Earliest records are from Turkey about 7400 ybp. Efforts to increase productivity have been relatively unsuccessful. Do not respond to fertilization with higher productivity. Tofu is made from soy milk via a curdling process. Tofu is flavorless but has a good texture and is used as a meat substitute.
Soy sauce is made from okara via a process involving fungi and salt water.
Origin in northeastern China, germ plasm base is being destroyed. Henry Ford had an obsession with soybeans and wore a suit made of soy fabric. High protein content and important meat substitute in many peasant communities. Drought resistant but yields are low. Grown in cool regions or as a winter crop in hot regions.