The soybean is an economically important leguminous seed crop for feed and food products that is rich in seed protein (about 40 percent) and oil (about 20 percent); it enriches the soil by fixing nitrogen in symbiosis with bacteria. Soybean was domesticated in northeastern China about 2500 BC and subsequently spread to other countries. The enormous economic value of soybean was realized in the first two decades of the 20th century, with world production of soybean tripling in the last 20 years. In addition to human consumption, it is a major protein source in animal feeds and is...