A meta-analysis of the effects of nitrogen fertilizer application on maize (Zea mays L.) yield in Northwest China - Jiang, Yuanbo; Li, Haiyan; Ma, Wenqiong; Yu, Wenjing; Chen, Junxian; Gao, Yalin; Qi, Guangping; Yin, Minhua; Kang, Yanxia; Ma, Yanlin; Wang, Jinghai; Xu, Liting (Frontiers in Plant Science, 2025)