One of my biggest questions regarding electroculture is the distance that the electric field is effective. It’s a bit of a difficult problem to wrap my brain around because soil science is a complex topic on its own. Deliberately adding electricity to the mix makes things really wacky. In this post I would like to share with you some of the factors that affect the effective distance with regards to electrical stimulation of plants.
Let’s begin with the basics. In case you didn’t know, when electricity is injected into the ground, it can travel great distances. While this is theoretically true, the strength of the field will be attenuated or reduced as distance increases. Other factors that can come into play are:
- Soil type
- Cation Exchange Capacity (CEC)
- Soil chemistry
- Moisture content
- And more..
Throughout the early part of electroculture’s history, earth batteries were the primary
Now, in modern times, we have many more power options available.
Here’s a picture showing the effects of decreasing electric field strength on plants:
In the picture above, taken from a garden experiment in 2013 (See post: Backyard Garden Electroculture Creates Large Broccoli, Tomato & Eggplants), you can see the effects of a diminishing electric field. In this picture, the source (positive electrode), is located off-page to the lower right, approximately 8 feet away from the plant in the center of the screen. Based on this photograph, it can be estimated that a 5V DC source will have an effect on plants up to about 13 feet away, with the most prominent growth occuring within 10 feet.
Despite what can be seen in the example above, I am still confused by the historical sources that state that electroculture (with Earth Batteries) can have an enormous effect of the growth of row-crops, when the electrodes are placed almost 200 feet from each other. Perhaps the difference is due to the size of the plates that were employed. From my understanding, the benefit of using larger zinc and copper plates in Earth battery construction is that it will provide a larger amount of current density through the soil region. Essentially making for a very stiff 1.1 Volt source.
At the same time the layout of the electrodes probably makes a difference too. In the 1st example, the electrodes were actually places quite close to each other (< 1 foot). In this case the majority of the electric field is situated close to the electrode pair since there is nothing “pulling” the electrons over any real distance. The spread of the electric field in this case is mainly a function of the source voltage.
Certainly there are other factors at play also, soil chemistry, cation exchange capacity (CEC), soil moisture, soil type, aggregate sizes and pore water, among other variables. I’m just not sure.
What do you think? Am I correct in my analysis of the situation?
Has anyone tried replicating electroculture on row-crops? How did they perform? (Note: we have applied electricity to row-cropped sunflowers in the Sunflower+ experiment, but we placed our (compound) electrodes only 5 feet from each other. Since our 1st round of results weren’t fully conclusive, we will probably keep the same configuration this spring. On the other hand, if the team thinks that the land should be tilled, then we may change to a length-wise electrode layout and perhaps then we’d have some results to share.
Let us know your thoughts in the comments below.