中国山区耕地利用边际化表现及其机理
李升发,李秀彬

Economic characteristics and the mechanism of farmland marginalization in mountainous areas of China
LI Shengfa,LI Xiubin
图4 1995-2013年黑龙江和重庆农业机械发展水平对比
Fig. 4 Comparison of agricultural mechanization between Heilongjiang and Chongqing during 1995-2013