Mapping soybean physiology research based on the web of science

The aim of this paper was to map the scientific research on soybean physiology by using bibliographic review and analyses of papers indexed up to July 31, 2014 in the web of science database. A total of 1682 non-redundant bibliographic records were curated. The soybean physiology research experienced two major periods. The first period was from 1943 when the first soybean paper was published to 1989 during which a small and gradual increase took place with no more than 12 annual publications. The second period being from 1990 to present, saw a substantial increase in annual publications ranging from 35 to 92 per year. Authors representing a total of 76 countries were involved in soybean physiology research. Drs. T.R. Sinclair and Dr. D.B. Egli were the most productive authors while the USDA/ARS, University of Illinois and Iowa State University published the most influential articles. The most productive journals were the Journals of Crop Science, Plant Physiology, Plant and Soil, Field Crops Research the most research subject categories were nitrogen fixation, photosynthesis, growth, mineral nutrition, genotypes, drought stress, yield and quality. Gene expression for quality and yield under drought stress has become a favored topic for soybean physiology. Eight out of the top ten productive institutions were located in the USA. The USA exceeded all other countries with the most independent and collaborative papers on soybean physiology research. The status of publications on soybean physiology described here may serve as a tool for guiding researchers in their future work.