140
Subtle Agroecologies
earth varied between 200 and 300 mV, which is in the same range as in herbaceous plants (Rajda
2004) and also concurs with the author’s own (unpublished) trials in 2015 of tomatoes grown in
rockwool. Unfortunately, while there are many publications about the positive effects of grounding
on human health, this is the only publication showing the positive effects of grounding on plant
growth, and the grounding devices for plants that the author has developed may have a commercial
potential. There is a patent fled for grounding rods for plants, 9 but it is unclear if this has yet been
commercialised.
Olyslaegers (2012) states that electroculture has been investigated for a long time, but with
inconsistent results. He defnes electroculture as any electrical stimulation of plants. His research
focused on the question of whether young tomato plants (Solanum lycopersicum) could be electrically stimulated in a manner that would be practically feasible in commercial greenhouses. As well
as the attempt to demonstrate the ‘proof of principle’ and investigate possible mechanisms, attention
was paid to the possibilities of this technique with regard to a decrease in the costs and quantities
of nutrient usage in intensive greenhouse cultivation. He worked with a low DC voltage (0.1−0.2
V/cm) and two polarities, applied via a piece of felt underneath rockwool blocks. The results were
inconsistent.
A recent publication from India (Patil, 2018) describes experiments to study the effect of electricity on germination and growth of radish (Raphanus sativus). Here, plants were only briefy exposed
to low DC voltage: 3, 6 and 9 V for 10 minutes per day. This helped increase germination rates from
85% in the control sample to 95% in the treated sample.
A very promising method to stimulate plant growth with electricity is described in PJJ van Zyl’s
thesis (2012) on radio frequency energy for bioelectric stimulation of plants. This principle uses
electromagnetism. The study is about utilising low power radio frequency (RF) energy signals from
leaky transmission lines for the beneft of plant growth and production in hydroponic systems. The
way it works is that plant cell walls are covered with tightly bonded, positively charged calcium
ions that affect the infow of nutrients into the cell. As calcium ions have a mass twice that of the
potassium ion, the fundamental harmonic of calcium is equal to the frst harmonic of potassium
(32 Hz). Thousands (10k:1) fewer positive potassium ions also exist around the cell wall, and when
stimulated at their resonance frequency (16 Hz), they will bounce against the bonded calcium ions
so that these calcium ions become dislodged from the cell wall. When this happens, more nutrients
can enter the cell causing an acceleration in plant growth. However, it is important to control the
process, because if too many calcium ions are released it would cause plant stress and a breakdown
in the plant structure. The amplitude modulated (block, as opposed to sinus) wave allows suffcient
time for the calcium ions to return to the cell walls during the period without externally applied
energy. One medium to apply radio energy to a plant is to transmit the energy into two leaky transmission lines to cause standing waves, which can then be absorbed by plants placed between these
transmission lines. The energy from the radio waves is then used to create window periods during
which the calcium ions are dislodged, allowing additional nutrients to enter the plant cell, enhancing plant growth and production. In the thesis, van Zyl also refers to a US patent from Kertz (1995)
where principles of electronic stimulation of plants are described extensively and illustrated with
trial results. Van Zyl himself performed some trials to validate the principle. In these trials, treated
plants were healthier and produced signifcantly more biomass and tomato yield than the control
plants.
DON’T FORGET THE ROOT MICROBIOME
From what has been described above, plants need electrons to aid all kinds of metabolic processes.
This is also the case for microorganisms (which make up the plant microbiome, part of the soil food
web). These microbes also need and give electrons for and through everything they do. They need
9 https://patents.google.com/patent/US20140020294A1/en.
Subtle Agroecologies
earth varied between 200 and 300 mV, which is in the same range as in herbaceous plants (Rajda
2004) and also concurs with the author’s own (unpublished) trials in 2015 of tomatoes grown in
rockwool. Unfortunately, while there are many publications about the positive effects of grounding
on human health, this is the only publication showing the positive effects of grounding on plant
growth, and the grounding devices for plants that the author has developed may have a commercial
potential. There is a patent fled for grounding rods for plants, 9 but it is unclear if this has yet been
commercialised.
Olyslaegers (2012) states that electroculture has been investigated for a long time, but with
inconsistent results. He defnes electroculture as any electrical stimulation of plants. His research
focused on the question of whether young tomato plants (Solanum lycopersicum) could be electrically stimulated in a manner that would be practically feasible in commercial greenhouses. As well
as the attempt to demonstrate the ‘proof of principle’ and investigate possible mechanisms, attention
was paid to the possibilities of this technique with regard to a decrease in the costs and quantities
of nutrient usage in intensive greenhouse cultivation. He worked with a low DC voltage (0.1−0.2
V/cm) and two polarities, applied via a piece of felt underneath rockwool blocks. The results were
inconsistent.
A recent publication from India (Patil, 2018) describes experiments to study the effect of electricity on germination and growth of radish (Raphanus sativus). Here, plants were only briefy exposed
to low DC voltage: 3, 6 and 9 V for 10 minutes per day. This helped increase germination rates from
85% in the control sample to 95% in the treated sample.
A very promising method to stimulate plant growth with electricity is described in PJJ van Zyl’s
thesis (2012) on radio frequency energy for bioelectric stimulation of plants. This principle uses
electromagnetism. The study is about utilising low power radio frequency (RF) energy signals from
leaky transmission lines for the beneft of plant growth and production in hydroponic systems. The
way it works is that plant cell walls are covered with tightly bonded, positively charged calcium
ions that affect the infow of nutrients into the cell. As calcium ions have a mass twice that of the
potassium ion, the fundamental harmonic of calcium is equal to the frst harmonic of potassium
(32 Hz). Thousands (10k:1) fewer positive potassium ions also exist around the cell wall, and when
stimulated at their resonance frequency (16 Hz), they will bounce against the bonded calcium ions
so that these calcium ions become dislodged from the cell wall. When this happens, more nutrients
can enter the cell causing an acceleration in plant growth. However, it is important to control the
process, because if too many calcium ions are released it would cause plant stress and a breakdown
in the plant structure. The amplitude modulated (block, as opposed to sinus) wave allows suffcient
time for the calcium ions to return to the cell walls during the period without externally applied
energy. One medium to apply radio energy to a plant is to transmit the energy into two leaky transmission lines to cause standing waves, which can then be absorbed by plants placed between these
transmission lines. The energy from the radio waves is then used to create window periods during
which the calcium ions are dislodged, allowing additional nutrients to enter the plant cell, enhancing plant growth and production. In the thesis, van Zyl also refers to a US patent from Kertz (1995)
where principles of electronic stimulation of plants are described extensively and illustrated with
trial results. Van Zyl himself performed some trials to validate the principle. In these trials, treated
plants were healthier and produced signifcantly more biomass and tomato yield than the control
plants.
DON’T FORGET THE ROOT MICROBIOME
From what has been described above, plants need electrons to aid all kinds of metabolic processes.
This is also the case for microorganisms (which make up the plant microbiome, part of the soil food
web). These microbes also need and give electrons for and through everything they do. They need
9 https://patents.google.com/patent/US20140020294A1/en.