Over the last couple years, I’ve been working towards fulfilling my itch to discover the science behind electroculture. At first I was completely amazed about the results I saw – I really couldn’t believe my eyes… since then I’ve completely delved into the topic so I could completely understand the science behind-the-scenes. Here’s high-level summary of my findings:
To start, I’ve learned that it is capable of having effects covering the following topics:
I’ve learned most of my insights by diving deep into various complex subjects including plant electrophysiology and electrochemistry. These sciences basically cover the role of electricity in the plant biology and chemistry, respectively. Here’s what I have learned so far:
The Electrical Nature of Plants
Plants are sensitive to many different forms of stimuli. Most people know that plants respond to well-known environmental conditions such as temperature, light quality and direction, and moisture. Plants respond to other forms of stimuli as well. Less well-known forms include touch stimulus as in the case of the Venus fly-trap, and stimulation by electric fields as well.
With regards to electricity’s role in plant development, it is known that by the nature of chemical compounds on their own, that electricity really governs life. It is everywhere in nature. From the tiniest of cells of which plants are made, their cell walls are made to react and respond to various electric fields that are everywhere. How is it everywhere? By the mere fact that the nutrients that plants take in are electrical via their innate electrical charges.
From calcium with it’s +2 charge to hydrogen with it’s +1 charge, in aggregate these charges can produce decent amounts of electrical voltage. While electric fields exist when the charges are just static, not moving around anywhere, it is their movement that makes things interesting. Since cells and in particular, cell walls, are composed of various gateways for nutrients to pass through, it is through these mechanisms that electric fields are constantly in a state of ebb and flow throughout the plant.
For instance, plant roots create electric fields within their internal structures due to the movement of ions through their cells and tissues. These ions enter the plant through the root hairs which absorb water-soluble nutrients. At the same time, other charged compounds, can be released from the plant roots as well. An example of this would be root exudates which are complex chemical compounds released from the roots that serve the purpose of acting as antibiotics or chemical messengers.
Physiological Effects of Electricity on Plants
Since plants are strongly affected by electrochemical reactions occurring at the cellular level, what would happen if electric fields were applied to plant directly or their nearby surroundings? What effect would they have?
It turns out that there is a quite a bit of research on this topic, and in this article I plan on sharing some of the highlights with you.
Did you know that plants have a high-speed communication networks within them?
It’s true, Instead of sending information in the form of bits and bytes as computers do, biological information is shared throughout the plant by way of two main signaling methods:
- Actions Potentials
- Chemical messaging
In case you never heard of an action potential (AP) before, it’s basically a response that occurs in certain types of electrically-sensitive cells. In essence, when there is enough of a charge buildup on the outside of a cell, there is a massive inrush of ions from the outside of the cell to the inside and back out again. The net effect of this back-and-forth of charge is the creation of a voltage spike that affects all of the surrounding cells that are sensitive to these types of signals. (See the Khan Academy’s tutorial on action potentials for more information – note: while this covers a slightly different version meant for human vs plant biology, they’re essentially the same)
Simultaneous to the release of the AP is the release of all of the chemical buildup. And like the AP, but slower, there is a chemical chain-reaction like effect that causes the ions flowing out of one cell to propagate to many other surrounding cells.
The chemicals and the APs are capable of spreading like a lightning-fast wildfire throughout the plant. APs can travel to most places within a plant within a fraction of a second!
Effects of Cellular Signaling
In addition to plants’ response to innate electric fields, the use of external electric fields have been known to bring about many physiological changes that affect the growth of the roots, shoots, flowers, fruits. Some high-level changes include:
- Changes in growth behavior due to electrotropism
- Increased nutrient uptake & assimilation
- Increased metabolism & respiration
- Controls enzymatic activities
- Genetic and hormonal activations, etc.
Effect on Soil Organisms
It is well-known that bacteria in soil provides benefits for plants and soils in many different ways. For example, one form of bacteria called Rhizobium that lives in the roots of the nitrogen-fixing plants (like peas and beans ) enters the plant roots and creates swellings called nodules where the bacteria further work on converting nitrogen in the air into a mineralized form that plants can absorb.
Research into the effects of electricity upon bacteria suggests the following:
- Bacteria possesses different charges
- Bacteria can be manipulated by electric fields
- Bacteria can be disseminated underground via electro-osmosis and electrophoretic processes
- Electric fields Increase bacterial activity
- Electric fields accelerate the bacterial reproduction rates
Effects on the Soil
Since living plants and microbes are both affected by electric fields in a myriad of ways, it turns out that they produce secondary effects upon the soil in which they reside. For instance, Researchers like Wang Yaqin, et. al. have found that it is capable of Improving soil structure – that is – increasing the size of soil aggregates. Why is this important? With larger aggregates of soil particles, greater amounts of surface area are exposed giving the soil mass more “pore space”, or spaces where air and water can collect. It also makes it easier for plant roots to grow, compared to growing in tightly compacted soils.
I believe that electro-horticulture is also capable of turning the soil-mass into a hydroponic-like growing environment. Let me explain… Since plant roots will normally come into contact with soil nutrients based on how far and wide the root mass grows, it’s limited by the growth of it’s root system and the nutrients that are available in the portion of soil over which a particular plant grows.
Image Source: Universida de Vigo
On the other hand, under the influence of electrokinetic transport ( a big word that describes how ions can move about in soils when in an electric field ), nutrient ions will be able to move about under the control of the electric field. So if ions that plants need are now mobile, then plant roots can then potentially increase the amounts and the diversity of nutrients from other sources.
This has some interesting implications – namely that fertilizers and soil amendments don’t necessarily have to be broadcast over a field in order to be applied. Instead, they can be electronically transported to where they need to be. It also enables a new way of companion planting, where companion plants don’t necessarily need to be right next to each other in order to be effective.
One last effect that I’ll mention is that there these methods cause an increase in the
oxygen levels within the soil. In combination with what was mentioned earlier via an increase in aggregate size, through electrolysis reactions at water-soil boundaries, oxygen is formed under the ground, more opportunities for plant roots to become oxygenated.
We hope that you learned a little about how vegetables grow when under the influence of electric fields. It’s amazing that only minute amounts of electrical current are needed to bring about substantial changes in both the ecosystems of the soil and the physiology of plants. In future posts you can expect us to go into more detail on each of these topics.
For the scientists out there, care to comment or add any behaviors I may have missed?