, and the increase rate of publications had enhanced markedly since 2017; (2) most of the authors had seldom cooperated, and a stable cooperative group had not yet formed among the core authors; (3) the institution with highest betweenness centrality was Chinese Academy of Sciences, indicating it made a nonnegligible contribution to the research of root exudates; (4) the research subjects of root exudates were mainly plant sciences, agriculture and soil science; and (5) microbiome, rhizosphere, and priming effect were always the research hotspots, and microbiome is becoming a burgeoning research hotspot. This study uses bibliometric analysis to identify frontier hotspots and developments in root exudates during the past decade to provide guidance for future studies.