 Many traditional regional cuisines rely on basic methods of preservation such as drying, salting, pickling and fermentation.In addition, the "rice theory" attempts to describe cultural differences between north and south China; in the north, noodles are more consumed due to wheat being widely grown whereas in the south, rice is more preferred as it has historically been more cultivated there.Chinese ancestors successfully planted millet, rice, and other grains about 9,000 and 8,000 years ago.