氮肥农学效应与环境效应国际研究发展态势

分析国内外农田氮素农学效应和环境效应研究的发展动态、研究热点,为以后研究农田氮素效应提供参考。基于ISI Web of Science数据库,检索出以"农田氮肥施用"为主题的所有SCI论文(1957—2014年8月),并分别提取出与"农学效应"、"环境效应"、"适宜施氮量"相关的文献,采用计量学方法,分析各研究方向的主要热点、研究机构、发文期刊和高被引论文等。共检索出关于农田施氮研究的SCI文献7460篇,其中与"农学效应"研究相关的文献2773篇,主要涉及到施氮肥对小麦、玉米、水稻、大豆等作物产量、氮素利用率和土壤有机碳的影响;与"环境效应"研究相关的文献1609篇,主要涉及到氮肥施用对氨挥发、硝化反硝化、温室气体排放、硝酸盐淋失、地下水水质等环境因素的影响;与"适宜施氮量"研究相关的文献408篇,主要涉及氮肥施用量、氮肥管理等。刊发各类研究成果最多的机构主要来自欧美发达国家,影响力大的期刊与高被引论文也主要来自欧美国家,中国在该领域的研究发展迅速,以中国科学院、中国农业大学、南京农业大学和中国农业科学院等为代表的中国研究机构的研究水平逐渐进入世界前列。文献计量学可用于分析农田氮素效应主题的研究热点和发展态势,目前氮素农学效应仍是研究的重点,随着当前环境污染问题日益突出,农田氮素环境效应研究越来越多,特别是氮流失对水体水质的影响备受关注,而基于氮素综合效应确定农田适宜施氮量是同时保障粮食安全和环境安全的有效措施。中国在相关研究领域的研究起步较晚,高影响力论文偏少,优秀国际期刊不足,但研究实力不断增加,研究成果也逐渐被国际社会所认可。

A bibliometrical analysis of status and trends of international researches on the agronomic and environmental effects of nitrogen application to farmland

The primary topics and trends in the development of research on the agronomic and environmental effects of nitrogen application, both in China and abroad, were analyzed to provide references and highlight opportunities for future research in the field of farmland nitrogen application. The Institute for Scientific Information (ISI) Web of Science database was used to retrieve Scientific Citation Indexed (SCI) papers published (1957-2014) on the topic of "nitrogen fertilizer application", and literature relevant to "agronomic effects", "environmental effects", and "appropriate nitrogen application" was extracted. The bibliometric method was used to analyze the main focus, research institutions, publishing journals, and citation indices of the publications in each research branch. A total of 7460 SCI articles on farmland nitrogen research were published during this period. Of these, 2,773 were related to "agronomic effects", which mainly included the effects of nitrogen application on nitrogen use efficiency, soil organic carbon, and yields of wheat, corn, rice, and soybeans, as well as other crops. There were 1609 articles related to "environmental effects", which mainly included the effects of nitrogen application on ammonia volatilization, nitrification and denitrification, greenhouse gas emissions, nitrate leaching, groundwater quality, and other environmental topics. There were 408 articles were related to "appropriate nitrogen application", which mainly covered the aspects of quantity of nitrogen fertilizer application and field nitrogen management. Most of the publications were by researchers affiliated to institutions in developed countries in Europe and North America; most of the publications in mainstream journals and the most highly cited publications were also by researchers based in developed European and American countries. However, research on farmland nitrogen application has developed rapidly in China, and some institutions, including the Chinese Academy of Sciences, China Agricultural University, Nanjing Agricultural University, and the Chinese Academy of Agricultural Sciences, have gradually become global leaders in this area. The bibliometric method can be used to analyze the primary topics and developmental trends in research on nitrogen application. Currently, investigation of the agronomic effects of nitrogen application is the main focus of research on nitrogen. Research on the environmental effects of nitrogen, especially the impacts of nitrogen loss on water quality, is receiving increasing attention, because of serious water quality problems around the world. Tremendous research opportunities lie in development of appropriate nitrogen management practices that could simultaneously guarantee food security and environmental quality. China has only recently entered this field of research, with few highly cited articles in well-recognized international journals by Chinese researchers, but the research capacity of Chinese institutions has been growing and their research achievements have increasingly been recognized by the international community.