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October 2009
Welcome to the October 2009 edition of Fertile Minds, the newsletter of Sydney Environmental & Soil Laboratory.
In this issue we’re pleased to tell you that we’ve bought another ICP-OES gizmo, effectively doubling our analytical capacity and relegating downtime to the past; and we begin the first of a series of articles on how soils form.
If you have any questions you would like answered in Fertile Minds, please write to info@sesl.com.au. If you have any special requirements, we would be pleased to talk with you and tailor a package and price. Please contact the office on (02) 9980 6554 or write to us at info@sesl.com.au.
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In this issue
- The Loam Ranger – Cadmium
- Allelopathy – biological warfare
- Soil horizons
- Another new gizmo!
- Star lab technician
- Did you know ... ? – E. coli
The Loam Ranger – Cadmium
Dear Loam Ranger,
What’s the deal about cadmium? Where does it come from and why is it a problem?
Cadmium (Cd), element number 48, is a heavy metal. Although Cd ores are rare, Cd is widespread and is a common contaminant of zinc ores and phosphorus (P) fertilisers. Because it is highly toxic and carcinogenic, Cd is banned around the world in electronics applications. Workers in smelters and factories that produce Cd products must take special precautions to avoid inhalation.
Because Cd is widespread, it is a natural component of many soils, even without the application of P fertilisers. The use of superphosphate will add Cd, although fertiliser laws now restrict the content of Cd to a manageable level. A study in New Zealand found that the natural average background level of Cd in soil is 0.16 mg/kg, and that levels in agricultural soils are up to 5 times this, most notably on dairy farms, in association with high use of superphosphate.
Click here to read about how to reduce the risks (650 words, 2 minutes)
Allelopathy – biological warfare
We might not see them in action, but many plants are engaged in active warfare with other plants. Because they can’t move around, plants must find other ways of evading enemies, finding mates and battling each other for resources.
Some plants win the battle by growing taller than others, catching the light and shading the competition. Others have aggressive roots that capture the water and nutrients before slower-rooted plants can.
As is becoming increasingly clear, many plant species engage in chemical warfare, excreting chemicals that suppress (or sometimes enhance) the growth of other plants. Eucalypts and casuarinas (sheoaks) are common examples. By suppressing potential competitors, the plants can gain access to all of the water and nutrients in their rootzone.
Soil horizons
We’ve all seen soils in cross-section – either in a trench we’ve dug or in a road cutting. The most notable feature of the soil in cross-section is the bands or layers of different colours or textures. These layers are termed soil horizons.
In this first of a series of articles on the origin of soils, we explore the formation and meaning of soil horizons, which have a huge impact on what we can do with a soil. Understanding a bit about soil horizons gives us the tools to understand the climate of the region, the way the soil behaves at different times, and what limits it will impose on us.
Click here for an introduction to soil horizons and what they can tell us (800 words, 3 minutes)
Another new gizmo!
At the start of this year we were proud to announce our new ICP-OES. The inductively coupled plasma optical emission spectrometer replaced two old atomic absorption spectrometers and brought our sample analysis into the 21st century. With it we could analyse up to 1000 samples a week, much more accurately, in less time.
The ICP-OES has proven such a boon that we’ve bought another! This will bring important benefits to us and to you.
Click here to see the benefits and a picture (250 words, 1 minute)
Star lab technician
In July this year we were pleased to feature our apprentice Josh Shaw, who received his Certificate III in Laboratory Skills. Only a month later, he received his Certificate IV in Laboratory Techniques. Josh is now a fully qualified laboratory technician.
The photo shows (from L to R), Michael McLeay, CEO of MD & Associates, who audited Josh’s training; Simon Leake; and Josh Shaw.
Did you know ... ? – E. coli
Escherichia coli, more commonly known as E. coli, is the most common bacterium living in the gut of all warm-blooded animals. The species name coli refers to its occupation of the colon.
It is a normally harmless rod-shaped bacterium that takes advantage of the conditions in the gut and benefits its host by excreting vitamin K and by physically excluding pathogenic bacteria.
Because E. coli can survive for a while outside the body (benefiting it by giving it time to find a new host), and because it is easily grown in the laboratory, it makes an excellent indicator of water contamination. Although it is normally harmless, coming from the gut in faeces, it is accompanied by pathogenic bacteria that can be hard to grow in the lab, so if you find E. coli, it means that you’ve probably also found pathogens.
Click here to read how E. coli, insulin and water tests are related (350 words, 1 minute)