Soil Evidence Suggests Farmers Grew Maize in Southern Belize 6,000 Years Ago

Soil records from southern Belize suggest that people in the Maya region were farming what was almost certainly maize about 6,000 years ago, along wetland edges. After a dry interval that ended around 4,000 years ago, farmers moved their crops to upland fields. The study, led by Keith Prufer of the University of New Mexico, appeared in Communications Earth & Environment on 22 September 2026.

What the soil shows

The team studied sediment and soil from the Rio Blanco watershed in southern Belize, including a floodplain record, the Agua Caliente wetland and a farmed upland slope near the Classic Maya center of Uxbenká. They used carbon isotopes, pollen, charcoal and a radiocarbon-based estimate of population change. The signal points to farming of maize and other C4 plants on wetland margins by about 6,000 years ago.

From wetlands to uplands

Wetland-adjacent farming declined steeply after about 4,000 years ago, and farming of C4 crops had moved to uplands, away from wetlands, by about 3,500 years ago. The authors link the shift to land clearing, population growth and farmers adapting to a dry interval. The university’s release says the upland fields were farmed through the Classic Period and are still farmed today.

What to keep in mind

The isotope and pollen evidence indicates maize and other C4 plants, and the researchers call it almost certainly maize. The paper also notes that this wetland-to-upland pattern was not seen in northern Belize, where wetland farming starts later. Mopan Maya farmer Jose Mes of Santa Cruz village contributed farming knowledge to the project.

Sources

Prufer, K. M., Walsh, M., Neff, N. C. and colleagues (2026), “An early shift from wetland-adjacent to upland farming in the Maya lowlands,” Communications Earth & Environment 7, article 739 (nature.com/articles/s43247-026-04026-5). University of New Mexico news release, 6 October 2026. Also covered by Phys.org. We read the paper’s abstract page, not the full text.