China has a long history of planting rice. It is recorded in ancient books such as Guanzi and Lu Jiaxin Yu that "five grains" were sown in the Shennong era in the 27th century BC, and rice was listed as one of the five grains. The record of "Jade Age is beneficial to ordinary rice, so it can be planted in low humidity" in Historical Records Xia Benji shows that in the 20th century BC, our people began to struggle with nature, dredge the "Nine Rivers" and develop rice in the "low humidity" zone. About 4200 years ago, rice cultivation has been extended from the middle and lower reaches of the Yangtze River to the middle reaches of the Yellow River.
The origin of wheat is in West Asia. The earliest site where wheat was found in China is the Peacock River Basin in Xinjiang, which is what we call Loulan, and the carbonized wheat 4000 years ago was found in the Xiaohe cemetery in Loulan.