Esu started his career in 1975 as an Assistant Lecturer in Soil Science at the Kaduna Polytechnic, Kaduna State and became a professor of
pedology in 1994. During these years he taught at the Kaduna Polytechnic, National Institute of Water Resources, Kaduna, Ahmadu Bello University, Zaria, University of Calabar, University of Ghana (visiting scholar) and the University of Uyo where he was an adjunct professor. He was also Dean of Agriculture, Provost of Okuku Campus, Deputy Vice Chancellor (Academic) and later the Vice Chancellor, at the University of Calabar. He taught pedology, soil survey and land use planning. == Awards ==