THE LURE OF PEDOGENESIS.

AN ANTHROPOLOGICAL FORAY INTO

MAKING URBAN SOILS IN CONTEMPORARY

FRANCE

__________________________________________

Germain MEULEMANS

MA; BA (University of Liège)

_________________________________________

A thesis presented for the degree of

Doctor of Philosophy in Anthropology at the University of Aberdeen

And Doctor in Social and Political Sciences at the University of Liège

2017

ix

Declaration ii

Summary of the thesis iii

Résumé de la thèse v

Acknowledgements vii

List of figures xii

List of acronyms and abbreviations xiii

Maps xiv

INTRODUCTION 1

NOTICING URBAN SOILS 6

AN URBAN SOIL BESTIARY 9

DIFFRACTING THE ‘ANTHROPOCENE’ 13

FIRST APPROACH TO FIELDWORK: A STUDY OF SOIL SCIENTISTS’ KNOWLEDGE PRACTICES 19

ANTHROPOLOGY WITH THE SOIL SCIENCES 22

SECOND PHASE OF FIELDWORK: FOLLOWING SOILS IN THE MAKING 30

SOILS IN THE MAKING 33

OVERVIEW OF CHAPTERS 35

A NOTE ON ETHNOGRAPHY IN THE PLURAL FORM 40

I. THE BIRTH OF AN URBAN SOIL SCIENCE

1. THE RISE AND CONTESTATION OF THE ABIOTIC CITY 44

A LOOK INTO THE BLACK HOLE 44

LIFE WITH CITY SOILS, ENLIGHTENMENT AND THE ENGINEERS 47

1850: THE ABIOTIC CITY 53

2009: ‘DESIGNING’ SOILS, ‘RECYCLING’ MATERIALS 58

GREEN WASHING AND ECOLOGY 63

THE EXCESSES OF URBAN SPRAWL 65

SOIL CONSTRUCTION AND EFFICIENCY 69

MAKING URBAN SOILS MATTER 70

2. THE NATURE OF MADE SOILS: ECOLOGICAL ENGINEERING AS A RESEARCH PRACTICE 73

NON-LINEARITY, NON-NATURE 77

ECOLOGICAL ENGINEERING: MEANS FOR TESTING HYPOTHESES? 79

GLACIERLIKE HUMANS 82

ON ‘FINDING’ WHAT YOU HAVE ‘MADE’ 86

MULTIPLYING SURPRISE? 89

FROM SURPRISE TO ASTONISHMENT 91

x

OSCILLATION BETWEEN CLOSURE AND OPENNESS 94

MAKING SOILS, WEAVING APARATUSES 97

3. ON DIGGING AND OTHER EXPLORATIVE PRACTICES IN PEDOLOGY 104

ATTENDING TO THE SHOVEL 104

SOIL: A LIVING COMPOUND 105

PEDOLOGICAL PITS AND THE HEGEMONY OF VISUAL METHODS 107

‘DIGGING FORWARD’ INTO PEDOGENETIC PROCESSES 109

A RISKY PRACTICE: FOLLOWING THE MATERIALS IN SOILS 115

LEARNING TO BE AFFECTED 120

4. A PROLETARIAT OF DIGGERS. WORMS AS ENGINEERS IN PRACTICES OF SOIL CONSTRUCTION 126

A BOUNDARY CASE OF COLLABORATION 126

WORMS AND THE LIVING SOIL APPROACH 128

STAGED CONTROVERSIES BETWEEN DARWIN AND DOKUCHAEV 130

THE ECOLOGICAL ENGINEER’S NOTION OF COLLABORATION 133

WORMS WORMING 138

A NOTE ON ‘AGENCY’ 140

A PEDOGENESIS PERSPECTIVE 143

WHAT ABOUT HUMANS? 147

EARTHWORMOLOGISTS… 148

…AND FUNCTIONALISTS 150

BUNDLED UP IN CONCRESCENCE 153

II. FOLLOWING URBAN SOILS WHERE THEY ARE GROWN

5. RUDERAL GARDENING AND MOUND MAKING: SOIL CONSTRUCTION IN CITY INTERSTICES 159

TWO WAYS OF MAKING A MOUND 166

LASAGNA BEDS 167

DRY STONE WALLS 170

PARTICIPATION AND INVENTION 176

THE RE-ANIMATION OF SOILS, SKILLS, AND COMMUNITY 179

6. A CITY ON PILES: SOILS AS GRAIN AND WATER IN THE BUILDING OF FOUNDATIONS 184

PRELUDE: HOW A CHURCH DRIFTED ON A CURRENT OF CLAY 184

THE UNGLAMOROUS OCCUPATION OF FOUNDATION DESIGN 186

MAKING VOIDS AND THE FORCES OF THE GROUND 189

xi

THE GÉOTECH LAB: ABDUCTING THE GRANULAR. 193

MOISTURE AND IT THRESHOLDS 200

A CRUDE ESTIMATE OF SOIL’S DIGESTION 205

BALANCING ACTS AND SAND CASTLES 207

7. THE LURE OF SOIL(S) FICTIONS: COLLABORATIONS IN ART, ANTHROPOLOGY AND THE SOIL SCIENCES 211

THE CHAMARANDE LAB 213

TEMPORARY STAGING OF A RESEARCH EXPERIMENT 220

A SCHOOL OF URBAN PEDOGENESIS: SUSPENSION AND RECOMPOSITION 223

IMAGINATION AS THOUGHT EXPERIMENT 226

LATENT SCIENCE AND THE MEDITATIVE PRACTICE OF DISTILLING 229

HOW CAN SOIL FICTIONS ADD TO THE WORLD 234

LURES FOR OTHER FEELINGS OF URBAN SOILS 238

CODA: EXTENDING SOIL FICTIONS TO OTHER CIRCLE 244

CONCLUSION 247

References 255

xiv

Maps

Figure 1: Northern France and Belgium (source: géoportail)

Figure 2: Paris region (source: géoportail)

1. Paris

2. Homécourt (chapters 2, 3, 4)

3. LSE, Nancy (chapter 2)

4. ULg, Liège

5. IEES-Paris, Créteil (chapters 1, 4)

6. IRD, Bondy (chapters 1, 4)

7. Parc des Expositions, Villepinte (chapter 1)

8. Villeneuve-sous-Dammartin (chapter 1)

9. Petite Ceinture (chapter 5) / Saint

Germain de Charonne (chapter 6) /

Boulevard Davout (chapter 6)

10. Géotech, Montigny (chapter 6)

11. Chamarande (chapter 7)

1

INTRODUCTION

Figure 3: Homécourt, 1962 (Photo by association Mémoire du Pays de l'Orne)

This is an aerial view of the coking plant of Homécourt in the Lorraine region. The

photograph was taken in 1964. In France, such a picture now seems like from

another age. Homécourt was a rather standard steel factory, and its history is

similar to that of many northern-French industrial areas. The first steel factory in

Homécourt was built in 1898 on the plateau of Haut des Tappes, not far from the

iron mines down in the valley. It was then called Marine. Most of the latter coking

plant was built in 1920. The steel factory in Homécourt became the most modern

in Lorraine in 1950, and continued growing to reach a production of 2400 tons of

cast iron per day at its peak. This was in 1964, when the aerial picture shown above

was taken. This photo, showing the factory with its environment of steel and

fumes, may have been hanging in the office of the director who could then admire

his little empire. At the time, many immigrants, mostly from Italy, were coming to

2

settle in Homécourt because there were jobs. In 1963, the director of the factory

proclaimed that the plant would be active for at least fifty more years. Factory

workers were assured there would be jobs for them, and later for their children and

even their grandchildren (Le Républicain Lorrain 1963).

In the 1970s, however, the steel sector in France entered a period of rapid

downturn. Marine – which was by then called by the less melodious name of Sacilor

– closed in 1980, hit by industrial collapse in Lorraine. Eager to turn their back to

a bygone industrial age, the mayor and the region ordered the demolition of the

factory in 1985, wanting to regenerate the site as soon as possible.

Figure 4: The demolition of the plant, 1983 (Photo by association Mémoire du Pays de l'Orne)

For Peter Sloterdijk (2016), one of the most salient traits of modernity is that it has

always been driven by aspiration for the future rather than nostalgia for the past.

Because of this ‘antigenealogical’ stance, modern people have taken ‘rupture’ as the

motor of progress. Each new accepted dream, each new narrative of the future

seems to come with the ambition that the territory must be ‘Reset’. To reset, in the

jargon of the computer sciences, is to clear any pending error and bring the system

to its initial state.

3

The industrial history of Lorraine was over, and its vestiges had to be forgotten. A

picture of the collapsing coal tower captured the cloud of black dust left in the

wake of the falling building. The black cloud then hovered for a few more minutes

above the tower’s debris, under the eyes of many workers who had come to see the

explosion. A member of a local association told me that several of them cried when

the factory was torn down. The plant had been at the centre of lives, successes,

hopes and miseries. Not only was it shut now: it was erased, as if it had never

existed. To the workers, forgetting the industry also meant forgetting them. The

town has since lost a third of its population, but many former workers still live

there. The association member says most of them never found a job again.

In fact, the fate of the site itself would soon prove as uncertain as that of its workers.

Most of the 80 hectares where the plant stood were left untouched, as natural

attenuation processes were expected to degrade the pollutants left by more than

eighty years of industrial activity. Oaks, beeches, and hornbeams now cover large

parts of the area. Another part of the site, situated closer to the road, was ‘treated’

by the last owner after the demolition. This was done at the demand of the mayor,

who wanted to turn it into a commercial zone for the redevelopment of

Homécourt. A clean layer of topsoil scraped off from a nearby field was brought to

the site, and a building was erected in order to attract companies. But on the day

the building opened, it was filled by a naphthalene smell, and the developers

realized that the substantial amounts of chemicals remaining in the ground were

poorly contained by the thin topsoil layer. In the nearby valley, the closed mines

that once fed the coking plant are now a ground collapse hazard. Here on the

plateau, the soil is stable but infiltrated with tar, PAHs, cyanide and heavy metals

that leaked from the coking plant’s reservoirs and pipes, or simply from material

that was discarded on the plant’s waste heap.

I was told about Homécourt’s industrial history many times. The first time was on

a cold morning in March 2014, as I met the team of the Nancy Laboratoire Sols et

Environnement (Laboratory for Soils and the Environment, henceforth LSE) –

which I shall introduce later – to embark on a three-hour drive from Nancy to

Homécourt. I remember thinking that history seems as if it were made of lines that

4

intermingle and reach into the present. Often, people attempt to erase history by

levelling over a specific place that furnished previous lives. The superstructure of

the coking plant was brought down in the hope that the ground thus planed would

offer a tabula rasa for the concretisation of new hopes that were forged

notwithstanding the past: hopes for renewed economic development for

Homécourt, based on services and goods production and consumption rather than

industry. These hopes forgot that lives are not only lived on the surface. They also

leak into the soil, and the soil was still there, as industrial as it was.

The story of Homécourt is exemplary of the forms of remembering and forgetting

embedded in the soils I will be exploring in this thesis. This story is similar to that

of many places left over by capitalism: not only former industrial sites, but also

retail districts, traffic areas, infrastructures, mines. These places have in common

with Homécourt that they were at the centre of a failed narrative of progress,

leaving the landscape in ruins. As Anna Tsing notes, the story of industrialisation

and progress has often ‘turned out to be a bubble of promise followed by lost

livelihoods and damaged landscapes’ (Tsing 2015, 18). However, for Tsing, we

cannot simply mourn the losses that come with this collapse: ‘If we end the story

with decay, we abandon all hope—or turn our attention to other sites of promise

and ruin’ (18). The task for contemporary anthropologists and concerned people,

Tsing suggests, is instead to be attentive to what emerges in damaged landscapes,

and to slowly learn to live in the postcapitalist ruins that we are stuck with.

As Maria Puig de la Bellacasa (2011) contends, taking the time to notice the things

that have been neglected by modernity, science and progress can tell us a lot about

their ways of functioning. Neglected things bear promises of renewed perspectives,

of opening black boxes that might shift orders and priorities. To Isabelle Stengers,

‘If a new materialism or new vitalism is to come to life, it will come by surprise,

from unexpected realms, from outsides that aren’t being taken seriously, that are

disqualified by principle’ (Stengers 2000a, 100 my trans.). The soils left in the wake

of modern projects for our habitation of the earth are a great example of such

neglected things. In this dissertation, I will call them urban soils, following the

casual category used by the soil scientists and ecologists with whom I have been

5

doing fieldwork. When they refer to ‘urban soils’, they do not necessarily refer to

the soils of city centres, but rather to the soils of important modern settlements –

including industrial areas and city outskirts that have been subject to urban and

economic ‘development’. Other words are used to describe pretty much the same

thing, such as the neologism ‘Technosols’, which is the scientifically accepted word

for them, or ‘SUITMA’ – acronym for Soils of Urban, Industrial, Traffic, Mining and

Military Areas. The industrial soils of Homécourt are only one tiny part of this

story, but as we shall see later, to soil scientists, they have become a symbol of our

contemporary neglect of the soils left in the wake of modern development.

Homécourt’s story is singular in that it has since also become the largest site

dedicated to research on what has become known as ‘soil construction’. In France

it is now the flagship for a movement of reclaiming urban soils.

Urban soils are currently becoming matters of concern in different fields, ranging

from basic research in the soil sciences to urbanism, gardening, or environmental

activism. In this thesis, I explore the reasons why they have been considered

uninteresting until recently, and the modalities in which they come to focus

attention today. My account is based on thirteen months of ethnographic

fieldwork carried out between the end of 2013 and early 2015 with soil scientists,

ecological engineers, city council workers, gardeners, geotechnicians and artists.

In exploring the unfolding of new relations between these people and urban soils,

I challenge the usual ‘epigeic’ (above-ground) view of human life and ways of

dwelling, I take seriously their decentering of the understanding of soils as more

than just ‘the ground where we grow food’, and consider its implications for these

different collectives and for soils . In so doing, I also challenge a growing approach

to urban soils as just a ‘resource’ or a ‘development opportunity’, or as a means to

benefit from the ‘ecosystem services’ they may provide to humans. My overarching

question is what it might mean to live with urban soils, what effects follow from

adopting a ‘below-ground’ view of cities – to approach a city from the perspective

of its soils – and what lessons can be drawn from this for anthropology.

6

Noticing urban soils

In the last two decades, many scholars, activists and journalists (Shiva 2015;

Denhez 2014) have warned that we should pay much more attention to soils in

general. In 1985, Marcel Bouché, then secretary of the committee of Soil Zoology

of the International Union of the Soil Sciences (IUSS), observed in a preface that

in many respects, scientists still know very little about soils and the lives of the

many creatures that dwell in it. Bouché concluded his paper with the following

statement:

If we compare, for example, the significance accorded to ornithology and the multitude of birdwatchers studying about one kilogram of birds per hectare, with the extremely limited number of research workers interested in the hundreds of kilograms or tonnes per hectare of earthworms, we must conclude that our knowledge of ecosystems is fundamentally distorted by our above-ground, visual perception of nature and our ignorance of life below-ground. (Bouché, in Lee 1985, ix)

Since Bouché wrote these lines, soil scientists’ vision of soils has undergone

profound changes. In the past twenty-five years, researchers have increasingly

learned to understand soils not just as a succession of horizons, or a support for

plant growth, but as an intricate fold of minerals, plants, fungi, microbes and other

organisms that construct, maintain and regulate the soil. This initiated a

convergence of ecology and the soil sciences under the auspices of a new ‘living

soil’ approach (Lavelle and Spain 2001; Gobat, Aragno, and Matthey 2004),

regarded by some as a ‘soil science renaissance’ (Hartemink and McBratney 2008).

Simultaneously, the past decade has seen the rise of a growing narrative of ‘peak

soil’, referring to the connection between expanding cities, and the availability of

agricultural soils to grow food for populations. Peak soil, a play on the ‘peak oil’

notion, refers to the global problems we will soon face if we do not care more for

our soils. It interweaves the topics of the increase of the world’s population, food

security, climate change, heat waves, floods, unsustainable agricultural practices,

and the pressure that urban-sprawl puts on arable land (Cheverry and Gascuel

2009). Peak soil is described as heralding far more threatening ravages than any

other peak (Shiva 2015), it points to a coming convergence of crises. As one

7

journalist argues, ‘we will probably find ourselves dealing with a widespread

hydrocarbons collapse right when we have to face a greatly reduced global capacity

to grow crops and find people enough water to drink’ (Wild 2010). To demonstrate

that contemporary modes of production are overtaxing the ground, the same

figures regularly come to the fore, such as warnings that ‘about 30% of the world's

croplands have become unproductive’ (Ahmed 2013), that in France, 26m² of fertile

soil disappear every second (Denhez 2014), or that there are ‘only 60 years of

farming left if soil degradation continues’ (Arsenault 2014 n.p.). In general, the

conclusion is that we are running out of time, and that urgent action is needed. As

Maria Puig de la Bellacasa sums up, we must invent ways of ‘making time for soil’

(2015, 695), and develop new modes of caring for the soil. Recently, the European

Parliament project for a ‘Soil Framework Directive’ to protect ‘soil resources’ across

the EU – finally withdrawn in May 2014 – and the FAO’s ‘International year of soils’

in 2015, attracted more public attention to soils and the dangers they faced than

they probably had ever received since the dust bowl.1

Yet, this awakening towards soils often concerns agricultural and forest soils. In

the mind of most people, soils are associated with rural culture – in which they are

said to be either highly revered, or shamefully overburdened. From the priapic

satyrs of antique myths to the romantic awe of modern literature, the western arts

brim with plethora of examples of ‘symbolism’ associated to soils, often related to

ideas of agricultural cycles and fertility (Landa and Feller 2010). Most of us tend to

think of soils as that which lies beneath the fields, the horizontal foundation of the

environments we must nurture so as to produce quality food and sustain the

livelihoods of those who grow it – the two pillars of the French notion of Terroir.

Even in the current movement of soil-sensitive literature, urban soils get very little

1 On the EU’s ‘Soil Thematic Strategy’ and ‘Proposal for Soil Framework Directive’, see http://ec.europa.eu/environment/soil/process_en.htm. The proposal was formally withdrawn on 21

May 2014, under the pressure of the UK, Germany, France, the Netherlands and Austria, which

considered the Directive would impede their agricultural sectors. The main goals of the FAO

International Year of Soils were to ‘Educate the public about the crucial role soil plays in food

security, climate change adaptation and mitigation, essential ecosystem services, poverty

alleviation and sustainable development’ and to ‘Support effective policies and actions for the sustainable management and protection of soil resources’ (http://www.fao.org/soils-2015/en/).

8

attention if at all. This disinterest is most noticeable in the soil sciences community

itself, where urban soils are still often regarded as ‘non-soils’.

Figure 5: A map of France's soils and non-soils in rapport GISSOL (2011, 39) [Source: Inra, Base de données Géographique des Sols de France à 1/1 .000.000, 1998]

This map (Figure 5) was published by the French National Institute for

Agronomical research in one of the main reference books on the soils of France

(INRA Orléans 1998). It was recently reproduced in a national scientific report on

the state of soils (Gis Sol 2011). Here, urban soils lie in the same category as glaciers

and lakes: all of them are considered to be ‘non-soils’. They are seen, at best, as a

soil ersatz, the heavily disturbed remnants of a once natural soil. It seems as if to

most soil scientists there was nothing interesting to learn from them. Still today,

perhaps because of the largely agricultural focus that marks the historical

development of the soil sciences, soils are considered to lie in those places we can

appropriate to grow food, hay or timber.

Could it be, then, that urban soils are better considered by defenders of

permaculture2 who are often critical of the mainstream scientific approaches to

2 Permaculture is an alternative approach to growing food that relies on inspiration in the

functioning of natural ecosystems rather than chemicals and mechanisation. It is notable for its

heightened attention to soils and their life (see chapter 5).

9

soils found in Agronomical Institutes? A quick examination of the literature issued

by advocates of the ‘sustainable revolution’ (Birnbaum and Fox 2014) suggests that

they show no more interest towards them than the scientists. For example, for

Elaine Ingham, a well-known proponent of permaculture in the US: ‘Soil shouldn’t

be so boring, but urban landscapes mean dead dirt. It means being bent over a

microscope for long hours looking at … nothing but inert particles. Boring!’

(Ingham 2010, 9).3 From all sides of the debate, urban soils are merely thought of

as off topic, uninteresting, lifeless, or simply boring. On maps representing the

layout of cities and their outskirts, unlike rivers and farmed areas, urban soils are

represented as a neutral, white background. Neutral and absent they are to our

minds too. If they get any attention, it is merely as polluted environments, as a

public health issue (Cheverry and Gascuel 2009). They are then treated as a

problem for confinement and remediation techniques. They are at best an

embarrassment, and we seem to have nothing to learn from them.

An urban soil bestiary

In 2013, I started my thesis with the vague idea of doing an ethnography of research

and development projects linking urban ecology and the soil sciences. I wanted to

continue to explore a thread I had begun to follow in my Master’s thesis at the

University of Liège, which consisted in an examination of how certain agricultural

practices were permeated by insights coming from the ecological sciences, and

vice-versa (Meulemans 2011). I was aware of the general indifference towards urban

soils, and I had been intrigued to discover that a small group of soil scientists were

defending the development of a specifically urban soil science. Alone against all the

others, they seemed to find urban soils interesting and well worth studying in and

for themselves. For over ten years, these scientists had tried to convince the

International Union of Soil Scientists (IUSS) to recognise human activities as a soil

forming factor, and thus to settle on new soil categories for urban and

3 I am thankful to Maria Puig de la Bellacasa, whose talk in Brussels on April 29, 2016 brought this

passage to my attention.

10

anthropogenic soils (Rossiter 2007). The IUSS had finally accepted their claims,

and in 2006, the new soil group of ‘Technosol’ made its appearance in the World

Reference Base for Soil Resources (WRB), undoubtedly the most important

international taxonomic classification system for the soil sciences.

Figure 6: Garbic and Ekranic Technosols

According to the WRB, a ‘Technosol’ is any soil that contains ‘20 percent or more

(by volume, by weighted average) artefacts in the upper 100 cm from the soil

surface or to continuous rock or a cemented or indurated layer, whichever is

shallower’ (Food and Agriculture Organization of the United Nations 2006, 54).

The category also encompasses soils that are covered by an artificial impermeable

layer, or that contain such a layer within its first metre of depth.4 The category has

since been refined, to the point that there are now thirty-two qualifiers for them

4 We should note that an ‘Anthrosols’ category already existed in the WRB since 1998 and referred

to ‘soils that have been modified profoundly through human activities’ (Food and Agriculture

Organization of the United Nations 2006, 71). However, the human activities that this category

covers are the ‘addition of organic materials or household wastes, irrigation and cultivation’ (ibid.), and the descriptive clarifies that ‘influence of humans is normally restricted to the surface horizons’ (ibid.). Anthrosols are thus agricultural soils – such as the plaggen soils of Western Europe, the

Terra preta of the Amazons, or the soils of Saharan oases – and the category was never meant to

cover urban and industrial soils.

11

in the WRB. These form a growing bestiary of urban soils, the diversity of which

makes it a herculean task for the classifiers who take up the task of fleshing the key

out. For instance, a soil scientist digging a pit in a suburban area might discover a

‘Garbic Technosol’, a soil developed from thick layers of waste or garbage. In

another area, they might find themselves looking at an ‘Ekranic Technosol’, the

upper horizon of which consists of ‘technic hard rock’ – that is, a layer of asphalt

or concrete (Figure 6).

Back in 2013, what mostly intrigued me was that this seemed to challenge the

agricultural tendencies of most contemporary discourses on soils. Even in the

branches of pedology which have studied soils in themselves rather than as a food-

growing substrate, humans have usually been considered only as agents that

disturb, interrupt and manipulate natural processes. They have never been seen as

part of the soil system. And whereas some daring scientists of the more

conservative approach may have conceded that there were soils in urban parks and

gardens, to the new urban soil science, soils were to be found everywhere in the

city. For Alan, an urban soil ecologist I worked with a lot during a later stage of

fieldwork, soils aren’t just media in which we grow food or grass and park trees.

Instead, “as soon as you have accumulation, alteration and formation of horizon,

you have a soil”. Colleagues of him had shown that in some respects, these cycles

continued even in soils classified as fully sealed (Wessolek 2008). The processes

that the soil sciences study could be observed more or less anywhere in the city:

on a rooftop, pavement or ruined building.5 And as another urban soil scientist

explained to me, "I don’t just mean to say that there is soil under a road. The road

itself is a soil. There is a layer that cuts, that gives special characteristics to the soil,

but the soil is the whole profile. The road is a surface horizon”. It seemed as if

5 Soil scientists such as Charzynski et al. (2015) study how bacteria, fungi, mosses and lichens

deteriorate buildings. Combined with deposits from atmospheric dust and bird excrements, this

forms good conditions for the growth of pioneering plants, leading to further weathering of

buildings as they grow. They identify this as the formation of ‘Edifisols’, and argue for this to be recognized by the IUSS as a specific qualifier for Technosols. In his best-selling opus The World

Without Us, Alan Weisman argues that it would be a matter of only a few decades for cities to turn

into thick-soiled forests, were the humans that maintain them to disappear (Weisman 2007).

12

suddenly, we could completely change the ways we looked at all kinds of ground

surfaces in our environment and start to see them as soils.6

Furthermore, the few soil scientists who venture into these ‘anthropogenic

environments’ (Lehmann and Stahr 2007) argue that one of the reasons why urban

soils should definitely be granted more attention is that they are already present

everywhere on Earth. Whether we like it or not, since the beginning of the

industrial era Technosols have developed on a massive scale. Alan sometimes asks

the following question of his students at the University of Montpellier: ‘among all

organisms, which one do you think moves soil the most?’ The students, who have

all followed classes in general soil sciences, generally take earthworms or ants to

be the main suspects. But Alan replies: ‘not at all, it is us, humans’. The soil

sciences, Alan continues, cannot continue to ignore the soils that humans make.

To him, as we shall see, this is both a matter or sustainability, and a matter of

developing the soil sciences. Seeing humans as ‘the sixth factor of soil formation’ 7

(Dudal, Nachtergaele, and Purnell 2002) leads some pedologists to say that they

are not sure they are still ‘natural scientists’, to the point at which some argue that

a new discipline of ‘anthropedology’ (Richter and Tugel 2012) should be recognised.

6 A note on translation: in the French language, the word sol encompasses both the English terms

‘ground’ and ‘soil’. The Littré French dictionary defines sol as both the ‘surface upon which

terrestrial bodies rest’ and ‘the upper layer of agricultural land’ (my trans.), whereas the Cambridge English Dictionnary defines soil as ‘The upper layer of earth in which plants grow’, and ground as ‘The solid surface of the earth’, ‘an area of land’, or ‘the floor of a room’. In this thesis, for clarity reasons, I have translated my informant’s use of sol as either ‘soil’ or ‘ground’ depending on the context. I understand that this may introduce a bias in the mind of the reader, so I would enjoin

the reader to remember that whenever a French person speaks of ‘urban soil’ in this thesis, he probably means more than just ‘The upper layer of earth in which plants grow’.

7 Since its inception with Dokuchaev (1879), pedology has recognised five factors of soil formation:

climate, parent material, topography, time and organisms. In what regards organisms, only the role

of plants was dealt with for a long time (Donald L. Johnson and Schaetzl 2015), but tenants of the

‘living soil’ approach now take into account many more kinds of organisms (see chapter 4). Some

of its tenants now argue that ‘in the Anthropocene, pedology is fundamentally challenged to bring humanity entirely within the soil continuum’ (Richter and Tugel 2012, 38–1).

13

Diffracting the ‘Anthropocene’

Around the same time that ‘natural’ sciences such as the soil sciences were diving

into the subject of anthropogenic ecosystems, some areas of anthropology realised

that many non-western human groups had ‘no nature, no culture’ (Strathern 1980),

and began to question their old denomination of sciences of the ‘social and

cultural’ to develop an ‘anthropology beyond anthropos’ (Demeulenaere 2017). To

many, this has been an important shift. As Eduardo Viveiros de Castro has noted,

the dualism between nature and culture was ‘the first article of the discipline’s

constitution’, where it ‘pledged allegiance to the old western metaphysical matrix’

(Viveiros de Castro 2009, 20 my trans.). The rest of the story is now well accepted:

within this ‘matrix’, the social sciences have grown with the idea that human

histories take place against a background of inert nature. In this view, the ‘natural

world’ is external to society, separate from humans (even though it sometimes

intrudes into their plans), and everything worth talking about happens within the

realm of ‘the social’ (Chakrabarty 2009). In the last twenty years, anthropologists,

sociologists and philosophers have started to treat objects, plants, materials, and

the many entities that would classically have been relegated to the realm of ‘nature’

as more than just place-holders for cultural interpretations or meanings. They have

done this in diverse ways, ranging from the rather Kantian ‘anthropology of nature’

of Descola (2005), to the ‘new materialisms’ of Bennett (2010) and Barad (2007) and

to the ‘ontological turn’ of Holbraad, Pedersen and Viveiros de Castro (2014).

Much thinking about the consequences of removing conceptual boundaries

between humans and the rest of the world has recently coalesced into the popular

notion of ‘the Anthropocene’. The notion was originally proposed to define a new

geological epoch, marked by the impact of human activities (Steffen et al. 2011).

According to proponents of the Anthropocene, Anthropos – ‘the Human’ – has

become the primary agent of change through erosion, of changes in carbon and

hydrogen levels in the atmosphere, and in the extinction of species. They generally

claim that we entered this new age at the time of post-war globalization, which led

to a ‘great acceleration’ in several domains, such as the volume and speed of

economic exchanges, the rate of species extinction, the damming of rivers,

14

migration from rural areas to cities, and levels of atmospheric carbon dioxide

(Steffen et al. 2015).

The debate over the Anthropocene has many parallels with the one on urban soils

– even though their respective protagonists largely ignore each other. Just like Alan

tells his students, the geologists who carry the Anthropocene argument point out

that every year, around the earth, humans move ten times more rock and soil than

natural processes of erosion (Wilkinson 2005). This, for many scientists, is an

observation serious enough to question many of the assumptions about ‘nature’

and how the sciences are supposed to know it.

The Anthropocene proposal has since met with even greater success in the

humanities than it had in its original cradle, the geological sciences. In geography,

anthropology, philosophy and STS, many scholars took it as their favourite

expression for the processes from which most current ecological crises emerged

(Palsson et al. 2013; Robin 2013; Latour 2014; Lorimer 2015). Understood as a

merging of historical and geological forces, the Anthropocene has been taken as a

powerful conceptual means of escape from the tendency of the humanities and

social sciences to see active humans acting on an inactive stage of nature. As they

become a geological force, humans, like other entities, are thrown in the turmoil

of a new kind of History that no longer separates between Natural History and

Human History (Chakrabarty 2009). Proponents of the Anthropocene in the

Humanities aim to go beyond anthropomorphism and naturalism by placing

humans, rivers and glaciers on the same geological scale – again, just as many

urban soil scientists do, as we shall see. The Anthropocene event has been

described as a game changer for scientific disciplines and for politics. As scientists

cannot pretend to be the modest witnesses of an independent nature, they cannot

arbitrate and pacify truth claims (Latour 2004b). The consequences of the

Anthropocene have been explored in many fields such as disciplinarities (Bhangu

et al. 2016), the arts (Davis and Turpin 2014), conservation (Lorimer 2015) or

theology (Northcott 2013). For these reasons, Bruno Latour has called the

Anthropocene ‘the most powerful and decisive philosophical, religious,

15

anthropological and, as we shall see, political concept that has ever been crafted as

an alternative to the notions of “Modern” and “modernity"’ (2014, 32 my trans.).

Clearly, the Anthropocene narrative has allowed – and continues to foster – much

thrilling discussion. By gathering so many threads together, it has enlivened

debates about the environment, and brought many scholars from different

disciplines and fields of study from both the ‘natural’ and ‘social’ sciences to talk

together (Swanson, Bubandt, and Tsing 2015). It seems now that the ‘anthropocene

event’ (Bonneuil and Fressoz 2013) is giving rise to a new field of ‘the environmental

humanities’, which promises to extend these advances in a host of fascinating

directions. Not only is it commendable to make visible the current changes in the

rate of destructions; the Anthropocene narrative is also the result of the

recognition that sometimes, events demand that we think differently and that we

reconsider boundaries between fields of scholarship. It continues to provide great

service in that respect.

However, some sceptical voices have argued that it might be best not to ‘swallow’

the whole Anthropocene package too quickly – to use the words of Malm and

Hornborg (2014). One of the accusations is that the Anthropocene trope might be

a bit too epic in the face of the challenges it faces. Indeed, the Anthropocene often

sounds like yet another tale of the progress of humanity – one in which it would

have grown the mighty rank and powers of a telluric force. The problem is, of

course, that ‘humanity’ is far too anonymous a term, and that only a small portion

of humanity can be deemed responsible for what is happening to the earth. This is

why Haraway (2015) half-jokingly suggests to rename the Anthropocene as ‘the

capitalocene’. Furthermore, as Bonneuil and Fressoz (2013) suggest, the use of a

vocabulary of epochs extracted from the geological sciences also risks making it

seem as if the choices and destructions operated in the last couple of centuries

were unintended or inevitable. As an item of this vocabulary, the Anthropocene

buys into the linear historicism of modernism.8 Finally, and perhaps most

8 Whenever I use the adjective ‘modern’ in this thesis, I do not want to refer to some ‘modern mind’ or ‘naturalist ontology’ (Descola 2005). I rather adopt, with caution, Pickering’s definition of modernisation as a trope that proceeds by ‘thematizing a certain stance in the flow of becoming, a particular tactic of being in that flow which resists a recognition of the flow by attempting to step

16

importantly, one might wonder about the consequences of subsuming all changes

in the relations between humans and the earth under one metaphor, situated in

the very particular field of geology. The Anthropocene trope has brought a lot of

attention towards the geological sciences, and many humanities scholars have

sought to draw new insights from it. However, if humans change the topology of

the earth, why shouldn’t we use a hydrological metaphor instead? Or a botanical

one, since the moving around of plants is causing immense changes in the world’s

ecologies? Or perhaps it shouldn’t be situated in science at all? Other metaphors

would give a different feel, a different nuance to how we approach these issues. As

Haraway (2013) put it (building on Strathern), ‘It matters what matters we use to

think other matters with (…) It matters what stories make worlds, what worlds

make stories’ (2013 n.p.). I believe, with her, that we would gain a lot from

multiplying the grounds from which we address the many faces of the ecological

situation that stories such as that of Homécourt have gotten us into, and I will say

a bit more about this in a few pages. 9

Let us accept for now that a safe position is to continue to learn from the

Anthropocene debate, but that the tale of the Anthropocene must be counter-

balanced at the same time. To use an expression from Barad, we should aim to

provide ‘diffractive readings’ (Barad 2007, 200) that allow us to step back from

narratives that are too grand, too global and too encompassing. Barad’s notion of

diffraction comes from her reservations about the idea of ‘reflexivity’ in the social

sciences. Built to encourage the critical reflection on the researcher’s own role in

outside it’ (Pickering and Guzik 2008, 4 their emphasis). I am aware of the risk of essentialization

that comes with any recourse to the category of ‘modernity’. I keep in mind Didier Debaise’s (2015)

understanding of Whitehead’s ‘bifurcation of nature’ as a series of operations by which the world bifurcates into dichotomized domains such as knowledge and world, nature and culture, human

and non-human. Likewise, I insist that in talking about modernization, we should understand it as

residing primarily in a series of sustained achievement – such as, in our case, the material separation

of earth and sky in modern cities, or the separation between the disciplines of engineering and

‘basic’ research in the soil sciences – rather than in a ‘worldview’ from which these operations would

derive.

9 There are many striking resemblances between claims made within debates over the

Anthropocene, and those made within debates over urban soils. In this introduction, I simply keep

to a critique of the flattening effect of the Anthropocene trope. I shall return to it in chapter 1 to

examine the ‘tales of awakening’ that are present in both debates, and in chapter 2 to address the

idea of the anthropisation of the planet as a global, real-world experiment.

17

the constitution of knowledge, the concept of reflexivity is built on the optical

metaphor of reflection and mirroring. In this, Barad argues, ‘reflexivity’ still sets

the endeavour of social studies at the level of renderings which may be more or

less faithful to the ‘real’ situation. It is still founded on representationalism, and

entails a distinction between the knower and the known that continues to hold the

world at a distance. Drawing on Haraway, she prefers the alternative optical

metaphor of ‘diffraction’, which, to her, is marked by patterns of difference rather

than sameness. Diffraction is what happens to a sea wave or a light beam that

passes through a lens or an aperture. It is changed by the encountered obstacle

into patterns of interference. Diffraction doesn’t represent, but aims to be

suggestive and creative – and I shall expand on this in chapters 2 and 7.10

Isabelle Stengers is one among others to have suggested a diffraction of the current

tales of that which is killing the earth.11 In In Catastrophic Times (Stengers 2009),

she builds on James Lovelock’s figure of Gaia, but rather than framing Gaia as a

cybernetic system, as Lovelock had suggested, Stengers frames it as an ‘event’ – or

a set of interconnected ecological events, namely, the announcement that massive

climate and environmental changes are on their way. Naming it an event serves to

attract attention to the fact that there is, or should be, a before and an after Gaia.

Gaia is something that now forces people to think differently. It forces us to accept

that we live on a limited earth, the dynamics of which we are entangled in.

Stengers’s approach is diffractive, in the sense that her revisiting of Gaia refuses to

express itself in an exclusively critical key, but also in the sense that it works

actively to conceive other possibilities, in an experimental sense. To Stengers, the

ties we might develop with Gaia are different from those we might develop with

Nature: they are not indifferent to politics, and humans cannot think of themselves

as supreme engineers of it. Instead, we must learn to compose with it. To name

10 Barad goes further than suggesting that diffraction is only a methodological tool. To her,

diffraction patterns are the fundamental constituents of the world. Hence, diffraction as a method

draws from a commitment to an ontology and an ethics of entanglements and differences that

matter, rather than externality – I shall make recourse to Barad’s notion of diffraction later in the thesis (see chapter 2).

11 Other examples include Tsing’s ‘disturbed beginnings’ (2015) of Haraway’s ‘Chthulucene’ (2015).

18

this Gaia is a step in learning what it means to grant it the power of making a

difference, of making us think and feel. This, to Stengers, is to initiate practices

that resist the ‘barbarity’ of neo-liberalism and the blind bureaucracy which seeks

to address Gaia as a ‘matter of fact’ – that is, as a question about which the only

legitimate opinion is that of ‘experts’.12

Stengers’s framing of Gaia as ‘she who intrudes’ is an apt expression for the way in

which I want to address urban soils. In Homécourt, the industrial soil intruded in

the course of the authorities’ project of ‘redevelopment’. Stories of intrusion apply

– each time in a different way – for all the players I shall introduce in this thesis.

The word I have in mind to characterise this quality is the French word épreuve.

This word is used by sociologists or philosophers inspired by pragmatic philosophy

in France, and can be translated as a trial (as in Serres and Latour 1995), a test (as

in Stengers 2009), an ordeal, a challenge, or even a pull. The first advantage of these

words is that they help us avoid managerial formulations such as ‘the problem’ or

‘the opportunities’ of urban soils (see section on ‘Anthropology with the soil

sciences’). In this thesis, I shall refer to the ‘trial’, the ‘pull’ or the ‘testing’ of urban

soils, depending on the nuance I want to convey. In chapter 2, I use the word

‘testing’ to refer to the soil construction apparatus built by Homécourt soil

scientists to see what an urban soil pedogenesis might be like. ‘Testing’ has the

double meaning of something one tests, but in which one is also put to the test.

For many people involved in my fieldwork, soil construction is indeed a means

both to test soils and to test themselves and how they relate to soils. In many ways,

to describe such practices as tests or as trials is also in line with the etymology of

the word ‘experiment’ (experiri is Latin for ‘to try, to test’). In chapter 3, I show how

in the digging of soil pits, soil scientists follow the ‘pull’ of the soil they dig, and

describe it as their ‘learning to be affected’ by soils. As we bring in the topic of

affect in chapter 3, and that of imagination in chapter 7, I will gradually suggest

that these various themes can be gathered within the Witeheadian concept of

12 As Schaffer (1992) reminds us, the problem isn’t so much about expertise in itself, but rather of deciding who the experts are. To Stengers, difficulties arise when collectives – be they scientific or

otherwise – appropriate the status of experts for themselves based on universal categories such as

‘facts’ or ‘the scientific method’, even though she doesn’t reject these categories in themselves.

19

‘lures for feelings’ (Debaise 2015), from which the title of this thesis draws its

inspiration. Throughout the thesis, I follow how urban soils affect the practices of

those who accept the challenge they bring to them, and who notably respond

through experimental practices of soil construction. Urban soils interject into

normal habits, but they are far from necessarily arresting. In a more general way,

as I shall explain later, I have myself attempted to make the best of the way I was

put to the test by urban soils. The attitude I have followed throughout my inquiry

was always to leave open the question of how they might be a challenge. This

meant not to try to explicate what they are, but rather to inquire with those who

witness them through their practice and can teach us something about them. I take

as a standpoint that we must start from these witnesses’ practices to work around

the open-ended question of how we might study urban soils, and what might be

‘right questions’ to ask them (Despret 2002). As I shall now explain, for me, this

position itself emerged on fieldwork.

First approach to fieldwork: a study of soil scientists’ knowledge practices

Highly intrigued by the riddles that appeared to show in the surface of the

venerable science of soils when its practitioners agreed to recognise urban soils as

soils, I started to do fieldwork at the Institute of Ecology and Environmental

Sciences (IEES) in Paris, towards the end of 2013. I set out to work with soil

scientists who were working specifically on urban soils (Technosols), and had

developed experimental ways of reframing their approach to soils. Preliminary

contacts with them had suggested that the recognition of urban soils as a valid

research topic, the influence of non-linear ecological theories in the soil sciences,

and the development of new experimental approaches within the same field,

seemed linked. I wanted to find out more about these links. I started off by mainly

following Dr. Manu Blouin – an ecologist and proponent of Ecological Engineering

in France, Maha Deeb, one of his PhD students, and the team that worked with

them as they were developing a ‘constructed soil’ on a landsite in Villeneuve-sous-

20

Dammartin, in Paris’s periphery (see chapter 1). A few months later, I continued

fieldwork at the Laboratoire Sols et Environnement (LSE) in Nancy with Prof.

Christophe Schwarz, Dr. Geoffroy Séré, and Dr. Apolline Auclerc. This unit is the

one that has undertaken most research in France on Technosols and constructed

soils. They also host the GISFI, which I introduced at the beginning, and manage

the experimental station of Homécourt. I made several field trips to Homécourt,

whenever it was possible for me to join a research team there. The IEES, LSE and

Homécourt proved good places to learn about the new soil sciences.

My fieldwork among soil scientists in Paris and Nancy started as a rather classical

ethnography of laboratories of the kind STS scholarship exemplifies (Lynch 1988;

Goodwin 1994; Latour 1987). Over the six first months of fieldwork, I

complemented my ethnography with about 20 interviews with researchers, PhD

students, civil servants, enterprises and association members. In these interviews,

I asked people about their work, how they had come to be interested in urban soils,

what they thought what they did changed to ongoing debates in the domains or in

regards to the soil and environmental sciences. I foraged with great appetite in the

soil sciences literature, in debates and reports related to urban soils, and in the

many online and newspaper publications that address the contemporary

challenges of soils and cities. I also attended several soil science conferences,

meetings and classes. On the ethnographic side of things, I followed scientists in

the lab and in the field. I was particularly attentive to the movements of scientists,

to their daily practices of measurement, watering, calibration of devices and

inscription, and to the material settings in which they performed their activities of

knowledge making. I filled several notebooks with my descriptions of these

activities. After a few months, I took the occasion of having to write a report to my

supervisors to read through all the notes I had taken so far. I had a lot to say about

how knowledge grows in the interaction between methods, incorporated routines,

scientific metaphors, tools and equipment. I could finely describe laboratory

practices, and the ways in which scientists oscillate between the phenomenal world

and scientific categories. I could explain how scientists divided tasks between

themselves and instruments and how machines come to embody aspects of

21

experimenters’ skilled practices. All of this was in the fashion of classical STS

studies of scientific practices, as found in Latour’s Science in Action (1987), or

ethnomethodological work on professional vision and inscriptive practices

(Goodwin 1994). However, I soon realised that I had very little to say about soils

themselves.

Indeed, the more a relation of friendship developed with some of the scientists I

was working with in the field, the more I started to feel uncomfortable about the

way I had approached their work in my ethnography. All of them were passionate

about soils and the new possibilities that urban soil research was opening up.

During these first months, I had learned many things about this ‘most

unparsimonious of all Earth’s natural entities’ (David L. Johnson, Domier, and

Johnson 2005), and ‘most complex of Earth’s biomaterials’ (Young and Crawford

2004). I had discovered how some things become defined as soil and others not. I

had learned to see soils among many things I had always looked at as mere surfaces

for walking. Thanks to the everyday discussions with ecologists, I had come to see

soil less as a substrate, and more as an impulsive, vivacious compound thriving

with the life of microorganisms and currents that traverse it. I had started to

question dichotomies such as that between above and below ground, artificial and

natural, knowledge and technology, city and countryside. All of these made me feel

increasingly that the power of such a material could not be neglected in the way it

had been in modern culture. Yet there seemed to be a mismatch between what I

learned with people in the field, and my ethnography. In my notes, it seemed as if

the research topics of the people I was working with could almost have been

interchangeable. Soils, the very object of these scientists’ scrutiny, did not seem to

make a difference in my account. I felt that had they worked on another topic,

approached in a similar lab-experimental way, I would have ended up with a very

similar account. My focus had been solely on human knowledge practices, but soils

had remained completely out of the scene. This is when I started to seek ways in

which I could take the passion of Manu, Maha and the rest more seriously. After

all, it was soils they were fascinated with. I decided to change my approach to the

field, and to follow the thread of soils and of their construction more specifically.

22

Eager to discuss these doubts about my approach to the field, and wanting to make

more space for soils, I presented my ideas in two different research seminars in

May-June 2014. In one anthropology department, a professor in the audience who

was quite dubious about my approach asked me why I didn’t do a thesis in

pedology rather than in anthropology, since soils were my focus rather than the

humans who live upon them. At the time, my reply was vague, but I would now say

that even though my focus became urban soils, I do not seek to adopt the

definitions and practices that pedologists have about them uncritically. To the

contrary, I wish to open up the question of what soils are to address questions of

entanglement, life of materials, joint-becomings and individuation. To me, this has

implied moving away from an exhaustive study of lab practices, and instead to

follow several of the multiple threads that led to urban soils in a more explorative

and speculative way. To the sceptical professor, my research question may have

felt like a strange one for a student in the social sciences: what are urban soils, how

can they be a research topic for anthropology, how can they be studied? I started

to wonder more about what an anthropology which does not place humans directly

at the centre might be like, leading me towards discussions about anthropology

beyond the human, and the approaches of Stengers, Despret and Ingold. I started

approaching non-scientists working with soils, and, while continuing fieldwork

with the scientists, I began working with urban gardeners, geotechnicians, road

constructors, and several artists, each in their own way. All involved forms of soil

construction. What they make with soils, the very concrete play on and with

materials in various ways and with various aims, became the focus of my research.

Anthropology with the soil sciences

Before I return to the topic of making soil, I should perhaps clarify the relation I

have developed with the soil sciences, which isn’t just a descriptive one. In line

with Barad’s ‘diffractive methodology’, I have attempted to take soil scientists, their

practices and their propositions seriously, to follow them where they might open

23

up worlds and perspectives.13 The idea isn’t to put some pedology in anthropology,

nor is it to bring some anthropological sensitivity to the soil sciences but rather to

do anthropology with pedology, to become a pedologist in anthropology. In this,

my goals differ from those of the soil sciences – however speculative they might

be. Those remain sciences, and will always attempt, in the last instance, to stabilize

the world – despite of their interest in regards to things that they themselves

explain cannot be stabilized (see chapter 2).14 Doing anthropology with the soil

sciences also requires to pay attention to where certain propositions coming from

the soil sciences can foster closure rather than further speculation. Indeed, it

appeared during fieldwork that current urban soil science is following different

paths, and that these are in tension. On the one hand, scientists take up the

challenge of urban soils, and accept their presence as ‘intruders’. Rather than trying

to characterise them in a way that would be ‘simply accurate’, they follow where

these soils might lead them and their science in an open fashion that fosters

thinking and speculation. As I explain in chapter 2, the LSE and GISFI were

important research units, and were following research goals that concerned the

very foundations of the soil sciences – such as re-opening the classical definition

of a soil, and questioning the use of still ‘soil categories’. In this respect, these

scientists were accepting the trial of urban soils, engaging in a process of learning

what it might mean for them to do research in a world where urban soils have to

be taken into account. But on the other hand, the same scientists also tended to

appeal to a growing narrative of control, utilitarianism and conquest that seemed

far more arresting. This was quite clear when they appealed to a narrative of

13 Barad’s critique of ‘reflexivity’ closely echoes arguments formulated by tenants of the ‘ontological turn’ in anthropology. Viveiros de Castro, for instance, condemned that ‘Anthropology seems to believe that its paramount task is to explain how it comes to know (to represent) its object – an

object also defined as knowledge (or representation). Is it possible to know it? Is it decent to know

it? Do we really know it, or do we only see ourselves in a mirror?’ (Viveiros de Castro 1998, cited in

Henare, Holbraad, and Wastell 2007, 8). This observation foregrounds the ontological turn’s impetus to ‘take seriously’ the practices and ideas of people on fieldwork – we shall come back to it

in a few pages.

14 As Latour mentioned about another kind of science interested in far from equilibrium dynamics

– the physics of Prigogyne that Stengers build her ‘new alliance’ upon : ‘No matter how time-

dependent a science of phenomena far from equilibrium can be, it remains a science, that is, an

attempt at stabilizing the world’ (Latour 1997, X).

24

‘reclaiming’. Consider for instance the way in which the GISFI approaches

industrial Technosols in one of its leaflets:

Soil is a non-renewable resource. In the middle-ages, if there was a shortage of surface area, the solution meant drying out swamps or cutting down forests. But reclaiming is now taking up a different meaning. For the GISFI, reclaiming means tearing soils away from their industrial past, and giving a new fertility to sites that are uncultivable, but rich in opportunities and resources. To reclaim is to start the conquest of spaces that have been degraded by human activities. It draws a new frontier, with its pioneers and its unexplored lands, at the crossroads of scientific excellence and technology, of real-scale observation and responsible innovation (GISFI 2010, 2 my trans.)

This excerpt, through its narrative of resources to be reclaimed, its inscription in a

history of colonisation of the land, and the figures of pioneers and ‘scientific

excellence’ to which it refers, seems to set soil construction right into the frame of

the Modernist tale of development and progress. Urban soil scientists and

ecological engineers often formulate their hopes in ways that parallel those of

advocates of a ‘good Anthropocene’. In 2015, an ‘Ecomodernist manifesto’ was

published by the Breakthrough Institute. It was soon to be either greatly celebrated

or criticised. It exhorted scientists and engineers to ‘make more’ of the

opportunities of the Anthropocene, and to put ‘humankind’s extraordinary powers

in the service of creating a good Anthropocene’ (Asafu-Adjaye et al. 2015, 7). In this

manifesto, a group of eighteen influential scientists and personalities argued that

environmental challenges should be addressed by developing more and better

technologies – such as the mitigation of climate change through geoengineering,

or the intensification of agriculture through GMO – in order to accommodate the

protection of nature, economic growth and human progress. For scholars such as

Bruno Latour (2015) or Clive Hamilton (2015), the Ecomodernist Manifesto’s

arguments are perfect examples of what must be resisted in the Anthropocene

proposal. To Latour, the idea that technological progress will save us and the

planet:

sounds much like the news that an electronic cigarette is going to save a chain smoker from addiction. A great technical fix which

25

will allow the addicted to behave just as before, except now he or she will go on with the benefit of high tech product and the happy support of his or her physician, mother and significant other. In other words, “ecomodernism” seems to me another version of “having one’s cake and eating it too” (Latour 2015, 2)

One idea that often comes through in the discourse of urban soil scientists is that

of taking advantage of, and enhancing, ‘ecosystem services’. The expression was

introduced by neo-Malthusian economists towards the end of the 1970s (Westman

1977; Ehrlich and Ehrlich 1981), and suggests that ecosystems can be managed so

as to provide ‘services’ that would otherwise require the building and maintenance

of expensive infrastructures. Three scientists – two of whom I have met on

fieldwork – recently published a paper in which they review the ‘services’ that

urban soils can provide. Those encompass runoff and flood control, air

purification, carbon sequestration, and food production (Morel, Chenu, and

Lorenz 2015). The scientists note that ‘Urban soils face the paradox of being of

highest interest regarding property and building issues, and being almost totally

ignored with regard to consideration of their functions and roles for the

management of urban ecosystems’ (2015: 1660), and set out to awaken the interest

of their readers towards them. In order to do this, they propose their own

classification of urban soils – they use the acronym SUITMA – and suggest a scale

on which they may ‘score’ in regards to various ‘services’. During fieldwork, and

especially during meetings or conferences with local authorities, urban soil

scientists often referred to how their constructed soils were an attempt at

contributing to the improvement of standards of living in cities. Such hopes for the

future of soil construction sit squarely within the ambitions of ecomodernism,

which assumes that ‘modern technologies, by using natural ecosystem flows and

services more efficiently, offer a real chance of reducing the totality of human

impacts on the biosphere. To embrace these technologies is to find paths to a good

Anthropocene’ (Asafu-Adjaye et al. 2015, 16). The ecosystem services narrative isn’t

only anthropocentric, it also relies on the monetarization of the environment,

framing our ‘relation’ with the environment this time as a problem for economics.

It seems that ‘ecosystem’ is only an adjective to ‘services’, and the extent to which

the first might be worthy of interest depends on its ability to deliver the second

26

(Gomez-Baggethun and Ruiz-Perez 2011; Robertson 2012). The scientists I worked

with conceded on several occasions that the approach had little scientific value,

and that it was mainly a way to ‘better communicate’, ‘better inform policy’ and

‘stakeholder decisions’. This relates to the idea that politics is about making wise

decisions. However, for Latour (2004c), this is a highly problematic view of politics,

which is not a problem-solving activity, even less a matter of attributing scores

based on scientific evidence - matters of fact – but rather about the construction

of ‘matters of concern’. The idea of ‘communicating’ about the environment in this

way also relies on the assumption that knowledge can be ‘transferred’ between

science and society in the form of bounded categories and in a language of ‘services’

that largely rests on the premises of commercial commodity exchange.

For the anthropologist, one possible position in regard to this would be to adopt

the standpoint of some STS scholars who claim that they strive to remain ‘agnostic’

about ‘the world’, and that their task is only to ‘describe’ the emergence of truth

claims. However, this would prevent us from engaging with what scientists say, as

we would simply register how and by what means they say it. As many STS scholars

have argued, by taking care not to speak for anything else than our translations of

the world – and not about the world itself – such approaches also reinstate a

distinction between primary properties (nature) and secondary qualities (culture)

(Haraway 1997; Latour 1999; Ingold 2000; Barad 2007). As Latour (1996) has himself

recognised about some of his earlier work, this can also be found in more

sophisticated forms of constructionism such as those based on pragmatics, or

ethnomethodology, which focus on how corporeal and perceptive practices are

constitutive of the making of knowledge. In this, ethnographers are only interested

in the scientists, while scientists’ object of study remains passive in the account as

it ‘circulates’ inside the networks of science. 15

15 The over-emphasis on ‘knowledge’ in pragmatist and ethnomethodological accounts of science has also been noted by Pickering, to whom pragmatism ‘displaces many of the standard philosophical problematics in valuable ways, but it remains representationalist, epistemological,

largely centered on knowledge (…) It is as if knowledge remains the luminous sun around which these little planets called “practice” and “performance” revolve’ (Pickering 2010, 380). Hence, as

with my first steps on fieldwork, these accounts often leave us not knowing much about the stuff

of the world.

27

Another possible reaction that would more readily engage with the proposition at

hand would be to adopt a critical standpoint, in other words, to demonstrate that

the knowledge and vocabulary of these scientists are situated within a field of

power relations in which, with state and corporate interests, they occupy a

dominant position. The critique would consist in ‘unveiling’ (Bourdieu 1984) this

position, and ‘debunking’ the justifications that make it appear to be something

else, such as disinterested knowledge, economic or ecological necessity, or

progress. However, by adopting such a standpoint, we would also risk blinding

ourselves to the impact that urban soil science might have on other practices.

Scholarship that attempts to critically ‘unveil’ the actor’s claims tends to operate

as an all-encompassing machine (Massumi 2002), applied a priori to every kind of

endeavour to swiftly replace it into a structural, explicative ‘context’ and label it

with a specific position and identity with little attempt to attend to what the

protagonists actually do or want to say. We distance ourselves from it as a whole.16

In his article ‘Why has critique run out of steam’ (2004c), Bruno Latour argues that

the critique of science cannot do much more than debunk truth claims, and is unfit

actually to say anything about the world. Yet, as Schneider puts it, after we’ve said

that all knowledge claims are relative and contingent, what more do we want to

say? (J. Schneider 2002). For Latour, critique is only able to substract from the

world, to dismiss what shouldn’t be taken as a guide. It stops short of helping us

imagine alternative stories and, in the words of Erin Manning, risks to ‘stifle the

very opening through which fragile new modes of existence can come to

expression’ (Manning 2016, 13). Without falling back into the excessive confidence

that scientists sometimes show, we can instead learn to take science and the world

seriously again. We may then endeavour to help describe ‘matters of concern’ and

adopt a position of care towards them – which may involve unsettling them –

rather than one of debunking. For Latour, we should aim to ‘transform the critical

16 Caroline Gatt (2010; 2011) makes a similar point in her work on transnational environmental

activism. She shows that the recourse to large over-arching critical theories has hindered both

activists’ confidence in anthropologists, and anthropologists’ self-confidence in the possibility of

being useful in regards to the political engagement of their informants. Gatt argues in favour of a

processual form of critical thinking based on ‘serial closure’ (2010), which can be more responsive

to particular situations, and more careful about its effects in the world.

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urge in the ethos of someone who adds reality to matters of fact and not substract

reality’ (Latour 2004c, 232).17 This relates to the impetus I introduced before: the

urge to build methodologies that are diffractive rather than reflexive. The point of

these approaches would be:

to make a difference in the world, to cast our lot for some ways of life and not others. To do that, one must be in the action, be finite and dirty, not transcendent and clean. Knowledge-making technologies, including crafting subject positions and ways of inhabiting such positions, must be made relentlessly visible and open to critical intervention’. (Haraway 1997)

As I explain in chapter 1, the discourse on ecosystem services is probably the one

that will weigh most in how we relate to urban soils in the near future – not least

because it is favoured by administrators, who happen to place growing importance

on the orientation of academic research. Whether with sadness, cynicism, or

genuine enthusiasm, the scientists who endorse it have understood it well:

environmental action, and the environmental sciences themselves, are more and

more tied to modes of knowledge that allow easy transposition to a managerial

vocabulary (Theys and Kalaora 1992). However, the ecosystem services trope falls

far short of encompassing the rich ways of knowing that these scientists develop

in their work. In the first and second chapters of this thesis, I show how the

practices of urban soil scientists even contradict the load carried by the notion

ecosystem services. Indeed, much of their practice is speculative, open ended, and

offers a much more interesting possible becoming to urban soils than that

promised, as probable, by the ecomodernism of ‘services’. This is why, in order to

keep open-endedness and care at the centre of attention, I suggest that we should

17 To Latour, one of the best examples of the transition from matters of facts to matters of concern

is the explosion of spaceship Columbia in 2003: ‘What else would you call this sudden transformation of a completely mastered, perfectly understood, quite forgotten by the media,

taken-for-granted, matter-of-factual projectile into a sudden shower of debris falling on the United

States, which thousands of people tried to salvage in the mud and rain and collect in a huge hall to

serve as so many clues in a judicial scientific investigation? Here, suddenly, in a stroke, an object

had become a thing, a matter of fact was considered as a matter of great concern’ (Latour 2004c,

234–35). This example of how something that was considered perfectly mastered and thereby

uninteresting suddenly becomes a much more complicated problem, and gives rise to a host of

interested and interesting practices is particularly evocative when thinking about the case of urban

soil, as we shall see in chapter 1.

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maintain a distance from some of the mainstream ways in which the epistemology

of ‘research by making’ is currently framed (most of chapter 2 is dedicated to this

question).

However, as I have mentioned, practices of soil construction are still far from being

stabilised, as several lines intertwine in them. For Deleuze and Guattari, every kind

of experimentation comes with its dangers, and contains the possibilities of a bad

becoming. In ‘The war machine’, they ally themselves with what they call ‘Nomad

thought’, because of the way it allows one to take a distance from the idea of the

universal subject or method. Nomad thought allows them to ground part of their

conceptual development because its starting point is ‘A tribe in the desert instead

of a universal subject within the horizon of all-encompassing Being’ (Deleuze and

Guattari 1980, 379). However, they immediately warn us that much care is needed,

for this starting point can also lead to racism, sectarianism, or mere folklore.

Hence, ‘We immediately see the dangers, the profound ambiguities accompanying

this enterprise, as if each effort and each creation faced a possible infamy’ (379).

Analogously, activities that seem to have versed into closure can sometimes also

be reclaimed. In their plateau on the ‘body without organs’, Deleuze and Guattari

refer to the use of drugs, and ask ‘There is a fascist use of drugs, or a suicidal use,

but is there also a possible use that would be in conformity with the plane of

consistency?’ (Deleuze and Guattari 1980, 165). The fascist or suicidal use is to them

a ‘cancerous double’ of drug using practices, which can otherwise be ‘generative’ of

other ways of thinking and being. To them, such topics can also be addressed (or

‘agenced’) in ways that make it possible to resist their closing or destructive

tendencies, and to prevent their generative forces from remaining ‘marginalized,

reduced to means of bordering, while on the "other plane" the emptied or

cancerous doubles will triumph’ (166). Identifying and intensifying the cracks that

make a more interesting story is to recognise, with Haraway, that ways of naming

and articulating contemporary changes have implications in terms of the social

and environmental ecologies that might be called for – again, this is true for the

Anthropocene, but also for urban soils. We can take the soil sciences seriously by

learning to see more in the world by allying with some of its venture. In chapter 4,

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I shall notably develop the concept of pedogenesis, a founding idea in the soil

sciences, and propose a way it can be extended to serve in an anthropology of life

with soils. In chapter 7, I introduce an experiment that involved artists and

scientists, in which we aimed to intensify, through performance and the trope of

fiction, propositions carried in past and present scientific practices. In these

chapters, I sometimes critique scientific propositions on the grounds of whether

or not they make urban soils more interesting, but never on the grounds of

debunking some truth claims that they generally do not even make. As Whitehead

argued, ‘in the real world it is more important that a proposition be interesting

than it be true. The importance of truth is, that it adds to interest’ (Whitehead

1929, 259). All the chapters here follow this idea, and attempt to put into words

some of the possibilities and necessities offered by the different practices

addressed – be they situated in the realm of the soil sciences, earth working and

architecture, or gardening – in order to address the theme of living with urban

soils. The last chapter, however, experiments with it in slightly different ways. In

it, I describe an experimental residence bringing together scientists – including

myself and people from my fieldwork – and artists, in which we explored other

ways of living with urban soils. Following Stengers, I introduce the methodologies

and installations that we have developed as ways of ‘resisting the probable’ in

favour of an ‘intensification of a possible’.

Second phase of fieldwork: following soils in the making

Now that I have clarified where I situate myself in regard to the soil sciences, let us

return to the progression of my fieldwork. Halfway through fieldwork, I tried to

take up the challenge of urban soils myself. I decided to follow ‘urban soils’ and not

just ‘people who work on soil’. Of course, I never stopped following people too. But

instead of being primarily interested in the abstract question of ‘how knowledge

grows’, I became interested in how people, soils and knowledge grow together, and

how this could diffract the accepted view of reclaiming urban soils. As I have

already mentioned, in this second phase of fieldwork, it often felt as if the fieldwork

31

equation had changed: I wasn’t making a study of knowledge, or of the soil

sciences. I was rather learning from soils, along with scientists, geotechnicians,

gardeners and artists.18 The ‘second phase’ of my fieldwork took place between June

and December 2014, after which I left Paris to start working on my field notes at

the University of Liège in Belgium. From Liège, I continued to make regular field

trips and interviews until I returned to the University of Aberdeen for writing up

in October 2015. I then made six trips to France between September 2015 and June

2016 to participate in an art and anthropology experiment which I consider to be

part of this second phase of fieldwork, and that I describe toward the end of the

thesis (see chapter 7).

Following soil construction as a line of inquiry departs from the way ethnographic

fieldwork is classically conceived. Of course, we have moved on since the days

when ethnography was practised within the neat boundaries of a village or a family.

According to contemporary approaches to fieldwork and its boundaries – notably

those defended by Marcus (1995) and advocates of multi-sited ethnography in the

1990s – the boundaries of the field cannot be known a priori, and probing where

these boundaries lie is part of the inquiry. Latour develops similar views on the

boundaries of fieldwork in Aramis (1992): since every study has to limit its scope,

we should keep it within the boundaries that the informants propose (rather than

deciding for them, as an analyst, what is the ‘wider social context’ of their action).

We should let the actors add whatever they choose to the ‘framework’, let them

18 This, in fact, is at the core of the approach developed within the Knowing from the Inside (KFI)

project, in which I have had the chance to participate at the University of Aberdeen. KFI is an

anthropological project that gathers anthropologists, artists, architects and designers, with the goal

of developing scholarship that proceeds by studying with things and people rather than by

elaborating studies of them. The aim is to reverse the tendency, in some strands of anthropology,

of viewing the world as a reserve of data that can be extracted from it, through ethnography, in

order to reorganise and interpret them in a later theory building stage (Ingold 2014). In KFI, we

have sought to practice anthropology as a craft, to grow knowledge from our practical engagement

with things and people, and to join with them in their speculation of what life is or might be like.

For Tim Ingold, the ‘principal investigator’ of KFI, anthropologists willing to heal the rupture between theory and the world can take inspiration from the ways of working of artists and makers.

For them, Ingold argues, creativity is constantly caught between the leading forward of imagination

and the friction of material engagement. In the form of inquiry that he proposes, the two go

together: to research is to find an opening and to push it towards wherever it leads. It is what I

allude to when I mention ‘following urban soils’, and I shall further develop the topic of imagination in chapter 7, the last one of the thesis.

32

take it as far as they care to go. Even though I was guided by this idea in the first

phase of fieldwork, I slightly detached myself from it in the second half. Instead of

letting ‘the actors’ delimit the ‘boundaries’ of fieldwork for me, I picked the line of

soils, and started to follow it across sites, leading me to meet people who had no

effective connection with one another.

The idea of ‘following a line’ rather than reproducing a system or ‘network’ comes

from Deleuze and Guattari’s distinction between ‘reproductive’ (or ‘royal’) and

‘following’ (or ‘itinerant’) sciences. Whereas the ‘reproductive’ sciences constantly

‘reterritorialize things around a point of view, a domain, or an ensemble of

constant relations’ (1980, 461 my trans.), in the following sciences ‘it is the process

of deterritorialisation that constitutes and extends the territory itself’ (ibid.).

Deleuze and Guattari insist that the following sciences are simply different from

the reproductive ones, not better. To them, ‘One must follow when one is

interested in the “singularities” of a matter, or rather of a material, and not in the

discovery of a form’ (ibid.). Following soils meant learning more about soils, and

about our entanglements with them. It meant proceeding like soil scientists do

when they dig soil pits (see chapter 3): to know more, one must follow the vein,

take it as a guide along a way of knowing (Ingold 2013b). I wanted to make my

research more fluid, malleable and unsettled – like I had found urban soils to be –

yet, this still meant holding to a vein I already had a grasp of. This implied

continuing to learn in a diffractive way from what scientists had taught me during

the first phase of fieldwork. In order to do this, I decided to attend to multiple ways

in which urban soils could be understood and dealt with, and to make my fieldwork

multi-sited. I started to meet many different people: sewer maintenance workers,

archaeologists, park gardeners, soil radar operators, green roof builders (for lack of

space and sufficient information, only some of them will be introduced in this

dissertation). I wanted to attend to different practices of relating to and performing

soil in order to better understand the force, hopes, and dangers of urban soils and

soil construction. Many of these meetings were exploratory, and only a few gave

rise to important new fieldwork threads. Among these, in 2014, I was particularly

lucky to discover the work of Léo and Henri, two urban gardeners who have taken

33

the idea of constructing soils in town very seriously. I ended up spending countless

half-days with Léo and Henri, either in their ‘Petite Ceinture’ garden, or in other

ones (see chapter 5). I was also lucky to have the chance to do a week of fieldwork

with geotechnicians. Even though the time for this was rather short, I found the

insights I gained there important (see chapter 6).

Soils in the making

The red thread that I have followed across these different sites is that in each,

people are concerned with making soils. I had discovered how, for the scientists

who studied urban soils, construction and the ecological engineering of soils were

crucial to their art of inquiry. As I will explain in detail in chapter 2 and in chapter

4, urban soil scientists are passionately interested in pedogenesis – the growth or

making of soils – which outlines the very specific sense in which soil scientists

speak about the ‘life’ of soils. If the study of urban soils contributes to a renewal of

what is understood as a soil, it also renews what is understood by pedogenesis, as

humans are now seen as participants in the soil’s processes of growth. Soil

scientists have drawn an important conclusion from this: since humans participate

in the making of soils, why shouldn’t scientists attempt to make soils too in order

to better understand urban soil pedogenesis? With urban soils, ‘soil construction’

has become an important aspect of the soil sciences.

Making is also a powerful concept for Anthropology. It implies more than just

building a representation of the world, and it can be taken in a very material sense.

The point, as Bruno Latour explains (1987), is to be constructivist without referring

to ‘social construction’, which would imply that different social views apply to one

soil that in itself is always the same19. I am here following a thread of ideas

19 The idea that lies at the core of constructivism is to look at how things come to be, rather than

taking them as givens. However, in the 1990’s, constructivists overlooked the study of how the material world comes into being, and concentrated on epistemologies, and cultural and social ways

of ‘knowing the world’. In the 2000’s came a resurgence of interest for material things in the wake of ANT, Feminist Studies, and the STS. This resulted in the ‘neo materialist’ (Coole and Frost 2010;

Dolphijn and Tuin 2012) approaches protracted on making visible the form-generating processes

immanent in a world where no fixed boundary between the ‘material’ and the ‘social’ can be drawn.

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developed by some of my colleagues in the Knowing from the Inside project in

Aberdeen, who take interest in how, in making, thinking is not detachable from an

ongoing engagement with building materials. For example, in her dissertation on

builders of passive solar houses called Earthship in New Mexico and Scotland,

Rachel Harkness (2009) shows how ‘Earthshippers’ think in building, and how the

Earthship houses they build can be seen as creative explorations of their craft in

the world. Similarly, Caroline Gatt (2011; n.d.) develops the concept of ‘thinking

work’ to describe how, in making and tinkering policies and organizational forms,

environmental activists attend to the world (and not just to the particular policy

at hand). To Gatt, such thinking work is ‘where the interdependence of tangible

current realities and intangible imagination is most apparent’ (Gatt, n.d., n.p.).

Hence, ‘making’ directly addresses what it means to act in the world, to participate

in a world that is itself taken up in multiple processes of making (Ingold, 2013).

This also relates to a pragmatist ontology that I will refer to at several points

throughout the thesis, and in which ‘what really exists is not things made but

things in the making. Once made, they are dead’ (James 1958, 263). In this, knowing

isn’t to stand ‘in front’ of things, but to situate oneself in the making of things. As

Barad argues, ‘knowing is part of the world making itself intelligible to another

part. Practices of knowing and being are not isolable; they are mutually implicated.

We don’t obtain knowledge by standing outside the world; we know because we

are of the world. We are part of the world in its differential becoming’ (Barad 2007,

185). We shall share our path here with people who challenge the distinction

between making and theory, explanation and performance. For all of them, to

make is to engage in a process of soil making that overflows their practice. To

perceive and understand something, they have to be affected by engaging as

makers.

Each chapter in this thesis illustrates a different way in which the becomings of

both humans and urban soils entangle and participate in the ‘making’ of each-

other. In some cases, these entanglements are rather stable, to the point where

they might seem, from the outside, to be ‘black boxes’ in which identities seem

perfectly stable and natural – see the geotechnicians of chapter 6. In others,

35

different stories co-habit and nothing is decided yet – such as with the soil

scientists and ecological engineers I take as my starting point.

Overview of chapters

The thesis is separated into two parts. The first part (chapters 1-4) explores mainly

the world of urban soil scientists, whereas the second part (chapters 5-7) brings us

into gardening, geotechnical and then imaginative modes of soil construction. This

separation is by no means an attempt to oppose a ‘scientific’ view of soils to a

‘poetic’ or ‘sensible’ one. Scientists were simply the starting point of my research,

and as we shall see, their relation to urban soil is not opposite to that of other

actors. On the other hand, I thought it best to first resituate the production of

scientific knowledge over soils before I could turn to a more plural account.

The first chapter starts with a rather general question: how come that urban soils,

like other anthropogenic objects, fell into a ‘black hole of conceptualisation’ (Robin

et al., 2014) that make them seem ‘non-soils’ or ‘boring soils’? It reviews some

historical studies that address the gradual disciplinary split between the natural

sciences and the human sciences, and argues that urban soils always escaped being

categorised. I review the history of how the hard surfacing of urban soils initiated

a radical, large-scale separation between soils and the climate in the 19th century. I

describe it as a process of ‘blackboxing’ (Latour 1999) in which soils bcame

displaced to the background as resource and rubbish tip. From an organic element,

a matter of wonder to many, they became a mineral one, participating in the

performance of a dry ‘abiotic’ city, and the only question asked of them was how

to better conceal and control them. Noting that the lack of wonder and interest in

urban soils is historically situated and was not a necessary move also opens the

question of why many diverse actors have started to be interested in them again

since the 1990s, when ecologists and soil scientists started to examine them with a

renewed interest. I continue the chapter by addressing how French soil scientists

became gradually interested in urban soils at the end of the 20th century, how this

implied forming new bonds with the worlds of urbanism, administration, and

36

public works, and how this changed the way they do science. I present the field of

ecological engineering, explain how it came about in France, and why the new field

of city soil studies became one of the topics in which it could develop, pushed

forward more particularly by functional ecologists. I show how ecological

engineering tends to ally with discourse on ecosystem services, and with a resource

approach to soils. In this, soils are regarded as a fertile material that can be grown,

transported and sold. I show how this links to a discourse on ‘peak soil’, in which

soils are described as a scarce and disappearing resource.

In the second chapter, I show how urban soil science arises within the soil sciences

as they are forging ties with ecology and with renewed forms of experimentalism.

I draw on my ethnography of the experimental zone of Homécourt, where

scientists test methods of soil construction. Scientists from my fieldwork view soil

construction as a method that allows them to do research on soils, and to open up

fundamental questions about what soils are. Along with both the ecological and

part of the STS literature, they argue that soil construction is an ‘acid test’ for

theory. I address some of the implications of this view, and introduce an alternative

view of soil construction as an ‘apparatus’ (Barad 2007) in which soil scientists

‘learn to be affected’ by the soils they build – an idea that I further address in the

next chapter.

The third chapter continues exploring soil scientists’ experimental practices, but

does it this time by addressing the soil scientists’ ways of digging, in which they

become attentive to the affective qualities of soil materials. Conventional

approaches in pedology imply mostly visual methods of distinguishing soil

horizons. However, a pedologists’ knowledge of a soil also emerges through

corporeal and multisensorial engagement with the material, as he goes along

scratching, handling and shoveling it. Digging is a form of exploratory practice that

is particularly fit for soils, as their tactile texture, grain, cold or moist qualities vary

dramatically. Yet, the way digging is performed is renewed with every soil. In the

case of pedologists who study constructed urban soils, the task of digging pits is

frequently performed by the most advanced researcher in the team. Although

physically demanding, such a task is for them far from a chore, as it allows them to

37

‘feel’ how the soil works. Thus, even though only determined samples are

considered to yield ‘data’ suitable for scientific analysis, they have to grasp, every

time, what poses an interesting question in regard to each particular soil. I suggest

that this can be thought of in connection with anthropological studies of the work

of artisans, which show that they often let themselves be affected (Despret 2004)

by the materials with which they work. In this, touching earth is a particular mode

of learning to be actively affected by the material. I elaborate on the kind of

correspondence (Ingold 2013b) that grows between the soil as an active material,

and the pedologist inclined to be affected by the soil so as to reveal its

potentialities.

The fourth chapter is the third and last we shall spend in the company of urban

soil scientists. It addresses the capture of organisms and materials in ecological

engineers' practices of soil construction. Ecological engineering has come to take

the idea that all organisms are 'ecosystem engineers' as central to its approach to

ecosystem design and construction. In the field of soil construction by ecological

engineers, worms are described as ‘collaborators’ as large parts of the operational

chain are left to them. I examine the claims of a redistribution of agency in making

in scientists’ convocation of worms, and question the different notions of making

and engineering at play in them. I suggest that this obliges us to make a detour

through a description of the worms’ view of soils, and approach their activity as

‘worming’. I further elaborate this with the notion of pedogenesis – a concept

referring to the growth of soils, which lies at the heart of the ecological

understanding of soils. I rework the concept to denote a process that binds

together humans, worms and soil materials. In this, working with soils appears as

different from the usual notions of building and construction (as the

superimposition of design on matter). It is rather an intervention in a field of

forces, a careful collaboration with soil organisms and changing materials, and a

transformation of a path into the ‘movement in time’ (to use an ecologist’s

expression) that an ecosystem is. In so doing, I attempt to avoid the trap of

presenting ecological engineering as a practice that entails domination over worms

38

and nature. I envisage it rather as an experimentation of novel bounds between

humans, worms, rain, earth and rock.

Chapter 5 takes us away from labs and experimental zones, and brings us to the

middle of Paris’s largest wasteland – the Petite Ceinture. In this chapter, I present

alternative practices of soil construction with the work of urban gardeners who

develop their own methods for making soils. I first show how these gardeners’

understanding of plants and soils is grounded in their movements in the city, and

how observing plants and soils in the city leads them to develop a very different

vision of it, that of a city seen from the eyes of its intruders: soils, plants and

animals. I further elaborate on how they develop gardening methods that are

inspired by these observations. I show that actively engaging in gardening and

constructing soils is altogether a means to reclaim parts of the city, and a way to

further understanding of plants and soils by constant experimentation on them.

For them, constructing soils can be done in different ways, but these always imply

rearranging materials gathered in the city into some kind of mound. I describe a

practice of dry-stone wall construction, which was explicitly described by these

gardeners as a practice of soil construction. Indeed, such walls are not only

enclosures, but also take an active part in the development of the soil mix (the

pedogenesis) as they drain water, contribute to soil aeration, host fauna and retain

the warmth of the sun. At the end of the process, both soil and wall materials have,

in a sense, undergone a metamorphosis. They have now joined in a new existence,

that of a wall and a soil. I discuss the Simondonian concept of ‘metastable

artefacts’, which they describe as objects that can only hold together because of

the net of relations that traverse them. Their natural tendency is not to persist, and

they can only exist through the controlled exchange of material and energy with

their environment. I argue that the soils and gardens of these gardeners can be

seen as such, as they are constituted by the intricate fold of the fluxes that circulate

in them, which include human and material processes.

In chapter 6, we return to the question of the ‘stable’ and ‘abiotic’ city, against the

background of which urbanites live their lives. Geotechnicians, earthworkers and

road builders are precisely the ‘soil sealers’, who build the urban soils that we see

39

everywhere, everyday – those that hold houses, roads, sidewalks. I pose the

question of whether foundations are so different from the fertile made soils we

encountered in the first part of the thesis. Can they really be said to issue directly

from a plan, a representation fashioned in the imagination of the engineer prior to

its execution in the soil materials by means of machinery? During the fieldwork

phase I did with geotechnicians, I realised that to them too, urban soils are far from

being this static, inert thing. Their soils too move, slide, collapse and pack down

very often. This is a nightmare for architects whose buildings most often require

strong and persistent ‘grounding’. In order to achieve provisional stability and to

maintain it, geotechnicians need to be very aware of all the ways in which urban

soils are in fact moving all the time, and very lively. The practices of geotechnicians

also show that it is impossible to fully theorise urban soils, which illustrates the

point that knowledge of urban soils cannot be gathered into a single point (see also

chapter 1). The geotechnicians allow me to counter the claim often made by adepts

of the ‘fertile’ approach to city soils, according to which these people can only think

of soils as passive matter. I conclude by proposing that it is not engineers who

perform soil as inert by their action on it, but in the performance of soils as inert,

both soils and engineers are formed, achieve and maintain their identities as such.

In the seventh and last chapter, I introduce a collaborative experiment with

scientists and artists which wraps up what ‘reclaiming’ urban soils might mean. I

describe mostly the discussions and productions of the Chamarande Lab from

October 2015 to March 2016, and resulted in an exhibition at the Chamarande

centre of contemporary art, and in a series of workshops and happenings that took

place in various locations. The lab was framed as a process of co-inquiry, in which

the three ‘scientists’ (pedologist Alan Vergnes, anthropologist Marine Legrand, and

myself) did not play a consulting role, but rather participated in the framing of

‘research’ questions for the lab. Our methods were those of the two artists we

worked with: Anaïs Tondeur, who explores hidden or forgotten details of scientific

history and objects through poetic drawings, paintings and film, and Yesenia

Tibault Picazo, who designs future fossils and materials that reveal the fossil

futures of our own bodies and modes of life. In examining these examples, I try to

40

draw a speculative agenda. How can we craft good questions to approach urban

soils? How can we face the fact that human and pedological becomings are

enmeshed? How can we think of the future of disciplines, and might creative

experiments be a productive way to address this question? On what terms might

they allow anthropology to better address the future, if we are to follow Stengers

and Debaise’s (Debaise 2015; Stengers 2013) take on the whiteaheadian idea that

fiction might behave as ‘a lure for a feeling’?

A note on ethnography in the plural form

Before entering into the heart of the text, I would like to end this introduction with

a few words about pluralism and the multiplication of field sites. Bringing forth

different stories into a pluralistic account implies a form of comparison between

them, but the comparison I propose here is deliberately incomplete and partial.

The goal isn’t to draw a general map of ways of recognising urban soils, as in certain

contemporary anthropological projects of categorising and comparing various

ways of navigating between nature and culture (Descola 2005). The pluralism I am

referring to simply recognises that there are multiple ways of inhabiting the world,

that each way has its particular twist; that each entails different kinds of tensions

and attention, and that contrasting them may allow us better to notice their

particularities.

I have already mentioned how I intended to ‘take seriously’ the work of scientists.

This commitment continues in the worlds of gardeners, foundation builders, or

artists. I take inspiration here in current enthusiastic anthropological propositions

associated with the ‘Ontological turn’, which have set out to ‘take seriously’ the

ways of thinking of people encountered on fieldwork – be they Amerindian

tribespeople (Viveiros de Castro 2009) or anti-globalization activists (Escobar

2008). The core of this endeavour is not to see people’s ideas, behaviour or culture

as something that should be explained, but as embedding knowledge that is

legitimate for the ethnographer to think with. It is thus an impetus for the

ethnographer to think with these theories that arise from fieldwork (or from

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‘ethnographic data’) rather than with only pre-set theories.20 The speculative

framing of my research as following urban soils thus resonates with Holbraad,

Pedersen and Viveiros de Castro’s definition of Ontological anthropology as ‘a

“could be” experiment in which the emphasis is as much on “be” as on “could”’

(2014), which these authors exemplify with the following dialogue: ‘“Imagine a

cyclical time!” marvels the relativist; “Yes, and here is what it could be!” replies the

ontological anthropologist’ (ibid.). Even though they build on different examples

and theoretical traditions, the Ontological turn’s notion of ‘taking seriously’

resonates with Stengers’s or Despret’s attentive approach of scientific practices.

For the Ontological turn, the matter isn’t one of taking seriously different

knowledge only in their ‘effects in the world’, but to grant these knowledge the

power to open us (Westerners) to kinds of realities that are beyond us. The aim is

to ally with these knowledges to operate the ‘permanent decolonization of thought’

(Viveiros de Castro 2009) against the distinctively human and western kind of

reality that much of anthropology is premised on.

As I noted above while addressing the theme of the Anthropocene, I am interested

here in bringing forth stories that allow us, each time in a different mode, to

intensify our attention to urban soils. As Pedersen positively argues, taking

seriously might thus lead to an ‘explosion of potential concepts and “worlds” in a

given ethnographic material, or combination (comparison) of such materials’

(2012, n.p.). To follow practices in their plurality and diverging character is to

recognise ‘the importance of the question of what matters for each practice and of

how what matters effectively connects practitioners’ (Stengers 2011, 376). My aim

here is to work with the possibilities opened up in these different ways of relating

to soils, which all contribute to make us feel that we do not live on some global

earth, but in places filled with life, in which we participate. Hence, our existence

20 At least, the aim is not to give precedence to one or the other. To Escobar for example, taking

activists seriously means ‘to build on ethnographic research in order to identify the knowledge produced by activists and to use this knowledge and these analyses to conduct my own analyses

between related topics – or, as I like to put it, to build bridges between political-intellectual

conversations in social movements about environment, development, and so on and conversations

in the academy about corresponding issues’ (2008, 25). Escobar thus sets ideas coming from activists, such as self-organization, in discussion with academic theories such as ANT – the idea

being not to separate between ‘emic’ and ‘etic’ concepts.

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depends on such places, and their oblivion risks making us more fragile. Each of

the practices I describe here is a different means to attend to urban soils, each

entailing its own kind of tension and attention.

All the stories I build on in this dissertation are stories of people who learn to be

affected by urban soils, and who take soil construction as a means to weave soils

into apparatuses that have the power to affect them. Their making practices are,

each in its own mode, ways to enter into a relation of attention. For all the different

soils I will describe, humans and their actions are absolutely central, whether

because of pollution, the building history of the site, or the presence of graffiti

makers. It is notably humans that make these ecologies chaotic and impossible to

predict. In every case, people have to work with the accidental ecology of the site,

and find out that they learn from it as they engage in practices of soil construction.

They engage in a trial in which both people and soils come to be determined.

Urban soils bring up the question of indeterminacy and how we might develop

pragmatic ways of knowing and working with it.

Starting from a neglected thing such as urban soils, and following some of the

many uncertain and experimental processes through which urban soils are known

and built, in effect provides points of entry and leverage into the black box I

mentioned at the beginning of this introduction. They allow us to multiply the

takes we can have on the question. Urban soils can be interesting, they can be

known in very different ways, become different things, and afford different

possibilities. They are not just a non-resource, or an example of a non-natural

process, but they are not the opposite of this either. To think about them from the

vantage point of experiences that change the rules of the game and complexify the

story allows us to ‘feel’ (more than to define) a world that is neither social nor

natural, where humans have an impact, and can (at least) think about their impact

and the different future it implies. It opens different horizons for our relationship

with urban soils, and raises the question of the role of human actions in the future

of soils. They are no longer an inert surface, a backdrop for our actions, but evolve

and change depending on the ways in which we care for them or not.