Listening to the Soil Microbiome

Listening to the Soil Microbiome. Part1

The following is some documentation of an experiment using a device intended for recording electrical/chemical changes in plants to instead 'listen' for and compare activity in three different soil mixes in separate planter boxes.
After a few days of intermittent gentle winter rain all the planter boxes were fairly equal in the water allocation. Generally some outer edges of the soil media closest to the wooden frame were still a little drier and little or no conductivity was registered whereas placing the metal contacts on the surface or inserted only into the first two centimetres of the damper soil towards the middle of the planter boxes produced alot of conductivity and fairly constant changes. Inserting metal wires deeper into the soil produced less variety and interest in the signal- I found this interesting and not sure if this points to the influence of sun and wind on the surface of the soil or larger but still hard to see micro-organisms, chemical changes and creature activity closer to the surface. I am of course only guessing and am not even that interested in establishing and reducing the observations to some set of accounting certainty. My interest, apart from any potential sound-art inspiration, is in just 'listening' with greatest respect to the processes that might be taking place within and beyond my understanding with a view to drawing general impressions of use for next experiments in growing and listening.

COMPARISON OF THREE SOIL MIXES IN SEPARATE PLANTER BOXES

Planter Box 1 _ Mushroom Compost Mix-
chart of conductivity converted to music notes- 3 minutes of recording with sensors placed in middle of planter box growing media. Contacts inserted in first 1-2 centimetres for each planter box.

Planter Box 2 "B" Prepared Soil Mix.

This appeared to register the least changes of conductivity in the top surface of soil biome-maybe this represents a healthy steady state and or again could be the result of many influences from sun and clouds to wind and humidity and different plant growth and associated fungi etc.?? Another explanation or factor to consider is the question of duration timing and phasing of cycles of activity- there is a similar basic oscillation between high and low rate of changes when placing the contacts directly on plants as well.

Planter Box 3 - W _ Worm Farm mix.

This planter box full of worm farm soil mix and healthy broad beans with their no doubt busy nitrogen fixing nodules. There is an example of the cycling of activity and relative quiet 'resting'. Even the relatively monotone looking sections has an interesting pulsing rhythm. At about 7 minutes into the recording a burst of densely packed and wider spread of values or polyphony in music terms occurred for thirty seconds- this seemed to coincide with clouds clearing to bright winter sunshine.

Visual Comparison First Three Planter Beds

1st Planter Box Mushroom Compost. | 2nd Planter Box Prepared Soil Mix. | 3rd Planter Box Worm Farm Soil

CONCLUSIVE CERTAINTY- is not my forte, specialised knowledge or even aim here..Scientifically I am certain there are way too many variables and influences beyond my skills and technology- the actual soil moisture, the life in the water, soil organisms ,differing plants, plant roots, atmospheric conditions and so on. But I do think it fascinating to consider and observe or listen to what I can of these myriad of dynamic patterns going on in the nature that we are part of. I hope to run another series of recordings on these same beds and look for further patterns, similarities and differences that may be of interest or use or not!

VISUAL AND AUDIO COMPARISON
Sections of recordings of the soil conductivity from each of the three planters translated as midi notes as in the above graphs, were set up to be sounded by three layers of synthesiser instruments- no tuning or timing changes were applied and each recording uses the same sound set up.

Planter Bed 1

Ed Mundio · Bed1

Planter Bed 2

Ed Mundio · Bed2

Planter Bed 3

Ed Mundio · Bed3

Listening to the Soil Microbiome. Part 2