Soil Ecology

Principles

Soil is not a lump of carbon with holes. We must not reduce soil to one element - carbon, despite the temptation from all the carbon counting going on in the world. It is an underground universe, the last to be explored. We have seen how it has been built over half billion years, resilient of what otherwise would have been ‘extinctions’

It was the father of modern ecology - Odum, who first emphasised that we look at the whole first, and the parts later - not the other way round, as is common in many science teaching. In his ‘Fundamentals of ecology’ he pioneered the concept of ecosystem - the holistic understanding of the environment as a system of interlocking biotic communities.

This site follows the ideas of Odum and Biever (1984) - of feedback loops arising in the soil community over millions of years. From the early feedbacks 400mya between roots, fungi and springtails, to later ones 200my later between worms, mites, bacteria to make humus formation. Many like these have a major effect on net primary productivity. We need a lot more research looking into any hypotheses looking at positive effects of the soil biota on the environment.

The soil is the place for feedback mechanisms.  This very fine membrane round the planet, like all surfaces, can provide the place for interactions to take place. And it is not just the surface, but all those crevices in the soil. Clay has a lot of surface area for chemical reactions and can adsorb chemicals.  The soil has more carbon than vegetation and atmosphere together, yet it is also the surface where so many chemical exchanges occur that may well determine the future of our earth. These are not static exchanges, but a continuous dynamic.

Philosophies

Like any science, soil science has its ways of thinking - philosophies. The main philosophies of science are Popper (accumulation of knowledge), Kuhn (knowledge revolutions) and Lakatos. These discuss the way we produce knowledge, or what some call wisdom.

Much of my undergraduate ecological teaching explained everything by 'competition'. Competition - mainly for food - was what it was all about. This fits with some interpretations of Darwin - which conflate 'competition' with 'survival of the fittest'.  Organisms survive for a host more reasons. Particularly in soil, where creatures in extreme environments, deep and dry, have few 'competitors'. 

This led to various population dynamics. (Andrewartha and Birch..). 

Later I came the more peaceful ‘balance’ and ‘harmony’ type of thinking. We often read that a form of farming is being carried out in an 'ecological' way. What does that mean?

More recently we are moving to where everything is in continual movement, as spelt out by Thomas Niail.

Processes

Ecology is about the processes, like mineralisation that has been going 500my, glomalisation 400m, de-lignification, 300 m and humification 200m, that enable structures with amazing architecture housing a massive biome of thousands of different sorts of creatures relating with each other. Soil is moving all the time, just as it has for the last half billion year, and we have seen how many of these process evolved over the millions of years. Lets pick some of the key processes that have developed over the years in soil, many now attracting investigation  as the functions they perform could be vital. There are physical chemical and biological processes going on all the time.

The most familiar physico-chemical involves the acidity of the soil - measured by the pH value. It is usually the first soil test as it lets us know which plants are likely to grow best. Another process is that between aerobic and anaerobic states. Bacteria can work in both, but when acting anaerobically they turn to nitrates as an energy source, taking away what has just been applied as fertiliserr. Another process taht is emerging as significant is the |Redox one - where an electron from one molecule(oxidises)  passes to another one, now reduced. The ability to encourage this reaction is seen to be important but difficult to measure. Other major physico-chemical  processes include water holding, and how clay traps chemicals

Among the main chemo biologic reactions, some key ones had developed 400mya. there were free living bacteria which couild fix nitrogen and solubise phosphates, both processes we are dying to copy today. There was also the  trii-symbiotic process was the one between fungi ( mycorrhiza) roots and springtails set up that vital process of how carbon gets from the air into soil. There  was also an aerobic process with other fungi (saprophytes) -developing to decompose debris. Tens of millions of years later, processes were established that could do that in anaerobic conditions, but till then the carbon accumulated that we now know as coal. Yet it was several hundred million years later that some  mycorrhiza somehow linked up with the nitrogen fixing bacteria inside plants we now call legumes. But why not before?

All these processes possess dynamics which work alongside many other environmental process, like drying, flooding, warmth and freezing, water moving, air blowing. One example of this is how the increase in soil organic matter, we’ll call life, helps hold more water in soil.

We can continue studying these reactions for years to come, and will increasingly recognise, if you change one, then others change too. And while we try and predict the changes, they often appear novel. It is likely that there are more we need to factor in. It is the processes, not the lumps of carbon,  which are important, and have been for millions of years and will continue into the future. Can we identify the important processes? How many more are there to be discovered?

Ecology is about the relations between the various actors. In the past we heard about  ‘symbiotic’, ‘parasitic’ ‘predatory’ relations, as if relations in soil are  two way. But, as we saw earlier the weakness of IPCC and soil,  relations are always multiple. Mites breakdown debris because they have bacteria in their guts to do so. The IPCC looked only at bacteria and air, without considering they were prey to many other creatures providing their predators with carbon that would have been lost to the air. The IPCC saw it as a burning process whereas it is a building process.

That lump of dirt is continuous interactions of many processes and myriads of organisms and creatures, which are probably hiding a few processes to be discovered.

We, ecologists, are beginning to realise that we are making a major error when reducing the ecological crisis to ‘climate change’ and in turn reducing climate crisis to carbon. Reductionism may be handy for editors but not science. We have seen throughout the last ½ billion years in soil the totality of life, the many important processes, particularly involving water, which make soil work. While soil is resilient, small changes can have devastating effects, as seen with desertification.

The crisis is not just warming, but the killing of ecosystems - ecocide. Destroying soil life destroys those other ecosystems through which life flows. The complex feedback loops that keep things moving and stable start to disentangle.

The focus on single crops reflects deeper part of Western culture that tends towards single-focus problem solving. This ends up with solutions, many of which do not solve the original problem. We need systems, dynamic and complex, to work better. We can now analyse systems in ways we could not dream about even a few years ago.

IN the past the State would have stepped in to deal with a complexity of issues, but nowadays, that is seen as in the past. State funding was able to look at matters more holistically.

Holistic Management is: a decision-making framework to help us better make decisions using the three things that WE are able to manage: Social (human resources), Financial, and Environment. It’s NOT a “grazing system, although some confuse as HM is promoted by Allan Savory who also promotes ‘rotational grazing’ which is a grazing system. Continuous set-stock grazing is a grazing system. But not Holistic Management.

Systems thinking Stafford Beer.

Corporates are interested only in their products. It would not now be possible to get the funding I got for my research which looked at 10 herbicides at the same time. This is not just UK but across the world, there is less money for soil research in the State sector. This makes it very difficult to look at processes, which need to be examined across a wide range of conditions.

Globally there are two major moves - towards carbon counting and improving biodiversity. Each has its limitations, but must be explored.

Global warming and counting carbon may be important warning signs, but the earth is best understood as a living being with a complex physiology, whose soil must be in good health if we are to survive for a few more generations.  Working with soil are the forests, the wetlands, the grasslands, the estuaries, the reefs, the apex predators, the keystone species, the insects - every intact ecosystem and every species on - and in -  earth. “If we continue to degrade these, drain them, cut them, poison them, pave them, and kill them, earth will die a death of a million cuts. She will die of organ failure—regardless of the levels of greenhouse gases."

This approach - looking at the whole and how it works, is in complete contrast to the new economic one of reducing everything to counting carbon and calculating its value. Yet the two subjects must co-exist, so lets see how that may play out.