The main reason for this succession might be the changes in crops distribution, cultivation type, planting method, management technique and over-use of chemical pesticides and fertilizers.
导致这一演替的主要原因为作物布局、耕作制度、栽培方法、管理技术的变化和农药化肥的过量施用。
2
The fate of nitrogen fertilizer in current crop and successioncrops in winter wheat and summer maize rotation system were studied using field 15n micro-plot.