September was a very exciting month for me as I was invited to give a presentation for the St. Louis innovation think-tank, Openly Disruptive. The meeting was on the topic of food & sustainability and I ended up speaking on 3 ideas where electro-horticulture would be of benefit to urban agriculture. It was a great event and I’ll share more about it once the video is posted online. The only thing that I would like to mention is that the speaker before me spoke a great deal about food forests and permaculture – which re-sparked some thoughts I had regarding how electricity could be used in those settings.
Initial Thoughts of Mixing Electricity & Permaculture
I was insopired while hanging out at a friend’s house who wanted to have a garden in their back yard. While their yard seemed to be very shady, they thought that the bigger problem was their enormous black walnut tree, and the toxic root exudate that it produces, juglone.
Knowing that electric fields in soil are capable of a number of useful effects, I came up with two ideas:
- Using electricity to transport toxic root exudates away from our crop
- Using electricity to move our crop’s roots away from the tree’s roots.
Electronic Transport of Plants’ Root Exudates
In case you didn’t know, it’s possible to use DC electric fields to transport a range of ionic substances from one area to another. This is commonly used in high-tech biomedical systems ranging from microfluidic systems to the analysis of DNA using gel electrophoresis. If it could be used in the lab, then how about outdoors, in the soil? In one form of remediation or toxic waste cleanup, a technique known as electrokinetic remediation uses strong electric fields to draw charged contaminants towards special electrodes that enable the toxic substances to be sucked out of the ground (reference). Using the same method, but at much lower power, I thought that perhaps it would be possible to move the toxic root exudate that black walnut produces away from any desired plantings. If juglone can be transported through the soil using some form of electromigration, then there is a chance this may work.
Electronic Movement of Root Systems Away From Toxic Exudates
There may be another solution. One researcher of plant electrophysiology, Andrew Goldsworthy, applied external electric fields to callus cultures, and found that newly forming root cells had a charge associated with them, and found that they grew towards the oppositely charged electrode.
Perhaps this could be used to help direct the roots of a plant we desire to nurture away from roots that emit toxins.
Realize that in a simple configuration, when the field is applied, both sets of roots will grow in the same direction. I suppose that the placement of the electrodes, their polarity, and the age and spatial relationship between the different plant species will make a difference. This could be a really cool topic of exploration!
Do you think either of these approaches will work? Let me know what you think in the comments below.