Excessive N applications reduces yield and biological N fixation of summer-peanut in the North China Plain

Wenhai Huang, Yuhao Yang, Haoyu Zheng, Jørgen E. Olesen, Robert M. Rees, Jun Zou, Li Zhang, Suya Hu, Bowen Qiao, Xiaohui Wang, Shuaijie Shen, Biaoding Yang, Zhiyuan Bai, Axiang Zheng, Wenjie Li, Zhenwei Song, Xinya Wen, Fu Chen, Xiaogang Yin