Bibliographic Analysis of Japanese Rice Research Kazuko Morooka University of Tsukuba, Tsukuba, 305 Japan, kmorooka@mail2.accsnet.ne.jp Abstract The International Rice Research Institute (IRRI) has published the Rice Bibliography (RB) since 1963. IRRI had the Japan Library Office, which compiled the 1990-2000 Bibliography of Japanese Rice Research (BJRR) with the aims to provide more efficient information retrieval and bibliometrics in a specific-subject bibliographic database. We investigated the characteristics of Japanese rice research using bibliometric indicators based on the classifications of research subjects, organizational affiliation and literature source s publishers as well as the descriptors assigned to about 20,000 bibliographic records of the 1990-2000 BJRR. The main bibliographic results are as follows. i) The Japanese rice literature accounts for about one fifth of the world rice literature (RB). ii) Rice research covers many fields classified into 7 categories (general, botanical research, growth environment, cultural technology, plant protection, food processing, socio- economic aspects, and environmental conservation) and into 75 subcategories. iii) A large number of articles are distributed in small amount of core journals whereas a smaller number of articles in larger number of other journals following the Bradford s law. iv) Co-occurrence of specific descriptors assigned frequently appeared among different disciplines. v) There were about 1,800 organizations engaged in rice research as affiliation, mainly national & local government research institutes universities, and companies with priority given to specific research subjects. MAFF (Min. Agric. For. & Fish.) placed emphasis on subjects related to food security including crop disasters, infrastructure as well as basic sciences. Strong collaboration was seen between national and local government institutes or universities, and companies and universities in co-authors. The results suggest that rice research is interdisciplinarity science to achieve higher rice yield or sustainable farming. Introduction Rice is a staple food for half of the world population. The International Rice Research Institute (IRRI) has published Rice Bibliography (RB), bibliography on rice in the world since 1963. The staff of IRRI compiled the 1990-2000 Bibliography of Japanese Rice Research (BJRR) to provide more efficient information retrieval for Japanese rice researchers and bibliometrics in a specific-subject bibliographic database. Classifications for research subjects, affiliation and journal publishers were introduced to BJRR and rice terminology was edited based on CAB Thesaurus. This paper focuses on the characteristics of Japanese rice research during the period of 1990 to 2000 based on the number of publications, languages used, research categories, literature sources and organizations engaged in research activities. 597
Materials and methods The study uses JBRR. It covers a total number of 19,154 journal articles on rice published in Japan and contributed to international journals by Japanese scientists during the period of 1990 to 2000. Subject classification was revised with the addition of new categories such as environmental conservation and new subcategories covering genetics and breeding, etc. The names of publishers and affiliation were all unified and these organizations were classified into sectors such as universities, national & local government institutes. Rice terminology was edited based on CAB Thesaurus with the addition of terms specific to rice and proper names for rice varieties. Results I. Scientific publications on rice research Japanese rice literature in the period of 1990-2000 had decreased by 82% since 1995 (Fig 1). This is probably due to the fact that rice consumption somehow decreased in Japan. On the other hand, the number of Japanese articles relating to rice in CAB ABSTRACT and Web of Science that mostly focus on English language papers and core journals has kept mostly the same and increased since 2001 partly because rice plant studies play a major role in basic sciences such as genetics. 2500 2000 1500 1000 500 Fig. 1.Number of publications on rice in Japan during the period of 1990-2000 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 Fig. 2. Ratio of the used languages 1990-2000 JPN./Eng lish summary 21% JPN. 53% ENG. 26% II. Languages used in Japanese rice literature The Japanese language used in literature has impaired the activities of the researchers interested in the international dissemination of agricultural information. The ratio of usage of Japanese language was much higher than English (Fig 2). However, about one third of the publications in Japanese carry English summaries that may contribute to the enhancement of the international knowledge flow especially when titles of figures & tables are written in English. 598
III. Subject categories in rice research publications Rice research can be classified into 7 categories including general(a), botanical research (B), cultivation technology (C), plant protection (D), food processing and utilization (E), socioeconomic aspects (F), and environmental conservation (G) and into 75 subcategories. Figure 3 shows the ratio of the number of rice publications in each category between 1990-1994 and 1995-2000 excluding general (A). Proportional amount of publications in each category did not vary much during the 11 year period, possibly because those six categories were interdependent in rice research. For instance, progress in genetics and breeding (related to botanical research) affect the other categories, at the same time promoting their development. A major increase (4%) is seen in botanical research (B) including physiology, ecology, biochemistry, genetics and breeding with a notable increase in publications on biotechnology and genomics. The international visibility was higher than any other rice research fields in Japan as about 20% of those publications were submitted to international journals in 1990-2000. Fig. 3. Comparison of the percentage of articles on rice classified by subject categories 1990-1994 B, 23% C, 26% D, 12% E, 17% F, 15% G, 7% 1995-2000 B, 27% C, 27% D, 11% E, 17% F, 12% G, 7% IV. Distribution of subject in journals Accumulated number of articles Fig. 4. Distribution of a subject in journals. 25000 20000 15000 10000 5000 0 1 10 100 1000 10000 Accumulated number of journals (logarithm) Distribution of articles on rice in journals, especially in rarely appeared journals was investigated using subject categories assigned to articles and journal publishers classified into organizations such as university, company. A total number of 19,154 Japanese articles on rice were distributed in 1,595 journals with a large number of articles in a smaller number of core journals and a smaller number of articles in a larger number of journals showing a S-shape curve corresponding to Bradford s law (Fig. 4). There was a total number of 615 journals which appeared only one time during the period of 1990-2000 and about 40% of 599
articles from those journals were related to food processing and utilization including rice properties, composition & nutrients, cooking, by-product & non-food utilization such as use of straw, husk & bran for animal feed, organic fertilizer in horticulture, medium for mushroom, bioceramics, etc. Various disciplines such as medicine, nutrition, pharmacy, domestic science, animal science, forestry, electronic engineering, and industry were related to those articles. The literature appeared in international journals which accounted for 22% of the total number of journals related to food processing and utilization, Japanese journals from academic societies 17%, universities 18%, and local government institutes 21%. Thus the articles in rarely appeared Journals were largely related to food processing and utilization that included a lot of non-crop sciences and distributed in various literature sources. V. Co-occurrence of descriptors among subject categories Relationship among subject categories was investigated using 159,670 descriptors assigned to the articles and subject categories to descriptors through articles, which were totally 8,199 terms without duplication and the frequency appeared ranged from 1 to 1,737. Table 1 shows the co-occurrence of descriptors which most frequently appeared among subject categories. The descriptors in botanical research of category B and cultivation technology of category C most largely co-occurred except for the descriptor, varietal difference. This implies that these two categories may have closer relationships. Further studies will be needed with statistical methods such as correlation coefficient. Table 1. Co-occurrence of descriptors that most frequently appeared among subject categories Descriptor B C D E F G Frequency Cultivar 823 456 98 248 90 22 1,737 Yield 434 867 31 58 168 56 1,614 Rice 556 421 151 59 193 71 1,451 Growth 331 602 34 37 14 36 1,054 Varietal difference 468 172 87 283 4 17 1,031 * Botanical research (B), Cultivation technology (C), Plant protection (D), Food processing & utilization and (E), Socio-economic aspects (F) and Environmental conservation (G) VI. Organizations engaged in rice research i) Organizations The organizations engaged in rice research were characterized in terms of scientific production output and research fields using affiliation classified into organizations as well as subject categories assigned to articles. In counting a publication by multiple authorship, full credit to each of the authors (fractional counting) was given, for example in case of a paper by four authors, productivity of the paper per author is 0.25. Table 2 shows that a total number of 2,311 organizations engaged in rice research during the period of 1990-2000. National institutes were divided into MAFF, Ministry of Agriculture, Forestry and Fisheries organizations (30 ones) and non-maff organizations (56). About 96% of the publications were written by MAFF. Local government Institutes into agricultural organizations, government offices including extension offices, plant protection offices, food industrial organizations and public heath ones. About 80% of the publications were written by the agricultural organizations and about 10% for plant protection and extension offices. Foundations include various organizations such as research institutes, agricultural 600
co-operatives, hospitals, those for international cooperation and for release of current agricultural information. One third of companies belonged to research laboratories such as the Japan Tobacco Inc., Life Science Research Laboratory. Foreign organizations appearing in the affiliation of Japanese rice literature were located in various countries. According to geographical codes assigned to foreign affiliation, the number of articles by affiliation located in Asia (except for Japan) accounted for the largest ratio 55% in the total number of those written by foreign affiliation. International organizations which seemed to be not adequate to be divided by countries for 17% in which the International Rice Research Institute showed the highest ratio 68% in the total number of publications, FAO 7%, Asian Institute of Technology 7%, and International Food Policy Research Institute 6%. North America for 13% in which USA for the largest ratio 84%. Table 2. Number of organizations engaged in rice research and number of articles per organization Number of organizations Number of articles Number of articles per organization National iinstitutes 95 3,849 41 Local government institutes 318 4,717 15 Universities 437 7,332 17 Foundations 222 1,116 5 Companies 561 1,163 2 Foreign institutes 643 901 1 Other organizations 35 76 2 Total 2,311 19,154 ii) Productivity of publications Table 2 shows the number of rice publications per organization, in which national institutes, mostly MAFF organizations accounted for the largest among organizations. This is probably due to the fact that MAFF places emphasis on research on rice as staple food in terms of food security. iii) Research fields Table 3 shows that the ratio of number of articles with subject fields in organizations. Each organization appears to conduct research with varying emphasis on subject fields as follows. The universities account for the highest ratio 17% of the total number of articles on plant physiology, ecology and biochemistry closely related to basic sciences, National institutes for 19% of those on genetics and breeding, specifically varietal improvement for diversified consumer needs as well as stable rice production. Local government institutes accounted for the highest ratio 37% of the articles on cultivation technology most suitable for local environment. The foundations displayed the highest ratio of publications on social & economic aspects (30%), especially on rural medicine mainly done by the Institute of Rural Medicine of Japan and also on international cooperation mostly by the Institute of Developing Economies, the Association for International Cooperation of Agriculture & Forestry (AICAF) and the Japan International Cooperation Agency (JICA). The highest productivity of rice 601
literature among foundations was shown by the Institute of Physical and Chemical Research (RIKEN). Its researches focused on plant growth regulation and blast fungi during the period of 1990-2000. Companies showed the highest ratio 39% on food processing and utilization related to rice products such as fermented products, confectionery, noodles, etc. Thus the organizations were engaged in rice research, with different emphasis placed on subject fields. Table 3. Ratio of number of articles related to research fields in various organizations Research Fields Universities National Institutes Local government Companies Foundations institutes Pysiology, Ecology, Biochemistry 17% 7% 2% 5% 5% Genetics, Breeding 13% 19% 16% 15% 8% Cultivation technology 21% 24% 37% 19% 26% Plant Protection 7% 14% 15% 17% 11% Food Processing, Utilization 18% 10% 17% 39% 12% Social & Economic Aspects 17% 15% 5% 2% 30% Environmental Protection 7% 9% 7% 3% 3% Total 100% 98% 100% 100% 96% * Literature on general was excluded and total ratio in national institutes and foundations resulted in less than 100%. VII. Knowledge flow among organizations Research collaboration among organizations was investigated by co-authorship in literature. In case of a paper written by multiple organizations, fractional counting by two pairs was done like co-authors. Publications by single author accounted for about one third of the total number of 19,154 publications. Those by co-authors belonged to the same organization such as university, national & local government institutes accounted for 90% in the total number of articles by co-authors. Table 8 shows the number of publications with co-authorship among the different organizations. It was found that the frequency of co-authorship with other organizations was the highest in universities. Table 4. Number of articles in co-authorship Organizations Organizations Number of articles Ratio Company Local Government Institute 68 5% Company National Institute 77 6% Company University 306 23% Local Government Institute National Institute 234 17% Local Government Institute University 272 20% National Institute University 388 29% Total 1,343 100% Conclusion The results obtained using bibliometric indicators of JBRR were as follows. i) Rice research covered various disciplines in addition to crop science ii) Higher and stable rice yields appeared to be achieved by interaction of related research fields. iii) The respective organizations were engaged in rice research, with emphasis placed on specific fields. These results indicate that rice research is conducted on an interdisciplinary basis. 602
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