transect points

We would be well served if we stopped manufacturing unnecessary body soaps and scents. They end up in sludge, er biosolids and, as is necessary, on the land, where they can have unintended consequences. Let's just stop manufacturing the offending molecules.

... asks Melinda Wenner. Geographer Harold Foster is convinced that it is due to low soil selenium levels. Selenium is mobile, prone to leaching as well as accumulation. Health-wise, it is one of the more interesting elements. Reputed to be an immune system stimulant, yet it is notorious for accumulating in plants and soil to a toxic degree.

Sub-Saharan Africa, with 96 percent of all AIDS cases, has a wide variety of soil types (see soil map provided) but which generally have low soil selenium.

Senegal has a significantly lower level of AIDS infection than the rest of sub-Saharan Africa. It also has uncommonly high soil selenium.

Foster's most recent article is pay walled by Elsevier, but the abstract is certainly intriguing:

The global diffusion pattern of HIV/AIDS is strongly suggestive of a protective role for the trace element selenium. It is hypothesized here that the body's antioxidant defense system, especially the selenoenzyme glutathione peroxidase, acts as an initial defense against viral infection, preceding the formation of antibodies. [emphasis added] For this reason, HIV is having its greatest difficulty in infecting those with diets elevated in amino acids and the trace element selenium which, when eaten together, stimulate the body's production of glutathione peroxidase.

Since this virus encodes for glutathione peroxidase, as it replicates it deprives its host of selenium, cysteine, glutamine and tryptophan, eventually causing severe deficiencies of each in HIV-1 seropositive individuals. AIDS is the end product of these declines and the majority of its symptoms are caused by these deficiencies. Selenium and cysteine inadequacies, for example, undermine the immune system in a process that is accelerated by other infectious pathogens. A deficiency of glutamine promotes muscle wasting and digestive malfunction, while a lack of tryptophan and the compounds it biosynthesizes (such as niacin and serotonin) causes dermatitis, diarrhea and various neurologic and psychiatric symptoms including dementia. It is also clear from the literature that supplementation relieves these symptoms and would, therefore, appear to be the most logical treatment for AIDS. The major aim of this treatment would be to return body levels of selenium, cysteine, glutamine and tryptophan to normal. The evidence suggests that this would greatly reduce HIV-1's ability to replicate. Doses, therefore, would vary with the disease stage. It also is probable that niacin and serotonin would prove beneficial.

Crop residue is not a waste. It is a precious commodity and essential to preserving soil quality.

Production systems must be developed so that ethanol produced must be at least C neutral if not C negative. Temptations [to mine soil vitality] aside, biofuels produced from crop residues may neither be free nor cheap.

Harvesting crop residues for use as fodder for livestock, residential fuel for cooking and heating, construction material, and other competing uses is a reality in sub-Saharan Africa, South Asia, China, and other developing countries. Therefore, it is not surprising that these are also the regions that have been plagued with severe problems of soil degradation.

With a severe decline in physical quality, degraded soils do not respond to fertilizers even if made available at a subsidized price. Adverse effects of none or low rates of applications of fertilizers and other amendments on agronomic production and soil quality have been exacerbated by the perpetual and indiscriminate removal of crop residues coupled with uncontrolled and excessive communal grazing.

The stubborn trends of low crop yields and perpetual hunger and malnutrition in sub-Saharan Africa and in regions of rainfed agriculture in South Asia cannot be reversed without returning crop residues to the soil and also supplementing them with liberal applications of other biosolids.

Cornell’s Soil Health team has completed a final version (”1st edition”) of a comprehensive “Soil Health Assessment Training Manual” (PDF).

At 59 pages, it touches on many areas of interest.

This well organized, and informative, manual has helped warm my still tepid enthusiasm for the soil health assessment movement as well as the closely related soil quality assessment movement.

The soil health assessment movement is a good hearted effort to better understand soil biology and soil function, but it is sabotaged by a dependence on simplistic numeric indexes. Since this could describe the history of the whole of soil science, it seems I have been unfair, condemning the soil health assessment movement in isolation and simply because it is new.

The Manual provides some qualifying documentation that I truly appreciate. The larger list of indices considered and the test locations used for developing the approach are described. This is important information which adds considerably to the value of the Manual. The discussion sections in support of the indicators and in support of the management options are well informed. I am gratified to see that the indices in this manual are much better suited to the challenge of assessing soil health than I have seen in past efforts. Beyond that, I was impressed with how the language used reflects an unfolding understanding of the complex interaction of soil biology, physical characteristics and chemical regimes, especially the forms of carbon involved. I get the distinctive impression that the wording is different than would have been used a year ago, and different than will be used even a year from now. For instance soil fungi is described in terms of thriving in slightly more acidic soil regimes than bacteria. In the past, that distinction would have been left out as inconsequential. In a future soil health assessment, discussion on how to manage soils to enhance beneficial fungi and, later, assessing soils for the presence of beneficial fungi would be natural advancements.

This Manual is a regional and cropping-system specific in nature. It describes "soil constraints and soil quality issues common to soils in New York and the Northeast region, especially in vegetable and field crop production systems." The defined focus frees it from the generalizations that limit broader assessment approaches. At the same time it provides a provides a structure for those interested in applying a soil health assessment approach in other areas.

Users of the Manual send soil samples and data sheets to Cornell's laboratory for analysis and interpretation. The training provided through the Manual is in support of gathering field data and in understanding the resulting report from Cornell.

It will be difficult for self-directed individuals to use the Manual as a resource to delve deeper into some of the assessment techniques. Take for instance, the root health rating. This involves germinating bean seeds in the sampled soil and observing the developed roots for indications of damage by pathogens. No specific references are provided in support of readers seeking to better inform themselves on this approach.

My criticisms of the manual are minor. I highly recommend anybody interested in soil quality, soil health, soil assessment, and soil function download the Manual as a PDF and treat yourselves to at least a quick thumb through.

Blog sources that announced the Manual: Lori Bushway, Molly Day

I've posted on my concern for triclosan-containing products before. I think far too much of it is being land applied in our biosolids:

It makes little sense to land apply recalcitrant compounds that needlessly get rid of soil microbes. Fomenting the growth of resistant strains of disease organisms is only one concern. Soil functional capacity is largely mediated by living processes. It is the height of folly to jeopardize those functions for a useless consumer item.

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.

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.

This UPI article is inspiring. Appreciate the dedication of the subject and the Bill and Melinda Gates Foundation for supporting this work.

Peter Hotez has spearheaded a 25-year fight to eradicate hookworm, and 12 other neglected diseases, illnesses of the poor and powerless. These ailments bear frightening names such as leishmaniasis, human African trypanosomiasis and schistosomiasis. Some are vector-borne diseases, spread through animals or mosquitoes, others are bacterial, and many more are caused by worm infections.
"When you work on a neglected disease, you're neglected by your scientific colleagues. It's hard to be taken seriously sometimes," Hotez says.
"He's the ideal scientist -- someone who is honest, works hard, and is passionate about what he is doing," says H.R. Shepherd, the chairman of the Sabin Institute who has known Peter for almost 10 years.
Hotez is developing the world's first hookworm vaccine, now in Phase 1 trials, and he'll know for sure if it works by 2011.

If you walk your property with an eye to understanding how it works, knowing what orange ooze is and what it means is a worthy skill. Orange ooze forms where anaerobic waters seep from the ground. This can be a good and natural thing, as in the image.
Reduced iron (Fe(II)) is a source of energy for life, including iron-oxidizing bacteria. The oxidized iron gives orange ooze its distinctive color. Another distinctive feature of anaerobic waters is a surface sheen, reminiscent in appearance of an oil sheen, but brittle.
Anaerobic waters form for specific reasons.
Unfortunately, one reason is contamination. A classic source of Fe(II) laden waters are acidified drain waters associated with mining and industrial wastes. Other reasons are septic systems, waste water lagoons and land fill leachate. Fuel leaking from a transfer line is a classic source. Any substance that can be rapidly decomposed by microbial activity, even a benign dust control product like lignin sulfonate, can result in anaerobic groundwater if concentrated by runoff in a roadside ditch.
Anaerobic groundwater formation is usually natural. Examples are flows through wetland conditions (as in the image) and through pond bottoms. In natural cases, orange ooze relates to elevated microbial activity. This biological activity usually needs a temperature above 41 degrees F (5 decrees C) and an adequate food supply to support microbial respiration in excess of oxygen supplies.
Now look closely at the image. Notice the greenest vegetation is in the band of water with the anaerobic sheen, parallel, and below the orange ooze. That is because the seep water is warmer than the surface water it is flowing into, stimulating a difference in plant growth. The elevation of the orange ooze shows the anaerobic water is dropping into the stream. Not shown is that it is on only one side of the stream and only along a limited stretch. This gives important clues as to where to look for the source, in this case wetland conditions in the pasture adjoining the stream. The warmth of the seep indicates that the hydrology supporting wetland living conditions is not localized winter precipitation and snow melt, but has deeper, less seasonal, origins.

Soil scientists at work. In many states, professional soil scientists conduct the septic system site assessments required for permit approval. Soil scientists also get involved in adapting alternative on-site disposal technologies. This brief newspaper interview with Leonard Cornish, owner of Pocono Soil and Environmental Consulting Inc., Wilkes-Barre, PA reveals some of the basic scientific and technical requirements needed in this type of a business. The news article should be of particular interest to soil scientists considering going into the business of environmental consulting or individuals looking to hire on with a soil scientist owned business.

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

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.