Biochar and sequestration of toxics

[Richard Haard]

Followup of Heathers announcement of WSU conference on herbicide contamination readers might be interested in this poster I prepared for a conference last year. 

 

In the experiment I was comparing biochar from a known sources to grosafe, a commercial type of activated carbon used to clean up pesticide spills. So far I have tried with several types of preemergent herbicides and all work well. 

 

Also very interesting to me is evidence that biochar and AC deactivates naturally occurring growth inhibitors that are very widespread in most soils. These materials are released by plants to control growth around their perimeter. They are called allelopathic compounds. Released by sunflower, aster family, walnut, reed canary grass and many others. In Ponderosa pine forest researchers have noticed after a fire charcoal remaining inactivates these compounds and certain grasses and understory shrubs appear whose seed have been kept dormant. 

 

Here is flickr link to my poster

http://www.flickr.com/photos/rchaard/5366487002/sizes/l/in/photostr...

here is link to a larger scale version of same poster. Scroll to the images in the control group on left.

http://www.flickr.com/photos/rchaard/5366487002/sizes/o/in/photostr...

Notice the biochar on left,and AC on right are considerably larger than untreated. This shows deactivation of natural compounds found in this sterile peat/perlite mix. 

 

 

 

[Richard Haard]

David and Permie

Any charcoal may not have adsorbtion properties I demonstrated with Alterna and California gasifier char.I have a good reference on this you can read. Rather than lose another season on a garden patch I would recommend. 1. prescreening actual soil toxicity to broadleaf seedlings and 2. Using grosafe applied as a slurry at 300 lbs/acre worked in 6 inches. With charcoal of unknown property you can powder it and try a challenge test with caseron and radish or mustard seeds as I demonstrated on my poster

[Charles Kelm]

This is fascinating and exciting news.  Thanks for sharing it with us. I am still pretty bitter over my loss of production from last year's tainted compost from Smit's Dairy, but this is great to see.

[Richard Haard]

Is simple screening technique that gives result in few weeks. I used mustard seed. Easy to challenge with off the shelf herbicides. 

 

Might be interesting to try to screen your contaminated soil. Will determine if contaminant is still present. 

[David Pike]

thanks Richard for working on this important topic. Good results with the charcoals! Just to throw an idea into the mix: I wonder how mycoremediation techniques would work against herbicide compounds? Inoculation with Stropharia, oyster sp. etc... or perhaps they wouldn't like the herbicide treated soils at all. I used contaminated soil in two of my garden beds last year and my crops suffered. Maybe I'll throw some charcoal in there.