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 |