5. Soil

The Living Skin of the Earth

2021-01-11. European Colonists Dramatically Increased North American Erosion Rates. By Rachel Fritts, Eos/AGU. Excerpt: ...human activities like farming can dramatically accelerate natural erosion rates. The arrival of European colonists in North America, for instance, sped up the rate of erosion and river sediment accumulation on the continent by a factor of 10, according to a new study. An international team of researchers from China, Belgium, and the United States analyzed 40,000 years of accumulated river sediment from sites across North America to determine the natural background rate of erosion on the continent. ...During the past century alone, humans moved as much material as would be moved by natural processes in 700–3,000 years, the team reported in November in Nature Communications. “By having this huge compilation [of data] that stretches back many thousands of years, we’re able to contextualize the human impact against that natural geologic variability,” said lead author David Kemp, a geologist with the China University of Geosciences in Wuhan. “It was a surprise to me that the jump was there and that it seemed to be so neatly coincident with European arrival.”.... [https://eos.org/articles/european-colonists-dramatically-increased-north-american-erosion-rates

2020-12-04. There’s an ecosystem beneath your feet—and it needs protection, new report says. By Elizabeth Pennisi, Science Magazine. Excerpt: Reach down and scoop up some soil. Cupped in your hands may be 5000 different kinds of creatures—and as many individual cells as there are humans on the globe. That random handful might hold microscopic fungi, decomposing plant matter, a whisker-size nematode munching on the fungi, and a predatory, pinhead-size mite about to pounce on the nematode. One bacterium may fend off another with a potent antibiotic. It’s a whole world of often overlooked biodiversity. Today, on the eve of World Soil Day, the Food and Agriculture Organization of the United Nations has released its first ever global assessment of the biodiversity in this underground world. ...Hidden below ground, these ecosystems seemed immune to aboveground disturbance, Wood says. “For a long time, soil scientists thought that soil microorganisms were so well spread around the world that land management would not harm them,” he explains. “We now know that soil microorganisms can be very specific to very specific habitats and species,” habitats that are rapidly disappearing as farms and cities expand. The report lists a dozen human activities taking a major toll on soil organisms. They include deforestation, intense agriculture, acidification due to pollutants, salinization from improper irrigation, soil compaction, surface sealing, fire, and erosion. “If you pave over a site, you are sealing off an entire belowground ecosystem,” Fierer says. “And that’s happening all over the globe.”.... [https://www.sciencemag.org/news/2020/12/there-s-ecosystem-beneath-your-feet-and-it-needs-protection-says-new-report]

2020-10-20. Dust Bowl 2.0? Rising Great Plains dust levels stir concerns. By Roland Pease, Science Magazine. Excerpt: Earlier this month, a storm front swept across the Great Plains of the United States, plowing up a wall of dust that could be seen from space, stretching from eastern Colorado into Nebraska and Kansas. It was a scene straight from the Dust Bowl of the 1930s, when farmers regularly saw soil stripped from their fields and whipped up into choking blizzards of dust. ...According to a new study, dust storms on the Great Plains have become more common and more intense in the past 20 years, because of more frequent droughts in the region and an expansion of croplands. “Our results suggest a tipping point is approaching, where the conditions of the 1930s could return,” says Gannet Haller, an atmospheric scientist at the University of Utah who led the study. ...Lambert came across the trend unexpectedly, while reviewing data from NASA satellites that remotely measure atmospheric haze due to smoke and dust. No matter how far back he went in the data, the trend remained. Using a network of dust sensors in the region, Lambert and his colleagues were able to corroborate the satellite data and push the trend back more than 20 years. The findings, reported on 12 October in Geophysical Research Letters, show that across large parts of the Great Plains, levels of wind-blown dust have doubled over the past 20 years. One clue that agriculture is responsible is that the dust levels tend to peak during spring and fall—planting and harvesting seasons, Hallar notes.... [https://www.sciencemag.org/news/2020/10/dust-bowl-20-rising-great-plains-dust-levels-stir-concerns

2020-08-21. Five charts that will change everything you know about mud. By David Malakoff, Nirja Desai, Xing Liu, Science Magazine. Excerpt: ...mud—a mixture of fine sediment and water—is one of the most common and consequential substances on Earth. Not quite a solid, not quite a liquid, mud coats the bottoms of our lakes, rivers, and seas. It helps form massive floodplains, river deltas, and tidal flats that store vast quantities of carbon and nutrients, and support vibrant communities of people, flora, and fauna. But mud is also a killer: Mudslides bury thousands of people each year. ... humans are a dominant force in the world of mud. Starting about 5000 years ago, erosion rates shot up in many parts of the world as our ancestors began to clear forests and plant crops. Even more sediment filled rivers and valleys, altering landscapes beyond recognition. In some places dams and dykes trapped that mud, preventing fresh sediment from nourishing floodplains, deltas, and tidal flats and causing them to shrink (see graphic below). And industrial processes began to produce massive quantities of new forms of mud—mine and factory waste—that is laden with toxic compounds and often stored behind dams that can fail, unleashing deadly torrents. ...Although the Nile carries one of the world’s largest sediment loads to the sea, dams across Africa now block up to two-thirds of the sediment that flowed downstream just decades ago. ...Deforestation has increased sediment loads in the Amazon and other South American rivers in recent decades, helping expand the continent’s river deltas by some 16 kilometers per year.... [https://www.sciencemag.org/news/2020/08/five-charts-will-change-everything-you-know-about-mud] See also four other articles in the sam issue of Science:

Red mud is piling up. Can scientists figure out what to do with it? [https://www.sciencemag.org/news/2020/08/red-mud-piling-can-scientists-figure-out-what-do-it]

‘Electric mud’ teems with new, mysterious bacteria [https://www.sciencemag.org/news/2020/08/electric-mud-teems-new-mysterious-bacteria]

Catastrophic failures raise alarm about dams containing muddy mine wastes [https://www.sciencemag.org/news/2020/08/catastrophic-failures-raise-alarm-about-dams-containing-muddy-mine-wastes]

A secret hidden in centuries-old mud reveals a new way to save polluted rivers [https://www.sciencemag.org/news/2020/08/secret-hidden-centuries-old-mud-revealed-new-way-save-polluted-rivers]

2016-02-06. Cover Crops, a Farming Revolution With Deep Roots in the Past. By Stephanie Strom, The New York Times.

2015-10-09. Symphony of the Soil. Lily Films.

2015-03-09. Farmers Put Down the Plow for More Productive Soil. Erica Goode, The New York Times.

2014-02. A nanoscale look at how soil captures carbon.  Excerpt:  ...Soil is a huge component of the global carbon cycle. Organic material in soil, stabilized by interactions with mineral particles, contains about twice as much carbon as the atmosphere. An accurate treatment of soil’s capacity to sequester carbon is thus an essential ingredient in climate models. It’s long been assumed that all mineral surfaces are equally good at stabilizing carbon, so a soil’s carbon-storage capacity is determined by its total surface area. But Ingrid Kögel-Knabner and colleagues at the Technical University of Munich have now laid that assumption to rest. Using nanoscale secondary-ion mass spectrometry (nanoSIMS), a technique for mapping chemical species on a surface, they’ve shown conclusively that organic matter binds to just 20% of the mineral surface area.... http://scitation.aip.org/content/aip/magazine/physicstoday/news/10.1063/PT.5.7047. Johanna L. Miller, Physics Today.

2012 July 04. Searing Sun and Drought Shrivel Corn in Midwest. By Monica Davey, The NY Times. Excerpt: Across a wide stretch of the Midwest, sweltering temperatures and a lack of rain are threatening what had been expected to be the nation’s largest corn crop in generations. Already, some farmers in Illinois and Missouri have given up on parched and stunted fields, mowing them over. National experts say parts of five corn-growing states, including Indiana, Kentucky and Ohio, are experiencing severe or extreme drought conditions...Crop insurance agents and agricultural economists are watching closely, a few comparing the situation with the devastating drought of 1988, when corn yields shriveled significantly, while some farmers have begun alluding, unhappily, to the Dust Bowl of the 1930s. Far more is at stake in the coming pivotal days: with the brief, delicate phase of pollination imminent in many states, miles and miles of corn will rise or fall on whether rain soon appears and temperatures moderate...The driest, hottest conditions have steered clear of some crucial Corn Belt states, including Minnesota, North Dakota, South Dakota and western Iowa, the nation’s most prolific corn producer…. 

2010 January. University of Michigan web page on Land Degradation.

2008 August 9. Devastating Drought Settles on High Plains. By Rebecca Lindsey, NASA Earth Observatory. Excerpt: Devastating drought has returned to the heart of Dust Bowl country. On the High Plains of northeastern New Mexico, southeastern Colorado, southwestern Kansas, the Oklahoma Panhandle, and northern Texas, drought has been creeping up since fall 2007. By mid-June 2008, the Oklahoma Panhandle and surrounding areas slid into “exceptional drought,” the most severe category of drought classified by the U.S. National Drought Mitigation Center.
Cimarron County, Oklahoma, the westernmost county in the state, is “at the epicenter of the drought,” according to staff climatologist Gary McManus with the Oklahoma Climatological Survey (OCS). The land is occupied by wheat farms, corn fields, and pasture. It’s an area of periodic drought; the Dust Bowl years have not yet faded from living memory.
“The area has been in and out of drought since the start of the decade. Mostly in,” McManus said. “But fall of last year was when it really started to get bad. In some places, this year has been as dry or even drier than the Dust Bowl.” As of early August, the Oklahoma panhandle was experiencing its driest year (previous 365 days) since 1921, according to OCS calculations. Through July, year-to-date precipitation in Boise City, Cimarron’s County Seat, was only about 4.8 inches, barely half of average and drier than some years in the 1930s, the height of the Dust Bowl.
...Viewed from the ground, the situation is equally discouraging. According to Cherrie Brown, district conservationist for the USDA Natural Resources Conservation Service in Boise City, subsoil moisture is virtually non-existent. “Any rain that falls is sapped by evaporation in two or three days. Four feet down, there is literally no moisture left in the soil. Recently we were digging as part of a project to decommission a county well, and we dug down to a depth of 7 feet, and there was still no moisture. Even irrigation can’t offset these deficits,” she said. As a result, crops have failed and pasture is severely degraded....

Summer 2008. Great Grasslands. Curtis Runyan, Nature Conservancy Magazine. Excerpt: While the Amazon rainforest gets much of the attention, most of the Brazilian land cleared for ranching and farming is in the Cerrado, a vast stretch of grasslands and savanna about half the size of North America's Great Plains. In recent years more than 50 percent of the region has been cleared or plowed under; only 2 percent is protected.
But in one corner of the Cerrado-the 1,400-square-mile district of Lucas do Rio Verde-The Nature Conservancy is partnering with the local government and all 360 major landowners to help ensure at least 35 percent of their lands are protected as natural habitat, the amount required by Brazilian law....

2008 February 29. Transylvania: Welcome to the Future. By Bruce Stutz, OnEarth. Excerpt: The steeply rolling hills of the Transylvanian plateau lie within the gnarled grasp of the Carpathian Mountains, which curve down through Central Europe into the heart of Romania...
"In Transylvania you will see a preindustrial, self-sufficient agricultural system," Jessica Douglas-Home, the slim, soft-spoken founder and chairwoman of the Mihai Eminescu Trust, assured me when I visited her London office. Since 1997, the trust, partnering at times with the United Nations Development Program, the World Bank, and the European Union (E.U.), has worked to restore and maintain the region's ancient villages, homes, churches, and, especially, agricultural traditions.
The region, Douglas-Home told me, is the very model of an integrated, sustainable world that consumes only what it can replenish, that treads lightly on its environment and leaves barely a carbon footprint behind. "When fuel shortages begin to make things bad for the rest of us," she said, "Transylvania will hardly have to cough."
With its small common grazing meadows and forested hilltops, this preindustrial landscape also holds great reserves of biodiversity, where rare wildflowers, insects, birds, reptiles, and amphibians thrive. According to the E.U., some two-thirds of Europe's threatened and endangered bird species are found on such lands...
The effort to preserve these Saxon lands has become all the more urgent since Romania's accession to the European Union in January 2007. E.U. regulations designed to standardize and modernize farming methods, milking and dairy production, as well as the breeding, grazing, transport, and slaughter of cattle, have created difficulties for small farmers throughout the E.U., but especially in countries such as Romania, Bulgaria, and Poland, where subsistence farms number in the millions...

10 October 2007. NEW FINDING: Organic farming combats global warming É big time. The New Farm -- Rodale Institute. By Laura Sayre.Excerpt: Data from The Rodale Institute's¨ long-running comparison of organic and conventional cropping systems confirms that organic methods are far more effective at removing the greenhouse gas, carbon dioxide, from the atmosphere and fixing it as beneficial organic matter in the soil.
Kutztown, PA. Discussions of global warming in the popular press seldom fail to note its potentially disastrous consequences for agriculture as we know it: more extreme and unpredictable weather, coastal flooding, even the loss of pollen viability for some crop species at higher temperatures all threaten to push the usual unpredictability of farming into the realm of the completely unworkable. But while these threats are indeed grave--and many farmers believe they are witnessing such effects already--researchers at The Rodale Institute¨ have been looking at the problem from the other direction: what impact do agricultural practices have on global warming?
On October 10, The Rodale Institute¨ (TRI), the Pennsylvania Department of Environmental Protection (PDEP), and the Pennsylvania Department of Agriculture (PDA) signed a memorandum of understanding designed to help answer that question. Twenty-three years of ongoing research at The Rodale Institute Experimental Farm already provides strong evidence that organic farming helps combat global warming by capturing atmospheric carbon dioxide and incorporating it into the soil, whereas conventional farming exacerbates the greenhouse effect by producing a net release of carbon into the atmosphere.
Organic Farming -vs- CO2 Fast Facts
If only 10,000 medium sized farms in the U.S. converted to organic production, they would store so much carbon in the soil that it would be equivalent to taking 1,174,400 cars off the road, or reducing car miles driven by 14.62 billion miles.
Converting the U.S.'s 160 million corn and soybean acres to organic production would sequester enough carbon to satisfy 73 percent of the Kyoto targets for CO2 reduction in the U.S.
U.S. agriculture as currently practiced emits a total of 1.5 trillion pounds of CO2 annually into the atmosphere. Converting all U.S. cropland to organic would not only wipe out agriculture's massive emission problem. By eliminating energy-costly chemical fertilizers, it would actually give us a net increase in soil carbon of 734 billion pounds.

5 May 2007. Switch to organic crops could help poor. By NICOLE WINFIELD, Associated Press Writer. Excerpt: ROME - Organic food has long been considered a niche market, a luxury for wealthy consumers. But researchers told a U.N. conference Saturday that a large-scale shift to organic agriculture could help fight world hunger while improving the environment. ...Nadia El-Hage Scialabba, an FAO official who organized the conference, pointed to other studies she said indicated that organic agriculture could produce enough food per capita to feed the world's current population. One such study, by the University of Michigan, found that a global shift to organic agriculture would yield at least 2,641 kilocalories per person per day, just under the world's current production of 2,786, and as many as 4,381 kilocalories per person per day, researchers reported. ...The United Nations defines organic agriculture as a "holistic" food system that avoids the use of synthetic fertilizers and pesticides, minimizes pollution and optimizes the health of plants, animals and people. It is commercially practiced in 120 countries and represented a $40 billion market last year, Scialabba said. ...FAO conference is athttp://www.fao.org/organicag/ofs/index_en.htm

15 December 2005. Prairie: Long-Range Forecast. By Candace Savage, Forest Magazine, Winter 2006. Excerpt: In 1960, 3 million acres of land were designated national grasslands, and put under U.S. Forest Service purview. There are twenty national grasslands, all managed by the Forest Service. ... the Loess Hills in Iowa, the Mescalero Dunes in New Mexico, the Black Hills Coniferous Forest in South Dakota, the Little Missouri Mountains in Montana-and others in almost every region. Candace Savage's book Prairie: A Natural History explores these remarkable ecosystems, celebrating this oft-unsung landscape with perspective and affection. ...when the Earth is losing species at an average rate of one every twenty minutes-the wide-open spaces of the Great Plains are a landscape of hope. ...According to a recent "biological-trends assessment" conducted by a team of researchers from several western universities, a total of about 1.2 million square kilometers (465,000 square miles) of natural grassland has been destroyed in the western United States since the onset of intensive settlement. Of these losses, almost 10 percent-110,000 square kilometers (43,000 square miles), an area half the size of Kansas-were incurred between 1950 and 1990. ... the destruction is relentless. In Colorado alone, more than 1,100 square kilometers (420 square miles) of farm and ranch land are lost every year, and the rate is accelerating. ... this continuing assault on the prairie ecosystem imposes an escalating stress on species that rely on wild grasslands for their survival. ...The cause of prairie restoration has found some unexpected advocates, among them the Iowa Department of Transportation. ...What the state does have...is a go-anywhere grid of roads, all of which have vegetated margins. Taken together, these strips add up to about 2,000 square kilometers (roughly half a million acres) of unproductive land that requires mowing, spraying and other regular maintenance. In an attempt to reduce costs in the late 1980s, the transportation authorities began to experiment with the use of native plants, on the assumption that they were adapted to local conditions and could look after themselves. Since then, more than 20,000 hectares (about 50,000 acres) of roadside have been seeded, a little more every year, to either a four-grass mixture-typically big and little bluestem, side- oats grama and Indian grass-or to a colorful assortment of native grasses and wildflowers. The results have exceeded all expectations. In addition to controlling expenses, the flower-rich plantings in particular have become slender oases of life, blooming not only with flowers but also with butterflies. In 2001, for example, researchers found five times as many butterflies and twice as many species in the high-quality restorations as in comparable grassy or weedy ditches...

Fall 2005. Prairie: Home on the Range. By Candace Savage. Forest Magazine. Excerpt: In 1960, 3 million acres of land were designated national grasslands, and put under U.S. Forest Service purview. There are twenty national grasslands, all managed by the Forest Service. ...Rangelands-expanses of native grassland that are grazed by livestock-exist only where the prairie has somehow managed to escape the plow, usually because the soil is too dry, too thin, too rocky, or too steep to be suitable for crops. ...In some ways, the introduction of domesticated livestock onto the Great Plains was not much of a shock to the ecosystem. Bison and cattle belong to the family Bovidae, and trace their ancestry back to India and China some 2 million years ago. ...This is not to say that the introduction of cattle to the Great Plains has been completely benign-it has not. ... bison like to throw themselves on the ground and flail around in the dirt, a self-care routine that is thought to coat the skin with dust and offer protection from biting insects. In the process, they wear away shallow bowls, or "wallows" in the earth. By rubbing out the grasses from these hollows, bison create openings for other kinds of plants. The increased diversity of plants available for shelter and food also augments the diversity of insects, birds, and mammals. If the depressions fill with water, they provide seasonal habitat for aquatic insects and water-loving shorebirds. Or at least they used to. Because cattle do not wallow, this dynamic has been lost....

18 March 2004. NASA RELEASE: 04-095. NASA EXPLAINS "DUST BOWL" DROUGHT. NASA scientists have an explanation for one of the worst climatic events in the history of the United States, the "Dust Bowl" drought, which devastated the Great Plains and all but dried up an already depressed American economy in the 1930's. Siegfried Schubert of NASA's Goddard Space Flight Center, Greenbelt, Md., and colleagues used a computer model developed with modern-era satellite data to look at the climate over the past 100 years. The study found cooler than normal tropical Pacific Ocean surface temperatures combined with warmer tropical Atlantic Ocean temperatures to create conditions in the atmosphere that turned America's breadbasket into a dust bowl from 1931 to 1939. The team's data is in this week's Science magazine.



 

Articles from 2004–present

Non-chronological links:

SEE ALSO...Ecosystem Change
-chapter 2: Energy Through a System
-chapter 4: Changes in the Global System
-chapter 5: Carbon in the Biosphere
-chapter 7: Neighborhood and Global Stewardship

Soil Science Education Homepage, NASA. "Soils in the News" section archives soil-related stories, particularly erosion and dust storms.

California Certified organic Farmers (CCOF) -- http://www.ccof.org/

USDA Organic Production Data Sets

Rainforest web