Professor, Plant and Soil Sciences, Oklahoma State University

Research Professor, Norwegian Institute of Bioeconomy Research

University of Manitoba, Northwest A&F University, University of Alberta

Professor of Soil Science & Conservation, University of Nigeria, Nsukka, NIGERIA

USDA/UMD

Western Kentucky University

Jenderal Soedirman University

PhD. Student, Ben Gurion University of the Negev

University of Calabar