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Humans may have been cultivating plants on a narrow coastal strip in Brazil as far back as 4,800 years ago, according to a new study.

Source: Coastal strip in Brazil sheds new light on early farming

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(Photo: Courtesy of Jean-Michel Ané)

Much of this article is about current and future agriculture practices but i’ve printed in bold the link to ancient farming and how farmers cultivated for this nitrogen trait. JLP

 

Original Article:

usatoday.com

By Anna Groves

Farmers in a small area of southern Mexico knew that a variety of corn grown in the area was special.

But a group of researchers believe the corn could ultimately transform the way the largest crop in America and the world is grown.

The potential improvements in water and air quality – not to mention financial savings – are staggering. In fact, the lead researcher acknowledged he and his colleagues spent a decade studying the corn before going public this month because the conclusions were “almost outrageous.”

And, like so much research in its early stages, there are still a lot of “ifs.”

But scientists at University of Wisconsin-Madison, University of California-Davis and Mars Inc. (yes, the candymaker) have determined that farmers in Oaxaca, Mexico, have been growing corn that creates its own fertilizer for centuries, if not millennia.

Understanding the process requires a short course in biology.

The plants in Mexico have bizarre fingerlike roots sticking out of their stalks. The roots secrete a goopy mucus, in which bacteria live. The bacteria take nitrogen from the air – which plants can’t use – and convert it to a different form of nitrogen that they can use. The plants soak up the fixed nitrogen in the gel through the fingerlike roots.

The nitrogen is a critical nutrient for all plants; it’s the primary ingredient in chemical fertilizers.

The process is part of a cycle. The bacteria live on carbon, which the plant supplies in the form of sugar. The sugar is produced through photosynthesis. Through this odd trade agreement, the plant gets usable nitrogen, the bacteria get necessary carbon and both parties are happy.

Nitrogen fixation is best known for occurring in legumes like soybeans. The bacteria live in their roots and the surrounding soil. But this had not been demonstrated in grasses like corn.

A decade of research

The researchers found out about the corn from Howard-Yana Shapiro, the chief agricultural officer at Mars and adjunct professor at UC-Davis. Decades ago, he had the idea to look for unusual traits in crops that traditional farmers have adapted to their particular climate and soil. He hoped to find something that could improve crops globally.

When Shapiro came across 16-foot-tall cornstalks growing on an Oaxacan mountain slope where nutrient levels and fertilizer availability should have been low, he knew they deserved a closer look.

Jean-Michel Ané, professor in the UW-Madison Department of Agronomy, has been involved in the project since 2010. “They came to me and asked if I thought it was possible that corn could be associated with nitrogen-fixing bacteria, and I thought, no way.”

The research group first collected samples from cornfields in the Sierra Mixe area of Oaxaca in 2010. When they noticed the goopy aerial roots, “We were like, that’s weird,” Ané said.

They tested the goopy gel, and it tested positive for one of the byproducts of the nitrogen fixation process.

But that alone didn’t prove the plant was getting nitrogen from the bacteria instead of the soil, Ané said. The researchers ran tests from every angle they could think of: Are any of the bacteria found in the gel known nitrogen-fixers? Does the corn soak up less nitrogen from the soil than a similar, non-nitrogen-fixing variety? Does the corn for sure soak up nitrogen from the gel?

The answers were yes, yes and yes.

“It took us several years to convince ourselves that it was true. That’s why it took us almost 10 years to publish that paper. It’s a big claim. We wanted to be sure,” Ané said.

An ancient trait

Researchers have spent decades trying to get corn to create its own fertilizer by partnering with nitrogen-fixing bacteria, with no luck. But these new findings show that nature had already given corn that potential.

The researchers decided to essentially turn back the clock and examine a type of grass native to Mexico and Central America thought to be the ancestor of corn. In the same way that modern dogs were bred from ancient wolves, corn had been bred from teosinte. 

They looked at species of teosinte to see if any had signs of the gel or the nitrogen-fixing bacteria that the Oaxacan farmers could have amplified over time, just like Midwestern farmers later amplified traits like kernel size and uniformity.

They did.

“I see this as a good argument for preserving biodiversity,” said Chase Mendenhall, tropical biologist at the Carnegie Museum of Natural History. “Nature had innovated something we would never be able to innovate. The lab couldn’t have developed that on its own.”

A sustainable future?

The researchers found that the Mexican corn gets 29% to 82% of the nitrogen it needs from this partnership instead of the soil. Its nine-month growing season and other traits mean it’s not ready to grow as-is worldwide. But if that trait can be bred into other corn, it would mean an equivalent reduction of nitrogen fertilizer use globally.

Christopher Kucharik is associate professor and department chair of the UW-Madison department of agronomy. Not involved with this research, Kucharik studies agriculture issues related to land management, climate change and sustainability. He said the study has the potential to be a watershed moment.

Kucharik said that some people argue the energy use that will be saved from reducing fertilizer use on corn is “only” 1 percent to 2 percent. “But any little bit helps. … There’s no silver bullet to reduce our energy use. If we can come up with 30 or 40 things that each reduce our energy use 1%, that’ll add up.”

“It’s pretty encouraging and could be a game-changer,” Kucharik said.

Credit where credit’s due

Samples of the corn are now back in labs at UW-Madison, where Ané and his colleagues are putting it through more tests.

Ané said the people of Sierra Mixe agreed to the researchers publishing the findings and that the Mars company is working to make sure they are protected and will benefit from the discovery. “They and their ancestors are the ones that did the breeding to amplify that trait,” emphasized Ané.

“The people have a strong cultural attachment to that corn and they’re proud of that corn.” One interesting fact not in the (published research) paper is the farmers who are there actually collect the gel and keep it in their homes in jars. They use it in various rituals. They know that the gel is special – the more gel the corn is producing, the better the corn is producing.”

Scientists may have figured out a more environmentally friendly way to protect crops from bugs. But instead of pesticides, it involves fake caterpillars made of Play-Doh and fake larvae made of orange pinheads.

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The authors believe that the Teotonio waterfall is what attracted people to this location for over 9,000 years, as it was an extremely rich fishing location and an obligatory stopping point for people traveling by boat on this stretch of the Madeira river. It was the location of a fishing village (the village of Teotonio) until 2011, when residents were forced to move inland ahead of dam construction. The dam submersed the village and the waterfall. Eduardo Neves, 2011

 

Original Article:

popular-archaeology

 

Ancient people in the region began cultivating plants and altering forests earlier than previously thought.

PLOS—The remains of domesticated crop plants at an archaeological site in southwest Amazonia supports the idea that this was an important region in the early history of crop cultivation, according to a study published July 25, 2018 in the open-access journal PLOS ONE by Jennifer Watling from the Museum of Archaeology and Ethnology at the University of São Paulo, Brazil and colleagues.

Genetic analysis of plant species has long pointed to the lowlands of southwest Amazonia as a key region in the early history of plant domestication in the Americas, but systematic archaeological evidence to support this has been rare. The new evidence comes from recently-exposed layers of the Teotonio archaeological site, which has been described by researchers as a “microcosm of human occupation of the Upper Madeira [River]” because it preserves a nearly continuous record of human cultures going back approximately 9,000 years.

In this study, Watling and colleagues analyzed the remains of seeds, phytoliths, and other plant materials in the most ancient soils of the site as well as on artifacts used for processing food. They found some of the earliest evidence of cultivated manioc, a crop which geneticists say was domesticated here over 8,000 years ago, as well as squash, beans, and perhaps calathea, and important tree crops such as palms and Brazil nut. They also saw evidence of disturbed forest and a soil type called “Anthropogenic Dark Earths” which both result from human alteration of local environments.

These findings suggest that the people of this region transitioned from early hunter-gatherer lifestyles to cultivating crops before 6,000 years ago, much earlier than previously thought. Along with plant domestication also came the familiar human habit of landscape modification, suggesting that human impact on Amazonian forests in this region goes back many thousands of years. Altogether, these results point to the Upper Madeira as a key locality to explore the earliest days of crop domestication in the New World.

Watling notes: “This discovery at the Teotonio waterfall in Southest Amazonia is some of the oldest evidence for plant cultivation in lowland South America, confirming genetic evidence”.

*Watling J, Shock MP, Mongeló GZ, Almeida FO, Kater T, De Oliveira PE, et al. (2018) Direct archaeological evidence for Southwestern Amazonia as an early plant domestication and food production centrePLoS ONE 13(7): e0199868. https://doi.org/10.1371/journal.pone.0199868

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Dr. Yoshi Maezumi,

 

Original article:

Popular-archaeology.com

UNIVERSITY OF EXETER—Ancient communities transformed the Amazon thousands of years ago, farming in a way which has had a lasting impact on the rainforest, a major new study* shows.

Farmers had a more profound effect on the supposedly “untouched” rainforest than previously thought, introducing crops to new areas, boosting the number of edible tree species and using fire to improve the nutrient content of soil, experts have found.

The study is the first detailed history of long-term human land use and fire management in this region conducted by archaeologists, paleoecologists, botanists and ecologists. It shows how early Amazon farmers used the land intensively and expanded the types of crops grown, without continuously clearing new areas of the forest for farming when soil nutrients became depleted.

The research team examined charcoal, pollen and plant remains from soil in archaeological sites and sediments from a nearby lake to trace the history of vegetation and fire in eastern Brazil. This provided evidence that maize, sweet potato, manioc and squash were farmed as early as 4,500 years ago in this part of the Amazon. Farmers increased the amount of food they grew by improving the nutrient content of the soil through burning and the addition of manure and food waste. Fish and turtles from rivers were also a key part of the diets at the time.

The findings explain why forests around current archaeological sites in the Amazon have a higher concentration of edible plants.

Dr Yoshi Maezumi, from the University of Exeter, who led the study, said: “People thousands of years ago developed a nutrient rich soil called Amazonian Dark Earths (ADEs). They farmed in a way which involved continuous enrichment and reusing of the soil, rather than expanding the amount of land they clear cut for farming. This was a much more sustainable way of farming.”

The development of ADEs allowed the expansion of maize and other crops, usually only grown near nutrient rich lake and river shores, to be farmed in other areas that generally have very poor soils. This increased the amount of food available for the growing Amazon population at the time.

Dr Maezumi said: “Ancient communities likely did clear some understory trees and weeds for farming, but they maintained a closed canopy forest, enriched in edible plants which could bring them food. This is a very different use of the land to that of today, where large areas of land in the Amazon is cleared and planted for industrial scale grain, soya bean farming and cattle grazing. We hope modern conservationists can learn lessons from indigenous land use in the Amazon to inform management decisions about how to safeguard modern forests.”

Professor Jose Iriarte, from the University of Exeter, said: “The work of early farmers in the Amazon has left an enduring legacy. The way indigenous communities managed the land thousands of years ago still shapes modern forest ecosystems. This is important to remember as modern deforestation and agricultural plantations expand across the Amazon Basin, coupled with the intensification of drought severity driven by warming global temperatures.”

*The legacy of 4,500 years of polyculture agroforestry in the eastern Amazon is published in the journal Nature Plants.

 

 

 

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The batches of chicha cooling before they are strained and added to a ceramic fermentation jar. Credit: Photo courtesy of the Cerro Baúl Archaeological Project

 

Original Article:

ByElizabeth Shockman

pri.org

 

Towering 2,000 feet above its surroundings in the southern Peruvian Andes, the Cerro Baúl mesa stands alone in a sun-baked, arid mountain zone. It was here that the Wari culture, a mighty empire that predated the Incas, built a colony — and a massive brewery.

“The Wari were one of the earliest expansive states in the Andes,” says anthropologist Patrick Ryan Williams. “They emerged in the central highlands of Peru some time before 600 AD. … At the height of their reign they actually held sway over an area 800 miles along the Andes.”

That’s similar to the same distance as between New York City and Jacksonville, Florida today — a really big expanse of land.

And, Williams says, they encountered all these different tribal groups and ethnic groups of different peoples that were incorporated into their realm. “The beer story is one that plays a lot in terms of understanding how they did that.”

The beer that Williams and his wife, anthropologist Donna Nash, are studying is not actually a beer. It’s a drink called chicha — a word used to describe fermented grains, fruit products or other things that were found in the native Americas.

In the case of the Cerro Baúl mesa, the chicha appears to have been made from corn flavored with a small Peruvian pepper berry.

Nash and Williams pieced together the ancient recipe based on pepper berry dregs discovered at the site and also chemical residues found on recovered archaeological vessels used in the brewing process.

The brewery, according to Nash and Williams, was capable of pumping out 500-gallon batches of the pepper berry-flavored corn beer, or chicha de molle. And the drink, while most likely consumed by the Wari on a daily basis, was also used for trade negotiations, calendar events, celebrations, marriages and funerals.

Nash, together with her team and a group of Peruvian women, was able to create a chicha brew with a chemical content very similar to the ancient residues found on excavated vessel fragments.

For anyone interested in getting a taste of the ancient drink, Chicago’s Field Museum has a chicha-inspired beer on tap for sale in their bistro.

“It’s pretty good,” Williams says, “It’s got a little bit of a sour taste to it. It does use the purple corn and the Peruvian pepper berries, which have been imported from Peru. But it’s also a beer so it has hops and a barley malt, so it’s inspired, not a recreation of this exact recipe.”

Williams and Nash are continuing further excavation of the Cerro Baúl mesa site, but they say the excavated brewery has already told them a lot about the ancient Wari people.

“The Wari as an empire liked to do expensive and elaborate things. And building a citadel on top of a mesa was one example of the kind of expense they went to as part of their empire,” Nash says.

“I think they were really trying to impress their neighbors by putting a brewery on top of this isolated mountain with no natural source of water no food,” Williams adds, “They were trying to show off.”

A Wari drinking vessel from Cerro Baúl with a half-gallon capacity, depicting the face of a principal Wari deity.

 

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Different varieties of sweet potato on display at the International Potato Center in Lima, Peru. The sweet potato originated in the Americas and spread across the globe. Robert Scotland

Many botanists argued that humans must have carried the valuable staple to the Pacific from South America. Not so, according to a new study.

Carl Zimmer APRIL 12, 2018

Nytimes.com

Of all the plants that humanity has turned into crops, none is more puzzling than the sweet potato. Indigenous people of Central and South America grew it on farms for generations, and Europeans discovered it when Christopher Columbus arrived in the Caribbean.

In the 18th century, however, Captain Cook stumbled across sweet potatoes again — over 4,000 miles away, on remote Polynesian islands. European explorers later found them elsewhere in the Pacific, from Hawaii to New Guinea.

The distribution of the plant baffled scientists. How could sweet potatoes arise from a wild ancestor and then wind up scattered across such a wide range? Was it possible that unknown explorers carried it from South America to countless Pacific islands?

An extensive analysis of sweet potato DNA, published on Thursday in Current Biology, comes to a controversial conclusion: Humans had nothing to do with it. The bulky sweet potato spread across the globe long before humans could have played a part — it’s a natural traveler.

Some agricultural experts are skeptical. “This paper does not settle the matter,” said Logan J. Kistler, the curator of archaeogenomics and archaeobotany at the Smithsonian Institution.

Alternative explanations remain on the table, because the new study didn’t provide enough evidence for exactly where sweet potatoes were first domesticated and when they arrived in the Pacific. “We still don’t have a smoking gun,” Dr. Kistler said.

The sweet potato, Ipomoea batatas, is one of the most valuable crops in the world, providing more nutrients per farmed acre than any other staple. It has sustained human communities for centuries. (In North America, it often is referred to as a yam; in fact, yams are a different species originating in Africa and Asia.)

Scientists have offered a number of theories to explain the wide distribution of I. batatas. Some scholars proposed that all sweet potatoes originated in the Americas, and that after Columbus’s voyage, they were spread by Europeans to colonies such as the Philippines. Pacific Islanders acquired the crops from there.

As it turned out, though, Pacific Islanders had been growing the crop for generations by the time Europeans showed up. On one Polynesian island, archaeologists have found sweet potato remains dating back over 700 years.

A radically different hypothesis emerged: Pacific Islanders, masters of open-ocean navigation, picked up sweet potatoes by voyaging to the Americas, long before Columbus’s arrival there. The evidence included a suggestive coincidence: In Peru, some indigenous people call the sweet potato cumara. In New Zealand, it’s kumara.

A potential link between South America and the Pacific was the inspiration for Thor Heyerdahl’s famous 1947 voyage aboard the Kon-Tiki. He built a raft, which he then successfully sailed from Peru to the Easter Islands.

Genetic evidence only complicated the picture. Examining the plant’s DNA, some researchers concluded that sweet potatoes arose only once from a wild ancestor, while other studies indicated that it happened at two different points in history.

According to the latter studies, South Americans domesticated sweet potatoes, which were then acquired by Polynesians. Central Americans domesticated a second variety that later was picked up by Europeans.

Hoping to shed light on the mystery, a team of researchers recently undertook a new study — the biggest survey of sweet potato DNA yet. And they came to a very different conclusion.

“We find very clear evidence that sweet potatoes could arrive in the Pacific by natural means,” said Pablo Muñoz-Rodríguez, a botanist at the University of Oxford. He believes the wild plants traveled thousands of miles across the Pacific without any help from humans.

Mr. Muñoz-Rodríguez and his colleagues visited museums and herbariums around the world to take samples of sweet potato varieties and wild relatives. The researchers used powerful DNA-sequencing technology to gather more genetic material from the plants than possible in earlier studies.

Their research pointed to only one wild plant as the ancestor of all sweet potatoes. The closest wild relative is a weedy flower called Ipomoea trifida that grows around the Caribbean. Its pale purple flowers look a lot like those of the sweet potato.

Instead of a massive, tasty tuber, I. trifida grows only a pencil-thick root. “It’s nothing we could eat,” Mr. Muñoz-Rodríguez said.

The ancestors of sweet potatoes split from I. trifida at least 800,000 years ago, the scientists calculated. To investigate how they arrived in the Pacific, the team headed to the Natural History Museum in London.

The leaves of sweet potatoes that Captain Cook’s crew collected in Polynesia are stored in the museum’s cabinets. The researchers cut bits of the leaves and extracted DNA from them.

The Polynesian sweet potatoes turned out to be genetically unusual — “very different from anything else,” Mr. Muñoz-Rodríguez said.

The sweet potatoes found in Polynesia split off over 111,000 years ago from all other sweet potatoes the researchers studied. Yet humans arrived in New Guinea about 50,000 years ago, and only reached remote Pacific islands in the past few thousand years.

The age of Pacific sweet potatoes made it unlikely that any humans, Spanish or Pacific Islander, carried the species from the Americas, Mr. Muñoz-Rodríguez said.

Traditionally, researchers have been skeptical that a plant like a sweet potato could travel across thousands of miles of ocean. But in recent years, scientists have turned up signs that many plants have made the voyage, floating on the water or carried in bits by birds.

Even before the sweet potato made the journey, its wild relatives traveled the Pacific, the scientists found. One species, the Hawaiian moonflower, lives only in the dry forests of Hawaii — but its closest relatives all live in Mexico.

The scientists estimate that the Hawaiian moonflower separated from its relatives — and made its journey across the Pacific — over a million years ago.

But Tim P. Denham, an archaeologist at the Australian National University who was not involved in the study, found this scenario hard to swallow.

It would suggest that the wild ancestors of sweet potatoes spread across the Pacific and were then domesticated many times over — yet wound up looking the same every time. “This would seem unlikely,” he said.

Dr. Kistler argued that it was still possible that Pacific Islanders voyaged to South America and returned with the sweet potato.

A thousand years ago, they might have encountered many sweet potato varieties on the continent. When Europeans arrived in the 1500s, they likely wiped out much of the crop’s genetic diversity.

As a result, Dr. Kistler said, the surviving sweet potatoes of the Pacific only seem distantly related to the ones in the Americas. If the scientists had done the same study in 1500, Pacific sweet potatoes would have fit right in with other South American varieties.

Dr. Kistler was optimistic that the sweet potato debate would someday be settled. The world’s herbariums contain a vast number of varieties that have yet to be genetically tested.

“There are more than we could look at in a lifetime,” Dr. Kistler said.

For his part, Mr. Muñoz-Rodríguez plans on searching for more wild sweet potato relatives in Central America, hoping to get more clues to how exactly a thin-rooted weed gave rise to an invaluable crop.

Working out the history of crops like this could do more than satisfy our curiosity about the past. Wild plants hold a lot of genetic variants lost when people domesticated crops.

Researchers may find plants they can hybridize with domesticated sweet potatoes and other crops, endowing them with genes for resistance to diseases, or for withstanding climate change.

“Essentially, it’s preserving the gene pool that feeds the world,” Dr. Kistler said.

Caption1 The distribution of the sweet potato plant has baffled scientists. How could the plant arise from a wild ancestor in the Americas and wind up on islands across the Pacific? Karsten Moran for The New York Times

Caption2 Different varieties of sweet potato on display at the International Potato Center in Lima, Peru. The sweet potato originated in the Americas and spread across the globe. Robert Scotland

Link https://www.nytimes.com/2018/04/12/science/sweet-potato-pacific-dna.html

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field of Quinoa

 

Original Article

eurelalert.org

Archaeological remains found in southern Bolivia reveal a flourishing agrarian society from the 13th to the 15th centuries, despite marked drying and cooling of the climate throughout the period. This unexpected observation is the result of an interdisciplinary study conducted by an international team (CONICET, CNRS, IRD and UCSD). This research, published in Science Advances, highlights the adaptive capacity and resilience of societies with little hierarchical differentiation, in confronting the challenges of climate degradation.

Source: Unexpected agricultural production allowed pre-Hispanic society to flourish in arid Andes

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