The practice of introducing the Yellow River which traverses the Plain for irrigation by digging canals was carried out as early as 2,000 years ago by the local inhabitants of Ningxia, known as one of the oldest irrigated area in China. There are sayings: "The Region is the only area benefited by the Yellow River while the rest along its courses suffered from its frequent flooding due to the river bed getting higher exceeding the banks caused by the accumulated deposit of the huge amount of sand rushed down from the upper reaches." "It is the richest region along the Yellow River" and "Its land is as fertile as the southern valley in the lower reaches of the Yangtze River, one of the most productive areas in China." After 1949, the top priority in farmland investment was to repair and built irrigation and drainage projects. The completion of the Bronze Gorge Power Dam, a key project, has greatly improved the water and power supply. With the old canals straightened and new ones added the acreage of the irrigated area has been expanded, water-logging areas controlled and the areas of saline-alkali reduced to a considerable extent.
Its farm produce has wheat, the major crop, mostly grown in the Yellow River irrigated area, rice and sorghum grown in the Plains accessible to irrigation and corn and millet grown highlands. Among the cash crops are sesame, hemp, leaf mustard, rape and sugar beet. The wolfberry, a kind of medicinal herbs, has high reputation on world market. It is also known for its sheep raising, being an important supplier of sheep fur both for home and world market. The Chinese wolfberry together with sheep fur, liquorice root, facia and Helan stone listed as Ningxia's five specialties or the five treasure described as "red, yellow, white, black and blue" because of their respective colors.
