Trends in the research on soil nitrogen leaching from farmland: A bibliometric analysis (2014–2023)

Abstract

This study aims to explore the current progress, hotspots, and future directions in the research on nitrogen (N) leaching from farmlands. We analyzed 793 publications on N leaching published from 2014 to 2023, which were collected from the Web of Science Core Collection database, using bibliometric tools such as CiteSpace and VOSviewer to visualize research networks and the thematic evolution of the field. The results revealed that China and the USA were the leading contributors to this field, which was driven by environmental policies and agricultural challenges in these countries. The Chinese Academy of Sciences, in cooperation with other institutions, produced the highest number of publications, reflecting a significant impact. High-frequency keywords, including “nitrate leaching,” “nitrogen management,” “cropping system,” and “yield,” indicated that the primary research themes were related to optimizing N fertilizer use efficiency while minimizing environmental impacts. Furthermore, emerging terms such as “organic nitrogen,” “controlled release urea,” and “microbial biomass” provided new insights into evolving research directions, emphasizing the crucial role of integrating sustainable nutrient management strategies to address groundwater quality and environmental sustainability goals. Despite these advances, a gap remains in understanding the link between microbial community dynamics, particularly in terms of functional microbes involved in the N cycle, and N leaching. In future studies, researchers should prioritize investigations of the role of microbiomes in N loss from farmlands by employing advanced modeling approaches and utilizing stable isotope tracing techniques to advance the field. These findings provide valuable guidance for future research directions and policy-making efforts to enhance agricultural sustainability and environmental protection.