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Carbon Soil Health Soil Measurements

How to Measure Soil Using the Magic of Science; The Soil Health Index.

In your family, is there a secret recipe? One that only your nanna knows how to make? Perhaps, a famous family lasagne, winter soup, or a cake? .. Of course, no one can make it quite like nanna does. 

Here at Soil Heroes, we are also a family, and similarly, we have our own secret recipe; the Soil Health Index. The index is an innovation that is truly unique to Soil Heroes. It is the output of our impact methodology. We use it as we measure changes in carbon, water, and biodiversity in the soil.

To create the index, we begin with a Timestamp 0 (TS0); the process of taking measurements and samples to understand the state of the farmer’s soil. It is a baseline, meaning it is taken before anything else practically happens. In having this data, we can remeasure at different points in time, and therefore, see the changes in the soil’s health.

The process itself is a list of various measuring techniques that we use in the quantification and verification of positive environmental impact. 

Like nanna, we can give you the list of ingredients and show you the final cake, but only we know the secret of making it taste so good. It is made from years of experience and a sprinkle of appearingly magical ‘know-how’. 

Knowing What We Have To Work With

Soil is complex. It is a dynamic and flowing entity, composed of relationships between biological activities, chemical reactions, and physical forces. Or simply; biology, chemistry, physics. Additionally, in agricultural soils, the management of the land has a significant impact on the soil’s health. 

Healthy soils consist of increased populations of Soil Organic Matter, Minerals, and below-ground Biodiversity. The right management approaches cultivate this ecosystem of abundant life. 

This truly dynamic phenomena is quantified and verified by the Soil Heroes Platform. We measure using data from various individual techniques (the ingredients), which are then run through the Soil Heroes system (the baking), then the outcomes are the Soil Health Index and impact calculations (the cake).

But, ‘What are the Ingredients?’ We Hear You Cry

As mentioned, Timestamp Zero is the baseline measurements that all future measurements will be compared against in order to analyse the soil’s health. This is achieved through various measuring techniques, some very technical, some very modest. The combination of results feed into our Soil Health Index.

The measurements are organised by biology, chemistry, physics, and management. The results and analysis feed data into the Soil Heroes platform, where we ‘bake our cake’.

Physics

Penetrometry  – measuring the ease of penetration of an object into semi-solid matter, in our case, soil. 

Bulk Density – an indicator of soil compaction. It is calculated as the dry weight of soil divided by its volume.

In-depth moisture – using a time domain reflectometer (TDR), we understand the soil’s capacity for irrigation. 

Aggregate stability – measures the amount of stable aggregates when submerged in water.

Texture – a lab analysis of the relative amounts of sand, silt and clay particles in a soil.

Horizon depth – the depths of the soil horizons contribute to understanding rooting patterns.

Biology

Earthworms and soil biology – an indicator of general soil health, worms play a key role in processing organic matter into new soil and cycling deep soil to the surface. 

Soil Respiration – an indicator of ecosystem metabolism. Achieved by measuring changes in carbon dioxide (CO2) concentration within a controlled volume.

Active Carbon – an indicator of the small portion of soil organic matter that can serve as a readily available food and energy source for the soil microbial community, thus helping to maintain a healthy soil food web.

Active Carbon – an indicator of the small portion of soil organic matter that can serve as a readily available food and energy source for the soil microbial community, thus helping to maintain a healthy soil food web.

Active Carbon – an indicator of the small portion of soil organic matter that can serve as a readily available food and energy source for the soil microbial community, thus helping to maintain a healthy soil food web.

Chemistry

Nutrients (availability and provision) – through using Eurofins, a laboratory in the Netherlands, we send soil samples in order to know the levels of nutrients such as potassium and nitrogen. 

Organic Matter – similarly, we send samples to the lab. They measure the weight lost by an oven-dried (105°C) soil sample when it is heated to 400°C. 

… We are literally baking here guys! 👨‍🍳

Management

Ground cover – a history and projection of cover crop management.

Cropping plan – a history and projection of cash crop management.

Plot history – a qualitative overview of the field or plot’s history. 

Fertilisation – a history and projection of input management.

Tillage – a history and projection of tillage management.

Yields – a history and projection of yield performance.

We Dig Holes!

What makes Soil Heroes truly unique is that we take real soil measurements. We are the only Soil Carbon certifier that has our hands in the soil. Therefore we provide you with the most accurate measurement of environmental impact. 

We dig a pit 50cm deep to take our measurements and collect transect readings across the plot in order to get an average overview. We invite the farmer and their agronomist into the process (if they have the time). It’s good for us all to have our hands in the soil. 

Many of our competitors only use modelled data alongside satellite imagery. This is a noble start, but the difference between us and them is quite stark. 

Other tools measure whole farm emissions and not the health of soil. Therefore, these providers are offering carbon credits for the reduction of emissions. 

Whereas, we remove carbon from the atmosphere and stick it in the ground, where it belongs. 

To be a real soil hero, you have to get down and dirty. 

The Soil Heroes Platform

We are nature nerds at heart. But also tech geeks.. 

The data that we can collect in the field is uploaded to the Soil Heroes Platform in real time or sent to the lab for analysis. 

This screenshot was taken from a recent TS0 in the UK. The plot that we were measuring is outlined in white. 

In the bottom right (on the white border) is an orange target; the viewer’s real time location. There are numerous labelled zones, this is where the soil’s fertility naturally differs across the field. We take an average reading of the plot by taking measurements along the transects (the blue dots). These blue dots cover a balance of low/medium/high fertility zones in order to take an average.  

On the right is a larger grey dot (in this image it is slightly obscured). This is the location of the 50cm soil pit. 

The platform also allows us to upload photographs in situ; a visual archive of the changes taking place within the soil and surrounding area.

Using a combination of on-ground science and satellite imagery in this way, allows for us to monitor and verify the environmental impact across time. 

The Soil Health Index

After the lab has returned our results, we feed the data into the Soil Heroes Platform. What comes out the other side is the Soil Health Index and our carbon calculations.

The Soil Health Index is a graphical representation of the soil’s components. It is provided to every farmer that we work with, as the entry point to understanding their soil. It gives a visual cue for the farmer, highlighting areas to improve. It is delivered with the results of the TS0 and an overview of the results by our chief soil scientist, Leandro Barbieri. 

Here is one we made earlier … 

The index is essentially a chart with three axes; physics, biology, and chemistry. These scores are made up using the data we received from the TS0.

In the example above, chemistry is at 66%. In this case, the farmer needs to add organic amendments (such as a fertiliser or compost) to fuel the soil’s chemical reactions. 

It is important to note that we are not agronomists, what type of organic amendment and when to apply it would be unique to each farmer’s individual circumstances. We provide a ‘walk through’ of the results and advise the farmer to work with their own agronomist to design the right path ahead. 

Modelling Impact

Soil Heroes quantifies and verifies environmental impact from building soil health. The holistic benefits of healthy soil is that it captures carbon, stores water, boosts biodiversity, and increases the nutritional value of the produce.

Out of the four benefits, we are currently selling three within our regular carbon credits (carbon, water, and biodiversity). The Soil Heroes Foundation is currently researching the relationship between regenerative agriculture and nutrition. We hope to be able to capitalise on that research in the coming years to sell the world’s first truly holistic soil credit. 

We use the Soil Health Index alongside the Rothamsted Carbon Model (RothC) to forecast and verify the amount of carbon stored in the soil. 

“RothC is a model for the turnover of organic carbon in non-waterlogged topsoils that allows for the effects of soil type, temperature, moisture content and plant cover on the turnover process. It uses a monthly time step to calculate total organic carbon (t ha-1), microbial biomass carbon (t ha-1) and ∆14C (from which the equivalent radiocarbon age of the soil can be calculated) on a years to centuries timescale”.

Rothamsted Research

Our modelling for water storage capacity uses texture, organic matter and soil compaction to estimate water holding capacity in the top 30cm of soil. Practices that foster soil biology, deep rooting plants and a good soil rotation are good for reducing compaction and creating porosity.

You can directly witness how healthy soil has beneficial impacts on biodiversity below and above-ground. We use an equation developed alongside the Soil Heroes Foundation that works on an area of m2. Our next modelling upgrade includes calculations for improvements on the connectivity of biodiversity spaces and provision of food.

Just like science as a whole, the more we grow and feed data through the Soil Heroes’ system, the more we refine our scientific understanding.

“Showsley Farm in Northamptonshire regeneratively managed 15.19 hectares of spring barley. They sequestered 17.8 tonnes of CO2, stored 97.37 m3 of water, and boosted biodiversity populations across 12,751m2 of agricultural land”.   

Want to know how soil captures carbon?

Our Platform, Your Environmental Impact

Our farmers align with companies on an annual contract with a long-term aim of 3-5 year working relationships. Our carbon calculations are modelled for each year and we repeat the Timestamp process at three to five year intervals.

At the end of the yearly growing cycle, we provide the farmer and company with an impact report detailing the improvements that have been made.

For example in 2021, our impact partner, Allplants, offset their emissions through Soil Heroes. Showsley Farm in Northamptonshire regeneratively managed 15.19 hectares of spring barley. They sequestered 17.8 tonnes of CO2, stored 97.37 m3 of water, and boosted biodiversity populations across 12,751m2 of agricultural land.  

The proof is in the soil. We just have to look for it. Are you a company looking to counter your environmental emissions? Or, are you a farmer interested in an additional revenue stream? Talk to Tom, our business development officer, using the link below.

Tom Ludwig Soil Heroes Carbon Insetting Regenerative Agriculture

Tom Ludwig

Business Development, UK

Let’s talk about Regenerative Agriculture

You know you’ll dig it too.

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