Technology to provide access to research literature in the sciences is evolving at the same rapid pace as most information technology innovations. Once the domain of a few specialized databases, much research literature is now covered by broad, multidisciplinary databases. In this changing landscape, how do researchers and librarians know which existing and new tools best serve information needs? A study to determine the most comprehensive database(s) for agricultural literature searching, in terms of the scope of agricultural subject content provided by each database, was developed to help answer this question for the agricultural and related sciences. We compared eight databases that cover a sample set of agricultural research literature for a range of agricultural sub-topics to determine how much overlap exists and which database(s) best support discovery of agricultural research literature. We found that the multidisciplinary databases provided the most comprehensive coverage, but also that one of the agriculture subject specific databases matched the coverage provided by the multidisciplinary databases. In addition to comparing the subject coverage of each database, we explored data visualizations tools developed for other disciplines to determine if they could be used to display associations between the eight databases. A couple network visualizations tools including Cytoscape, helped produce figures to illustrate the connections between the sample set of literature and each database, as well the databases relative to each other. This study will help researchers and librarians determine where to invest their effort when looking to find agricultural research content.