Web of Science (WOS) is widely recognized as the authoritative and consistently curated database for high-impact scientific literature, standing as a key authoritative source of citation data (Chen et al., 2022). Considering its data standardization, a comprehensive literature review was performed utilizing the Web of Science Core Collection (WoSCC) database. The search strategy employed the following Boolean query, which is derived from the operators of the expanded database within the Web of Science’s Science Citation Index: TS = Topic; TI = Title; AND = Conjunction keyword; OR = Keyword group connection; * = Wildcard (for singular and plural suffixes). The search string is as follows: TOPIC = ((TS = root exudates*) AND (TI =“Phosphorus*”OR”phosphate*”)), covering the period from 1 January 2001 to 31 December 2024, with the search conducted on 10 January 2025, including English only. The data retrieved included a total of 527 papers. To refine the dataset and exclude irrelevant studies, duplicates, review, experimental methods, meeting, book, and research with non-relevant topics were filtered out, reducing the final dataset to 276 records. These publications from WoSCC were exported in plain text format.

The study adopted a systematic three-stage workflow to establish a comprehensive bibliometric analysis framework for this field ( Figure 1 ).The first stage, the research design stage, identified the interrelationship between root exudates and soil phosphorus as the research theme and proposed three core research objectives. The second stage, the data collection phase, involved retrieving publications through advanced search queries in the target database. The third stage, the most crucial in the workflow, involved quantitative analysis of the 276 Web of Science articles published between 2001 and 2024 using CiteSpace (version 6.4.1) (http://citespace.podia.com, accessed on 10 January 2025), VOSviewer (version 1.6.20) (https://www.vosviewer.com, accessed on 10 January 2025) (van Eck and Waltman, 2010), and the R-based Bibliometrix package (version 4.3.1) (http://www.bibliometrix.org, accessed on 10 January 2025) (Aria and Cuccurullo, 2017). Publication counts, subject distribution, co-citation frequencies, international collaborations, and journal contributions related to root exudate-soil phosphorus interactions were analyzed using Microsoft Excel 2010 and the R-based Bibliometrix package, leveraging the bibliometric visualization and analysis functions of the Web of Science (WOS) database (https://bibliometric.com).

The Co-occurrence and Co-authorship networks in this field, including cooperative trends among countries, keyword Co-occurrence, and cluster analysis, were visualized using VOSviewer. Moreover, the top ten keywords with the most significant citation bursts were analyzed and mapped using CiteSpace. The time - zone map of research frontiers was drawn using CiteSpace, and the frontier trends in this field were identified through the method of keyword frequencies + burst term. The characteristics of the interrelationship between the root exudates and soil phosphorus field were systematically and objectively examined, with its research status, hotspots, and emerging trends delineated to facilitate a clearer understanding of its developmental trajectory and future prospects.

The annual trend of publications provides an intuitive measure of academic attention to research hotspots in specific fields (Tomasi et al., 2009). A bibliometric analysis of annual outputs from 2001 to 2024 reveals a consistent upward trend in studies on root exudate-soil phosphorus interactions ( Figure 2 ). Based on publication patterns, the entire period was categorized into two distinct phases: an initial development phase (2001-2015) and a rapid growth phase (2016-2024).

During the initial development phase, annual publications remained below 10, though notable citation counts were observed in 2002, 2011, and 2013, suggesting influential early contributions. Since 2016, however, research activity has accelerated significantly, with annual outputs averaging 12 publications and exceeding 10 papers per year. In 2017, the annual publication count exceeded 15 for the first time, reaching a peak of 28 papers in 2022, reflecting a substantial surge in disciplinary interest and collaborative efforts.

From 2001 to 2015, research outputs in this field remained relatively limited, primarily attributed to the inherent complexity of the root exudate-soil phosphorus system and technological constraints of the era (Giles et al., 2012). The influence of root exudates on phosphorus transformation involves multidimensional factors, including soil minerals, microbial communities, and plant physiological regulation. The dynamic coupling mechanisms of these factors across spatial and temporal scales are highly complex, making related research more challenging. Soil type, climatic variability, and divergent agricultural management practices further limit the generalizability of research findings (Hocking and Jeffery, 2004; Plaxton and Tran, 2011). The collection and analysis of root exudates require high-precision equipment and meticulous operational protocols, posing significant challenges for conventional techniques to resolve their transient dynamics. The different types soil phosphorus (e.g., labile phosphorus, organic phosphorus, and stable phosphorus) require specialized techniques such as isotope labeling and Hedley phosphorus fractionation to study transformation mechanisms. Notably, around 2016, the research in this field experienced explosive growth, with the number of related papers reaching 28 by 2022, reflecting an impressive growth rate of 64.7% compared with the previous year. The occurrence of this phenomenon may be closely associated with multiple contributing factors. Firstly, advances in chromatographic techniques, such as high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) have enabled more precise compositional analysis of root exudates (Nourozi et al., 2024), allowing the identification of various substances including organic acids, sugars, and amino acids. When combined with metabolomic analysis methods, these techniques facilitate a deeper understanding of their roles in phosphorus transformation. Advances in soil nutrient analytical techniques, including X-ray diffraction (XRD) and phosphorus isotope tracing, has also provided more precise approaches for characterizing the content and spatial distribution of different phosphorus forms in soil (Ke et al., 2025). Furthermore, the development of high-throughput sequencing technology have facilitated a more comprehensive analysis of the structure and function of rhizosphere microbial communities, revealing the interaction mechanisms between root exudates and microorganisms (Vinothini et al., 2024). Similarly, the processes and functions of substance migration and transformation at the rhizosphere interface have been accurately captured and quantified due to the development and application of in-situ visualization techniques for the rhizosphere (Gu et al., 2024).

This study reveals that research on the interaction between root exudates and soil phosphorus spans multiple categories. The number of these research categories covered by publications increased significantly from 5 in 2001 to 13 in 2023 ( Figure 3a ). This growth trend reflects the expansion of research into multidisciplinary domains as scientific investigations have deepened. From 2001 to 2024, the discipline with the highest publications was Plant Sciences (139 articles), followed by Soil Science (74 articles) and Agronomy (49 articles), which respectively accounted for 53.05%, 28.24%, and 18.70% of the total ( Figure 3b ). These findings indicate that the impact of root exudates on soil phosphorus transformation, particularly their effects on plants and crops, has remained a central focus of research in this field.

Additionally, the research categories also include Environmental Sciences, Microbiology, Biochemistry Molecular Biology, Engineering Environmental, Agriculture Multidisciplinary, Biotechnology Applied Microbiology, Multidisciplinary Sciences, Chemistry Analytical, Forestry. These categories provide valuable insights from diverse perspectives to further our understanding of the interactions between root exudates and soil phosphorus.

Twenty countries have conducted research on the interactions between root exudates and soil phosphorus between 2001 and 2024. The top ten countries in terms of publication output account for approximately 94.93% of global research contributions in this field, with a total of 262 publications ( Table 1 ). China has the highest publication output in this field (69 articles) ( Table 1 ), which is likely closely associated with Chinese government policies that prioritize improving soil phosphorus availability and enhancing phosphorus fertilizer use efficiency. Additionally, researchers from 15 other countries conducted studies on the correlation between plant root exudates and soil phosphorus ( Table 1 ; Figure 4 ). Similarly, China has the highest total citation frequency at 2,231 times (32 citations per article), suggesting a significant scholarly impact and a pronounced research advantage on the global stage. Although it has the highest publication output, its relatively lower citations per article indicate scope for enhancing research quality and depth.

Total link strength (Tls) serves as a critical metric for quantifying collaboration intensity between countries and regions. A higher Tls value indicates a stronger and more extensive collaborative network between the country or region and others (Wang and Tian, 2013). Among them, China (Tls=31), Australia (Tls=23), Germany (Tls=26), and the United States (Tls=24) rank highest, indicating that these countries are relatively active in research and collaboration within this field ( Table 1 ). Further integrated analysis of the cooperation between countries using VOSviewer visualization software revealed that China and Australia have particularly close collaboration in this field ( Figure 4 ), likely due to their shared research goals regarding the low efficiency of phosphorus utilization in soils (Cai et al., 2017). In the future, as global demand for sustainable agriculture and forestry increases, it is expected that cooperation between China and countries such as Australia, the United States, and Germany in areas like plant-microbe interactions and phosphorus use efficiency will further deepen.

Statistical analysis of journals with high overall publication output revealed that among the top 10 journals in terms of publication quantity, 29 articles were published in Plant and Soil followed by Plant Science (10 articles) ( Table 2 ). This results indicates that Plant and Soil accepts the highest number of articles in the fields of root exudates and phosphorus transformation, while also reflecting a high level of scholarly recognition for the journal’s prominence and influence in these research field. As an internationally renowned journal, Plant and Soil focuses on the intersection of plant biology and soil science, aiming to uncover the ecological processes of plant-soil interactions. By integrating multidisciplinary perspectives, the journal plays a crucial role in promoting the integrated development of plant science and soil science. The consistently growing publications of research on root exudates and phosphorus transformation in Plant and Soil reflects both its significant academic value in interdisciplinary research and its relevance to addressing the global challenge of efficient phosphorus utilization.

Further analysis of the top 10 most highly cited articles in the research fields of root exudates and phosphorus transformation on the Web of Science (WOS) ( Table 3 ) revealed that the article with the highest citation frequency is “Strigolactones are transported through the xylem and play a key role inshoot architectural response to phosphate deficiency in nonarbuscular mycorrhizal host Arabidopsis” by Kohlen et al., published in Plant Physiology. This study has been cited 351 times. The study found that, in response to phosphate deficiency, strigolactones played a central role in regulating the shoot architectural response of Arabidopsis thaliana, which is a plant that cannot form arbuscular mycorrhizal symbiosis. Moreover, this study developed a comprehensive analytical system for strigolactones based on high-performance liquid chromatography, column chromatography, and multiple reaction monitoring-liquid chromatography-tandem mass spectrometry. This system enabled systematic separation, high-sensitivity identification, and precise quantification of strigolactones in root exudates of Arabidopsis thaliana. The results not only provide a standardized analytical method for the isolation and identification of hormone-related substances in root exudates, but also offer important references for recent multi-omics studies on the composition of root exudates.

To further reveal the core research directions and evolving trends in this field, this study employed CiteSpace software to perform a temporal zone analysis of keywords from all relevant publications (2001-2024) in the Web of Science (WOS) database, and generated a visualization of frontier research frontiers ( Figure 7 ). These results may enable a more precise analysis of the central themes in past and current research and, to some extent, predict future developments in the field. In the temporal visualization of research frontiers, the size of the node denoting a keyword is proportional to its appearance frequency; the density and length of linkages between nodes reflect the temporal span of that keyword. Analysis of the WOS research frontier temporal zone diagram reveal that keywords such as “Root exudates”, “Phosphorus”, “Organic acids”, “Soil”, “Plant”, and “Lupinus albus” exhibit the highest frequently and strongest connections to other keywords. These keywords have consistently emerged throughout the 2001–2024 period, indicating their significant role in the research on root exudates and phosphorus transformation.

To identify keywords that exhibited sudden citation bursts in specific years and uncover deeper disciplinary developments and emerging research frontiers, this study utilized the “Timezone” function in CiteSpace to perform burst analysis on keywords from the WOS database. The top 10 keywords with the strongest burst strength are listed in Table 5 . An analysis of the burst timings for these keywords revealed that early researches focused on plant adaptive strategies, particularly the impact of root structure and exudates on phosphorus activation. Thus, “Lupinus albus L.” and “Proteoid roots” had the highest burst strength during 2002-2006. With the advancement of research techniques, the core theoretical frameworks underlying phosphorus activation mechanisms have been formulated. Meanwhile, research scope has expanded to encompass diverse plants species, as well as plant growth regulation, the synergistic effects of multi-nutrient interactions, thereby resulting in heightened burst strength for keywords such as “Plant,” “Growth,” and “Nitrogen” since 2018. These also reflect the dynamic interplay between academic advancements and societal demands. Future research should integrate microbial functional genes and microbial metabolic networks to further elucidate the mechanisms by which plant root exudates modulate rhizosphere microbial communities to promote soil phosphorus activation. Furthermore, gene editing and epigenetic regulation techniques should be utilized to improve plant adaptation to low-phosphorus soils environments. Research on root exudate-soil phosphorus interactions will advance towards an integrated framework that incorporates “micro-mechanism analysis—macro-ecological integration—technology application and translation”. Research hotspots will gradually shift toward four main directions: plant-microbe interactions, multi-nutrient coupling, gene editing, and smart agriculture and forestry ( Figure 8 ). Furthermore, while the keyword “intercropping” did not rank among the top ten terms, it is undeniable that significant advancements have been made in research concerning soil phosphorus availability and root exudates within crop planting systems, rotations, and intercropping practices. These studies are transforming the agricultural landscape across Europe, the United States, and other countries. For instance, in the intercropping system of leguminous plants and cereal crops, the root system of leguminous plants releases more protons and organic acids, locally acidifying the rhizosphere soil and increasing the availability of phosphorus, thereby promoting the absorption of phosphorus by adjacent cereal crops (Yu et al., 2021). These research accomplishments also offer valuable insights for agricultural transformation in developing countries. Overall, investigations into soil phosphorus availability and root exudates are steering global agriculture and forestry toward a more sustainable future. This represents not only a scientific and technological advancement but also a crucial step for humanity in addressing forthcoming food security challenges.

To better understand the interactions between root exudates and soil phosphorus, we counted 276 articles refined on WOS and systematically analyzed the overall trend of publications, research categories, active countries, journal, high frequency keyword, keyword Clustering, frontiers and future directions, revealing the core hotspots and developmental pathways in this field.

However, this study has several limitations that should be explained. First, this research exclusively utilizes articles sourced from the WOS database, it does not include publications from other databases such as Scopus or Google Scholar. The reason for this is that WOS is widely recognized as an authoritative and continuously maintained database for high-impact scientific literature, especially in the field of natural sciences. Additionally, bibliometric tools like CiteSpace and VOSviewer have been optimized to handle WOS data formats, and this compatibility minimizes technical errors during the construction of networks and cluster analysis. Finally, when integrating records from multiple databases, issues such as data deduplication, inconsistent domain coordination, and differences in term mapping are inevitable, which may compromise the visualization effect and the repeatability and validity of the indicators. To address this limitation, future studies could expand their scope by conducting multi-database bibliometric analyses, thereby ensuring a more comprehensive and representative assessment of the publications. Second, bibliometric methodologies predominantly rely on citation-based metrics, which may not serve as definitive indicators of scientific impact. Consequently, emerging research areas with relatively low citation counts may be underrepresented, despite their potential significance. Third, since WOS mainly indexes English-language publications, it could lead to the underrepresentation of significant works published in other languages. Future research should integrate multilingual datasets to improve the inclusivity and comprehensiveness of bibliometric evaluations.