Takuji Ohyama is a Professor of Faculty of Applied Biosciences, Department of Agricultural Chemistry, Tokyo University of Agriculture (2017 -present). He obtained a Ph.D. degree in agriculture from the University of Tokyo in 1980, and got an academic position in Niigata University in 1982. He has been a Professor of Faculty of Agriculture at Niigata University from 1982 till 2017. He has also served as Dean of Graduate School of Science and Technology at Niigata University (2010-2014) and Dean of Faculty of Agriculture at Niigata University (2006-2010). He was a president of Japanese Society of Soil Science and Plant Nutrition during 2007-2009. His research interests are: nitrogen fixation and metabolism in soybean plants, new technology of deep placement of slow release nitrogen fertilizers for soybean cultivation, and nitrogen and carbon metabolism in tulip, curcuma, and cucumber. He is also interested in use of stable isotopes and positron emitting radioisotopes.