Abstract:
Intercropping is one of the traditional agricultural planting patterns, which plays an important role in improving grain yield and soil fertility. This study was to clarify the differences in nitrogen utilization between domestic and foreign studies and its causes, in order to provide reference for further research in China. The domestic and foreign literatures on intercropping system nitrogen research in the past two decades were analyzed, as well as the development history, hot spots and frontier differences of domestic and foreign research in this field by means of bibliometric analysis, such as literature co-citation and keyword co-occurrence. Compared with developed countries such as Europe and the United States, the number of publications in English from China was relatively fewer in the early 21st century, but in recent years, China has become the country with the largest number of publications in English, accounting for 26.07% of the world's total. The intermediary centrality reached 0.26, and the quality of Chinese published journals was generally higher than that of foreign countries. Among the top 20 hot papers in the world, six were from China, and the number of published papers from six domestic research institutions, including China Agricultural University, Chinese Academy of Sciences and Sichuan Agricultural University, ranked among the top ten in the world. China has the greatest influence in this research field and played a good leading role. On the whole, intercropping research mainly focuses on agronomic benefits such as "yield", "growth ", "nitrogen uptake" and "quality", and environmental benefits such as "nitrogen use", "nitrate nitrogen" and "soil fertility". Domestic research hotspots focused more on bacterial community, photosynthesis and crop productivity. The research focused on essential oil, urochloa brizantha, weed control and intermediate wheatgrass. Due to the different status quo at home and abroad, the research focuses at home and abroad were different. The current research in China was more in line with the development trend of high yield and high efficiency of grain, and was in the forefront of the world. In future studies, the mechanism of intercropping microorganisms should be further study, the research and application of diversified intercropping and agricultural machinery and equipment should be strengthened as well. Moreover, those should be combined with the actual production to ensure the quality of the publications, so as to form a multi-disciplinary and multi-field cross-integration development model, to greatly promote the sustainable development of agriculture.