When we think of soybeans in our daily diet, it is typically as tofu, veggie burgers, or other meat substitutes. But most of the world’s fast-growing soybean harvest is consumed indirectly in the beef, pork, poultry, milk, eggs, and farmed fish that we eat. Although not a visible part of our diets, the incorporation of soybean meal into feed rations has revolutionized the world feed industry, greatly increasing the efficiency with which grain is converted into animal protein.
In 2004, the world’s farmers produced 223 million tons of soybeans, 1 ton for every 9 tons of grain they produced. Of this, some 15 million tons were consumed as tofu or meat substitutes. The remaining 208 million tons were crushed in order to extract 33 million tons of soybean oil, separating it from the more highly valued meal. Soybean oil dominates the world vegetable oil economy, supplying much of the oil used for cooking and to dress salads. Soybean oil production exceeds that of all the other table oils combined—olive, safflower, canola, sunflower, and palm oil.
The 143 million tons of soybean meal that remains after the oil is extracted is fed to cattle, pigs, chicken, and fish, enriching their diets with high-quality protein. Experience in feeding shows that combining soybean meal with grain, in roughly one part meal to four parts grain, dramatically boosts the efficiency with which grain is converted into animal protein, sometimes nearly doubling it.
The world’s three largest meat producers—China, the United States, and Brazil—now all rely heavily on soybean meal as a protein supplement in feed rations. The United States has long used soybean meal to upgrade livestock and poultry feed. As early as 1964, 8 percent of feed rations consisted of soybean meal. Over most of the last decade, the meal content of U.S. feeds has fluctuated between 17 and 19 percent.
For Brazil, the shift to soybean meal as a protein supplement began in the late 1980s. From 1986 to 1997, the soymeal share of feed rations jumped from 2 percent to 21 percent. In China, the realization that feed use efficiency could be dramatically boosted with soymeal was translated into reality some six years later. Between 1991 and 2002, the soymeal component of feed jumped from 2 percent to 20 percent. For fish, whose protein demands are particularly high, China incorporated some 5 million tons of soymeal into the 16 million tons of grain-based fish feed used in 2003.
The experience of these three countries simply indicates that the same principles of animal nutrition apply everywhere. The ratio of soybean meal to corn in the feed mix varies somewhat according to the price relationship between the two. Where corn is cheap, as in the United States, the corn share of the feed mix tends to be slightly higher. In Brazil, which has an economic advantage in soybean production, the soy component is higher.
As world grain production was tripling from 1950 to 2004, soybean production was expanding thirteenfold. The growth in this protein source, most of it consumed indirectly in various animal products, is a surrogate for rising affluence, one that measures movement up the food chain.
The soybean was domesticated in central China some 5,000 years ago and made its way to the United States in 1804, when Thomas Jefferson was President. For a century and a half the soybean was grown mostly as a curiosity crop in home gardens. Most farmers outside of China did not even know what a soybean looked like. But after World War II, production exploded as the consumption of livestock and poultry products climbed in North America and Europe.
By 1978, the area planted to soybeans in the United States had eclipsed that planted to wheat. In some recent years, the U.S. harvested area of soybeans has exceeded that of corn, making it the country’s most widely planted crop. In the United States, where soybean production is now five times that in China, the soybean has found an ecological and economic niche far larger than in its country of origin.
U.S. soybeans are grown mostly in the Corn Belt, often in rotation with corn. The soybean, a nitrogen-fixing legume, and corn, which has a ravenous appetite for nitrogen, fit together nicely on the same piece of land in alternate years. In fact, if the Corn Belt were being named today, it would be called the Corn/Soybean Belt.
Another chapter in the soybean saga has been unfolding over the past three decades in Latin America. After the collapse in 1972 of the Peruvian anchovy fishery—which accounted for a fifth of the world fish catch and supplied much of the protein meal used in livestock and poultry foods at that time—some countries in Latin America saw an opportunity to produce soybeans. As a result, both Brazil and Argentina began to expand soybean production, slowly at first and then, during the 1990s, at breakneck speed. As of 2004, soybean production exceeds that of all grains combined in both countries. Brazil now exports more soybeans than the United States does. And within the next few years Brazil is likely to overtake the United States in production as well.
While production was increasing thirteenfold over the last half-century, soybean yields have almost tripled, which means that the area in soybeans has increased some fourfold. In contrast to grains, where the growth in output has come largely from raising yields, growth in the harvest of the land-hungry soybean has come more from area expansion.
As a result, in a world with limited cropland resources, the soybean has been expanding partly at the expense of grain. Nonetheless, this expansion so greatly increases the efficiency of grain used for feed that it reduces the cropland area used to produce feedgrains and soybeans together.
Excerpted from Chapter 3, “Moving Up the Food Chain Efficiently,” in Lester R. Brown, Outgrowing the Earth: The Food Security Challenge in and Age of Falling Water Tables and Rising Temperatures (New York: W.W. Norton & Company, 2005), available for free downloading and purchase at www.earth-policy.org/books/out.