Can anything be done - or safely grown in deldrin effected soil? Our daughters property in Gembrook Victoria has beautiful,friable red soil but they have a soil test that shows deldrin from the days when it was part of a potato farm. They were advised that if they wanted to grow anything to eat then buy in soil and use raised garden beds - but if it's local soil it could have deldrin as well
A quick scan of the literature shows that dieldrin can have a half-life of 5 years or more in temperate areas, while 90% of it will be gone in a month or two in many tropical areas. Bioremediation doesn't seem to be very effective - dieldrin mostly photodegrades and evaporates. Water seems to be beneficial in degrading and diluting that toxin. For fastest remediation of a small plot, I would try to till it and irrigate it as much as possible for a few years... even though that is terrible for the soil ecosystem, soil structure, and organic matter. For larger areas, putting it into pasture or scrub and mowing it for green manure where it grows might be the best approach if one has more time - levels will eventually subside. Swales and terraces will help increase soil moisture and that route of reducing the chemical.
Wombat, they seem to be spelling it Dieldren, and here's an article about activated carbon and bioremediation. https://www.informaworld.com/smpp/content~content=a748802194&db=all Removal of Aldrin, Dieldrin, Heptachlor, and Heptachlor Epoxide Using Activated Carbon and/or Pseudomonas fluorescens Free Cell Cultures "Regarding adsorption of pesticides on activated vegetal carbon, we concluded that removal efficiencies between 95.45 and 97.18% can be reached, depending on the pesticide and the carbon dose applied. " Notice they are saying ADsorption, the chemical reaction between biochar or composted carbon in the soil and the chemicals/elements that go past it that cling, rather than ABsorption. Try searching on the new spelling, I saw lots more out there. Yay compost!! Yay biochar!! Yay mushroom compost!
Hi Wombat, I'm wondering if you could share where in Gembrook your daughter's property is. I'm just doing some investigations of my own. Cheers.
g'day david, don't use local soil or any soil for that matter to create the medium in the raised beds, see our raised gaden presentations we use spent mushroom compost. gatton in qld much the same with DDT residues from the bad old days of farming, dieldren & DDT the legacy of conventional farming nowadays there are other chemicals. also would be thinking the raised beds may have to be 12"s to 18+"s high https://www.lensgarden.com.au/straw_bale_garden.htm len
DDE 0.016 mg/kg Dieldrin 0.10 mg/kg Limit of reporting is 0.005 on both. Can anybody advise if these soil levels are safe for grazing or growing vegetables? (Unrelated to my 160 acres!!)
G'day DJ Sorry, not my field of expertise. However, you may find the following of interest: What is the accepted level of dioxins in humans? Internationally, in June 2001, the Joint Food and Agriculture Organisation and WHO Expert Committee on Food Additives concluded that given the long time it takes for dioxins to break down, it is only possible to assess their health risk by measuring how much has been consumed over a month or more. The Committee decided to express the tolerable intake of dioxins as a monthly value - the provisional tolerable monthly intake or PTMI. They recommended a PTMI of 70 pg dioxin toxic equivalents (TEQ)/kg body weight as a reference value to which a human can be exposed over his or her lifetime without harm. Source: https://www.environment.gov.au/settlements/chemicals/dioxins/factsheet3.html Cherio, Markos
Thanks Markos, according to my brother (he's the mathematician in the family) that's not a very large amount... Time to stop eating our home grown eggs
Read it again. What this means is that your chooks will not be infected by eating plants grown on your property, nor you either for that matter, unless there is a source of air pollution where the dioxin will settle on the leaves. Or unless they eat the soil particles - which they might do when digging around. The best thing to do would be to get tested as described. But if she is really worried, she should sell the property or grow timber on it.
For some sort of ray of hope, check out the following: https://www.suite101.com/content/mycoremediation---pollution-cure-a72006 Try google searching variants of Paul Stamets, mycellium running, fungi perfecti, dieldren (accepted spelling), organic reclamation. You best bet, this side of a century or so of "scientific" cures, is going to be fungus based. Keep us informed, please