Soil Biodiversity, The Sustainability Farming “Grail”
by Alberto Acedo on 23/Apr/21
Like Indiana Jones and the Last Crusade, agriculture seeks the soil biodiversity “grail", in hopes, perhaps, of achieving “eternal” sustainability.
Finding it, however, is not such an easy quest, especially because the definitions and metrics that define biodiversity are presented in different forms. Like Indiana Jones, farmers need to be highly selective in their pursuit, careful to choose the one, true Soil Biodiversity Grail that grants “eternal” sustainability, because false ones will have the adverse effect of killing the soil.
This week, the FAO presented a World Symposium on Soil Biodiversity, but what exactly does that entail? Let’s take a closer look at different definitions of biodiversity using different cases.
The most accepted interpretation of biodiversity defines it as the number of species found in a specific area, also referred to as taxonomy biodiversity. This definition requires a clear idea of what “species” means in this context and an equally clear delineation of the comparative area in question .
Case 1. Simply put, if in “Area A” 10 different species are detected, and in “Area B” only 5 are found, then “Area A” would be more biodiverse, right? We define this then as “species richness.”
But what if the comparative amount of species between the two areas is not enough to answer the biodiversity question? For example:
Case 2. If in “Area A” there are 10 different species, and 100 individuals, and one of the species’ correlates to 91 individuals whereas the rest correlate to only one individual per species, and we want to compare it with “Area B” with 5 species that represent 20 individuals each, then what is the most biodiverse area?
This is a more complex question, because if we only count the number of species, both areas have the same amount:10 species. In this case, the ratio between the “species balance” compared to the species present must be taken into account.
Using the Shannon index, “Area B” would be more biodiverse.
At Biome Makers, we offer this metric, referred to as the Taxonomic microbial-biodiversity index, and compare the balance between the species detected in one sample with other samples from the same crop. However, that’s only one factor.
If we want to link biodiversity with sustainability, the soil health definition is key. USDA defines soil heath as the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans. This means that biodiversity of the ecosystem is not enough to define soil health as previously described, and “functions” need to be included in the biodiversity equation.
Case 3. In this instance, let’s not count species that fail to function to provide for a vital ecosystem, using the same example with “Area A” (10 species, with one species counting for 91 individuals and the rest only representing one individual per species) and “Area B” (5 species representing 20 individuals each).
But here, in the case of “Area A”, the species consist of different plants, animals, fungi and microorganisms, whereas “Area B” consists of different monkey species. . Under this scenario, “Area A”, has more functional biodiversity, because more genes and functions can provide for the ecosystem. This is exactly what’s calculated per sample and compared with other samples from the same crop using Biome Makers’ BeCrop report under the functional biodiversity index.
In the same way Barcelona soccer fans are difficult to find at Real Madrid soccer celebrations, there are probabilities (to a lesser or greater extent) that certain species will be present if others are similarly present. Using this simple statistical approach, it’s possible to understand if species living together in an ecosystem are friends (i.e. if they depend on each other to survive), or are villains/rivals. Also, this index is very helpful for determining disease risk levels, given how pathogens register as part of life’s biodiversity as well.
Going back to our previous case examples, if in “Area A” all sp are rivals compared to “Area B” where sp are collaborative, the area then with more biodiversity would be “Area B.”
Sustainable Ratio Index Based on Biodiversity
With this “chess table” of different case studies, I can imagine your confusion about biodiversity. That’s why, at Biome Makers, we’re boiling down all biodiversity concepts into one, easy-to-interpret number system that uses microbial biodiversity to describe soil health and sustainability.
It’s not necessary to watch an entire episode of the tv show: “How Do They Do It?” to explain biodiversity. This simple breakdown published in our scientific paper on vineyards demonstrates the concept.
Each point represents a species, the density of the points refers to the richness, the size of each point correlates to the balance, and ecology is represented by the lines and functions of the clustering. Using this approach, it’s easier to differentiate high or low biodiversity levels and to track how different management practices can improve or hinder biodiversity, soil health and sustainability.
True Biodiversity “Grail”
In their quest to save the soil, foster sustainability, and improve production, farmers must embrace the one, “true” technology to discover the “Biodiversity Grail.” During this moment in agriculture, when many farming practices, such as regenerative agriculture, organic, agroforestry or biodynamics are trending, choosing the best biodiversity index to measure the change is of the utmost importance.
The vitality of soil health hinges on agriculture’s ability to distinguish easy (i.e. pretty) conceptions of biodiversity from more complex (i.e. less attractive) versions thereof, in much the same way Dr. Jones was able to choose the “true grail” that ultimately saved his father.
If you are a farmer, please, save your soil with the “true biodiversity grail” index.
Author of this article:
Co-founder and CSO at Biome Makers