This week begin with a piece from Iowa Learning Farms entitled: It’s alive! Scientists get closer to identifying what lives in our soil.
The importance of soil life cannot be overstated. That we know so little about this complex web of life is not surprising. Soil science has focused upon the most easily measured properties of soil, its chemistry and the physics involved in compaction, ploughing and so forth.
This article from Iowa Learning Farms refers to the University of Colorado – Boulder and their release of a world soil Atlas. This is basic science and shows how far we have come and need to travel. In much the same way a lot of 19th Century biology was about classification and basically listing and describing every living thing so soil science is at this base level. I might point out the 19th Century biologists didn’t list every living thing but they tried. And from this attempt at classification, which continues today, a few 19th Century biologists were heading in a direction which led to Charles Darwin and a little thing we call The Theory of Evolution. So good things come from classification practices.
So back to the soil.
Researchers at the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado-Boulder published their study in the January issue of the highly respected journal, Science. Analyzing 237 soil samples from eighteen countries across six continents of varying climates, the researchers discovered that 2% of soil bacteria—about 500 species—accounted for nearly half of the soil bacterial communities found worldwide!
This is intriguing. Unfortunately we don’t have a similar study from before 1940 so change over time cannot be inferred. Yet 500 species accounting for nearly fifty percent of world wide soil bacteria raises some questions.
- Have we inadvertently selected for these particular species through the application of fertilisers, herbicides and pesticides?;
- Have these bacteria always formed about half of the soil bacteria?;
- Do the communities vary between arable, grazing and forested soils? and;
- How do we work with what we have now?
The first two questions are more difficult to answer, obviously but there may be techniques to discover their answers. I’m thinking coprolite analysis might be provide a window into the past structure of bacterial soil communities, maybe.
Question three is easily answered by taking samples across the three land use types. Indeed it would be possible to toss in other variables such as the systems used on these options. So State forestry sprayed regularly versus “wild” forest soils, regenerative grazing lands versus set stocking options and plough and spray versus, no-till and spray versus no-till organic production.
The answers would be fascinating. And remember we are only talking about bacteria in the quoted study. There are many other life forms in the soil. All of the above options could be tested for effects upon mycelium. Now that’s a study I’d be very happy to read.
If anyone listening knows of research covering these areas, I’d love to hear from you. Either email me at firstname.lastname@example.org or leave a link on the World Organic News Facebook page. Both Links in the show notes.
Question 4: How do we work with what we have now?
Is also of great interest. I suspect given our understanding of what ploughing, set stocking and clear felling of forests does to soil carbon, I’m pretty sure it’s safe to say these practices aren’t optimal for soil bacteria nor soil biota at large. Still a rigorous set of tests across various climatic, altitude and latitude variables would be instructive. We can’t just guess, we need measurements. I know a strange suggestion in this time of feelings of facts but there you go. I’m old fashioned that way.
Some such research is being planned,
CIRES researchers believe this discovery sets up a “most wanted list” of soil bacteria, as it points to which bacteria should be targeted in future studies seeking to understand soil microbes and their contribution to soil fertility and ecosystem functioning. The next step is to begin categorizing these dominant bacteria into groups of co-occurring bacteria and habitat preferences, resulting in data that the CIRES group hopes will shed more light on the function of certain groups of bacteria, eventually leading to agricultural applications.
Not quite where I’d like to see the emphasis but I have an agenda, clearly not hidden, but an agenda nonetheless. For more on the work the Cooperative Institute for Research in Environmental Sciences there’s a link in the show notes.
We are at an interesting point in our understanding of soil biota and I’ll endeavour to keep all my listeners up to speed on this fascinating field of research.
And with that I’ll finish for this week. Remember: Decarbonise the air, recarbonise the soil!
Thank you for listening and I’ll be back next week.
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It’s alive! Scientists get closer to identifying what lives in our soil