Ba s e d on historical and geographical evidence and according to Hymowitz (1970), the soybean (Glycine max) first emerged as a domesticated crop in the eastern half of North China around the 11th century B.c. of the Zhou Dynasty. Because it is easily grown and adaptable to a wide range of soils and climates and because it contains high protein and oil, the soybean was consid­ ered one of the five sacred grains (or wu gu in Chinese), along with rice, wheat, barley, and millet, which are essential to the Chinese diet and civilization.