Saturday, December 23, 2006

George Demas - In Memoriam

Soil scientist George Demas (28 April 1958 - 23 December 1999) pioneered the study and classification of subaqueous soil. He passed away on this day seven years ago. His award winning work advanced the understanding of soil genesis and morphology sufficiently that USDA soil taxonomy required revision. George Demas' death occurred shortly after the importance of subaqueous soil became accepted. His sudden and untimely passing is a great loss to his family of colleagues and friends.

See also: George Demas Elected as Honorary Member of MAPSS, and Wikipedia Article.

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Sunday, December 17, 2006

Blog Break

I'll be diverting my energies to friends, family and such for the rest of the month. Hope everybody has a good Holiday season.

The picture I leave you with was taken a few miles west of Spokane, out by Fishtrap Lake, before the snow came in.

Saturday, December 16, 2006

My picks from Vadose Zone Journal

My picks from Vadose Zone Journal May 2005; Vol. 4 (2): 225 - 451

VZJ articles are released to open access 18 months after online publication. These articles became available on November 13, 2006.

Buckingham, 1907: An Appreciation.

Buckingham's methodical development of an unsaturated flow theory from first principles facilitates a grasp that one seldom gets from textbooks. As a physicist in the company of agricultural scientists, Buckingham articulated his findings mostly in written prose, without much reliance on mathematics. His foundational ideas are as valid today as when he proposed them.

Simplified Method to Estimate the Green–Ampt Wetting Front Suction and Soil Sorptivity with the Philip–Dunne Falling-Head Permeameter

A simple, innovative method is presented to estimate saturated hydraulic conductivity in soil. The only paired data points necessary for this proposed new method are the times when the permeameter is half full and when it reaches empty.

Thursday, December 14, 2006

Invasive Earthworms

Its in the news. Research shows that invasive earthworms are damaging forest soils and are a menace to species diversity. Brought to light in November, 2002, gardening experts have confirmed the concern and the news keeps spreading. Fortunate for inquiring minds, self-archived copies of published journal articles are available. The problem is most often associated with formerly glaciated regions, where native populations of earthworms are not present. One work has a general map of affected locations (can compare to map here).

Another work addresses damage to soil. Comparing soil in front of the invaders to post invasion conditions demonstrates that these worms cause soil compaction, reduce soil fertility, increase erosion. Alterations in the soil profile include thickening of A horizons and obliteration of E horizons. I am still processing this information, but it appears that these invaders are capable of alterations deep enough into the soil profile to result in a change in soil taxonomic classification at the order level.

What looks to be one of the more prominent invasive species, Lumbricus rubellus showed up in my maple leaf compost (now vermicompost). I can confirm that L. rubellus is voracious. I remember a shovel slice of some nearby soil that went in a week or so before L. rubellus showed so my guess is they came with the place. L. rubellus operates on the surface litter and organic material found where that layer rests on the mineral soil. There are strong indications that L. rubellus supplements its leafy diet by feeding on the fungi and bacteria in the rhizosphere of plant roots. Seeing first hand how these critters operate, I find this last aspect quite disturbing. With its carbon sequestration function and the highly mutualistic species that it supports, this planet needs all the rhizospheric biological capacity it can muster.

Monday, December 11, 2006

NC Science Blogging Conference Jan 20, 2007

The world needs more science bloggers.[1] There are a lot of science bloggers in NC.[2] Soil science bloggers are few.[3] There is a concentration of soil scientists in and very close to North Carolina.[4] Soil scientists should go to the 2007 Science Blogging Conference Sat, Jan 20, 2007, 8:30 a.m. to 5 p.m. Chapel Hill, NC.[5]


Sunday, December 10, 2006

New Soil Science Licensing Website

Renewed soil science licensing efforts are underway in Washington State. Supporting them is a new website. Titled Soil Science Licensing, the site is available to become a clearinghouse for all soil science licensing efforts. It links to the best available information, including the list of soil science licensing boards maintained by the Soil WikiProject.

For now, the Soil Science Licensing site effort is strictly focussed on Washington state's efforts. The latest revision (pdf) (December 7, 2006) has been posted and I have one concern with the new wording:

The practice of soil science does not include design work, such as would be carried out by either engineers, as defined in RCW 18.43.020 or architects, as defined in RCW 18.08.320.
We need something along these lines, but the term "design work" is not specifically defined in the cited sections, but is referred to somewhat broadly. Is this going to be a problem? Perhaps someone with experience in one of the licensed states can comment.

Saturday, December 09, 2006

GeoCorp America Soil Science Internships

GeoCorps America has announced that 40 jobs will be available this summer, 2007, for work with the National Park Service, US Forest Service, and Bureau of Land Management. These are paid geoscience positions at many interesting locations. GeoCorps Positions pay a $2,500 stipend for 10-12 weeks of duty and free housing is provided. The positions are open to students, teachers, professionals and retirees. Of the 40 jobs, two are soil scientist positions and I would characterise both as college internships. One is in the BLM Butte Falls Resource Area (out of Medford, OR), assessing trail conditions on hiking trails and assessing impacts from off-highway vehicle use. The other is in the Sierra National Forest (out of Clovis, CA) and involves sampling and monitoring under the supervision of the Forest Soil Scientist. Expectations of the candidates for the second one are a tad more demanding. Classwork in pedology, edaphology, geology, ecology and botany is a plus. Application postmark deadline is Friday, 2 February, 2007.

Source post: Geology News.

Soil and Bioavailability of P in Food

Researchers find that soil phosphorus levels may affect plant phytate levels as much as plant breeding. Phytate is the principal storage form of phosphorus in many plant tissues, especially bran and seeds.

Phytate is generally not bioavailable to humans and non-ruminant animals. Accordingly, there has been a push to develop low-phytate crop varieties. Not only is the phosphorus in low-phytate grain crops more digestible by people, low-phytate grains free up minerals essential to human nutrition: zinc, manganese and iron. This new research shows that grain raised with higher levels of soil phosphorus can have higher levels of phytate. I have not read ($) the journal article, but my thoughts are that the discovery of this soil connection was not anticipated: normally nutritional availability does not decrease with increased soil nutrient levels. If this relationship can be validated, it is an important breakthrough that affects human nutrition, efficient use of phosphorus (a non-renewable resource), farm costs, and environmental quality.

Swine and poultry operations benefit. Low-phytate feed results in lower manure phosphorus for these non-ruminants, a welcome prospect for waste management and addressing water quality concerns. Swine rations often need phosphorus added to ensure bone and muscle development for rapid growth, driving the market development for new, low-phytate crop varieties. The alternative to low-phytate feed is to use a feed additive, phytase. Currently, neither approach is particularly cheap.

Appreciation and attribution:
Sugar Creek Farm for a great photo.
GMO Pundit aka David Tribe for posting on this.

($) According to my read of HighWire Publishers Free Online Full-text Articles list, the journal article will be made available at no cost April 2, 2008 (18 months after publication).

Tuesday, December 05, 2006

New Soil Science Blog at University of Western Australia

Andrew Rates (UWA) has started a blog for UWA's caffeine-dependent Soil Science Journal Club. It is a closed forum, intended for "UWA Higher Degree by Research students and UWA staff only." This is the type of idea that we could see perpetuating similar efforts at other schools and research groups.

The idea of this blog is to record the progress of a journal club, and preferably to provide an ongoing resource for people interested in recent advances in Soil Science and related disciplines.

I have in mind running a Journal Club for interested postgraduate students and staff. I would like to focus on recent significant advances and developments in Soil Science, preferably including all subdisciplines (soil biology, soil chemistry, soil physics, pedology, ...).

Articles are likely to be sourced predominantly from premier / high-impact journals such as Science, Nature, Trends in Ecology and Evolution, Earth and Planetary Science Reviews, etc. This isn't to say that we can't access the more traditional soils journals, but I'd like (at least at first) to focus on big-picture, high-impact issues.
There is a promising post here of the group's first discussion subject: Marris, E. 2006. Putting the carbon back: Black is the new green. Nature 442:624-626 . It seems to me these folks are asking the right questions.

I have added this site to my (frightfully short) list of soil science blogs.

Saturday, December 02, 2006

Soil, or ground fit to bring forth fruit (1702)

Dating to the dawn of the 18th century, this may well be the first dictionary definition of soil. And a beautiful bit of prose it is. A term reserved for the good stuff, the definition has a hint of awe, of appreciation, of desire even. And of simple mystery.

At a time when the definition of soil has achieved some ambiguity, and some of us exclude lunar soil from "real" soil, I am intrigued by these old definitions.

Reading further in John Kersey's "A New English Dictionary", one finds that the ground meant earth. It also meant "the foundation of a thing". If he had chosen to use earth instead of ground, JK would have changed the meaning of soil to one less involved with our daily interaction. Was this an intentional distinction?

His meaning of fruit includes benefit. ''Fruit of the earth" and "first fruits" were common and established terms. JK has "first fruits" meaning "...profit of a spiritual living". At a time when we suppose the concept of soil to have been simple, why didn't JK keep the definition of soil simple and agronomic, unencumbered with spiritual and beneficiant tones? I find his wording wonderfully rich with subtle allusion.

Soils are commonly understood as materials with a capacity for plant productivity. That is too broad. Most soils have a history that includes alteration by living processes, a history that separates soil from non-soil material. Further refinement of the soil concept is occurring in view of an appreciation of energy transport and transformation within soil. Accurate to this unfolding understanding of soil is Nikiforoff's 1959 definition of soil as the "excited skin of the subaerial part of the earth's crust". Soil is a product of solar radiation. From this perspective the concepts of lunar soil and of martian soil are not so inconceivable.

John Kersey's dictionary is recognized as the first work that incorporated all words of important common usage. Prior to this work, dictionaries concentrated on difficult and obscure words. This is according to "Chasing the sun: dictionary makers and the dictionaries they made" by Jonathon Green. I turn the pages of JK's work and I sense tremendous care in his choice of words. In the case of soil, he relied on rich allusion to gently convey something of the knowing that he and his fellows had about this dark and excited resource. His definition of soil thus stands the test of time as well as, and perhaps better than, many that have been been written since.

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