The citation impact of Open Access agricultural research: A comparison between OA and non-OA publications

From the abstract: The main purpose of this study is to assess the citation advantage for self-archived Open Access (OA) agriculture research against its non-OA counterparts....At the article level, the paper compared the citation counts of self-archived research with non-OA articles based upon a sample of 400 research articles from ISI-indexed (ISI, Institute for Scientific Information) agriculture journals in 2005. At the journal level the paper compared impact factors (IFs) of OA against non-OA agriculture journals from 2005 to 2007 as reported by the ISI Journal Citation Reports....The results showed that there is an obvious citation advantage for self-archived agriculture articles as compared to non-OA articles. Out of a random sample of 400 articles published in non-OA agriculture journals, about 14 per cent were OA and had a median citation count of four whereas the median for non-OA articles was two. However, at the journal level the average IF for OA agriculture journals from 2005 to 2007 was 0.29, considerably lower than the average IF for non-OA journals (0.65)....