A personal journey to discover the nature of soils

“In the most recent edition of #YourCareerInSoilOrPlantSciences, Matthew Shepherd from Natural England gives his personal view in discovering soils.”

I could always “get” nature.  Birds appearing in my garden or on long holiday drives as a child could be readily identified, and nerdily catalogued as appealed to my geeky collector’s mentality, as well as (I hope) speaking of my deeper appreciation of the beauty of wildlife.  I learnt my first scientific name at the age of seven: Oedemera nobilis, a startlingly beautiful metallic green beetle with bulging thighs that would put any professional footballer to shame.    Much to the disgust of my brother and sister I amassed a wide range of specimens – mostly horrible dead things in jars, which I topped up with carcinogenic formaldehyde, purchased in Boots alongside my supportive mum.  Skulls and skeletons were prized objects.  If they still had inconvenient flesh on?  No matter – there were ways to deal with that, though not always very successful.  One particularly disastrous method was applied to a splendid beach-combing find: a dead cormorant.   For some reason I thought that leaving it in a washing-up bowl of water on the garage roof would provide a nice clean skeleton.  Instead it provided an abundance of appalling rancid stench that must have made my family the pariah of the street.   Not all my specimens were so stomach-churning.  I had a sturdy shirt-box in which an array of rocks and minerals collected from various travels and studiously identified lay heavily on a bed of cotton wool.  Later, the appeals of botany eclipsed those of zoology for me, and I enthusiastically dived into the enjoyable task of learning UK plants.  All this enthusiasm took me through school, tertiary college, A levels in biology and geology and a degree in Ecology at Sheffield.  There seemed to me no part of the natural world that I didn’t love and feel inspired by.

Except for soil – the few lectures we had relating to soil were drab, brown affairs, seemingly pointlessly obsessed with glum abiotic processes, and tiny particles of rock too small to excite a geologist.  One strange phrase kept being repeated “soil is alive”, and we were reassured that actually there was lots of life in soil.  However, the message followed that it was far too small to ever be accessible, or even seen, by the likes of us.  The conclusion drawn by all present – don’t bother even trying.  My love of nature, plus a desire to look after it and share it with others meant a career in conservation looked like a good option, so following my degree I ended up a penniless, seemingly eternal volunteer, desperately trying to rack up the many years of experienced required for even the most menial of conservation posts.  The final indignity of those undignified years was when I failed to get a traineeship as an unpaid dogsbody for a wildlife trust (chop it down, drag it off, burn it), being outcompeted by someone with a PhD.  “OK”, I thought, “If that’s what it takes…” .

The PhD topic was already set up and funded, and as a bright, local, ecologically experienced and enthusiastic candidate, I was a shoe-in.  And the topic?  Er…  soil.

I was extraordinarily lucky to have as my PhD supervisor, the brilliant and insightful Prof Jo Anderson.  He’d built a career on an understanding of the roles of soil organisms in decomposition in agroecosystems.   Less luckily, he’d stopped all that by the time I arrived, and was then presiding over a soil ecology lab developing and peddling a range of biochemical assays, with such sexy sound names as “phenylpropanoid moieties” and “hexose-pentose ratios”.   I had arrived in the world of black-box soil ecology, where you took a soil sample, poked, provisioned and poisoned it a bit, and then measured what trickled out of it, nodding sagely.   I did my best to understand every other living thing in the system (plants, above-ground animals etc.), but the soil black box remained firmly closed.  Luckily (again) I was privileged to be working on upland semi-natural soils, but unluckily (again) the range of standard soil science techniques available for soils were almost universally designed for mineral soils; most started with “sieve the soil to 2mm to remove roots and stones”.  I spent far too much of my life trying sieve a dried block of peat, and despairing as it pinged around the sieve like a demented pinball , completely intact.  At the end of this PhD process, I emerged, wiser, sadder, thinner of hair and completely sure I never wanted to go near soil again.  I ran back to botany and got a job in a government agency, doing vegetation surveys and haranguing farmers for succumbing to subsidy-driven overgrazing.  I was, at last, a professional ecologist!  I didn’t ever need to think about soil.  Or so I thought…

A few of the stars of the soil. Left: Dorsal component of a Neomolgus littoralis and Right: Dorsal component of a Ceratoppia bipilis

Some years later someone spotted my soily background and tasked me with managing a project on soil organic matter, I used this as a launch pad to highlight the plight of peatlands.  Before long I was up to my neck in waterlogged organic matter, writing reports, producing maps and advising just about everyone about the miseries faced by our beleaguered peatlands.  This felt like an important and urgent work area, but it still didn’t require “getting” soil.  Peat is a very strange soil characterised by an almost total lack of the thing that most characterises all other soils – decomposition.  A lot of this work was simply maths and modelling – how much builds up, how much is lost, from where, how fast, and in what form?  Peat was yet another black box, although pleasingly, at least this time it was actually black!

Then, bizarrely, out of the blue, some wonderful bright spark somewhere in my organisation had the idea of having a Soil Biodiversity specialist, and I leapt at the chance, and into the post.  I’m not sure who it was dreamed this up, or what they were thinking.  They might possibly have done it as a way of keeping me busy and out of trouble!  Finally, an invitation to open that box…

I wasn’t disappointed.  Inside the box was the most exciting and fascinating, unimagined diversity of amazing natural phenomena I’d ever encountered.  I’d dug out a child’s microscope that I’d got for Christmas when I was 5, fashioned a makeshift pooter (not a good idea – make a good one!), and made a few ham-fisted efforts to inexpertly extract soil organisms by sieving, washing and searching.  My early rewards were a wealth of chubby, skinny, pale, brightly coloured, scaly, patterned, iridescent springtails, and other weird creatures that I now know to be rotifers and tardigrades.  I responded to mites the same way everyone does – with equal horror and wonder at their obscene diversity.  No two mites appeared to be the same!  From a series of poorly-educated mistakes, I graduated to well-educated mistakes and gradually became more expert (experts make mistakes of the highest quality!).  The charming Peter Shaw of Roehampton University provided my first formal training on springtails, and the equally charming and much-missed David Harding dusted off his military acarology (an example of military mite?) to get a few of us started at a Field Studies Council course.  I knew only a fragment more than the others on the course, but in the world of soil biology that is almost enough to make you an expert!  I’ve been helping to run that course ever since, and (thankfully) have become a little more expert along the way, thanks to an increasing pile of ancient references penned by the giants of soil biology, onto whose shoulders I’m still attempting to clamber.

But it’s not just the amazing diversity of organisms that excited me.  At last, I was able to see soil for what it was: a complex, dark, wet cave system crawling with creatures I could now imagine and name, each fighting to survive and breed in a world that was both ubiquitous and unexplored.  The daily struggles of these organisms, I soon discovered, has led over millions of years, to a series of consequences that we (in our typically selfish way) have branded “ecosystem services”.   Suddenly soil structure made sense – it doesn’t just spring into being, but is built, rebuilt and shored up by the feeding and growth of soil organisms.  Organic matter doesn’t just decompose, it feeds an army of animals and microbes, and their bodies (living and dead) go on to feed other armies of predators.  The brown sand, silt and clay world of the soil science lectures I knew was suddenly the scaffolding, the landscape and stage-set to a fascinating struggle for life that was both scientifically engaging and vitally important to life on earth.

I now “get” soil the same way I “get” nature, because I know see it as very much part of that nature.  I can’t think of an ecosystem without considering the below-ground feedbacks that enable it to function, and for every animal or plant I see, I try to consider the myriad life forms that I can’t see.  I take this message to farmers through workshops in partnership with projects such as Catchment Sensitive Farming, to help farmers to understand how soil really works, and how to manage it better.  I train others in how to explore soil biology and how to identify the creatures that creep out of their samples.  I’m very privileged that my job has given me the opportunity to develop this, and to go out to spread the word and try to help others to truly understand the nature of soil.

Author: Matthew Shepherd

Twitter: @theloraxofsoil