Optimized nitrogen application methods to improve nitrogen use efficiency and nodule nitrogen fixation in a maize-soybean relay intercropping system
YONG Tai-wen, CHEN Ping, DONG Qian, DU Qing, YANG Feng, WANG Xiao-chun, LIU Wei-guo, YANG Wen-yu
Journal of Integrative Agriculture . 2018, (03): 664 -676 .  DOI: 10.1016/S2095-3119(17)61836-7