www.cranfield.ac.uk

Soil – an overlooked and

undervalued resource, at the

heart of UK agri-businesses

Professor Jane Rickson

Cranfield Soil and AgriFood Institute

Farmacy Focus Group Spring Meeting

Custodians of the countryside

– making every hectare count

February 27th, 2018

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Outline of the talk

1. The importance of soil

2. What makes a healthy soil?

3. The state of our soils

4. Conserving and improving our soils

5. Take home messages

Soil: an overlooked and undervalued resource?

Courtesy of Professor Karl Ritz

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“….And what do you do for a living?”

Traditional view of soil science

Soil as inert material

• Still so in many engineering disciplines

Expressions / sayings about soil

• Soil as ‘dirt’ – US

• ‘mud’ meaning worthless or polluting

• Connotations of the word “soil / soiled”

• ‘mudslinging’

• ‘His (her) name is Mudd’ [sic]

+ Cultural / artistic value of soils

1. The importance of soil

http://www.visualthesaurus.com/app/view

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1. The importance of soil: global challenges

1. Can 9 billion people be fed [and housed and

transported] equitably, healthily and

sustainably by 2050?

2. Can we cope with future demands for water?

3. Can we provide enough energy to supply the

growing population coming out of poverty?

4. Can we mitigate and adapt to climate

change?

5. Can we do all of this and reverse declining

biodiversity and loss of ecosystems

Sir John Beddington, Chief Scientific Advisor to HM Government

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Healthy soils as part of our natural capital, delivering multiple ‘ecosystem goods

and services’ (UN Millennium Ecosystem Assessment)

• Direct links with sustainability (economic, environmental and social pillars)

• Human health and wellbeing (Millennium Ecosystem Assessment)

• Individuals’ and national economic status

Ecosystem goods and

services delivered by soilExamples

Provisioning of material

goods and services

Agricultural production (food, fibre, fodder, fuel)

Water storage and supplies

Land for development (residential, industry,

infrastructure)

Regulation of ecosystem

processes

Water storage and release (hydrology)

Carbon storage (CO2 emissions: mitigate

climate change)

Cultural, non-material

services

Landscape aesthetic

Recreation / amenity, protection of heritage

Supporting services Habitats, biodiversity

Soil formation

1. The importance of soil

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Ecosystem goods and

services delivered by soilExamples

Provisioning of material

goods and services

Agricultural production (food, fibre, fodder, fuel)

Water storage and supplies

Land for development (residential, industry,

infrastructure)

Regulation of ecosystem

processes

Water storage and release (hydrology)

Carbon storage (CO2 emissions: mitigate

climate change)

Cultural, non-material

services

Landscape aesthetic

Recreation / amenity, protection of heritage

Supporting services Habitats, biodiversity

Soil formation

Healthy soils as part of our natural capital, delivering multiple ‘ecosystem goods

and services’ (UN Millennium Ecosystem Assessment)

• Direct links with sustainability (economic, environmental and social pillars)

• Human health and wellbeing (Millennium Ecosystem Assessment)

• Individuals’ and national economic status

1. The importance of soil

Whole apple % Planet earth

3/4 74% Water

1/4 26% Land

1/8 13% Uninhabitable to humans

1/8 13% Habitable

3/32 10% Only suitable for non arable

land

1/32 3% Suitable for arable

< 1/32 peel Topsoil

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Ecosystem goods and

services delivered by soilExamples

Provisioning of material

goods and services

Agricultural production (food, fibre, fodder, fuel)

Water storage and supplies

Land for development (residential, industry,

infrastructure)

Regulation of ecosystem

processes

Water storage and release (hydrology)

Carbon storage (CO2 emissions: mitigate

climate change)

Cultural, non-material

services

Landscape aesthetic

Recreation / amenity, protection of heritage

Supporting services Habitats, biodiversity

Soil formation

Healthy soils as part of our natural capital, delivering multiple ‘ecosystem goods

and services’ (UN Millennium Ecosystem Assessment)

• Direct links with sustainability (economic, environmental and social pillars)

• Human health and wellbeing (Millennium Ecosystem Assessment)

• Individuals’ and national economic status

1. The importance of soil

Whole apple % Planet earth

3/4 74% Water

1/4 26% Land

1/8 13% Uninhabitable to humans

1/8 13% Habitable

3/32 10% Only suitable for non arable

land

1/32 3% Suitable for arable

< 1/32 peel Topsoil

“The thin layer of soil covering the earth's

surface represents the difference between

survival and extinction for most terrestrial life.”

Doran and Parkin, 1994.

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1. The importance of soil

What is soil?

• Mineral content (texture: clays, silts and sands) ≈ 45%

• Chemical composition (bonds between particles)

• Air ≈ 25%

• Water ≈ 25%

• Organic matter content ≈ 5%

• Soil flora: roots and leaves

• Soil fauna

• macro-organisms e.g. earthworms

• micro-organisms “microbes”

• bacteria

• fungi

• viruses

• The physical arrangement of soil particles, air space, water content and organic matter = soil structure

• Allows roots to grow

• Allows movement of air, water and soil organisms

• Affects soil strength / loading capacity (resist compaction)

Clays, silts and sands45%

Air25%

Water25%

Organic Matter5%

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What properties make a healthy soil?

• Physical (texture, depth, structure,

porosity, density, water holding capacity,

infiltration rate)

• Biological (flora and fauna e.g. seed

bank and micro-biota)

• Chemical (nutrients, carbon, pH)

…and interactions between them: soil as a

complex ‘system’

2. What makes a healthy soil?ORGANIC

MATTER

BIOTA

NUTRIENTS STRUCTURE

WATERBIOTA

Soil health: the pivotal 5 (after K Ritz, pers. comm)

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Soils properties vary

• Texture

• Stoniness

• Organic content

• Depth to rock

• Mineralogy

• Permeability

• Natural drainage

• Consolidation

• Acidity

National Soil Map and Soil Inventory

• Product of 200+ years of field work

• 747 Soil Series (soil types)

• 306 Soil Associations (soil types occurring together)

3. The state of our soils: The soils of England and Wales

De

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igh

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gin

Hira

eth

og

Wilc

ocks

www.landis.org.uk

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Increasing pressure on finite soil resources

Estimated 12 million hectares of agricultural land worldwide

are lost to soil degradation every year.

Identified in Defra’s ‘Safeguarding Our Soils’ and the EU’s

‘Thematic Strategy for Soil Protection’ (2006)

3. The state of our soils

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Increasing pressure on finite soil resources

Estimated 12 million hectares of agricultural land worldwide

are lost to soil degradation every year.

Identified in Defra’s ‘Safeguarding Our Soils’ and the EU’s

‘Thematic Strategy for Soil Protection’ (2006)

3. The state of our soils

Processes of soil erosion in the UK3. The state of our soils: Soil erosion

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Field erosion surveysModelled erosion risk classes

3. The state of our soils: Soil erosion

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3. The state of our soils: Soil erosion rates

Wind erosionTillage

erosion

Co-extraction with root

crops and farm machineryWater

Typical erosion rate

range (t ha-1 year-1)0.1 – 2.0 0.1 – 10.0 0.1 – 5.0 0.1 – 15.0

Land use affected

Arable,

upland, some

pasture

Arable Arable

Arable,

pasture,

upland

Exported off field Yes No Yes Yes

Comparison of the magnitude of soil loss for different erosion processes (Owens et al.,

2006). N.B. Rate of soil formation ≈ 1 t ha-1 year-1 (Verheijen et al., 2009)

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• Irreversible loss of a natural resource / asset?

• e.g. loss of soil depth due to erosion

• Yield decline (quantity, quality and reliability; e.g. 20 million tonnes of grain per annum; UNCCD, 2011)

• Costs (e.g. reseeding, nutrient replacement)

• True impacts on food production currently masked by unsustainable inputs?

• Irrigation

• Chemical fertilisers

3. The state of our soils: soil erosion

0

10

20

30

40

50

60

70

80

90

0102030405060

Me

an B

iom

ass

(g)

Soil depth (cm)

Clay - Cereal

Clay loam - Cereal

Loamy sand - Cereal

Clay - Grass

Clay loam - Grass

Loamy sand - Grass

Yield related to soil depth (Defra SP1317)

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Pollution from agricultural land is thought to deliver up to

• 70% of sediments (eroded topsoil)

• 60% of nitrates (NO3-) (mostly soluble, in runoff)

• 25% of phosphates (PO43-) (mostly adsorbed to sediment)

to receiving waters (National Audit Office, 2010).

Specifically, 487 rivers in England are failing their water quality targets for sediments:

• 2480 due to excessive agricultural PO43- inputs,

• another 2346 due to the water industry not being able to meet PO43- discharge targets

(Source: Environment Agency, 2015b)

3. The state of our soils: soil erosion and loss of nutrients

© Cranfield University18

£ million per year

(2010)Ecosystem service

TotalProvisioning Regulating Cultural

Agricultural

production*

Flooding

**

Water

quality

**

GHG

emissions

* / **Other

Central

estimate% of

total

Soil erosion 30 - 50 46 - 80 55 - 62 8 - 10 ? ? 165 13%

Compaction 180 - 220 120 - 200 60 - 80 30 - 40 ? ? 481 39%

Loss of organic

matter2 ? ? 360 - 700 ? ? 558 45%

Diffuse contamination ? ? ? ? 25* ? 25 2%

Loss of soil biota ? ? ? ? ? ? ? ?

Soil sealing ? ? ? ? ? ? ? ?

TOTAL212 - 270 166 - 280

115 -

142398 - 750 25 ? 1,229

% 20% 19% 11% 49% 2% 100

*on-site costs **off-site costs *** cost of regulation to protect soils from contamination

? Estimates not available at national scale

The state of our soils: Total costs of soil degradation

Graves, A., Morris, J., Deeks, L.K., Rickson, R.J. , Kibblewhite, M.G., Harris, J.A, and Farewell, T.S. 2011. The Total Costs of

Soils Degradation in England and Wales. SP1606. Final Report to Defra, June 2011.

Graves, A.R., Morris, J., Deeks, L.K., Rickson, R.J., Kibblewhite, M.G., Harris, J.A., Farewell, T.S. and Truckle, I., 2015. The

total costs of soil degradation in England and Wales. Ecological Economics, 119, pp. 399-413.

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1. Enhance productivity (quantity, quality and reliability of marketable yield)

• Improve uptake of water and nutrients by roots

• Reduce pests / diseases / weeds

2. Control soil degradation

• Erosion; diffuse pollution; compaction; losses of C, organic matter and habitats; salinisation; acidification

3. Concept of “sustainable intensification”

• Producing more (quantity/ quality/ reliability of marketable yield) with less environmental impact / damage

1 + 2 = 3

4. Conserving and improving our soils

Aim: “To maintain a fertile seedbed and root zone, whilst retaining

maximum resistance to soil degradation”

Soil health: the pivotal 5

Soil erosion, Bedfordshire

ORGANIC

MATTER

BIOTA

NUTRIENTS STRUCTURE

WATERBIOTA

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• Cultivations and tillage practices

• Cover cropping

• Soil (organic) amendments

• Field engineering

• Erosion control products

4. Conserving and improving our soils

+ 14 minutes rainfallT D F E

Radish Mustard

Turnip

© Cranfield University21

4. Conserving and improving our soilsSoil and Water Protection in Northern Europe (SOWAP)

Farmer’s PreferenceSOWAP (Minimum tillage)Conventional practice

Duplicate erosion plots of 70m x 9m (c. 0.06 ha)

0

1

2

3

4

5

6

7

8

9

10

Conventional SOWAP Farmer’s Preference

Cu

mu

lative

se

dim

en

t o

ve

r 3

se

aso

ns (

t h

a-1

)

Season 3

Season 2

Season 1

© Cranfield University22

Nutrients in sediment (Tivington, Somerset)

SOWAP Field Soil Erosion Plot Results

Concentration Load

• Nutrient loads (N, P and K) were lowest for SOWAP,

but not significantly different to Conventional or FP• Linked to low sediment rates

• Concentrations of N, P and K from SOWAP and FP

were significantly higher than Conventional • Nutrient enrichment of the sediment due to high clay

contents?

• Clay % in sediment is lowest for the Conventional

treatment (p=0.007)

• Nutrient adsorption on clay particle surfaces

0

500

1000

1500

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2500

3000

3500

4000

4500

0

50

100

150

200

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Conventional SOWAP Farmer’s Preference

N c

on

cen

trati

on

(m

g l

-1)

N lo

ad

(g

ha

-1)

0

200

400

600

800

1000

1200

1400

0

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20

30

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50

60

70

80

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100

Conventional SOWAP Farmer’s Preference

P c

on

cen

trati

on

(m

g l

-1)

P l

oad

(g

ha

-1)

0

1000

2000

3000

4000

5000

6000

7000

8000

0

100

200

300

400

500

600

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Conventional SOWAP Farmer’s Preference

K c

on

cen

trati

on

(m

g l

-1)

K lo

ad

(g

ha

-1)

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Penetration

resistance

MPa

Organic

carbon

(%)

Microbial

biomass

carbon

(μg C g

soil-1)

Earthworms /

m2

1 0.50 c 2.710 b 339.1 b 75.0 c

2 0.60 bc 2.789 ab 321.8 b 118.8 b

30.70 ab 2.829 ab 380.2 ab 137.5 b

4 0.61 abc 2.714 b 379.8 ab 103.1 bc

5 0.76 a 2.985 a 443.8 a 187.5 a

Results: How tillage affects soil quality Different letters show statistically significant differences

4. Conserving and improving our soils:

Reduced tillage systems (Dr Mikhail Giannitsopoulos)

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• Disturbed v undisturbed areas at field and row width scale

Research questions include:

Does tillage reduce soil biology (fungi, bacteria, earthworms)?

Does the rate of soil biology recovery increase nearer the untilled plot?

Driven by colonisation / movement from untilled plots to tilled plots

4. Conserving and improving our soils:Can strip tillage improve soil conditions? Iain Dummett, PhD student.

Field trials, Lincolnshire

20cm

40cm

Plot trials, Cranfield

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4. Conserving and improving our soils:Can strip tillage improve soil conditions? Iain Dummett, PhD student.

Field trials, Lincolnshire

Plot trials, Cranfield

FEDCBA FEDCBA

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4. Conserving and improving our soils:Optimising soil disturbance and use of mulches for soil erosion and runoff control (Dr. Joanne Niziolomski)

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Shallow soil disturbance (175 mm), both with and without straw mulch (6 t ha-1).

Winged tineNarrow with two shallow

leading tinesModified para-plough

Conserving and improving our soils:Field trial tillage treatments

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The Soil Bin (Iain Dummett, PhD student, Frontier Agriculture, Douglas Bomford Trust)

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• Straw mulch always reduced runoff • MPP with straw reduced total runoff significantly (p<0.05) compared with

all other treatments.

Soil disturbance field trial results: Total runoff volume (l)

0

100

200

300

400

500

600

700

Non-SSD NSLT MPP WT

To

tal ru

no

ff (

l)

Shallow soil disturbacne typeNo shallow Narrow tine shallow Modified Winged tine

soil disturbance leading tine para-plough (Niziolomski, 2015)

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4. Conserving and improving our soils:The use of grassed waterways for sediment and runoff control

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4. Conserving and improving our soils:Application of organic waste to restore soil health and productivity of a degraded soil (Benedict Unagwu, PhD student)

Increase crop

yield?

Poultry

manure

Mushroom

compost

PAS

compost

(green

waste)

Anaerobic

digestate

Improve Soil Quality

Indicators (SQIs)?

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Effect of organic amendments on available water capacity

0

5

10

15

20

25

Availa

ble

wate

r capacity (

g g

-1)

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Amendment effects on maize height and biomass

control

10 t ha-1

Poultry

Manure

At 3 weeks after planting

10 t ha-1

Mushroom

Compost

At tasseling (9 weeks after planting)

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Jane RicksonProfessor of Soil Erosion and Conservation

Cranfield Soil and AgriFood Institute

j.rickson@cranfield.ac.uk

5. Take home messages

Thank you for your attention.

Any Questions?

• Soil is essential for the successful delivery of several goods

and services to society

• However, soil can be (irreversibly?) damaged by degradation

processes such as soil erosion

• Soil management can be used to conserve and improve the

state of soils