Corn was the royalty of Maya food crops, celebrated in religion and cosmology, but archaeologists have long suspected that a different crop, the lowly manioc plant, was the mainstay of Maya life, providing the basic sustenance that allowed their civilization to flourish in densely populated cities.
Now, Colorado researchers have provided the first direct evidence that manioc was indeed intensively cultivated by the Maya -- in quantities that would allow its use for many purposes.
Manioc tubers, also known as cassava, can grow to as much as 3 feet long and as thick as a man's arm. They produce the highest food energy yield of any cultivated crop, about eight to 10 times as much as corn. They can also be grown in infertile soils and require little or no irrigation.
The newly discovered manioc fields are in the village of Ceren, about 15 miles west of San Salvador. An eruption from a vent of the nearby volcano Loma Caldera in AD 590 buried the village under as much as 17 feet of ash.
The village, which had about 100 to 200 residents, has been called the "Pompeii of the New World" because of the remarkable preservation of artifacts there. So far, archaeologist Payson Sheets of the University of Colorado and his colleagues have excavated 12 buildings, including homes, a sauna and a religious gathering place. All of the inhabitants appear to have escaped, perhaps warned off by an earthquake that preceded the eruption.
In their initial investigations around 1990, the scientists found evidence that the residents ate cacao, fruits, seeds and berries, deer, ducks and snails. Two years ago, in their first excavations outside the village, they found manioc in one pit they had dug.
"The big question then was, was this one small field which we were fortunate to hit?" Sheets said Friday in a telephone interview.
When the team returned to the site in January, they dug 18 large test pits, each about 10 feet by 10 feet.
"We found two boundaries, the east and west, but not the north and south boundaries," Sheets said. The area of the field exposed so far is about a third the size of a football field and would have produced about 11 tons of manioc a year.
They did not find the manioc, of course. What they found were empty spaces occupied by the plants before they disintegrated. The team injected these holes with dental plaster before excavating carefully around them, revealing a cast of the remains of the crop -- which had just been harvested -- and stalks that had just been planted for the next season's crop.
The next big question is, what were the villagers going to do with so much manioc? The tubers normally rot in three to four days after harvest. They can, however, be peeled, cut into chunks and dried in the sun for eight days before being ground into a flour, which can be stored for long periods. The flour can be used in soups and stews to increase carbohydrate content and also to make tortillas and tamales.
Manioc can also be fermented into a kind of beer that was used in Maya festivals and celebrations. Sheets said he and his students plan to brew some in pots that he had specially made, then examine the pots to see what kinds of residues are left in the clay. The team will then examine pottery they have found at the site to search for the same residues and compare the results.
"We'll also see what it tastes like, but I don't really look forward to that because I don't think it will be very good," he said.