The Electromagnetic Field Effects on Plants

Electromagnetic Fields (EMFs) have magnetic and electrical properties that surround objects with an electrical charge which will interact with other objects within that field. For example, Earth has an electromagnetic field due to the movement of electrons within the core and used for navigation by birds and fish. Electrical fields result from the strength (voltage) of the charge and magnetic fields result from the motion (amperage) of the charge. The fields exist with varying strength and degrees, and wavelength and frequency will determine how it behaves.

EMF sources have steadily increased since the 20th century including electrical distribution lines, common household and occupational electrical appliances. This increase in exposure has lead to considerable scientific inquiry for associated health risks. The World Health Organisation (WHO) states that the effects of electromagnetic fields on the human body depends not only on the field, but on the frequency and energy, though has found negligible risk of health consequences from low level exposure. However, they recognise that there are some gaps in knowledge about biological effects that need further research.

The impacts of EMFs on plants is a question being explored since plants are just as readily exposed to low-level magnetic fields as humans as a consequence of power lines and other industrial technology. It appears that magnetic fields does have an effect on the growth of plants. Belyavskaya (2004) found that weak electromagnetic fields suppressed the growth of plants, reduced cell division, intensified protein synthesis and disintegration in plant roots. Conversely, other studies such as Ramezani Vishki et al. (2012) found an increase in plant growth while other studies like Davies (1996) found some seeds increased in growth and others showed no change.

Despite the variable results from research, one thing that is not well understood is how magnetic fields affect plants. One of the proposed mechanisms is related to the levels of calcium ions within plant cells. It is found that exposure to weak EMFs remove calcium ions from cell membranes influencing calcium availability and thereby affecting plant processes and ability to respond to stress (Pazur et al. 2006). Researchers like Ramezani Vishki et al. (2012) suggest that the intensification of growth is due to the increasing of metabolism in irradiated seeds. The leakage of calcium ions into the cytosol (the main part of the cell) acts as a metabolic stimulant, which accounts for the reported accelerations of plant growth (Goldsworthy 2007). Goldsworthy (2007) hypothesises that the loss of calcium ions from cell membranes is the reason why weak fields are more effective than strong ones, why low frequencies such as 16 Hz are more potent and why pulsed fields do more damage. Another proposed mechanism is geotaxis, a phenomenon where magnetic fields will affect cellular organelles such as amyloplasts and influence the direction of plant growth (Peňuelas et al. 2004).

Literature supports that weak EMFs interfere with plant physiology but the mechanisms are not clear. The inconsistency and contradictory outcomes from the studies appear to indicate that the effects of magnetic fields on plants may be species-specific and/or is dependent on the characteristics of field exposure such as intensity and duration. Research of the effects EMFs have on plants is relatively new, and information is still limited. Most research focuses on agriculturally important plants leaving a knowledge gap on other species such as algae. Considering possible consequences, including economic and ecological impacts, more work is needed to clarify the basics of biological effects by electromagnetic fields.

References

1. Belyavskaya, N.A. (2004). Biological effects due to weak magnetic field on plants. Advances in Space Research, 34: 1566–1574.

2. Davies, M.S. (1996). Effects of 60 Hz electromagnetic fields on early growth in three plant species and a replication of previous results. Bioelectromagnetics. 17(2):154-61.

3. Goldsworthy A. (2007). The Biological Effects of Weak Electromagnetic Fields. H.E.S.E UK. http://www.hese-project.org/hese-uk/en/papers/goldsworthy_bio_weak_em_07.pdf

4. Pazur A., Rassadina V., Dandler J and Zoller J. (2006). Growth of etiolated barley plants in weak static and 50 Hz electromagnetic fields turned to calcium ion cyclotron resonance. BioMagnetic Research and Technology. 4: 1 doi: 10.1186/1477-044X-4-1.

5. Peňuelas J., Llusià J., Martínez B and Fontcuberta J. (2004). Diamagnetic Susceptibility and Root Growth Responses to Magnetic Fields in Lens culinaris, Glycine soja and Triticum aestivum. Electromagnetic Biology and Medicine. Vol. 23, No. 2, pp. 97-112.

6. Ramezani Vishki F., Majd A., Nejadsattari T. and Arbabian P.S. (2012). Study of Effects of Extremely Low Frequency Electromagnetic Radiation on Biochemical Changes in Satureja Bachtiarica L. International Journal of Scientific & Technology Research Volume 1, Issue 7. ISSN 2277-8616 77 IJSTR.