Agriculture on EARTH Magazine

Humans accidentally created new rivers in Europe

Thu, 17 Jan 2019 13:26:26 -0500

The Lek River in the Netherlands formed as a result of avulsion triggered by human alteration of the surrounding landscape. Credit: Rijkswaterstaat/Joop van Houdt.

Meandering rivers that flow through and transport sediment to deltas often split off from their main courses and flow in different directions. This process, called avulsion, happens naturally when a river overflows its banks and the floodwaters carve out a new course for the river to follow. But humans can also trigger avulsions by changing the shape of the landscape, and in a new study, scientists report that people have been doing this for a very long time.

Did early agriculture knock the climate off track?

Thu, 08 Nov 2018 12:49:15 -0500

A new study indicates that animal husbandry and agriculture starting about 8,000 years ago (depicted here in a painting from the burial chamber of the Egyptian artist Sennedjem from about 3,300 years ago) postponed the next glacial period. Credit: public domain.

During the last 2.5 million years, Earth’s climate has seen cycles of advancing and retreating glaciers over much of the Northern Hemisphere. We are currently in a warm, interglacial period — one that’s been prolonged by increases in atmospheric concentrations of greenhouse gases, such as carbon dioxide and methane. According to a new study in Nature, these high concentrations of greenhouse gases have disrupted the recent pattern of cycling in Earth’s climate and pushed back the next ice age. The study also suggests that human activity, beginning thousands of years ago with early agriculture and continuing through to the present day, has fueled the rise in greenhouse gas concentrations.

Weedy seeds gathered in once-green Sahara

Tue, 05 Jun 2018 16:36:57 -0400

Today, the vast and arid Sahara Desert seems an unlikely place to find early signs of seed gathering and plant cultivation in Africa, but new evidence shows that, 10,000 years ago, people were collecting, sorting and saving seeds near a rock shelter known as Takarkori.

From farm to filter: Restored wetlands remediate nitrogen pollution

Mon, 09 Apr 2018 11:21:45 -0400

Bottomland hardwoods are a predominant wetland type in the Mississippi Alluvial Valley, the historic floodplain and valley of the lower Mississippi River. Credit: U.S. Fish and Wildlife Service.

Nitrogen giveth and nitrogen taketh away: It’s been estimated that roughly half of the world’s population today could not exist without nitrogen fertilization. Although land area on Earth remains roughly the same on human timescales, population continues to rise, requiring more intensive and rigorous use of existing agricultural land and the creation of more agricultural lands to meet the ever-growing demand for food. One way humanity has supported population growth is through the manipulation of nitrogen, a limiting nutrient in terrestrial ecosystems. In 1913, the advent of the Haber-Bosch process, which artificially converts nitrogen gas to bioavailable ammonia, revolutionized access to nitrogen and all but eliminated nitrogen limitation in terrestrial ecosystems. Now, nitrogen fertilizers are often heavily applied to croplands to increase plant growth and productivity.

Geomedia: Books: Putting 'Seeds on Ice' to protect crop diversity

Fri, 12 Jan 2018 14:48:22 -0500

"Seeds on Ice: Svalbard and the Global Seed Vault," Cary Fowler, Prospecta Press, 2016, ISBN: 9781632260574

“Tucked away, deep underground, in a frozen corner of the Scandinavian north is the safety net for our food supply. The Global Seed Vault, on the island of Spitsbergen in Norway’s Svalbard Archipelago and popularly known as the “doomsday vault,” shelters our most precious seeds from possible global catastrophe.

Dividing line: The past, present and future of the 100th Meridian

Tue, 09 Jan 2018 13:30:45 -0500

The Great Plains are well known for their sweeping grasslands, which, to the east, eventually turn into great farms, and, to the west, give way to deserts and mountains. Credit: ©iStockphoto.com/Danielrao.

In 1878, without benefit of the Landsat program, GPS or Google, and just a decade after the creation of the National Weather Service, John Wesley Powell first advanced the idea that the climatic boundary between the United States’ humid East and arid West lay along a line “about midway in the Great Plains” — almost exactly 100 degrees longitude west of the prime meridian in Greenwich, England. This line, the 100th meridian, runs from pole to pole and cuts through six U.S. states, forming a partial boundary between Oklahoma and Texas. The 100th meridian also corresponds roughly to the 600-meter elevation contour as the land rises from the Great Plains toward the Rockies.

When agriculture went to our heads

Wed, 18 Oct 2017 12:04:46 -0400

Researchers used points, or landmarks, on numerous crania and mandibles from a variety of preindustrial farming and foraging populations to compare features of post-agricultural skulls. Credit: David Katz and Tim Weaver, UC Davis.

The dawn of agriculture left an indelible mark on early human societies, and a new study finds that eating softer, cultivated foods subtly changed the shape of human skulls. Scientists have long suspected that the transition from hunting and foraging to farming and raising livestock would have affected our skulls, specifically the mandible and other anatomy involved in chewing, but quantifying such changes has proven difficult.

Nineteenth-century cows muddied Southern California continental shelf

Wed, 19 Jul 2017 11:44:14 -0400

When offshore ecosystems deteriorate, scientists often look at changing ocean conditions, urban runoff or fishing as potential explanations. Cows usually don’t come to mind. But new research investigating the seafloor off the coast of Los Angeles suggests that 19th-century cattle, despite their terrestrial lifestyle, left a lasting impact on the underwater habitat there.

Tibetan Plateau populated long before advent of agriculture

Mon, 15 May 2017 14:18:53 -0400

Due to the harsh living conditions of the Tibetan Plateau — which has an average elevation over 4,500 meters — archaeologists have long assumed that people didn’t live in the Himalayan high country until after the adoption of agriculture in this region of the world, about 3,600 years ago. But a new study of a trove of handprints and footprints found around a fossilized mud spring in Tibet is suggesting that people may have lived here as early as 13,000 years ago.

Grapes reveal impacts of sulfur-rich Samalas eruption on 13th-century climate

Wed, 19 Apr 2017 14:05:44 -0400

Lake Segara Anak fills the caldera formed during Samalas' 1257 eruption. Credit: Petter Lindgren.

The A.D. 1257 eruption of the Indonesian volcano Samalas sent an ash plume an estimated 43 kilometers into the sky in one of the most sulfur-rich eruptions of the last 7,000 years. A new study using tree rings, ice cores and historical records investigates how this colossal eruption impacted climate across the Northern Hemisphere, finding that the eruption triggered severe cold in some regions, while other areas were less affected. The pattern could be explained by the behavior of sulfate particles in the atmosphere, researchers suggest.

Neonicotinoids: Prominent pesticides escape into the environment

Fri, 14 Apr 2017 09:48:30 -0400

Credit: K. Cantner, AGI.

The 1990s was a watershed era in pest control — and, by extension, agriculture — thanks to a particular bit of chemical innovation. With the emergence of a compound called imidacloprid onto the insecticide market, farmers — from those growing rice, corn and other staples, to orchard owners cultivating fruit trees, to backyard gardeners tending vegetable patches — had a powerful new tool with which to combat aphids, beetles, weevils, whiteflies and a host of other insects with a knack for damaging crops.

Ants developed farming millions of years ago

Thu, 09 Feb 2017 09:12:04 -0500

A new study in Nature suggests that ants may have invented agriculture as much as 3 million years before humans.

On the Fijian islands of Viti Levu, Vanua Levu and Taveuni, the ant species Philidris nagasau actively cultivates at least six species of Squamellaria plants, using the plants for both food and shelter. All of the Squamellaria are epiphytes, or plants that grow on other plants, using their hosts for support and nutrients. The ants were observed gathering seeds from the fruits of the Squamellaria and inserting them into crevices in host trees. Worker ants constantly patrolled the seeds and, as the seedlings took root in the host, they defecated in the crevices, fertilizing the young plants. As the plants mature, they form hollow chambers at their bases, which the ants were observed using for nests. The ants also harvested the Squamellaria fruit, eating the flesh and collecting seeds for planting.

Burning grass releases more nitrogen pollution than burning wood

Thu, 26 Jan 2017 09:50:27 -0500

Researchers found that grass and crop fires produce more nitrogen pollutants than wildfires. Credit: USFWS, CC BY 2.0.

Smoke from fires — whether from wildfires or from residential and agricultural grass and crop burning — carries pollutants into the air that affect climate and can be toxic to humans and ecosystems. According to new research, smoke from crop and grass fires appears to contain higher levels of some hazardous nitrogen-containing chemicals than wood fire smoke. The work also calls into question whether certain chemicals commonly used as distinctive signatures of biomass burning are still valid.

Take a stand (or sit) for better water quality management

Thu, 16 Jun 2016 09:42:20 -0400

Referred to as "separation," "urine diversion" or "no-mix" toilets, the toilets of the future look, on the outside, like typical toilets today. The insides of the bowls are divided into two collection areas — one at the front for urine and another at the back for feces. Credit: Eawag, Ruedi Keller

The average person urinates four to seven times over a 24-hour period, producing about 1.5 liters of urine per day. Here are some things you can do today to help conserve water, improve water quality, and keep all that waste from going to waste.

'P' is for phosphate: Could urine solve a fertilizer shortage?

Thu, 16 Jun 2016 09:26:37 -0400

Researchers at the Rich Earth Institute are experimenting with using urine-derived fertilizer to grow crops. Here, institute researcher Abe Noe-Hays adds sanitized urine fertilizer to lettuce. Credit: Marcin Szczepanski.

Whether you’re enjoying a juicy burger from a fast-food drive-thru or digging into a brightly colored salad at a backyard barbecue, your meal likely started life on a farm. Each day, agriculture around the world produces an average of 27.3 million tons of food, enough to feed Earth’s current population of about 7.3 billion — although not all of that food reaches people.

Uranium contamination in aquifers could be linked to nitrate

Tue, 16 Feb 2016 10:49:05 -0500

Uranium (red) and nitrate (blue) levels in groundwater are indicated at sites across the U.S. in this map, including in the Central Valley (California) and High Plains (central U.S.) aquifers. Credit: University of Nebraska--Lincoln

Nitrogen is an essential nutrient for plant life, but plants can only take up so much so fast. When excess nitrogen enters the environment by way of fertilizer and manure runoff, as well as in automobile and industrial emissions, it becomes a pollutant that can leach into waterways, carrying with it unintended — and often undesirable — consequences. In a new study, researchers have found evidence of one such consequence: elevated uranium levels in two major U.S. aquifers.

Irrigation drives rain away in East Africa

Thu, 07 Jan 2016 11:31:33 -0500

Croplands in the Gezira Scheme in Sudan, near the confluence of the Blue Nile and White Nile, are watered by a vast network of irrigation canals. Credit: NASA.

Researchers have found that large-scale agricultural irrigation, intended to supplement precipitation, may actually drive rainfall away, potentially exacerbating conditions in some areas while improving them in nonirrigated lands.

How to feed 11 billion people: Addressing the 21st century's biggest challenge

Wed, 30 Dec 2015 10:03:38 -0500

A market in Delhi, India. Credit: Christian Haugen, CC BY 2.0.

In April 2008, violent protests erupted across the impoverished Caribbean nation of Haiti. Enraged by soaring food prices and all-too-frequent hunger pangs, protesters smashed windows, looted shops, barricaded streets with blazing cars and stormed the presidential palace in the capital, Port-au-Prince. The week of violence, during which five people were killed, flared after the cost of staples like beans and cooking oil spiked dramatically and the price of rice nearly doubled in four months, increasing hardships in a nation where 80 percent of the population survives on less than $2 per day.

Toxic Gardens: The long legacy of urban lead

Fri, 04 Sep 2015 11:49:09 -0400

Community gardens (such as the one above in Indianapolis) and playgrounds are common places where children can come into contact with lead-contaminated soils in the urban environment. Remediation at the playground above was funded by the Greater New Orleans Foundation and U.S. Department of Housing and Urban Development. Credit: top: Gabriel Filippelli/Indiana University; bottom: Howard Mielke/Tulane.

From a toxicological point of view, soaring lead levels in the home environment represented one of America’s lowest points — but efforts to improve the situation also led to one of our greatest success stories. After leaded gasoline and lead paints were identified as the culprits behind alarmingly high blood lead levels in children in the late 1970s, the federal government passed legislation banning the metal from these products, and many wide-reaching programs educated the public on how to reduce exposure to lead. By the 1990s, average blood lead levels in children exposed to lead in the home had dropped from 15 micrograms per deciliter of blood to just two.

Geologic Column: September 26, 1774: The man, the myth, the legend of Johnny Appleseed is born

Thu, 20 Aug 2015 12:45:54 -0400

Drawing of Jonathan Chapman, aka Johnny Appleseed from 1862. Credit: Public Domain.

You’ve probably heard about Johnny Appleseed, who, according to story and song, spread his apple seeds across America’s Midwest. But, unlike other figures from American folklore such as Paul Bunyan, Rip Van Winkle and Pecos Bill, Johnny Appleseed was a real man with a life far richer and more interesting than the legend.

Pre-settlement erosion rates illuminated

Tue, 12 May 2015 10:05:26 -0400

Researchers quantified background landscape erosion rates in the southeastern U.S. prior to European settlement by studying sediments along 10 major rivers, including the Dan River. Credit: ©MarmadukePercy, CC BY-SA 3.0.

Humans are one of the most powerful erosive agents on Earth, moving copious amounts of sediment to and fro, mainly through agriculture and development. But quantifying how much we actually move — often a necessary step for developing sustainable land management practices — hinges on determining erosion rates in an area before humans intervened. A new study using surface exposure dating to estimate pre-colonial erosion rates in the southeastern U.S. has now clarified the natural background rate in more detail than ever before, revealing the dramatic human impact on the regional landscape.

Geomedia: Books: Breaking New Ground

Tue, 07 Apr 2015 11:28:29 -0400

"Breaking New Ground: A Personal History," by Lester R. Brown, W. W. Norton & Co., 2013, ISBN 978-0393240061.

Agricultural scientist Lester Brown ponders the global future of agriculture, but his roots as a tomato farmer make him keenly aware of the local challenges of feeding a growing population. A 1986 recipient of a MacArthur Fellowship for his pioneering interdisciplinary work in the field of sustainable development, and the founder of the Worldwatch Institute, Brown reflects on his life and career in his autobiography, “Breaking New Ground: A Personal History.”

Rome's hidden water trade led to glory, maybe ruin

Mon, 09 Mar 2015 12:07:12 -0400

Crumbling aqueducts crisscross the lands that once belonged to Rome, relics of a water system that sustained an empire. But now, research suggests that much of the water that flowed into Roman cities did not come gurgling down a conduit — it came in copious quantities of grain, imported to feed a growing population.

Geologic Column: Lighting out for the territory

Fri, 30 Jan 2015 14:23:36 -0500

“I reckon I got to light out for the territory ahead of the rest.” – Huck Finn

Engraving of The elderly Daniel Boone hunting in Missouri by Alonzo Chappel (c.1861). Credit: Public Domain.

In 1799, Colonel Daniel Boone found Tennessee’s population density of 10 people per square mile irksome, so he moved to land west of the Mississippi. Boone’s fictional counterpart was James Fenimore Cooper’s hero Natty Bumppo (aka Leatherstocking), who left his stomping grounds alongside the Great Lakes and walked all the way to the Pacific to get away from the sound of trees being felled by homesteaders. He even got to the ocean ahead of Lewis and Clarke — not bad for an 80-year-old. I wonder what he would have thought of a future that would see Las Vegas, the largest city founded in the 20th century, built in the arid lands of the West?

Climate impacting a few of our favorite foodstuffs

Tue, 02 Sep 2014 13:15:16 -0400

Nectarine trees, shown here in an orchard near Traver, Calif., and other fruit and nut trees are threatened by a lack of "fog days." Credit: ©Nate Gray, CC BY-NC-SA 2.0.

Less fog means trouble for Central Valley fruits and nuts

Researchers have found that the number of foggy winter days in California’s agriculture-heavy Central Valley has dropped 46 percent on average over the past three decades. Fog shields the valley from sunlight and contributes to the amount of “winter chill” — the amount of time spent between zero and 7 degrees Celsius during winter dormancy — that fruit and nut trees there experience. Sufficient winter chill is necessary for buds, flowers and fruit to develop properly, and although winter chill has previously been observed to have decreased since the 1950s, no one had conducted a long-term analysis of fog occurrence trends in the area, according to Dennis Baldocchi and Eric Waller of the University of California at Berkeley.

Virtual water: Tracking the unseen water in goods and resources

Thu, 28 Aug 2014 13:57:57 -0400

China is a thirsty nation. Rapid economic growth and urbanization among its nearly 1.4 billion people in recent decades, as well as a growing taste for meat, have created an ever-growing demand for freshwater. And in the cities, industrial centers and farmlands of the more populous, more arid north, available resources — rivers, lakes and aquifers — are drying up.

Climate, terroir, and wine: What matters most in producing a great wine?

Thu, 12 Dec 2013 11:01:05 -0500

Wine can grow all over the world, including the pre-Alps of the Veneto region in Italy where Prosecco is produced. Gregory V. Jones

Weather and climate have played decisive roles throughout human existence — where and how cultures developed, where they migrated and even how some died out. The most successful early civilizations were those that developed strong agrarian systems based on what crops were most compatible with the climate. If conditions changed for one reason or another, people migrated to areas with a more suitable environment to grow a certain crop or raise specific animals. Today, as in the past, climate is clearly one of the most important factors in the success of all agricultural systems, influencing whether a crop — including winegrapes — is suitable to a given region, largely controlling crop productivity and quality, and ultimately driving economic sustainability.

Comment: Peak Soil: Does civilization have a future?

Fri, 20 Jan 2012 03:51:09 -0500

First there was Peak Oil, the idea that there’s only so much oil out there and we may have reached or even passed a turning point in global oil production. In his 2007 book “Peak Everything,” author Richard Heinberg said it’s not just fossil fuels: Everything from population to food production to freshwater availability has its own point of no return.

Crystal Ball EARTH: Agriculture: The future will have a different face than the past

Fri, 20 Jan 2012 03:51:09 -0500

U.S. Geological Survey

Tomorrow’s agriculture is facing an immense challenge. By 2050, the world’s population will reach somewhere between 9 billion and 10 billion people, and a greater proportion of those people will be enjoying a richer diet than today’s population. That means farmers will have to grow twice as much food. The world has already witnessed a preview of what might happen if large populations don’t receive an adequate supply of food: They do not accept their fates passively.