Life, a recent BBC nature documentary series, is a showcase of the diversity of the natural world and the extraordinary behaviour of living things. It seems that nature never fails to amaze the curious investigator; be it far, close or even underfoot.

“We know more about the movement of celestial bodies than about the soil underfoot.” - Leonardo da Vinci.

Yes, underfoot is the soil I want to talk about, which one of my professors fondly refers to as The Book of Nature. He would say, “Open The Book of Nature and read… here and there a chapter might be incomplete or you may not understand, but you can always learn about the past, the present and the future.” Indeed, my limited reading has found a lot of interesting chapters…

What is soil?

Technically defined, soil is a "natural body comprised of solids (minerals and organic matter), liquid, and gases that occurs on the land surface. It is characterized by distinguishable horizons and or the ability to support rooted plants in a natural environment".

In a much more ecological way, it is the basic structure that supports life’s primary producers, i.e. plants. It does this as a result of its unique capability to act as a reservoir of nutrients/water and then to supply those intermittently to the plants - very much like a prudent bank.

This is not the soil’s only role; it also acts as a foundation for infrastructure and as a cornerstone in the health of ecosystems, for example, by locking pollutants and harbouring ultimate decomposers. As such, it is considered as one of the three most vital natural resources, alongside air and water.

Why care for soils?

Knowledge of the soil's physical, chemical and biological make-up is important for various disciplines. For example, nutrient levels are important for crop production, soil shear strength is crucial for engineering construction, and its structure could also be a deciding factor for football pitches! It also has more exotic uses, such as a beauty accessory (see the intricate hair-styling of the Hamer of Ethiopia, for instance).

In addition to their functional roles, soils have been part of our life and culture in many ways. A recent book, Soil and Culture by Edward R. Landa and Christian Feller, pays tribute to their impact from visual arts to religion and from archaeology to disease and warfare, and as a further example, many states in the U.S. have a specific soil that is legislatively established as a ‘state soil’, just like a state bird or flower.

What is the status of soils today?

Like most of earth’s resources, soils in all parts of the world are under threat. From the physical problem of compaction to erosion, and from salinity to pollution, are increasingly degrading our soils, with negative effects on ecosystems, economy and human health. In addition, global warming threatens to release carbon trapped in soil's organic matter, exacerbating climate change and having grave consequences for life on earth.

What's being done?

As the concern on soils has come to the forefront of public awareness, national and international bodies are moving towards legislation and action. For example, the UK government’s Department for Environment, Food and Rural Affairs (DEFRA) recently published a revised strategy on soils.

Hilary Benn, Secretary of State for Environment, Food and Rural Affairs, explains the importance of caring for soils.

Take it further

Educate yourself and others with the Soil Science Educational Resource.

Join surveys, for example, the OPAL national soil and earthworm survey.

Support those who are working to improve soils situation, such as the Soil Association.

Open University courses

Neighbourhood nature

Environment: journeys through a changing world

Other links

BBC Life

British Society for Soil Science

International Union of Soil Sciences

European Union Soil Thematic Strategy

About the author

Dr Yoseph Araya is a plant ecologist and associate lecturer at the Open University. He works on the biology and conservation of South African fynbos vegetation. Environmental education and the role of the public in research is one of his key interests.

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The Institute of Mechanical Engineers (IMECHE) has published a report suggesting the geo-engineering could help provide a 'breathing space' while the world decarbonises the global economy. James Warren offers a first response.

The geo-engineering report gives readers of IMECHE's ideas some food for thought. The report selects three possible ideas which might help us lower CO₂ emissions, but all three are proven at large scale stages, and all three won't necessarily help us change our behaviour.

In fact, this is probably the one big worry here - even if geo-engineering, or what I would call a "pure techno-fix" could reduce our historical emissions to nil, we may find ourselves polluting even more.

The report does make some allusions to the rebound effect but probably not enough for my liking. One of the three ideas put forward is that of artificial trees which capture CO₂ which seems very interesting indeed.

Geo-engineering voice the opinion that we ought to get on with something, rather than wait for drawn-out multinational agreements which are sometimes not met anyway... these arguments to some extent are convincing. We might ask ourselves, just like other forms of basic science research, even if emissions capture or reflective materials don't hugely reduce our overall historic CO₂, might we still learn something useful from this exercise? I suspect the answer to this is yes, and to some extent, even if these ideas seemed very far-fetched, and don't significantly reduce CO₂ without other energy penalties, we may still gain something from them which is very important indeed.

We may learn which options to go for in a big way in terms of easy gains for example, and which are much harder to achieve with engineering, whether it be mechanical or social. With respect to reflectivity and countering the urban heat island effect, we also ought to be thinking much more deeply and widely about how we can lower the current overall energy use in heating homes.

Some estimates say that more than 50% of UK building stock needs to be torn down in order to start this new lower consumption process - so how does this square with the urban heat effects.

The one thing which still comes across is the rebound effect; if we reduce a typical UK citizen's 12 or 13 tonnes of CO₂ per year to, say, half that - by whatever means - what will we be doing to keep it at six, or even - if possible - to lower it further and further? The report describes artificial trees as eventually being decommissioned, but who will police emissions to ensure that the growth of artificial forests doesn't take over?

Even the idea of artificial trees, or bio-algae buildings is a good start to get people thinking about their own use of energy - but we need to be careful: too many techno-fixes may result in a strong but unwanted backlash in further emissions.

Find out more

Discover more about The Design Group at The Open University

Explore The Open University course Environment: Journeys Through A Changing World

The University of Melbourne's Jon Morris explains Urban Heat Islands

In-depth guide to the rebound effect