Where You At Q3: What soil series are you standing on?

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Claire and students of the 2015 Design 4 ACTION Permaculture Design Course observing a London soil sample

The third question in the Where You At? bioregional quiz is:

What soil series are you standing on?

A question to which my first response is ‘soil what?’ An alternate version of the bioregional quiz frames this question as ‘Describe the type of soil around your house.’ which is a bit more approachable. Another version asks ‘Describe the basic geology of the place you are living. What type of natural ground is there?”, which is also useful – but starts to move in on the territory of a later question (#16).

So I’m not familiar with the term ‘soil series’ – but I do know something about the soil here. My experiences of soil in London and Essex gardens have be characterised by repeatedly digging thick clays. Our last garden in South Woodham Ferrers, about 15km away from where we live now, was the same. I remember reading once that Essex was dominated by brick clays and marine clays – but I don’t know the difference. or how to tell them apart – although I imagine that one is better for making bricks out of than the other.

Here in Burnham-on-Crouch, both in our garden and at the allotment the soil is different – it is much easier to work and does not have the cloying quality of clay. I think this is because the soil is a river deposit. Thousands of years ago, what would become the River Medway flowed here into a River Thames that curled high through Essex and exited somewhere near where Clacton–on-Sea is today. Later the Thames itself may have flowed here.

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Essex c.400,000 BP, just before the arrival of the Anglian Ice Sheet. 
Illustration from Essex Rock (1999)
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Essex at the maximum extent of the Anglia ice-sheet. Illustration from Essex Rock (1999)

The UK Soil Observatory (UKSO) ‘provides a unified starting point for accessing UK soils data and underpinning research, with the specific objective of providing these data for free where possible’ – so that sounds like a good resource to use in order to find out the soil series here. Even better, it has an interactive soils map. Using that I can get an official confirmation of what the soilscape is like here: ‘freely draining, slightly acid loamy soils’.

UKSO

That descriptor is not a soil series type however – those are recorded extensively in The Soils Guide published by Cranfield University, which lists 753 soil types related to England and Wales. It’s a daunting list for the layperson, with the names of the soil types having no general cultural resonance. Clicking on the UKSO map for more detail on the local soil steers me to a more specific section of The Soils Guide, informing me that the soils here are ‘Freely draining slightly acid loamy soils (6)‘ – which seems to represent a class of soil types. Within this class there are 48 ‘included soil associations’ – which is less daunting than 753 but equally baffling.

A google search for Dengie peninsula soil types also takes me to The Soils Guide website – straight into information about one soil type/series: 0812c AGNEY, which includes the lines:

In Essex the association is mainly on the Dengie peninsula and the seaward side of Foulness and Havengore Islands. On parts of the Dengie peninsula Romney and Newchurch series are common, and near the southern end of the peninsula the association is bounded to the west by shell ridges.

Agney is described as ‘Deep stoneless calcareous fine and coarse silty soils. Groundwater usually controlled by ditches and pumps. Flat land.’ – that sounds like the Dengie edges, but it’s not the soil type of Burnham-on-Crouch. Hmm… this is just getting more confusing.

Some more searching turns up that there is a 1976 publication called Soils in Essex, 2: sheet TQ99 (Burnham-on-Crouch) by Robin Geoffrey Hardy, which is 160 pages long… but does include folded maps. This must surely provide the granularity I need. There are several copies within the Essex Library service, but they are all reference only apart from one in Colchester, the availability of which is listed as  ‘check shelves’ – my previous experience as a library assistant does not fill me with hope about the chances of locating it. So a trip to the local studies section of Chelmsford Library looks in order.

Somewhere at home, I’ve got a soil map of Essex produced by the British Geological Survey – but I don’t know exactly where right now. At the British Geological Survey website, they have their own interactive map of the Geology of Britain – and because it includes an overlay of street data, I can zoom right in on our garden.

BGS

So, according to the BGS our garden (and allotment which is the same area) sits on a geology of:

Superficial deposits: River Terrace Deposits, 1 To 2 – Sand and gravel. Sedimentary superficial deposit formed between 11.8 thousand years ago and the present during the Quaternary period.

Bedrock geology: London Clay Formation – Clay, silt and sand. Sedimentary bedrock formed between 56 and 47.8 million years ago during the Palaeogene period.

Which is all interesting, confirms something of the river deposits theory, and gives a deep time perspective on our backyard – but still doesn’t give my soil series.

So my interim answer, pending that trup to Chemlsford Library, is going to have to be: Freely draining, slightly acid loamy soils.

Resources:

Books:
Robin Geoffrey Hardy, Soils in Essex, 2: sheet TQ99 (Burnham-on-Crouch)
Gerald Lucy, Essex Rock: A Look Beneath the Essex Landscape, (1999)

Websites:

Geoessex

The Soils Guide

UK Soil Observatory

Geology of Britain

 

Next up: I’ll try and answer – What was the total rainfall in your area last year?

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