Bolivians Look to Past to Enrich Harvest

Four Aymara Indian women in long red skirts grab anthropologist Alan Kolata by the hands and feet and spin him around until he is laughing and dizzy.

It’s the potato harvest celebration at Chambi Grande, a village in the Bolivian Altiplano, the stark, haunting 13,000-foot-high plain in the Andes Mountains.

Chambi Grande was the most recent Aymara village to dare to try the ancient ancestral agricultural methods that would turn their gray, golfball-size potatoes to grapefruit size.

The return to the old farming ways was advocated by Kolata, a University of Chicago anthropologist and archeologist whom the Aymara call El Doctor , and Oswaldo Rivera of Bolivia’s National Institute of Archeology.

The challenge was to persuade the Aymara, who distrust outsiders. Years earlier, the two scientists were blamed for a severe drought and stones were thrown at them.

The Aymara are descendants of a vast pre-Inca empire known as Tiahuanacu. The empire, which stretched from what is now Peru south into Chile and Argentina, lasted for about 1,200 years, mysteriously vanishing about AD 1000.

For 800 years, Tiahuanacu farmers fed the valley’s teeming population of 250,000. The abundance of food supported an army, artisans who carved gold-leaf stone statues and laborers who built elaborate palaces, temples and irrigation systems.

The 7,000 modern Aymara in the valley around Chambi Grande have struggled to feed themselves from hillside fields that produce puny potatoes.

The ancient methods were unearthed after Kolata and Rivera began exploring Aymara ruins in 1978. Digging around the main temples, they discovered a complex irrigation system and extensive patterns of ridges and depressions.

They speculated that these scars were the remnants of raised planting beds and irrigation canals, perhaps similar to ones constructed by the Aztec and Maya, highly developed early civilizations in Mexico and Central America.

The Aymara, who now live along the edge of a Lake Titicaca flood plain, did not know what the ridges and depressions were. They believed no one could grow crops on the plain. When the plain was dry, they grazed their cattle on the grass. Because it was often too soggy for crops, they planted potatoes on hillsides at its edge.

The scientists knew that to determine the size of the Tiahuanacu civilization, they had to calculate how much food their farmers produced. Kolata and Rivera began reconstructing the raised beds.

Their first harvest, in 1987, produced tons of potatoes per acre--seven times the average yield on the Altiplano.

To convince the Aymara, they met often with village leaders and invited them to the experimental plot.

The bravery of Roberto Cruz changed the attitude of his fellow farmers. Cruz agreed to plant potatoes using the methods of “the grandfathers,” as he calls his ancestors.

Dirt dug from canals was put on layers of cobblestones. Clay kept the salty lake water from moving into the topsoil. Gravel and sand provided drainage. His potatoes planted, Cruz waited.

The Altiplano is a cruel place for conventional farming. The clear days give sunshine, but at these altitudes temperatures often drop to freezing at night.

The old methods work so well, Kolata says, because during the day, “the canals act as a solar sump by soaking up heat.” At night the water releases the heat as a layer of fog. The fog blankets the beds, protecting the plants from the cold until the sun rises.

The turning point came just before harvest, when the temperature dropped below freezing. Terrified that he had lost his crop, Cruz awoke before dawn. In his fields he saw a mystical sight. Fog swirled silently over his plants.

“Three days of frost wiped out 90% of the crops on the hillsides,” Kolata said. “In our crops, there was only 10% damage.”