Because the wild soybean was sensitive as to the amount of daylight it required, and because the length of growing seasons varied from region to region, domestication involved much experimental planting and breeding to match different varieties with different areas. That this was done so successfully is a tribute to ancient Chinese farmers who, as noted, were doubtless impelled by an ever-increasing need to feed larger and larger populations of humans and animals. Soybeans ground into meal and then compressed into cakes became food for travelers and soldiers on the move who, in turn, widened knowledge of the plant.
Buddhist priests, however, were perhaps as instrumental as anyone in the domestication of the soybean and absolutely vital to its dissemination (Yong and Wood 1974). As vegetarians, they were always interested in new foods and drinks (such as tea, which they also nurtured to an early success in China). In their monasteries, they experimented with soybean cultivation and usage and found flour, milk, curd, and sauce made from soy all welcome additions to their regimes. As missionaries, they carried the soybean wherever they went, and in the sixth century A. D., they introduced it to Japan from Korea, which they had reached in the first century. Buddhism merged with the native Shinto religion, and the plant quickly became a staple in the Japanese diet.
Not only missionaries but also soldiers, merchants, and travelers helped introduce soybeans to Asian countries. The northern half of Vietnam had soybean food products as early as 200 B. C. During the sixth through the tenth centuries A. D., Thailand received soybeans from southwest China, and India was exposed to them during the twelfth century by traders from Pakistan.
World History
