1. College of Resources and Environment, Shandong Agricultural University, Fulvic Acid Fertilizer Engineering Laboratory of Shandong Agricultural University and Quanlin, Tai'an, Shandong, China
2. National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Shandong Agricultural University, Tai'an, Shandong, China
3. College of Agronomic Sciences, Shandong Agricultural University, Tai'an, Shandong, China