Xuejun Liu, a prominent scholar in environmental science, serves as a professor at the College of Resources and Environmental Sciences, China Agricultural University. He pursued his undergraduate studies in Soil and Plant Nutrition at Hunan Agricultural University from 1987 to 1991, earned a master's degree in Soil Science there, and obtained his Ph.D. in Plant Nutrition from China Agricultural University in 1997. Since 1997, he has held successive positions at China Agricultural University, starting as a lecturer and advancing to his current role as a full professor; he has also been a visiting scholar at institutions like Colorado State University, Stanford University, and Rothamsted Research. His research interests focus on nitrogen cycling in farmlands, particularly exploring nitrogen sources, fates, and their impacts on soil acidification, eutrophication, and greenhouse gas emissions, with extensive international collaborations and over 200 SCI papers published in top journals.