Bibliometric analysis of research on critical nitrogen dilution curves from the China National Knowledge Infrastructure and Web of Science databases

Nitrogen is one of the critical elements for crop growth and production. Reasonable nitrogen management contributes to high production yields. The critical nitrogen dilution curve is a precision nitrogen management model for improving nitrogen utilization efficiency, reducing environmental pollution, and decreasing production input. To better present the current domestic and foreign research status and development trends of critical nitrogen dilution curves and objectively reflect how different countries, research institutions, authors, and journals have influenced this research field, we econometrically analyzed relevant literature over the 15-year period from 2006 to 2021 using the Web of Science (WOS) Core Collection and China National Knowledge Infrastructure (CNKI) databases. CiteSpace and the VOSviewer were used to analyze the annual number of papers, authors, institutions keywords, etc, and draw relevant maps. The results showed that the number of papers published on the critical nitrogen dilution curve slowly increased in the initial stage and then rapidly increased. The top three countries for publications were China, France, and the United States. By comparison, researchers in China performed larger studies in this field. By studying the zone view of research frontiers and keywords that have suddenly increased in citation frequency in critical nitrogen dilution curve research, we found that the research including keywords such as “corn” and “yield level” have been the research hotspot in recent years, and that studies to improve the crop yield will be a key research direction.