Project 2010: Testing Data Transfer Over Plant Roots






 Initially, testing took place with copper wire to ascertain the test bed baseline transmission rate.  Brine water and tap water were also tested initially to establish baselines.  Before this preliminary testing, it was expected that a much slower rate would be achieved by the brine, tap water, and cotton string soaked in brine, however this was not true.  The copper wire was only slightly faster than the other tested media.


Common belief tells us that metals are the only true “highly” conductive materials, but perhaps in this instance, conductivity was not the issue.  The data itself is transmitted by electromagnetic waves at certain frequencies, not through electricity which involves the flow of electrons.  The power of the signal is determined by the transmitting end and is referred to in decibels.  The portion of the signal that is received correctly must be detected above background noise/frequencies and thus the ability to detect the signal is in direct proportion to the signal-to-noise ratio.  In this experiment, possibly the main cause of  signal dampening over the distance in the root is effected by the lack of liquid in the root due to drying once the probes were inserted.  Even the carrots seemed to dry out over the time used to test them.


Before requiring adjustments to the original main procedure, fibrous plant root systems were crudely tested (multiple small roots going out in all directions), but data rates could not be established.    The fibrous roots may have been too small or our transmission probes may have been too big.  The root system type used is tap root, which uses a single large root, and proved the concept that data can be sent over plants.  It is possible that fibrous roots systems with multiple side shoots that come into contact with the roots of other plants in multiple instances would equate to an overall high enough data rate to signify communications.


After testing different plant tap roots with the same test presented to the other media, it was found that actual bit rates of these plant roots were actually not much slower than that of copper wire.  For instance, on a 9600 bit rate test, 9560bps was achieved by copper wire, and 9400bps was achieved by the plant root.  While an expected slowdown in data rate over distance was expected, the roots transmitted data at a fairly high rate, then dropped off transmission altogether.  The tested root types (dandelion, turnip and carrot) did not demonstrate a slowing of data rate gradually over distance.  There appears to be a direct relationship between the diameter of the plant root itself and the distance that the data signal can be carried.  In each case, transmission ended at a particular distance – the data rate did not gradually slow down over that distance. 


The hypothesis that distance the data can travel is a function of the diameter of the media is somewhat supported by the fact that a distance limit was never reached with the large diameter turnips.  In fact, very high data speeds of up to 115200 bits per second were observed with all of the turnips.


Using the least squares calculation with all the maximum distance data transmission actually showed a Coefficient of Determination of ~0.95 which indicates that 95%  of the maximum distance travelled was due the the diameter of carrot (this calculation was only performed on the carrots).


In future, further experimentation should include several smaller, less intrusive probes used together over multiple “rootlets” which would protrude from the main root.  This would allow the cumulative measurement of possible data transmission between plant root systems that are intertwined.  This would be comparable to the bonding of data transmission signals over multiple modems or transmission paths.    


Practical applications of the plant root experiment could include probe based systems that monitor agriculture such as fields of wheat, barley, rye, etc.  These cereals have long root systems with lateral rootlets that could be capable of forming a subterranean data network could be monitored with solar-based probes located in strategic locations.  As trees have larger root systems, we can assume that the distance data can travel would be greater and that more widely placed probes could be used to monitor the health of forests beyond standard satellite imagery.




Plant roots were able to transmit data, although only over a short distance.  A direct relationship was discovered between the diameter of the transmission media, the root diameter, and the length of the transmission path, the root length.  Plant roots may not be a feasible alternative to copper wiring, but could still have some practical applications.  More field testing will be required to determine whether plant roots will prove an effective way to transmit data in the process of monitoring forests, farms and orchards.