Navigation Links
Taking the guesswork out of soil classification

COLUMBIA, Mo. A University of Missouri doctoral student has developed a technique that uses digital imaging of soil samples to take some of the guesswork out of wetland identification.

Identifying wetlands isn't always easy. The U.S. Army Corps of Engineers' manual on wetlands identification is 143 pages long. Land that is wet isn't necessarily a wetland, and some wetlands aren't always wet. One important tool is looking at the soil for colors and patterns characteristic of frequent and prolonged saturation, said Kevin O'Donnell, a doctoral student in soil science at MU.

Chronic saturation changes a soil's structure and chemical composition and affects the types of microorganisms it harbors. These changes determine the colors and other visible features of soil. Soil scientists use those features to identify what they call "hydric soils."

A trusty companion of soil scientists in the field is a small loose-leaf binder holding a set of "Munsell Soil Color Charts," which contains 238 color chips and other visual aides for classifying soils.

There's a small hole adjacent to each chip that lets you compare the color chip and soil sample side-by-side.

"There's a lot of room for error," O'Donnell said. Cloud cover, time of day and many other factors can affect perception of a soil's appearance. Experienced soil scientists learn to take this into account, but even seasoned pros might come to different conclusions about a given sample.

"You're dealing with jurisdictional identification of wetlands," he said. "Imagine you're a landowner and a soil scientist comes out and says you have a hydric soil."

Wetlands are protected under the federal law, so landowners can end up facing restrictions on developing or farming their land based on a subjective assessment of the soil. "Will that hold up in court? I saw some major issues there."

In an earlier project, O'Donnell used software to analyze aerial photos of large areas and determine land use based on color and other attributes. "Why not use that technology on a smaller scale?"

He decided to bring soil samples to the laboratory and photograph them under controlled conditions.

For advice on photo equipment, O'Donnell sought out David Rees, chair of photojournalism at MU. O'Donnell procured a Nikon D80 camera, a 60mm f/2.8 macro lens and a pair of lens-mounted flashes to provide uniform, consistent lighting. His equipment purchases were funded in part by a scholarship named in honor of the late C.E. Marshall, an MU soil scientist and, as it turned out, the father-in-law of David Rees.

O'Donnell calibrated the software by photographing a brand-new set of Munsell color charts.

"I didn't know if this was going to work," O'Donnell recalled. The goal was to precisely quantify a soil sample's dominant colors in terms of hue, chroma (saturation) and value (lightness or darkness), as well as the abundance and distribution of those colors.

"It turns out that it works really well," he said. "The color identification was approximately 99 percent accurate for all the colors in the book."

Not only does the technique provide a more reliable way to identify hydric soils, it opens an avenue for collaboration with other disciplines by producing data about soil in a standardized, quantitative form, he said.

"Once you get here it opens up a door to new ways of looking at soils that haven't been looked at in the past," he said.

"It is a pretty ingenious amalgamation of techniques and ideas that provides soil scientists with a new tool for the 21st century," said Keith Goyne, an MU soil scientist.

O'Donnell describes his project in a paper that appeared recently in "Geoderma," considered a top-tier journal by soil scientists. O'Donnell's co-authors on the paper were Goyne, Stephen Anderson and Randall Miles of MU, and Claire Baffaut and Kenneth Sudduth of the USDA Agricultural Research Service.

O'Donnell's research is funded by a grant from the USDA's Conservation Effects Assessment Project with partial support from the University of Missouri Research Council.

O'Donnell said that it should be possible to adapt his system for use in the field by attaching a box to the camera to block out natural light when photographing a soil sample. In certain instances, this would avoid the expense and burden of extracting hefty core samples and hauling them to the lab.


Contact: Curt Wohleber
University of Missouri-Columbia

Related biology news :

1. Tracing natural hazards by taking Earths pulse
2. Taking sharper aim at stomach ulcer bacteria
3. Research shows that invisible hand guides evolution of cooperative turn-taking
4. Taking the pulse of our planet
5. Taking the next step toward advanced artificial limbs
6. Taking a cue from breath fresheners, researcher develops new method for taste testing
7. Harmful algae taking advantage of global warming
8. Taking the fight against cancer to heart
9. Aging gracefully requires taking out the trash
10. New test takes guesswork out of diagnosing early-stage Alzheimers disease
11. Gene expression findings a step toward better classification and treatment of juvenile arthritis
Post Your Comments:
Related Image:
Taking the guesswork out of soil classification
(Date:4/14/2016)... Israel , April 14, 2016 ... Authentication and Malware Detection, today announced the appointment of ... assumed the new role. Goldwerger,s leadership appointment ... on the heels of the deployment of its platform ... BioCatch,s behavioral biometric technology, which discerns unique cognitive and ...
(Date:3/31/2016)...   LegacyXChange, Inc. ... LegacyXChange is excited to release its first ... be launched online site for trading 100% guaranteed authentic ... also provide potential shareholders a sense of the value ... industry that is notorious for fraud. The video is ...
(Date:3/29/2016)... , March 29, 2016 ... "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are pleased to ... ink used in a variety of writing instruments, ensuring ... of originally created collectibles from athletes on LegacyXChange will ... analysis of the DNA. Bill Bollander ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... CLEVELAND , June 27, 2016  Global ... average 4.6 percent through 2020 to $7.2 billion.  ... (food and beverages, cleaning products, biofuel production, animal ... and biotechnology, diagnostics, and biocatalysts). Food and beverages ... gains driven by increasing consumption of products containing ...
(Date:6/27/2016)... ... , ... Parallel 6 , the leading software as a service (SaaS) ... Virtual Patient Encounter CONSULT module which enables both audio and video telemedicine communication between ... Using the CONSULT module, patients and physicians can schedule a face to face virtual ...
(Date:6/27/2016)... Ginkgo Bioworks , a leading organism design company ... as one of the World Economic Forum,s Technology ... companies. Ginkgo Bioworks is engineering biology to manufacture ... the nutrition, health and consumer goods sectors. The ... Fortune 500 companies to design microbes for their ...
(Date:6/24/2016)... ... June 24, 2016 , ... Researchers at the Universita Politecnica delle Marche in ... peritoneal or pleural mesothelioma. Their findings are the subject of a new article on ... biomarkers are signposts in the blood, lung fluid or tissue of mesothelioma patients that ...
Breaking Biology Technology: