Takuji Ohyama was born in Japan in 1951. He obtained a Ph.D. with a thesis entitled “Studies on the fate of nitrogen fixed in soybean nodules” in 1980 from the University of Tokyo. Dr. Ohyama is currently a full professor in the Faculty of Applied Biosciences, Department of Agricultural Chemistry, Tokyo University of Agriculture. He was a professor in the Faculty of Agriculture, Niigata University, from 1982 to 2017. His research interests include symbiotic nitrogen fixation and metabolism in soybean plants, new technology of deep placement of slow-release nitrogen fertilizers for soybean cultivation, nitrogen and carbon metabolism in tulip, curcuma, and cucumber, and the use of stable isotopes and positron-emitting radioisotopes. Dr. Ohyama has published more than 150 papers and 20 book chapters. He has also edited five books.