Tuesday, January 31, 2006

Precise common sense

Precision ag implies computer mapped lab data and GPS controlled field equipment. Higher yields, less flying blind and easier farming. The reality is that the expense of data collection, analysis and interpretation can quickly wipeout any added value. Reading this article about variable rate management of cotton, it struck me that common sense and curiosity are the missing ingredients. Elton Robinson with Delta Press reports on cotton producer Kenneth Hood, Mississippi, who attributes his success with variable rate agriculture to, among other things, reliance on aerial photo interpretation, an approach not typical of precision agriculture. Hood says that the “... advantage to imagery is that very little data collection is required, according to Hood, “which is unlike most precision agriculture practices.” Put this experience together with the recent cryptic news on the lukewarm record of precision agriculture in Germany, which I touched on earlier, and what do you get? My sense is that Kenneth Hood is going to have lots of company.

Sunday, January 29, 2006

Farm tile drainage progressing rapidly

As told by Chris Niskanen over at the St. Paul MN Pioneer Press there is a tremendous amount of tile drainage going on in the north central USA: 100 million feet per year or about 19,000 miles by one estimate. Improved flexible drain tile is making this unprecedented rate of installation possible. The article mentions a number of areas of potential concern: loss of duck habitat and increased nitrate levels in surface water. Where no jurisdictional wetlands are being tiled, no permits are needed to perform this work. However the extent of the practice has caught the attention of folks and a community effort to address the impact of farm drainage on wetland habitat is being discussed.
Image source: South Dakota State University – Ag environmental issues page
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Saturday, January 28, 2006

Tallahassee waste water sprayfield nitrate concern for Wakulla springs

I have been following news on a 2600 acre sprayfield on the edge of Tallahassee, Florida. It is suspected of causing environmental problems 10 miles away in Wakulla Springs State Park and the Wakulla River. A recent 1000 Friends of Florida report (pdf) ties excessive hydrilla plant growth to nitrate from the sprayfield. The news this week is that the city, USGS and Florida DEP will be conducting dye tests to better understand how the groundwater beneath the sprayfield moves down gradient. I am reading the report. Striking is the relatively low (1.0 mg/l)nitrate-N needed to control the situation.

Image source: Tallahassee Democrat

Glomalin, science, CO2 and climate change

Atmospheric CO2 concentration is expected to increase by 50% near the middle of this century. Indications are strong that rising CO2 effects higher soil organic carbon content in some cases. Glomalin, which accounts for 1/3 of soil carbon, is of particular interest because of its important role in binding soil aggregates and increasing nitrogen use efficiency. The Center for the Study of Carbon Dioxide and Global Change has updated their excellent summary about the CO2 - glomalin relationship. There is a great reference list to dive into.

Image source: USDA-ARS: Glomalin: A Manageable Soil Glue (pdf brochure)

Jobs web site: demand is up for soil scientists

While playing around with Indeed.com's nifty graphs for displaying trends in job postings, I made a graph at Indeed for "consulting soil scientists" or "soil science consultants" and was pleasantly surprised to get a definite upwards trend. Removing the consultant label has the same trend and about double the job listings. It'll be interesting to see how this plays out into 2006.
A year ago, Fast Company had geoscientists listed among the top 25 jobs for 2005 in an index weighted 35% to job growth. Seems they predicted correctly, at least as far as soil scientists are concerned. Fast Company also has a top 25 list for 2006.

Thursday, January 26, 2006

Product review - new vadose zone research tool moves to farm

Irrigated farm fields lose water to deep percolation. This groundwater recharge, and what it contains, is difficult to research. This is because sampling tools designed to intercept saturated flow tend to miss unsaturated flow. And visa versa. New technology extracts deep soil moisture using a wick rather than the active suction or gravity.

The first wick samplers were passive capillary samplers (PCS). This approach has now evolved into the current water flux meter (WFM) designed recently by Batelle soil scientist Glendon Gee. Two offspring WFM designs are commercially available: the Gee passive capillary sampler drain gauge (Decagon Devices, Pullman WA) and the vadose zone water flux meter (Sledge Sales Consulting, Dayton OR). In a recent journal article, the Decagon device is referred to as a capacitance water flux meter (C-WFM) and the Sledge device is referred to as a tipping-bucket water flux meter (T-WFM). The T-WFM is close to Glendon Gee's designs published in journal articles. The C-WFM was developed by Decagon soil scientist Gaylon Campbell in collaboration with Glendon Gee.

The original PCS devices needed a pit, best dug with a backhoe. Fiberglass wick length and strand size were calibrated to site specific conditions to prevent oversampling of unsaturated conditions. Today's WFMs can be placed in an auger hole or hand-dug pit. WFM configurations use a standard size and length wick which works for most situations. A recent journal article has an example of an oversampling problem.

There are strong similarities and distinct differences between the two firms. Like Decagon, Sledge maintains strong ties with Glendon Gee. Like Decagon, many of the 200 devices Sledge has produced have been for agricultural research. Compared to Decagon, Sledge is more a hands on, farm service and farm chemical oriented consulting business. With Wayne Sledge, the T-WFM is his flagship product. With Decagon, the C-WFM is a sensible addition, part of an extensive and well supported line of soil and agricultural measurement instrumentation. It appears that Decagon and Sledge have produced a similar number of devices and they are clearly on parallel tracks of success in refining their individual product.

Both firms have supplied most of their instruments to agricultural researchers, farms and clients concerned with water use efficiency and nitrogen use eficiency such as golf courses. There has also been environmental project placements, most often associated with landfill and mine-tailing closure

Decagon has put considerable effort into refining unit capacity to record water flux, less into water sample handling. The larger base of the Sledge unit enhances water sample handling options. Decagon has a stepped design which accommodates hand auguring the deepest portion, shortening installation time. Decagon has an extensive list of complementary devices and highly capable technical support staff. The Sledge unit is substantially lower in price. Choice is good.

Of particular interest in Washington State is wastewater spray field management. As mentioned in a government report: "The Department of Ecology has identified 20 spray field situations where wastewater was [improperly] applied [and conditions] ... led to contamination of groundwater...". This report was discussed here previously.

I spoke with Don Nichols, with Washington Department of Ecology's Water Quality Program, Eastern Regional Office, Spokane, WA. Don has encouraged the installation of WFMs for gathering vadose zone water quality information. Don referred me to Cascade Earth Sciences and Soil Test Farm Consultants for more information.

Dan Burgard, soil scientist with Cascade Earth Sciences (CES) in Spokane, WA has installed 7 Decagon C-WFMs in the Pasco, WA area, and 11 Sledge T-WFMs in southern California. CES modified the equipment to enhance sample collection capabilities. (See his photos below)

Dan Nelson, soil scientist with Soiltest Farm Consultants, Inc. in Moses Lake, WA has four Decagon C-WFMs installed in the Moses Lake, WA area. Both had nothing but good things to say about the potential uses of this type of data. Mass balance calculations will demonstrate if target water use efficiency and target nitrogen use efficiency is being achieved. Detailed daily data logs show exactly when percolation occurs. Percolation events observed to date are closely correlated with irrigation and precipitation events and even soil thawing events. As expected with the difference in weight between soil and the field capacity water portion, percolate nitrate and dissolved solids (salts) are several times higher than soil levels above the sample point. The devices are performing as intended.

One question I have is how many devices are needed to achieve statistical confidence in a mass balance calculation? Users independently tend toward sets of 3 units, with singles for spot comparison data. That is a sensible starting point but determining coefficient of variability on selected data would put the results into perspective.

None of the installations have been entirely glitch-free, mostly due to various data logger challenges or site specific soil related factors, such as coarse sands or depth limits. Users of the units are looking forward to continued refinements in data logger compatibility and would like to see costs come down and but give high marks for ease of installation and setup. This and available tech support make sampler units from Sledge and Decagon an attractive alternative to the do-it-yourself installations that predate this equipment.

Brown, K.W., J.C. Thomas, and M.W. Holder. 1986. Development of a capillary wick unsaturated zone water sampler. Coop. Agreement CR812316-01-0. USEPA Environ. Monit. Syst. Lab., Las Vegas, NV.
Cary, J.W. 1968. An instrument for in situ measurements of soil moisture flow and suction. Soil Sci. Soc. Am. Proc. 32:3–5.
Gee, Glendon W., Zhang, Z. Fred, Ward, Andy L. 2003. A Modified Vadose Zone Fluxmeter with Solution Collection Capability Vadose Zone J 2003 2: 627-632 (highwire link) http://highwire.stanford.edu/
Knutson, J.H., and J.S. Selker. 1994. Unsaturated hydraulic conductivities of fiberglass wicks and designing capillary wick pore-water samplers. Soil Sci. Soc. Am. J. 58:721–729.
, J.S., C.K. Keller, J.T. McCord. 1999. Vadose Zone Processes, Lewis Publishers, ISBN 0-87371-953-0, GB1197.7.S46 1999 [1] [2]
van der Velde, M., Green, S. R., Gee, G. W., Vanclooster, M., Clothier, B. E. Evaluation of Drainage from Passive Suction and Nonsuction Flux Meters in a Volcanic Clay Soil under Tropical Conditions Vadose Zone J 2005 4: 1201-1209 (DOI: 10.2136/vzj2005.0011) (highwire link)

An unsolved mystery in science

Then again, maybe there is a reason Mars has that old familiar lived in look ...
Unsolved Mystery No. 6 Viking's methane
JULY 20, 1976. Gilbert Levin is on the edge of his seat. Millions of kilometres away on Mars, the Viking landers have scooped up some soil and mixed it with carbon-14-labelled nutrients. The mission's scientists have all agreed that if Levin's instruments on board the landers detect emissions of carbon-14-containing methane from the soil, then there must be life on Mars.
Viking reports a positive result. Something is ingesting the nutrients, metabolising them, and then belching out gas laced with carbon-14.
So why no party?
Because another instrument, designed to identify organic molecules considered essential signs of life, found nothing. Almost all the mission scientists erred on the side of caution and declared Viking's discovery a false positive. But was it?
The arguments continue to rage, but results from NASA's latest rovers show that the surface of Mars was almost certainly wet in the past and therefore hospitable to life. And there is plenty more evidence where that came from, Levin says. "Every mission to Mars has produced evidence supporting my conclusion. None has contradicted it."

Life and the look of landforms

Geomorphologists report surprising similarity in landforms on Mars with landforms on Earth, considering the importance that soil life has on landform processes. They conclude:
"Despite the profound influence of biota on erosion processes and landscape evolution, surprisingly,…there are no landforms that can exist only in the presence of life and, thus, an abiotic Earth probably would present no unfamiliar landscapes," said Dietrich.
URL: Life leaves subtle signature in the lay of the land - UC Berkeley
It's a thought provoking read, especially for those of us who interpret the land at the more arid end of the spectrum.

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Tuesday, January 24, 2006

Science and nitrogen use efficiency

Nitrogen use efficiency (NUE) is a term maintaining its currency. Worldwide, NUE is 33%. Once a concern primarily due to groundwater quality and health concerns, rising natural gas prices have moved economic concerns to the forefront. Economics must certainly have resonated in the government NUE workshop "Roadmaps to more N efficiency" held in Germany recently and mentioned in a previous article. Climate change concerns have increased interest as well as the availability of grant funding for research. NUE is affected by many factors: fertilizer form and placement, irrigation management, climate, soil characteristics and CO2 levels.
Nitrogen loss due to denitrification is caused by microbial respiration when soil oxygen levels are depleted. It is negligible in some parts of the planet and the dominant form of loses in others. This from the University of Kentucky, somewhat buried in an
article about economic concerns:
Worldwide nitrogen use efficiency is only about 33 percent, so 33 percent actually makes it into the crop. A lot of nitrogen is applied that never gets used by the crop. In the United States, the rate is 50 to 60 percent, but still half the nitrogen never makes it to the crop.
In Kentucky the biggest loss of nitrogen comes from denitrification, when nitrate is converted to nitrogen gas and dissipates into the air. By controlling denitrification, a farmer can potentially reduce the amount of nitrogen needed to produce a crop.
The other forms of reduced efficiency are leaching of nitrate and volatization of ammonia. Part of the loss to percolation can be attributed to uniformity of application and even off-target losses. Necessary to complete a zero-sum balance point of view is accounting for microbially fixed nitrogen, and changes in soil biomass,both microbial and plant roots.
Those of us who work in support of permitted land application of waste water and waste water solids are very interested in advances in understanding of NUE. Our client projects are generally held to a land treatment capacity based on a design philosophy that an NUE of 100% is a reasonable target, the legacy of a simpler time in history. With the higher level of information and better technology available today, this simplistic design standard may well be approaching the end of its useful life.

Friday, January 20, 2006

German science workshop news critical of precision agriculture performance

A German soil science research center reports that Precision Agriculture has not delivered on promised benefits, stating:
...worse are the actually reported effects of ..."Precision Agriculture" (PA) ...on N efficiency. Still after 15 years of implementation no results proving consistent increases in yields or decreased fertilizer application are available. Quite the contrary: some of the techniques developed in PA may even decrease fertilizer N efficiency...
The Federal Agricultural Research Center (FAL) - Institute of Plant Nutrition and Soil Science's workshop, Options for reducing the nitrogen surplus in plant production, has individual presentation pdf files available, including the one on PA.

Thursday, January 19, 2006

Jane Jacobs Meme: on the Ethics of Politics and Business

A meme is an infectious idea, infectious because it is a construct within which new achievements become possible. Complementary yet incompatible ethical syndromes separating public servants from other professions, including scientists, is a Jane Jacobs meme. Understanding this enables us to distinguish universally bad behavior from acts that merely offend our own syndrome's sensibilities, acts that are otherwise in character. A guardianship syndrome is shared by those who serve a closed and corporate group, and protect that group from outside threat. A commercial syndrome is shared by those that trade goods or skills, an occupation that requires trusting and selflessness extended to even to those who fall outside the responsibilities and protection of the guardianship structure.

One example is not sufficient but it will have to serve: Assuming traders will become raiders given sufficient opportunity is a timeless guardianship syndrome perspective. Assuming such a worst case scenario without basis is abhorrent within the commercial syndrome.

The National Society of Consulting Soil Scientists' most recent newsletter has a review of Jane Jacobs' book, "Systems of Survival". A portion is reproduced below.

If there is anyone who deserves the label "critical thinker," then it is Jane Jacobs.
From: Jane Jacobs: Her Life and Work By Gert-Jan Hospers
A refreshing book for exploring ethical consistency is Jane Jacobs' “Systems of Survival: A Dialogue on the Moral Foundations of Commerce and Politics” (1994). 214 pp. ISBN 0-679-74816-4

In Systems, Jacobs describes the ethics of commerce as a moral syndrome equal, antagonistic and complementary to the ethics of politics, or guardianship. Neither commerce nor guardianship sectors do well in the absence of the other. Government protects commerce, provides stability, administers justice and enforces uniform standards. Commerce provides the economic engine and the ethical framework for trade, technological advance and individual rights that combine to make governments worth living under. Yet these two ethical systems are mutually exclusive and cannot be rashly integrated without the risk of moral confusion.

Jacobs is careful to limit Survival to the ethics of how we eke out a living. Greater questions of good and evil are wisely set aside.

Jacobs warns that when entities cross the functional boundary that separates the two systems, morally corrupt hybrids can emerge: organized crime and corporate raiders. Jacobs uses cold-war era Soviet Union as a particularly apt example. Jacobs opposes military models for managing business.

Jacobs' observations on the professions of art and science are entirely novel. Drawing on history, Systems demonstrates that artists are grounded in tradition and are necessarily supported by largess. Tradition and largess are characteristics of a guardianship system. In contrast, scientists make advances in an environment of innovation and trust but are frustrated when subordinated to tradition and ideology. Jacobs warns that academic institutions steeped in guardianship values are antagonistic to objective science.

Both moral syndromes are consistent with social mores, yet are incompatible with each other. This paradox was not anticipated when the author first conceived the book. Jane Jacobs mentions in her footnotes that she started the book expecting that she would show that the “trading” ethic was good and existed in opposition to an antagonistic “raiding” ethic.

Jacobs uses an inductive approach to critical thinking making her ideas difficult to test. No one doubts her abilities as a profound thinker but some question her methods, seeking to weaken the impact of her most uncomfortable conclusions. Yet her underlying observations ring true. Systems confirms that making a living is wonderfully challenging at many levels, regardless of whether we choose to survive through commerce or through serving the public.

This book is available from Amazon.com for $10.50 new, often less than $3.00 used. This reviewer highly recommends it.

Some supporting information from outside sources:
Jane Jacobs Interviewed by James Howard Kunstler (author, The Geography of Nowhere) For Metropolis Magazine, March 2001 September 6, 2000: Toronto Canada
Jane Jacobs, The Anti-Planner by Gene Callahan

New organic garden book: Teaming With Microbes

For over 30 years, Jeff Lowenfels has written a free-lance gardening column in Anchorage. Among other things, Lowenfels and a couple of like-minded friends have patented a cool one-eye device for looking at plants and insects in the field, the macroscope, available now through Brunton. Lowenfels now has a forthcoming book on soil microbes, a subject he has written and lectured on abundantly for the last 5 years. He has been promising a book on this for most of those years and a lot of gardeners are looking forward to it. The subject of microbes and plant nutrition offers a lot to get excited about. I've mentioned some bits a time or two. And, as back40 reminds us, it was only in 1996 that glomalin was discovered. Glomalin is the durable soil carbon produced by mycorrhizal fungi and responsible for many positive attributes of soil function, plant nutrition and soil health.
According to a news article this week, Lowenfels book "Teaming With Microbes: A Gardener's Guide to Using the Soil Food Web." is being published by Timber Press and is due out sometime in late summer. Tag me "easily entertained", but I really like the double sens of the word "teaming" in the book title. In 2004, the working title was "Soil Science for Gardeners", and thankfully Lowenfels has wisely prevailed upon Timber Press to use "Teaming With Microbes" as he originally proposed.

Monday, January 16, 2006

Tetany animal health issue and soil, hay links

Tetany is a complex disease in that no specific condition triggers it in all cases. Gauge tetany risk using soil and tissue analysis when growing or feeding hay comprised solely of cool-season grasses. A grass-legume mix does not have this risk.

Tetany is a disease affecting ruminants and is associated with feeding or grazing bluegrass, bromegrass, fescue, orchardgrass, ryegrass, timothy and wheatgrass. It is caused by low blood levels of calcium and/or magnesium. Classic risk conditions occur when the forage grass is growing quickly in the spring and nitrogen levels are high. Less well known is that tetany can be a problem when hay is grown on soils with excessive soil potassium. Manure and potassium hydroxide cleansers are two potential sources. Lactating animals are more susceptible to tetany, thus dairies are particularly alert to the concern and tend to avoid growing or feeding grass hay exclusively. Forage guides may not mention it as a concern. A forage tissue ratio of K/(Ca+Mg) of more than 2.2 indicates a high risk of tetany and the need to supplement feed with magnesium (Mg) (see also). If an animal goes down and tetany is suspected, a veterinarian should be contacted for immediate treatment. Often an animal will recover if it can be given an injection of magnesium sulfate (Epsom salts) early on.

Preventative Mg feed supplement and the ready supply of alfalfa tends to keep the incidence of tetany to a minimum. My thought is that tetany is additionally controlled by the close knit nature of farm communities. Caring neighbors and long memories tend to interact sufficiently that tetany symptoms don't take more than an animal or two, usually the weakest anyway, before it is figured out. Perhaps this explains why analytical laboratories in my region are generally unaware of tetany or the role of soil and tissue nutrient levels. My opinion is that cooperative extension publications in the Pacific Northwest can do better in this area. Tips for preventing animal loss due to tetany should be included in the fertility guides published to help folk interpret forage test results.

See also:
Spring Mineral Considerations by Jeff Heldt (link added 03MAR06)
Controlling Grass Tetany in Livestock, by Cooperative Extension, New Mexico State University, available in pdf format

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Friday, January 13, 2006

Tap Roots

Some plant species do the opposite of saving for a rainy day. They sop up rain water that would otherwise run off or evaporate. They redistribute the water to a long tap root where it is safely stored in deep soil out of reach of their shallower rooted neighbors. In the intervals between rainy periods, they return water to the shallow portion of the root system and prevent it from drying out. Researchers indicate that this capability is not restricted to the tree species in the the Amazon basin they researched. While the researchers refer to the "hydraulic redistribution" phenomenon being observed by others, first in small plants two decades ago, this appears to be the first time that a statement has been offered to gage the potential global scale and the significance to water balance and climate models.

The new study in the Amazonian forest shows that trees use water in a complex way: The tap roots transfer rainwater from the surface to reservoirs deep underground and redistribute water upwards after the rains to keep the top layers moist, ... The researchers estimate this effect increases photosynthesis and the evaporation of water from plants, called transpiration, by 40 percent in the dry season, when photosynthesis otherwise would be limited.

"This shifting of water by roots has a physiological effect on the plants, letting them pull more carbon dioxide from the atmosphere as they conduct more photosynthesis," said co-author Todd Dawson, professor of integrative biology at UC Berkeley. "Because this has not been considered until now, people have likely underestimated the amount of carbon taken up by the Amazon and underestimated the impact of Amazonian deforestation on climate."...

Dawson, Lee and their colleagues, including Inez Fung of UC Berkeley, reported their findings last month in the Dec. 6 issue of the Proceedings of the National Academy of Sciences. ...

"Evapotranspiration stays higher than previously expected during the prolonged dry season because of this private reserve of water banked during the wet season by the tap roots," said Dawson. "Just as perspiration cools us off, increased transpiration by trees in June and July explains the drop in temperature in the Amazon."

This effect changes the way the atmosphere heats and cools, and will change the way rain is distributed, he noted. Depending on the extent to which trees elsewhere in the world, especially in Africa and other tropical and extratropical areas, redistribute water in the soil, the impact on global climate could be significant.

"The impact on transpiration is greatest in the Amazon and Congo forests, but our model also shows an impact in the United States and other places that have dry and wet periods," Lee said.

Trees have long been known to lift water from the soil to great heights using a principle called hydraulic lift, with energy supplied by evaporation of water from leaf openings called stomata. Twenty years ago, however, some small plants were found to do more than lift water from the soil to the leaves - they also lifted deep water with their tap root and deposited it in shallow soil for use at a later time, and reversed the process during the rainy season to push water into storage deep underground. Dawson discovered in 1990 that trees do this, too, and to date, so-called hydraulic redistribution has been found in some 60 separate deeply rooted plant species.

Earlier this year, Dawson's colleague and former UC Berkeley doctoral student Rafael Oliveira of the Laboratório de Ecologia Isotópica at the University of Sao Paulo, Brazil, discovered that Amazonian trees also use hydraulic redistribution to maintain the moisture around their shallow roots during the long dry season. During the wet season, these plants can store as much as 10 percent of the annual precipitation as deep as 13 meters (43 feet) underground, to be tapped during the dry months. [emphasis added]

"These trees are using their root system to redistribute water into different soil compartments," Dawson said. "This allows the trees and the forest to sustain water use throughout the dry season."

The process is a passive one, he noted, driven by chemical potential gradients, with tree roots acting like pipes to allow water to shift around much faster than it could otherwise percolate through the soil. In many plants that exhibit hydraulic redistribution, the tap roots are like the part of an iceberg below water. In some cases these roots can reach down more than 100 times the height of the plant above ground. Such deep roots make sense if their purpose is to redistribute water during the dry season for use by the plant's shallow roots, though Dawson suspects that the real reason for keeping the surface soil moist is to make it easier for the plant to take in nutrients.

"Hydraulic redistribution is definitely related to water, but it can't really be discussed outside the context of plant nutrition," he said.

The article goes on from there, but this point concerning nutrition is worth expanding upon. The article indicates that stored water is transferred to the shallower portion of the root system where it must exude into the soil "for keeping the surface soil moist". Soil ion adsorption and plant nutrient exchange processes are moist (vs dry) soil phenomena. Keeping the soil moist just at the root surface would put minimal demand on plant water reserves but have a significant effect on nutrient availability.

It would also support the symbiotic community of soil microorganisms supported by the root system. Arbuscular mycorrhizal fungi and symbiotic soil bacteria are sustained by rhizodeposition, a term which can encompass both liquid root exudates and solid plant cell material. In my experience, root exudates are normally explained as simply an energy or carbon source for the microbes, a carbohydrate quid-pro-quo in exchange for mineral nutrients. It is a fairly thrifty exchange. The water supply component of root exudates highlighted in this new research is an exciting emphasis, at least to your author. Access to steady and stable supply of water, even a parsimonious supply, is ideal for sustaining soil fungi. Resulting beneficial effects, in the form of mycorrhizal hyphae, can extend out from a few centimeters to many meters. Perhaps future observations will be able to determine if the fungi component also plays a role in moistening soil.

Root water uptake and the dynamic availability of water to plants is a phenomenon that tends to be overlooked by soil scientists, despite the often dominant role of roots as a sink for water in the soil.

quoted from: Roots: The big movers of water and chemical in soil. Clothier, BE; Green, SR. Soil Science. Vol. 162, no. 8, pp. 534-543. Aug 1997.

Color photo is from http://earthobservatory.nasa.gov/Laboratory/ICE/Images/panama_canopy.jpg

Line drawing to left is Fig.113.--Root of sunflower where plants were spaced 8 inches apart. From Root Development of Field Crops. Weaver, John. 1926 posted at http://www.soilandhealth.org/

Line drawing in middle of article is from

How a Tree Grows, FS-32, 1970, USDA Forest Service
(A) Tap Root — Provides main support of tree and anchors it firmly in the ground. (Not all trees have one)
(B) Lateral Roots — Help support and anchor trunk, may extend far out, beyond crown spread.
(C) Fibrous Roots — Masses of fine feeding roots close to ground surface.
(D) Deeply Descending Roots (‘Sinkers’) — Grow downward from lateral roots

EurekaAlert! news release for cited article
UPI news release for cited article

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Monday, January 09, 2006


The current round of research into soil microbial life holds the door open onto insights that stagger the imagination.
Discoveries about vesicular arbuscular mycorrhizal fungi (VAM) and arbuscular mycorrhizal fungi (AMF) transformed our understanding of the contribution of soil fungi to soil function. Current research indicates that similarly monumental discoveries may await us.

Genome research and computational improvements demonstrate that the number and diversity of soil bacteria species far exceed the levels anticipated.

Bacteria make up the bulk of life on Earth and play a vital role in the lives of other organisms. But scientists have barely scraped the surface when it comes to identifying bacteria – 99% of species cannot be grown by standard techniques in the laboratory. ... Soil is ... a complex microbial environment containing thousands of distinct species – most of them bacteria – in just a half-gram sample.


More than one million distinct genomes occurred in the pristine soil, exceeding previous estimates by two orders of magnitude.

The distribution of this diversity is unequal in ways that may seem counter intuitive. The following was reported earlier today in What's New in Science and Technology .

Ironically, in the diversity of soil bacteria, the otherwise species-rich Amazon is a more like a desert, while the arid desert is a teeming microbial Amazon, researchers have found. Their first-ever continental-scale genetic survey of soil bacteria revealed that the primary factor that seems to govern the diversity of soil bacteria is soil pH. Thus, the acidic soils of topical forests harbor fewer bacterial species than the neutral soils of deserts.

The researchers said that, since soil bacteria play a fundamental role in a vast array of ecological processes, their survey constitutes an initial step in a new research pathway to understanding that role.

As exciting as these studies are, they are tentative and simplistic in comparison to the dynamic they reveal. These results are the product of capacity building needed before the real work can begin.

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Saturday, January 07, 2006

Ida Powell

In southeast Yakima is a Carpathian walnut tree. It was planted long ago and the trunk is now 3-4 feet thick. It towers over the expansive 1895 farmhouse that it shades. Beneath its spreading branches, four huge picnic tables wait patiently for spring. That is when the neighbors will return, as they have every year since the early 1980's, to work alongside church and trade school volunteers to reawaken the proud building at the corner of Spruce and Union (Union is where 9th St. would be). Others work to rejuvenate the 1 acre of pioneer planting that helped qualify this Estate's placement on the State's Register of Historic Places. Restoring the property to the community is the vision of the South East Neighborhood Improvement Committee (SENIC), a 501c(3) non-profit corporation. SENIC's unofficial motto is "we can do more good with nothing than others accomplish with thousands." In support of SENIC's efforts at the Historic Ida Powell estate, a PayPal donations link is provided below. Please make a donation and please visit this summer to share in the project. Parcheesi players are especially welcome for late summer evening games in the shade of the walnut tree.

(Historic Property Inventory Form for this site - PDF )
(If you have MS Internet Explorer you can get to a nice write up and picture using the query function at the State Department of Archaeology and Historic Preservation's WISAARD site, but it takes some doing to get there. "Query" (lower Left) for POWELL HOUSE)

UPDATE: I neglected to mention that the POWELL HOUSE is also on the National Register of Historic Places)

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Thursday, January 05, 2006

Retirement of Gary Muckel

Access to data. Access to standards. Access to continuing education. Soil consultants need all three to thrive professionally. The reciprocal is that the profession needs the participation of consultants to thrive. This is less of a disconnect than in 1992, when Gary Muckel began in his efforts to bring soil science consultants in closer with the efforts and products of the National Cooperative Soil Survey (NCSS). Gary retires today. He will be missed.

Just a quick note to pass along the attached notice of Gary Muckel's retirement. Gary has been a wonderful facilitator to us via his NRCS NCSS position in Lincoln -- he has always gone out of his way to forward us publications and other helpful resources and information.

Gary B. Muckel, soil scientist at the National Soil Survey Center in Lincoln, Nebraska, is retiring January 3, 2006, following a 35-year career with the Soil Conservation Service/ Natural Resources Conservation Service (SCS/NRCS).

Gary is a native of California but grew up in Reno, Nevada. He received his bachelor of science degree in plant science and his master of science degree in soil science at the University of Nevada, Reno. Gary began his SCS career in Burley, Idaho, in November 1970 as a field soil scientist. In 1974, he became the soil survey party leader in Twin Falls, Idaho.

In 1977, Gary moved on to Bismarck, North Dakota, as the soil correlator. He later became the assistant state soil scientist in North Dakota. His next stop was in 1980 at Albuquerque, New Mexico, where he served as the state soil scientist. In 1988, Gary joined the West National Technical Center in Portland, Oregon, as the head of the soils staff. It was during this time that Gary initiated activities for the National Soil Survey Centennial.

In 1992, Gary joined the National Soil Survey Center with primary responsibility for the National Soil Survey Handbook. He chaired the Soil Survey Centennial in 1999, during which time more than 1,000 projects were completed nationwide. Gary initiated the Soil Quality Information Sheets and has published more than 50 articles on soil survey. He recently released the publication “Using Soil Survey to Identify Risks and Hazards to Human Life and Property.� Gary has managed the national soils website at http://soils.usda.gov for many years, as both content manager and webmaster. As national marketing coordinator for soil survey for several years, he successfully established a marketing plan for the National Cooperative Soil Survey program. Gary developed and authored soil education CDs and soil profile cards that are used by thousands of schools. He is a member of the Soil and Water Conservation Society and the Nebraska Society of Professional Soil Scientists.

The above was passed along through PSSAC (Thanks, Mary!).

As we in Washington gear up for the next stage in pursuing state licensing of soil scientists, no doubt we will be dusting off Gary's "Understanding Soil Risks and Hazards", mentioned above. I have a link for downloading it below.

Understanding Soil Risk and Hazards: Using Soil to Identify Areas with Risks and Hazards to Human Life and Property. Gary B. Muckel, editor. 2004. 93 pp. Available free online from the U.S. Department of Agriculture, Natural Resources Conservation Service, National Soil Survey Center, 100 Centennial Mall North, Room 152, Lincoln, NE 68508; (402) 437-5499; ftp://ftp-fc.sc.egov.usda.gov/NSSC/Soil_Risks/risks_print_version.pdf.

By drawing on local knowledge and experience, this publication aims to expand awareness of various soil risks and hazards to human life and property and encourage city and county officials, planners, developers, and others to consider the soil in their land use decisions.

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In 1794

On January 4th in 1794, was born Edward Ruffin the father of soil chemistry in the U.S., who showed how to restore fertility to depleted soil. Though without formal science education, Ruffin determined that the soil of southeast plantations that had been overused with single-crop production had become more acidic and unable to benefit from fertilizers. The remedy he published (1818) was the spreading of marl to neutralize the acidity. He went further by specifying effective methods of fertilizing, plowing and rotating crops to increase production of grains. He expanded his recommendations in book and journal article form, as well as lecturing up to the 1850's. He then became an outspoken secessionist, and took his own life upon the South losing in the Civil War, at least when he learned of it on June 18, 1865.

Today in Science History

Adapted from a post at XDA blog by Roger Fraley.

This would be a good addition to soil science articles in wikipedia.

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Sunday, January 01, 2006

Happy New Year's with Writely and Zoho Writer!

Today I comparison tested two web-based beta-version word processors: Writely and Zoho Writer. Both make it deliciously easy to post to blogger. Both are free and are painless to start into. Both can import and save documents in HTML, MSOffice and OOo formats (I'm partial to OOo, which is free, and allows me to export as a pdf). Of the two, I like Zoho Writer's interface, feel, pace and task flow better, but I have to stick with Writely because of some critical features.

Both Writely and Zoho Writer allow the use of tags, which like gmail, allows you multiple labels to help organize files, in my mind a superior feature to a directory tree structure assuming you have a decent file content search function. Which neither does as of yet. (Note: It would be handy if these tags translated to technorati tags in the document.)

Writely has two critical advantages over Zoho Writer. First, Writely has an html editor, essential for inserting and finessing special bits like technorati tags, etc. Zoho Writer has some minimal html editing capabilities which you see when you right-click on selected text.

Second critical difference is that Writely I can replace my blog entry with an updated version using an "update post" option. Not so with Zoho Writer - every time I uploaded this article, it had to be a new entry, forcing me to delete the old one. Also, with Writely, you can use special character's in the title (', !, ?) and it is possible to edit the article title at the point it will be uploaded to the blog, even when you update the post. In Zoho Writer my workaround is to Save As Template, and reopen as a new document.

Indications are that ZohoWriter has got more work to get out of beta than Writely does. Cut-and-paste between documents requires going into a Mozilla file and hacking it to allow an unauthorized script. Editing styles and character fonts is a little dicey. The date-time stamp when I post to my blog is straight up UTC - not what I want.

Unlike Zoho Writer, Writely has the ability to insert bookmarks and internal links, although I haven't been able to get that feature to work so well for me yet in the blog. Neither program has the image file import interface I want. If I want to import a lofi thumbnail that links externally to a the original version (ala blogger's editor) it is going to have to be done the old fashioned way. I can't even resize the image to be inserted. Zoho Writer has an "anchor" button that may support image insertion and placement but I haven't figured it out yet. Again, an html editor would be nice.

Zoho Writer's advantage over Writely are that it is significantly faster, doesn't open the document in a separate window, and in my personal opinion, has a cleaner touch to the interface. For example, you don't close (or "done" button) a document - just save (or not and lose changes) and cleanly move on to the next task. The login procedure is faster. I find Zoho Writer more pleasant to use than Writely and thought I would like it better until I got into it deeper. I am compelled to stick with Writely for now.

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