How different agricultural practices affect soil health KATARINA HEDLUND LUND UNIVERSITY

Agriculture and soil threats

Decline in: Lead to: soil carbon soil erosion biological activity soil compactionsoil biodiversity reduced

resistance to pests

reduced nutrientprovisioning

Intensificationof agriculture

Soil ”health” - ecosystem services

Intermediate ecosystem services

Nutrient retentionCarbon storageWater retentionResistance to pestsRegulation of above ground diversity

Final ecosystem services

FoodFeedBiofuelClean waterClimate mitigation

Soil biodiversity

Actions and inter-actions among soil organisms

feedingdigging burrowsmycorrhiza

Agriculture and ecosystem services

Foley et al Science 2005

Long term decline of soil-C in Europe

Brady et al 2015 Agronomy Journal

How can we change Soil C ?

Management C decline per year  

Intensive cereal production -1.0% UK

Inorganic fertilisers -0.5% SE

Farm yard manure (5 ton/ha) -0.2% SE

Straw addition (3 ton/ha) -0.2% DK

Management C increase per year  

Cover crops 0.2% FR

Straw addition (12 ton/ha) 0.3% DK

Farm yard manure (35 ton/ha) 0.4% UK

Ley 2 yrs (in 8 yr rotation) 0.3% SE

Miscanthus grass 2.0% US

Soil carbon and agriculture in Europe?

SOC in agricultural land 2009 Wheat yield

g/kg 100 kg/ha

Soil carbon and management

• Systematic Rewiew (Global scope)

– Soil carbon and agricultural management

– 25000 publications

– 750 papers used in review

• Management

– Tillage

– Amendents

– Fertilsers

– Crop rotations

http://www.eviem.se/en/projects/Soil-organic-carbon-stocks/

Systematic map – review of global evidence

25000 papers checked750 in the database to be used in meta-analyses

Systematic map – review of evidence

Interactive map – with metadata and links to published evidence

Open access during 2015

Soilservice project

Soil management across EU

SwedenGreece

Soil carbon and biodiversity

Gradient of intensive crop rotation to pastures

Tsiafouli et al Global Change Biology 2014

Producers of ecosystem servicesThe soil food web

Food web diversity

Lower food chain length

Steeper biomass pyramid

Lower C & N mineralization rates

Loss of larger species

low intensity

high intensity

Greenhouse gas emissions

De Vries et al PNAS 2013

Nutrient retention

Pasture Extensive rotation

Intensive rotation

0

5

10

15

20

25

30

35

40

CZGRSEUK

Le

ac

he

d N

(m

g/l)

0.0

2.0

4.0

6.0

8.0

10.0

CZGRSEUK

AM

fu

ng

al b

iom

as

s

De Vries et al PNAS 2013

Soil biodiversity & intensive agriculture

• Reduce species diversity

• Lower food chain length

• Soil carbon: 10 – 0.8 %C

• Soil nitrogen: 0.4 - 0.1%N

• Specific groups that are influenced:

– AM fungi, earthworms, larger predatory mites

Pastures to crop rotation:

Smart management decisions?Support ecosystem services

Nutrientretention

Food

Fiber

Water regulation

Natural pest controlCarbon

retention

Soil formation

Climate regulation

Nutrient retention

Food

Fiber

Water regulation

Natural pest controlCarbon

retention

Soil formation

Climate regulation

Using ecosystem services for decisions

Ecosystems &biodiversity

Ecosystem services

Decisions

Institutions(farmers, EC)

Values

Agricultural management

Information on sustainable soil use

Incentives

After Daily et al 2009

”decision loop”

Valuation models

Mapping services

Information transfer

"Natural Capital” - The ecosystem services from nature which are essential for human life.

http://bankofnaturalcapital.com/category/ecosystem-services/agriculture/

Value of soil ecosystem services

Value to farmers

• Fertile soils

• Water retention

• Less erosion

• Less use of – fertilizers

– pesticides

Value to society

• Reduce eutrofication

• Clean water

• Carbon retention

€?

Economic valuation:Carbon a currency for natural capital

Brady et al 2015 Agronomy Journal

Optimal use of soil C

0.75 1.25 1.75 2.25 2.75 3.253000400050006000700080009000

100001100012000

Sweden DenmarkEngland Germany

% soil Carbon

Yiel

d t/

ha

0.75 1.25 1.75 2.25 2.75 3.250

20406080

100120140160180200

Sweden DenmarkEngland Germany

% soil Carbon

Nitr

ogen

kg/

ha

Optimal yield Optimal fertiliser use

Carbon a natural capital

0.75 1.25 1.75 2.25 2.75 3.25200

400

600

800

1000

1200

1400

1600

1800

Sweden Denmark England Germany

% soil Carbon

Max

imum

pro

fit €

/ha

400

450

500

550

€/ha

2008 2012 2016 2020 2024 2028 2032y ear

Sweden

250

300

350

400

€/ha

2008 2012 2016 2020 2024 2028 2032y ear

UK

Ley in the crop rotation Profit per hectare

40

42

44

46

48

50

52

2008 2012 2016 2020 2024 2028 2032 2008 2012 2016 2020 2024 2028 2032

Sweden UK

0% set aside 7% 15% 25%

kg w

heat/kg N

year

Graphs by region

N-efficiency

Saarbacher et al in prep /SOILSERVICE project

Soil natural capital

• Promoting soil C means increasing soil biodiversity and soil ecosystem services

• Processes are long term and yields will be affected in the future

• The value of soil natural capital can be used to promote sustainable management

• Soil C- investment banks?

1960 1970 1980 1990 2000 2010 20200

100020003000400050006000700080009000

Wheat Scania Sweden

Year

kg

/ha

Yield increase and soils?

Filling yield gaps (wheat) with natural capital (20 years)

Business as usual 0.3% SOC/yr increase rate

100kg/ha

Nelson E, Brady M, Hedlund K in prep

Tools for valuation of services – project with Swedish EPA

Local level: C bank (open access tool)

Production model where yield is related to fertiliser and ecosystem service levels

Regional level (Skåne): AgriPoliS “Agricultural Policy Simulator”

Agent based model, optimise farmers profit and predict land use within 25 years future

National level: Cost benefit analys of policy

Evaluate decisions and incentives to reach environmental objectives