China's maize research has reached the international forefront
Maize is one of China's three major staple crops, and over the past 10 years, maize's share in China's grain crop production has continued to increase.
In 2006, the domestic maize planting scale and output surpassed wheat for the first time, rising to second place among cereal crops, with its output approaching 30% of total grain; in 2009, the maize planting area reached 26.66 million hectares, surpassing rice for the first time; in 2012, maize output also overtook rice, making it the largest grain crop variety.
Recently, a study by Li Chenying and her team at the Information Research Center of the Library of China Agricultural University shows that, in step with production development, China's maize-related scientific research is also flourishing.
The study presented the ten-year changes in China's maize field academic research from the aspects of publication volume, the comprehensive influence indicator I3, and the number of high-level papers: Chinese researchers achieved a leap over the decade; and the research strength of China Agricultural University stood out remarkably in this leap.
China's maize field research keeps climbing the stairs
"Scientific research is the foundation for driving industrial development, and a major maize-producing country is often also a high-output country for maize research academic papers." Li Chenying said in an interview with a reporter from China Science Daily, "The purpose of doing this research is to examine the academic influence of China's scientific research institutions and the country as a whole in the field of maize research."
Li Chenying's research used the Thomson Reuters WOS collection database as the basic data source, adopted bibliometric methods, and conducted a statistical analysis of 20,302 academic journal papers on maize research published since 2005.
The data show that China's maize research has become a leader in quantity and has also ranked among the front runners in quality.
According to statistics by the country of the corresponding author, over the past 10 years, the publication volume of the United States has basically remained at 450-500 papers; while in 2005, China's number of papers was 62, and it climbed year after year thereafter, reaching 507 in 2014.
In terms of ranking, the United States, with stable research article output, held first place for a long time; China ranked second in quantity for 6 consecutive years starting in 2006, and began to "turn the tables" in 2013, leading in paper quantity for two consecutive years.
It is worth mentioning that, in addition to commonly used research evaluation indicators such as the number of papers, citation frequency, the number and proportion of high-level academic papers, and international cooperation, this study also selected the comprehensive influence indicator I3 for analysis.
"This is a new research influence evaluation indicator that is more suitable for being limited to a specific research field." Li Chenying introduced. When using this indicator to evaluate the quality of research articles, the United States has always remained in first place; while China's number of papers grew rapidly, the influence gap continued to narrow - if reflected in a chart, compared with the steady trend of other countries, China's paper quantity and comprehensive influence I3 show a trend of rising steadily higher.
"From the data of the top ten countries by comprehensive influence indicator for the whole period from 2005 to May 2015 and for each year, it can be seen that future competition among countries in the maize research field will mainly be competition between China and the United States," Li Chenying analyzed. "This competition is no longer a competition in quantity, but a competition in paper quality."
China Agricultural University's maize research results are remarkable
On the basis of completing the comparison of academic influence at the national level, Li Chenying and her team also measured academic influence at the institutional level.
The study found that in recent years, the paper output of China's research universities and institutes has grown rapidly. According to statistics, a total of 22 institutions entered the top ten in annual publication volume in individual years, among which the Chinese Academy of Sciences and China Agricultural University remained in the list for 9 consecutive years, while the Chinese Academy of Agricultural Sciences and Sichuan Agricultural University entered 5 times and 2 times respectively.
Among them, China Agricultural University's report card is particularly outstanding: first, after China Agricultural University entered the first tier in annual publication volume in the maize research field in 2006, it has always appeared in the top ten, and since 2012 its publication volume has remained above 70 papers, ranking first in the world for 3 consecutive years; second, China Agricultural University's comprehensive influence indicator I3 in this field is second only to the Agricultural Research Service of the United States Department of Agriculture. The Agricultural Research Service of the United States Department of Agriculture and Iowa State University remained in the top ten of the rankings for ten consecutive years; China Agricultural University made the list nine times, with I3 rising to second place in 2008, and beginning to surpass the Agricultural Research Service of the United States Department of Agriculture in 2012, though its overall ten-year level was still not as good.
However, if one simultaneously examines the difference between the ranking of high-level papers and the ranking of publication volume, and the ranking of the comprehensive influence indicator I3, China Agricultural University still needs further improvement compared with the Agricultural Research Service of the United States Department of Agriculture and other institutions. By contrast, institutions such as the University of Minnesota, the University of Hohenheim, and the International Maize and Wheat Improvement Center performed relatively more notably in high-level papers.
"China's scientific research institutions have made rapid progress in the number of publications, but there is still room for further improvement in high-level papers, and in this respect the gap between China and the United States is even more obvious," Li Chenying wrote in the research report. She believes this suggests that Chinese researchers should strengthen high-level cooperation with top institutions in countries such as the United States, Canada, Germany, and France.
Behind the paper data: the power of seeds
So, what is the secret behind China Agricultural University's remarkable achievements in the maize research field in recent years?
Reading the statistical data further, in terms of internal institutions, the National Maize Improvement Center is the key base for maize genetic breeding research at China Agricultural University, and researchers at the center contributed more than one third to the above-mentioned "report card."
Since the 1950s, a research team led by the older generation of Chinese scientist Professor Li Jingxiong as the discipline leader vigorously promoted research on the utilization of maize heterosis in China, thereby driving the selection and promotion of maize hybrids nationwide and making major contributions to increasing maize production and income in China. Afterwards, innovative research teams represented by Professors Dai Jingrui, Xu Qifeng, and Song Tongming successively carried out work in resource innovation directions such as high-yield breeding and high-oil maize - in 1998, the Ministry of Agriculture relied on China Agricultural University to establish the National Maize Improvement Center, and this generation of scientists were the founders of the center.
After the maize center was established, this team led by Academician Dai Jingrui, while carrying out population improvement and inbred line and hybrid breeding, also carried out research and application of molecular breeding technology relatively early. Aiming at molecular marker-assisted breeding, they successively explored molecular marker technologies such as RAPD, RFLP, and SSR for cluster analysis of breeding materials and division of heterotic groups, carried out research on the construction of whole-genome linkage maps and molecular marker mapping of important agronomic traits, and at the same time conducted progressively deeper research on differential expression of maize genes, QTLs for yield traits and the genetic basis of heterosis, and prediction of heterosis.
If the accumulation and release of innovative research results is the basic reason for the center's high paper output, then high research output in recent years is also the inevitable result of the flourishing talent at the maize center.
On the second floor of the National Maize Improvement Center building, there is a "pedigree chart" of the maize breeding research team - a research team composed mainly of young and middle-aged people has already taken shape. These researchers are precisely the authors of high-level papers in maize breeding research: since 2005, among the papers published by China Agricultural University in C-N-S and NG journals, the 4 papers mainly involving maize all came from these young and middle-aged researchers. And when searching in WOS, among the author group of "highly cited papers" whose corresponding authors are researchers from China Agricultural University, this team at the maize center is also one of the groups that appears more frequently.
Multidisciplinary research around the industrial chain
Li Chenying and her team's research also found that the advantage of scientific research institutions in the maize research field is also jointly formed by multiple departments of different disciplines within the institution. Specifically for China Agricultural University, in the formation of its overall advantage, the contribution of the resource and environment discipline cannot be ignored. From the statistical results of the research, it can be understood that in this decade of work, maize has been one of the basic and most important objects in the research on the "theoretical and technical system of integrated nutrient resource management" in the resource and environment discipline.
The resource and environment discipline at China Agricultural University is the birthplace of modern Chinese soil science and plant nutrition. Around 1992, they proposed the concept and research field of plant nutrition science, basically established the theoretical system of plant nutrition research in China over 10 years, and developed a large number of applied technologies.
In 2004, researchers in the resource and environment discipline at China Agricultural University jointly completed the article "Some Progress and Insights in China's Plant Nutrition Research over More Than Ten Years," one important analysis of which was that "developing a theoretical and technical system of integrated nutrient resource management with Chinese characteristics is one of the important future research directions for plant nutrition in China." This article may also be an entry point for understanding research in this discipline - this not very long article has more than 10 authors, and "coincidentally," a search found that these scientific researchers are also precisely the basic group of corresponding authors of China Agricultural University's "highly cited papers" in this academic field.
It can be said that the "encounter" of the resource and environment discipline and the crop genetics and breeding discipline in the maize research field is precisely a miniature of how China Agricultural University's traditional disciplines, starting from different research origins and centering on major national agricultural science and technology needs and the international academic frontier, continue to carry out research forward.
"The biggest inspiration I got from the research is that the improvement of international influence and discourse power in maize field research does not rely on just one discipline, but depends on all maize-related disciplines carrying out research at the same time," Li Chenying said. "Only when scientific researchers across the entire industrial chain carry out all-round joint efforts can our research strength truly be improved."