Takuji Ohyama graduated from the University of Tokyo in 1975 and achieved his PhD from the University of Tokyo in 1980. He worked at Niigata University from 1982 to 2017. He worked at the University of Illinois in 1987 as a visiting professor. He was a project leader of the Biofertilizer project in the Forum for Nuclear Cooperation in Asia from 2000 to 2006. He was President of the Japanese Society of Soil Science and Plant Nutrition from 2007 to 2009. He was a professor at the Department of Agricultural Biological Chemistry, Faculty of Applied Biosciences, Tokyo University of Agriculture (2017 to 2012). He is currently a chairman of The Foundation of Fertilization Science.