Soil Lab Test Series #1: Soil Biodiversity Testing
This is the first post in the Soilmentor Soil Lab Test Blog Series exploring soil lab analyses, what we can learn from them, and where to get them done. In this blog we look at soil biodiversity tests, and we’ll be exploring nutrient analysis, leaf and tissue analysis, and SOM / SOC tests in future posts.
We’re often asked for lab test recommendations, and although we don’t offer them directly with Soilmentor, we want to support you in choosing which tests you can learn from, and to keep building your soil health.
It’s worth noting that we don’t necessarily see these tests as essential for understanding your soil health – every system is different and many people get great results by simply observing their soil with in-field tests. It’s important to consider soil sample testing as a snapshot of your soils at one moment in time. Soils are dynamic, so we keep testing and monitoring over time to understand the full soil health picture.
If you want to add your lab tests to be viewed alongside other tests in Soilmentor, this is possible for key results in the Soilmentor lab tests category. We work with some fantastic soil advisors who help you to understand your soils and soil test results. If you’d like us to put you in touch with an advisor, let us know.
Soil Biodiversity Testing
Soil biodiversity tests quantify your “underground herd” (as Nicole Masters puts it in her book, ‘For the Love of Soil’). Understanding the proportions of different microbes living in your soil ecosystem helps to inform what kind of management techniques would support a balanced soil food web – and balance is key, as soils that are dominated by one type of microbe can lead to problems.
For example, a disrupted ratio of fungi:bacteria in your soil can be an early warning of soil health issues. Fungi and bacteria occupy different habitats within the soil, and have different roles and diets. Productive and healthy agricultural soils tend to have a fungi:bacteria ratio close to 1:1, so learning where your soil sits on this ratio can help you to manage your soils to encourage more bacteria or fungi as necessary. The proportions of bacteria and fungi also have a knock-on effect to other soil microbe communities, such as protists, viruses and nematodes. Following the Soil Health Principles is the best way to keep these soil communities in harmonious balance, and observation and testing is the best way to understand where action may need to be taken.

Fungal mycorrhizal associations with roots. Image source here.
Where to get your soil biodiversity measured
- MicroBIOMETER is a global company that offers microbial biomass tests that can be done with a starter kit in the field – no need to send your samples off for soil analysis. Their ‘lab grade’ tests also indicate the fungi:bacteria ratio in your soils, and results can be returned in as little as 20 minutes, removing the risk of your sample degrading on its way to the lab. In the UK, you can order a microbiometer testing kit by contacting Jack Ingle here. If you’re not in the UK, get in contact with the MicroBIOMETER team on their website to find out how best to get a kit!
- In the US, Harrington’s Soil Testing Laboratory offer a ‘qualitative soil food web package’ for determining counts of total bacteria, total fungi, and presence of protozoa and nematodes. Find out more here.
We have never personally sent soil samples to any of these companies, so we are really keen to hear people’s feedback! This list is also by no means exhaustive – if you have any good suggestions for us to add or any other feedback, please let us know at info@vidacycle.com