中国农业化肥施用技术效率演变特征及影响因素
王萍萍, 韩一军, 张益

Characteristics of change and influencing factors of the technical efficiency of chemical fertilizer use for agricultural production in China
WANG Pingping, HAN Yijun, ZHANG Yi
图2 各地区不同时期化肥施用技术效率
Figure 2 Technical efficiency of chemical fertilizer in different periods for various regions