大气氮素固定
fixation of atmospheric nitrogen
氮素M型追肥法
nitrogen “M” model dressing method
氮素变化
dynamic change of nitrogen
氮素表观损失
Apparent soil nitrogen loss
氮素表观盈亏量
Apparent budget of soil N
氮素垂直分布
Vertical gradients of nitrogen
氮素调控
Nitrogen regulation
Nitrogen control
nitrogen management
N fertilizer regulation
Nitrogen fertilizer regulation
nitrogen applying