Why soil is important
Healthy soil is the foundation for a healthy life, a healthy planet and healthy people.
It provides anchorage for the roots of plants, it stores both the nutrients necessary for their growth and large amounts of CO2 in the form of organic carbon, while also filtering water.
Because of these highly important functions, healthy soil is not only crucial in mitigating climate change by acting as a natural carbon sink but also plays a decisive role in the production of food for the ever-growing world population.
A future without soil
Despite soil playing such a key role in the challenges the world is currently facing – and will have to cope with for the coming decades – about 24 billion tonnes of fertile soil is lost each year, soil being our most significant non-renewable geo-resource!
The cost of this land degradation reaches about 490 billion US dollars per year and roughly 40% of the world’s degraded land occurs in areas with the highest incidence of poverty. In total, land degradation directly impacts the health and livelihoods of an estimated 1.5 billion people.
According to the UN’s Food and Agriculture Organisation, the future outlook is even more alarming. If we continue to degrade the soil at the current rate, the world could run out of topsoil in about 60 years.
To combat this shocking development, we can’t just apply the same treatment measures to every “unhealthy” soil. Soil is a part of the ecosystem and its properties vary greatly. Therefore, every soil needs to be seen as being unique, and only after testing the soil will we be able to appropriately protect and optimise it.
As soil testing has often been an expensive and slow process, while also delivering results that are difficult to compare between laboratories, the usage of soil spectroscopy has increased in recent years. Compared to wet chemistry, it is the faster, non-destructive, and more cost-effective alternative with increased comparability. There are handheld NIR sensors on the market already, which provide users with soil testing results right in the field.
Despite these advances, soil testing is still impossible at a scale that would be relevant for the majority of farmers. The startup Audili was founded in response to this lack of an adequate solution to analyse basic soil properties at a country or even global scale. The underlying goal is simple: Audili aims to transfer the proven principles of soil spectroscopy used in laboratory or handheld scanners into space to enable the regular creation of global soil maps.
Understanding soil spectroscopy
After obtaining the spectral signature of the soil, which represents the frequencies at which light is being absorbed, we look at the drops in this absorption curve. These drops are called absorption bands and correspond to specific soil properties. Therefore, these absorption bands are the most important factor in predicting the soil properties. Simply put, soil properties are determined by putting the amount of absorption in relation to concentrations.
Making it remote
When applying these methods to remotely sensed imagery, it is important that the spatial and spectral characteristics of the sensor used are adequate for the task. For example, the spatial resolution needs to be high enough to match the spatial variability of the analysed properties. For large-scale monitoring to be commercially viable, it is also important that the data is freely available.
Audili utilises Sentinel-2 data to obtain the spectral measurements while Sentinel-1 and Sentinel-3 data are used to correct these measurements for influential factors such as soil moisture and temperature.
Soil insights are not just used to create a map. They are an important tool which supports three of the UN Sustainable Development Goals:
Through the adoption of best practices based on soil insights, soil quality is progressively improved. Healthy soil produces healthy food and better nutrition. Additionally, ecosystem services are restored, biological diversity and resilience to climate change effects, especially flooding and droughts, is increased.
According to a recent paper from 2019, just a small enhancement in topsoil organic carbon could increase drought tolerance for 70% of the global harvested area, and farmers’ economic output would be increased by 16% during drought years.
By giving farmers, companies, and consultants insights into the current state of the soil, fertiliser inputs can be optimised. This reduces the impact on global warming. Furthermore, by providing insights into the current state of SOC, initiatives can be taken to remove CO2 from the air naturally through carbon sequestration.
Life on Land
In order to combat desertification and restore degraded soil, it is important to be able to monitor conditions at a farm-relevant scale to improve decision-making and establish support frameworks. Audili makes the required monitoring finally possible on an efficient scale.
Audili – Copernicus Masters BayWa Challenge Winner
Audili was founded in 2019, accepted into the ESA Business Incubation Center Austria, and also announced as the BayWa Smart Farming Challenge winner of the leading Earth observation innovation competition Copernicus Masters.
Today, Audili is part of the Copernicus Accelerator and PARSEC accelerator. With their support and the ESA BIC Austria, Audili is aiming to release soil maps and additional services by 2021.
About Armin Schöpf:
Armin Schöpf is the CEO and Co-Founder of Audili. Together with his brother Stefan Schöpf, founded Audili in 2019.
 Iizumi, T., Wagai, R. Leveraging drought risk reduction for sustainable food, soil and climate via soil organic carbon sequestration. Sci Rep9, 19744 (2019). https://doi.org/10.1038/s41598-019-55835-y