Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Agricultural bacteria: Blowing in the wind

It was all too evident during the Dust Bowl what a disastrous impact wind can have on dry, unprotected topsoil. Now a new study has uncovered a less obvious, but still troubling, effect of wind: Not only can it carry away soil particles, but also the beneficial microbes that help build soil, detoxify contaminants, and recycle nutrients.

Using a powerful DNA sequencing technique, called pyrosequencing, a team led by USDA-ARS scientists Terrence Gardner and Veronica Acosta-Martínez analyzed the bacterial diversity in three Michigan agricultural soils, and in two eroded sediments generated from these soils during a wind tunnel experiment: coarse particles and fine dust.

Not only were the microbial assemblages on the coarse particles distinct from those on the dust, report the scientists in the current issue of the Journal of Environmental Quality, but the two types of eroded sediments were each enriched in certain groups of microbes compared with the parent soil, as well.

The findings suggest that specific bacteria inhabit specific locations in soil—and thus different groups and species can be carried away depending on the kinds of particles that erode. "It's important to know which microbes are being lost from soil," says Acosta-Martínez, a soil microbiologist and biochemist at the USDA-ARS Cropping Systems Laboratory in Lubbock, TX, "because different microbes have different roles in soil processes."

For example, the Proteobacteria—a diverse group critical to carbon and nitrogen cycling—were more associated in the study with eroded, coarse particles (those larger than 106 microns in size) than with the fine dust. Similarly, the dust housed its own community, in this case Bacteroidetes and other bacteria that are known to tolerate extreme dryness, gamma radiation, and other harsh conditions that may develop on dust particles as they float through the air, says Gardner, a postdoctoral researcher who is also affiliated with Alabama A&M University.

What this means is that wind erosion can both reduce the overall microbial diversity in farm fields, as well as deplete topsoil of specific groups of essential bacteria, say the researchers. At the same time, certain important groups, such as Actinobacteria that promote soil aggregation, remained in the parent soil despite the erosive conditions generated in the wind tunnel. And while fine dust can travel extremely long distances, coarse particles rarely move more than 20 feet, suggesting that they—and their associated microbes—should be fairly easy to retain with cover cropping and other soil conservation measures, Acosta-Martínez notes.

Helping farmers and land managers adopt practices that better conserve soil is one of the main goals of the USDA-ARS team's work, which also includes Ted Zobeck, Scott Van Pelt, Matt Baddock, and Francisco Calderón. In the Southern High Plains region, for example, intense cultivation of soil combined with a semi-arid climate can result in serious wind erosion problems. In fact, last summer's drought brought Dust Bowl-like conditions to the area, says Acosta-Martínez.

But "wind erosion is a national problem," she adds, with significant erosion occurring even in places where the growing season is humid and wet. Organic histosol soils in Michigan and many other parts of the country, for instance, are very susceptible to wind erosion when dry, especially since they're usually intensively farmed and often left bare in winter. Cover cropping or crop rotations not only help keep these soils in place, but can also build soil organic matter, which in turn promotes soil aggregation, water penetration, and general soil health.

It can take years, however, for farmers who've adopted new management practices to detect noticeable changes in levels of soil organic matter and other traditional soil quality measures. This is why Acosta-Martinez and Gardner have been analyzing soils with pyrosequencing, a method that yields a fingerprint of an entire microbial community, and well as identifies specific groups and species of bacteria based on their unique DNA sequences.

In this study, these microbial signatures told the researchers what's potentially being lost from soil during wind erosion events. But the fingerprints can be early indicators of positive outcomes, too.

"The microbial component is one of the most sensitive signatures of changes in the soil," says Acosta-Martínez, because of microbes' involvement in soil processes, such as carbon accumulation and biogeochemical cycling. "So, we're looking for any shifts in these signatures that could lead us to think that there are benefits to the soil with alternative management."

Teri Barr | EurekAlert!
Further information:

More articles from Agricultural and Forestry Science:

nachricht Forest Management Yields Higher Productivity through Biodiversity
14.10.2016 | Technische Universität München

nachricht Farming with forests
23.09.2016 | University of Illinois College of Agricultural, Consumer and Environmental Sciences (ACES)

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: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>