华北冬小麦开花期补灌的增产效应及其影响因素
张经廷,吕丽华,董志强,张丽华,姚艳荣,申海平,姚海坡,贾秀领

Yield-increasing effect of supplementary irrigation at winter wheat flowering and its influencing factors based on water and nitrogen coupling in north China
Jing-Ting ZHANG,Li-Hua LYU,Zhi-Qiang DONG,Li-Hua ZHANG,Yan-Rong YAO,Hai-Ping SHEN,Hai-Po YAO,Xiu-Ling JIA
图4 不同施氮水平耕层土壤有机质(a)与土壤全氮(b)含量逐年变化
Fig. 4 Changes in organic matter content (a) and total nitrogen content (b) in the topsoil with different nitrogen application levels