SOIL+ CO2 Probe

The Problem

The soil can be a highly variable factor for farmers of all types, with its performance determining this year’s results, and the following years success or failure. When the the soil is prosperous, so is the farmer. If the soil is deteriorating, so too does a producer’s ability to recover profits.

To combat this challenge of the unknown, farmers employ the use of agronomists to collect soil samples as a way of monitoring soil health. Although useful for decision making, this exercise can be time consuming and costly with results taking two weeks or more to return, leaving producers in the lurch when their livelihood is underperforming.

Current soil testing methods revolve around removing a large range of soil samples from a given area, mixing these samples together to create aggregated results, and then often sending the results away to be analysed.

As tried and true as these methods are, the results gained only show overall field health, and do not allow farmers the ability to hone their soil productivity in areas that are underperforming. This method also discourages regular soil check-ups to ensure the security of their investment for the current season, and the seasons to come.

Having detailed data about soil health can save farmers upwards of $50,000 yearly
Dr Cassandra Schefe – AGRISCI

The identified problems were uncovered through comprehensive research involving observations, interviews, and academic study.

An ethnographic observation with a QUT PhD student at the CAB office provided insights into soil CO2 measurement techniques for Carbon Sequestration research. This experience offered a firsthand look at various tools and methods used for CO2 measurements, as well as their data outputs, enhancing my academic understanding of the field.

Subsequently, interviews with two Victoria-based agronomists shed light on the practical aspects of soil core testing, predominantly its strengths and limitations. These discussions also provided valuable information on soil theory, covering topics like the carbon cycle, microbial activity, Soil-Based Carbon Dioxide, and Soil Organic Carbon, which are crucial for developing a scientifically sound device.

To complement this primary research, a review of academic journals and other sources was conducted to gain a comprehensive understanding of soil CO2 measurement, its significance, and the potential applications of accurate data.

Definition of Key Terms

Ethnographic Observation

Ethnographic Research is a qualitative method for collecting data often used in the social and behavioural sciences. In a design sense, data is collected through observations and interviews within a “natural environment”, based around interactions with existing products, and learning through listening when the user discusses their experiences.
Atmospheric CO2

Atmospheric CO2 is the overarching term for Carbon Dioxide that exists in the air we breathe. This gas is found in natural systems, however levels are exacerbated by human interference.
Carbon Sequestration

Carbon Sequestration is the storage of atmospheric CO2 within the soil. Generally, this is accomplished through plants absorbing CO2 during photosynthesis, and storing it in the soil as Carbon (or SOC) after they die.
Microbial Activity

Microbial activity is the generalised term for the part that the micro-organisms play within the carbon cycle. Microbes play an important part in soil health as they both ensure the cycling of nutrients for plants, as well as act as a key indicator of soil health. If a soil system is healthy, more microbes will be present than if a system is unhealthy.
Soil Organic Carbon (SOC)

Soil Organic Carbon is the term used to describe carbon found in the soil, that is inherited from organisms such as plants and animals.
Carbon Cycle

The carbon cycle is defined as the constant movement of CO2 within nature, and is made up for four key parts (in relevance to this project):

1. CO2 in the atmosphere is absorbed by plants and stored in their cells. This CO2 is converted into carbon.
2. When a plant dies, the carbon integrates with the rest of the soil and matter, becoming Soil Organic Carbon.
3. This Soil Organic Carbon is then eaten by Microbes. These Microbes consume the Carbon, and emit CO2 as a by-product (otherwise known as Microbial Respiration).
4. This emitted CO2 is then released back into the atmosphere, therefore closing the cycle
CAB

CAB is QUT’s Centre for Agriculture and the Bioeconomy.
This research centre specialises in future-proofing crops, creating sustainable fuels from agricultural waste, and unlocking the potential of agriculture to make positive environmental change. This centre is also the leading group in Carbon Sequestration research.
Soil CO2

Soil CO2 is the term used to define the carbon dioxide emitted by the soil. Although it is the same concept as Microbial Respiration, this term only denotes the Carbon Dioxide emitted from the soil, not the other gasses like Methane or Nitrous Oxide.

Name: View my Research Report here
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The solution

The SOIL+ CO2 Probe

SOIL+ offers functionality and results in a way not currently seen in the agricultural landscape. By utilising both soil and CO2 testing methodologies, this device has the ability to provide live insights into soil health and performance, boasting a highly hands-off approach for the producers who benefit from its data outputs. With consideration to existing soil testing methods, SOIL+ is a set and forget solution that can be easily scaled to provide in-depth data over large distances. This product leverages farmer-agronomist relationships to honor the trust and human factors of farming, as well as ensuring that data outputs are actioned in a manner that works for the user.

How is it used?

One short press of the power button will provide the user with the device’s battery life through the means of the green ‘Sorghum Lights’. A full head of sorghum (like shown) means the battery is full.
On the other hand if only two at the bottom light up, then the device requires charging.

Press and hold the power button to turn the device on or off. Power on is indicated by a blue ‘Sorghum Light’ (as demonstrated). This light will begin to flash as it connects itself to the local LoRa receiver based at the farm house. Once connected, the light will turn off, and data will begin transmitting.

Once all of the probes are connected, they can then be transported to the field. With their durable components, the probes are able to withstand a rough ride in the back of the buggy, or being thrown into the back of a ute.

When the user arrives at their location, the probes can be easily installed using any off the shelf drill, impact driver, or even spanner to screw the devices into the ground. If it fits the 13mm hex head at the top, then it can be used as an installation tool.

Users have the option of installing 2 to 40 of these probes in their fields, with a greater density of devices creating a more detailed dataset. These probes will remain in the field collecting data until harvest time, where the probes will be removed from the field to ensure no damage is caused to the harvester, or the probes.

Instead of having to take samples from the field manually, the probes will send data to a designated farm computer automatically through the means of a LoRa (Long Range) antenna and receiver. This data is automatically processed by the SOIL+ program and provides producers and/or agronomists the ability to see live soil health per field.

For the user, they will be able to manipulate this dashboard to only show the information important to them, with the software providing both farmer and agronomist centric models. The farmer version of the software manages raw probe data automatically to give the user the information they need now, and provides insights into areas of improvement. The agronomist version will have this same functionality, however will also prioritize the raw data output from the devices so the agronomist can explore and develop solutions using their expertise and familiarity of their client’s situation.