13.12.2024

Amazon farmers domesticated wild rice 4,000 years ago 

Amazonian farmers discovered how to manipulate wild rice so the plants could provide more food 4,000 years ago – long before Europeans colonized America.

Archaeologists discovered that ancient South Americans learned how to grow bigger rice crops with larger grains, but this expertise may have been lost after 1492 when the indigenous population was massacred.

The evidence of the success of early rice farmers could help modern day plant breeders develop rice crops which are less susceptible to disease and more adaptable to the effects of climate change than the Asian varieties.

Researchers arriving at Monte Castelo, Brazil. The archaeologists analyzed 16 samples of microscopic plant remains from ten different time periods, found during excavations during 2014 led by the University of São Paulo in South West Amazonia

Different species of rice were first grown approximately 11,000 years ago in the Yangtze River, China, and around 2,000 years ago in West Africa.

A new study, conducted by researchers at The University of Exeter, explains the early success of rice farmers on the wetlands near Guaporé River in Rondônia state, Brazil, and how important the huge wetlands and tropical forests of lowland South America.

Ancient inhabitants domesticated cassava, peanuts and chili pepper crops for food.

The archaeologists analyzed 16 samples of microscopic plant remains from ten different time periods, found during excavations during 2014 led by the University of São Paulo in South West Amazonia.

WHAT THE STUDY FOUND

Archaeologists at the University of Exeter analyzed 16 samples of microscopic plant remains from ten different time periods, found during excavations during 2014 led by the University of São Paulo in South West Amazonia.

The excavations took place in Monte Castelo, Brazil. Monte Castelo is a 6.3-meter-high platform-shaped freshwater shell-mound, exhibiting a 160-meter-long elliptical base and dating from 9,400 years ago

More phytoliths: hard, microscopic pieces of silica made by plant cells, were found at higher ground level, suggesting that rice began to play a larger role in the diet of people who lived in the area – and more was farmed – as time went on.

The researchers also found changes in the ratio of husk, leaf and stem remains at different ground levels, also suggesting that Amazon residents became more efficient harvesters over time, bringing more grain and fewer leaves to the site.

The rice grown, Oryza sp, also became bigger over time compared to the wild rice first cultivated by the South Americans – and this area has been occupied by humans for at least 10,000 years.

Increase in size from wild to domesticated rice phytoliths. Phytoliths are hard, microscopic pieces of silica made by plant cells

Increase in size from wild to domesticated rice phytoliths. Phytoliths are hard, microscopic pieces of silica made by plant cells

More phytoliths: hard, microscopic pieces of silica made by plant cells, were found at higher ground level, suggesting that rice began to play a larger role in the diet of people who lived in the area – and more was farmed – as time went on.

The researchers also found changes in the ratio of husk, leaf and stem remains at different ground levels, also suggesting that Amazon residents became more efficient harvesters over time, bringing more grain and fewer leaves to the site.

Study region. (a) Distribution of Oryza species, wetlands in South America and important early shell mound sites in South America. (b) Map showing the location of the Monte Castelo. (c) The Monte Castelo locality, topographical map and location of the 2014 trench excavation

The rice grown, Oryza sp, also became bigger over time compared to the wild rice first cultivated by the South Americans – and this area has been occupied by humans for at least 10,000 years.

‘This is the first study to identify when wild rice first began to be grown for food in South America,’ said Professor Jose Iriarte, from the University of Exeter.

‘We have found people were growing crops with larger and larger seeds.’

‘Even though they were also eating wild and domesticated plants including maize, palm fruits, soursop and squash, wild rice was an important food, and people began to grow it at lake or river edges.

‘During a time when the climate was getting wetter and the wetlands expanding, this critical seasonal resource that is ripe at the peak of the flooding season when other resources are dispersed and scarce, residents of Monte Castelo began to grow larger rice.’

Monte Castelo, Brazil excavation in progress – collecting samples. Monte Castelo is a 6.3-meter-high platform-shaped freshwater shell-mound, exhibiting a 160-meter-long elliptical base and dating from 9,400  years ago

Добавить комментарий

Ваш адрес email не будет опубликован. Обязательные поля помечены *