Credited to Bolivia. The raised fields lie on both the Bolivian and Peruvian sides of Lake Titicaca. The earliest dated fields reported by the Penn Museum are at Huatta on the Peruvian side, and the Pukara culture of Peru also farmed them. Bolivia shares the origin through the Tiwanaku fields in its part of the basin.
How it began
Ancient farmers built raised fields across the high plain around Lake Titicaca, in what are now Bolivia and Peru. Excavations by Clark Erickson dated early fields to between about 1000 BCE and the start of the common era, with several building stages and periods of abandonment. Farmers of the Pukara culture (200 BCE to 300 CE) and the Tiwanaku culture (600 to 1000 CE), whose territory included the Bolivian side of the lake, expanded the system. The remains cover some 82,000 hectares of low-lying land in both countries.
Before it existed
Most land near the lake was either steep, rocky slope or flat lake plain that was waterlogged and flooded in some seasons. The land lies above 3,800 meters, nights are very cold, and frost can strike without warning, especially in low depressions. Soils were poor, and government studies in modern times still classed these areas as having limited farming potential. Simple cultivation on floating islands in the lake may have been a step toward raised fields.
How it works
Farmers dug parallel canals and piled the earth between them into long, low platforms with flat or rounded tops. The fields were generally 4 to 10 meters wide, 10 to 100 meters long and about 1 meter tall. The platforms improved drainage and soil fertility, and they reduced the risk of frost. The canals held water through dry spells and may have supported aquatic plants, fish and lake birds. Decomposed organic matter from the canals could be spread on the platforms to keep them fertile.
What changed first
The fields turned marginal lake plain into productive farmland for potatoes, quinoa and other crops. Archaeological survey found many habitation mounds among the fields, which points to a dense population during the period of use, larger than the population of the same area in the 1980s. Thousands of worn basalt hoe fragments show the tools used to build and work the fields.
What lasted
Spanish chroniclers described terraces and irrigation canals but did not mention raised fields, which suggests the fields had been abandoned before the Spanish arrived. Their outlines remained visible on the ground and in aerial photographs. Between 1981 and 1986 researchers rebuilt experimental plots and found that construction was not especially labor intensive and that yields were high.
Where it stands today
From 1982, a small development project put raised fields back into use with local farmers, and communities in Peru and Bolivia took part in rehabilitating them. The Penn Museum account also warned that the old fields were being destroyed in many places around the lake by plow farming, urban growth and road building.
