Some 3,000 years ago, farmers in eastern China domesticated the
soybean. In 1765, the first soybeans were planted in North America.
Today the soybean occupies more U.S. cropland than wheat. And in
Brazil, where it spread even more rapidly, the soybean is invading the
Amazon rainforest.

For close to two centuries after its introduction into the United
States the soybean languished as a curiosity crop. Then during the
1950s, as Europe and Japan recovered from the war and as economic
growth gathered momentum in the United States, the demand for meat,
milk, and eggs climbed. But with little new grassland to support the
expanding beef and dairy herds, farmers turned to grain to produce not
only more beef and milk but also more pork, poultry, and eggs. World
consumption of meat at 44 million tons in 1950 had already started the
climb that would take it to 280 million tons in 2009, a sixfold rise.

This rise was partly dependent on the discovery by animal
nutritionists that combining one part soybean meal with four parts
grain would dramatically boost the efficiency with which livestock and
poultry converted grain into animal protein. This generated a
fast-growing market for soybeans from the mid-twentieth century onward.
It was the soybean’s ticket to agricultural prominence, enabling
soybeans to join wheat, rice, and corn as one of the world’s leading
crops.

U.S. production of the soybean exploded after World War II. By 1960
it was close to triple that in China. By 1970 the United States was
producing three fourths of the world’s soybeans and accounting for
virtually all exports. And by 1995 the fast-expanding U.S. land area
planted to soybeans had eclipsed that in wheat.