ANALYSES OF THE DIFFERENCE BETWEEN IRRIGATED AND NONIRRIGATED AREA FOR LUMINOUS ENERGY UTILIZATION RATIO AND PRODUCTIVE POTENTIALITIES IN NINGXIA

<正> Situated in arid and semi-arid lands, the Ningxia Hui Autonomous Region is locatedat the middle reaches of the Yellow River. An adequate system of gravity irrigation was es-tablished in the north of Ningxia. Adding to abundant sunshine, strong solar radiation andmoderate heat, the agriculture is very developed. The south mountainous area of Ningxia, including both Yanchi and Tongxin counties,is short of rain, The vast lands cannot be irrigated. Nonirrigated agriculture and serious

ANALYSES OF THE DIFFERENCE BETWEEN IRRIGATED AND NONIRRIGATED AREA FOR LUMINOUS ENERGY UTILIZATION RATIO AND PRODUCTIVE POTENTIALITIES IN NINGXIA