Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Agricultural bacteria: Blowing in the wind

09.05.2012
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:
http://www.agronomy.org/

More articles from Agricultural and Forestry Science:

nachricht Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University

nachricht New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>