20年来宁夏中南部山区农业生产发展分析
崔勇,马自清,田恩平

Analysis on the Development of Agricultural Production in Central and Southern Mountainous Areas of Ningxia in Recent 20 Years
Yong Cui,Ziqing Ma,Enping Tian
图11 宁南山区化肥施用量的变化
Fig.11 The change of chemical fertilizer application rate in Central and Southern Mountainous Areas of Ningxia