Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Conventional plowing is 'skinning our agricultural fields'

13.08.2007
Traditional plow-based agricultural methods and the need to feed a rapidly growing world population are combining to deplete the Earth's soil supply, a new study confirms.

In fact, long-established practices appear to increase soil erosion to the point that it is not offset by soil creation, said David Montgomery, a University of Washington professor of Earth and space sciences.

No-till agriculture, in which crop stubble is mixed with the top layer of soil using a method called disking, is far more sustainable, he said.

"Soil loss through conventional agriculture is in a range of 10 to 100 times greater than the rate at which soil is created. No-till agriculture brings it into the ballpark, surprisingly close to being balanced with soil creation," he said.

Montgomery looked at data from more than 1,650 measurements published in more than 200 studies examining various aspects of farming practices, soil creation and erosion. His findings are being published this week in the online edition of the Proceedings of the National Academy of Sciences, and will be published in a print edition later in the year.

Long-term erosion rates worldwide average less than one-tenth of a millimeter per year, which is similar to the rate at which soil is produced through mechanical, chemical and biological processes that dissolve rock and mix the grains with organic matter. The research shows that erosion rates consistently exceed 1 millimeter a year – less than a half-inch per decade – only in steep alpine terrain, and plowed fields erode at about the same pace as the Himalayas, home to the highest mountain peaks in the world.

The paper supports arguments Montgomery put forth in a popular book, "Dirt: The Erosion of Civilizations," published earlier this year by the University of California Press. In the book, he linked the demise of history's major civilizations to how long it took them to deplete their soil supply.

In the case of civilizations past, when the soil wore out the people could move to other places and find rich enough soil to sustain them. But with the world population now exceeding 6.6 billion people, Montgomery argues that there are few, if any, places left where the soil can feed a large population for very long.

"We are skinning our agricultural fields," Montgomery said. "But there are methods of farming, no-till in particular, that don't have to lead to that result."

No-till agriculture does away with plowing, which often involves stripping crop stubble from fields before deeply turning the soil. Often a plowed field will be disked to remove stubble and weeds. No-till agriculture uses disking to turn only the top layer of soil. Some other methods, such as hand-tilling on terraced fields, also preserve the soil but are more labor intensive and so are not practical on a large scale, Montgomery said.

He noted that as oil becomes more expensive and less available, it will be even more important to preserve soil fertility through methods such as no-till farming, which requires less fertilizer and many fewer passes with a tractor.

No-till farming can build soil fertility even with intensive farming methods, he said, and it could prove to be a major benefit in a warming climate. By stirring crop residue into the soil surface, no-till farming can gradually increase organic matter in soil, as much as tripling its carbon content in less than 15 years.

"Returning the organic matter to the soil stores carbon," Montgomery said. "If all farms on the planet were converted to no-till, the range of estimates for sequestered carbon runs from 10 percent of current carbon emissions to about half.

"It's probably closer to 10 percent, but even that would be a significant benefit," he said. "It's one of the few win-win options in trying to forestall the effects of climate change."

Vince Stricherz | EurekAlert!
Further information:
http://www.washington.edu

More articles from Agricultural and Forestry Science:

nachricht Researchers discover natural product that could lead to new class of commercial herbicide
16.07.2018 | UCLA Samueli School of Engineering

nachricht Advance warning system via cell phone app: Avoiding extreme weather damage in agriculture
12.07.2018 | Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>