Climate change and carbon sequestration in the Mediterranean basin:

Contributions of No-tillage systems

Dr. Rachid MRABET

http://rachidmrabet.googlepages.com

rachidmrabet@gmail.com

4th Mediterranean Meetings on No-tillage systems Setif, Algeria, May 3 -5 2010

Features of Mediterranean Basin

Myriad of atmospheric and climatic processes

Regional vs global influences

Mistral, Tramontane, Bora, Etesiens, Sirocco

A semi-closed basin

Sea-land interaction & contrasts

No More land for production: case of Morocco

7,4

7,6

7,8

8

8,2

8,4

8,6

8,8

9

9,2

9,4

1971

1982

1992

1993

1994

1995

1996

1997

1998

1999

2001

2003

Year

Ag

ricu

ltu

ral A

rea

(M

illio

ns H

a)

•The land available to produce this extra food is

shrinking because of urbanization and use of

agricultural land for other purposes.

Agriculture as driver of global warming

Carbon Dioxide is the most important GHG

Other GHG (Methane, Nitrous Oxide) more powerful

Still 77% of total GHG in CO2 equivalent is due to

CO2

Agricultural land use contributes 32% of all GHG:

24% of all CO2

61% of all CH4 and N2O

The major largest components are:

Deforestation: 18.3%

Nitrogen emissions from soils: 6%

Methane from livestock: 5%

Projected Impacts of Climate Change

Source: Stern Review

Pressures on Med-countries

•Mitigation of greenhouse gas emission

•Control of desertification & erosion

•Sustainable environment-friendly agricultural productions

•Reduction in reliance on fossil fuels

Air Temperature (°C): 2070-2099 vs. 1961-1990

using AORCM

Winter

Summer

(Somot et al., 2007)

•Increased

temperature

•Global warming

• frequency,

duration and

intensity of hot

periods “canicules”

9

Winter

Summer

(Somot et al., 2007)

Rainfall (mm/d): 2070-2099 vs. 1961-1990

using AORCM

Rainfall totals are likely

to decline between 4 and

27%.

Frequency of extreme

storm events

Drought is Morocco’s leading natural hazard

0

100

200

300

400

500

600

700

800

900

1000

mm

year

Total seasonal rainfall measured throughout Meknes

Agourai

Ain Jemaa

Sidi Slimane

609 mm

453 mm

Cereal yield trends

Focus on Water & Food, Africa & Asia

Impact of climate change on crop productivity for cereals and food legumes

Giannakopoulos et al., 2009

Wheat consumption

CHABANE, 2010

Algeria

Mediterranean basin is the hotest spot region

Living with drought and dealing with

climate change are unavoidable

Drought is expected to continue and get linked to desertification, the longer we wait,

the fewer our options!!!

Major Global Challenges with conventional agriculture

•Poor Energy Efficiency

•Poor Fertilizer Efficiency

•Poor Water Efficiency }

Its not difficult to fix, if we try

All guarantee poor carbon

balance

What is no-tillage?

B A C

NO-TILL SYSTEM

A = Absence of soil tillage: No Mechanical Soil Disturbance

B = Biodiversity: Crop Rotation / Cover Crops;

Integrating Livestock & Farming

C = Cover of the soil: Permanent Cover with Crop Residues

No-tillage is like a three legged stool

Pillars that Sustain the No-tillage System

Conservation agriculture motion

Argentina Brazil

USA Australia

Conservation Agriculture

Before….. Actually

C

O

N

S

E

R

V

A

T

I

O

N

A

G

R

I

C

U

L

T

U

R

E

Organisations

Partnerships Policies

Industries/Technologies

R&D Training

CA

Capacity Building

Financing

Knowledge Management

Environmental Impact of CA

Question!

Conservation agriculture has large environmental benefits,

but is it climate-friendly?

Emission Mechanisms

Inputs: (energy) Fuel, Machinery

Herbicides

Fertilisers

Outputs: (losses) Gaseous Carbon dioxide, nitrous oxide & methane

Nitrate in runoff and drainage

Carbon & Nitrate in eroded soil

}

}

Easily Quantified

For Known Systems.

Substantial

System Effects

Highly Variable,

Poorly Understood.

Very Large

System Effects,

Atmospheric Carbon as CO2

Plant biomass and

roots left on or in the

soil contribute to Soil

Carbon or Soil

Organic Matter and

all associated

environmental and

production benefits.

Energy from

bio-fuels

CO2 CO2

Biological carbon cycle. Fossil carbon cycle.

CO2

C Energy from

fossil fuels

Renewable Nonrenewable

60% reduction in fuel

20% reduction in fertilizer/pesticides

50% reduction in machinery

no burning

Conservation Agriculture mitigating climate change

Franzluebbers (2005) Soil Tillage Res. 83:120-147

Nitrogen Fertilization (kg . ha

-1 . yr

-1)

0 100 200 300

Changein

SoilOrganicCarbon

(Mg . ha

-1 . yr

-1)

0.0

0.4

0.8

1.2

1.6

Conventional Tillage

Nitrogen Fertilization (kg . ha

-1 . yr

-1)

0 100 200 300

Changein

SoilOrganicCarbon

(Mg . ha

-1 . yr

-1)

0.0

0.4

0.8

1.2

1.6

Conventional Tillage

No Tillage

Soil Carbon Sequestration

Nitrogen fertilization effect

Nitrous Oxide Emission

Interaction of tillage with soil type

Rochette (2008) Soil Till. Res. 101:97-100

Soil Aeration

N2O

Emission

(kg N .

ha-1

)

0

1

2

3

4

5

6

7

8

Good Medium

Conventional tillage

No tillage

Poor

p = 0.06

45 site-years of data reviewed

Brazil, Canada, France, Japan,

New Zealand, United Kingdom, USA

C

Crop biomass is a critical component of

the biological carbon cycle!

Soil carbon is an important link between sustainability and

productivity within agricultural ecosystems.

Soil Surface

Carbon comes into crop

biomass and system

through photosynthesis.

Carbon goes out of

the soil system

mainly through

respiration.

- increased water holding capacity and use efficiency

- increased cation exchange capacity

- reduced soil erosion

- improved water quality

- improved infiltration, less

runoff

- decreased soil compaction

- improved soil tilth and

structure

- reduced air pollution

- reduced fertilizer inputs

- increased soil buffer capacity

- increased biological activity

- increased nutrient cycling and storage

- increased diversity of

microflora

- increased adsorption of

pesticides

- gives soil aesthetic appeal

- increased capacity to handle

manure and other wastes

- more wildlife Carbon central hub of environmental

quality.

C

Environmental benefits are spokes that

emanate from the Carbon hub of the

“Environmental Sustainability wheel.”

Soil Carbon Sequestration

Soil organic carbon can be sequestered with adoption of conservation

agricultural practices

Enhanced soil fertility and soil quality

Mitigation of greenhouse gas emissions

Soil erosion reduction is most notable

Long-term changes are most scientifically defensible

Soil C vs Time

Carbon in Med-Soils

Country Soil order Horizon (cm)

Years NT CT References

France Alfisol 0-5 4 21.5 17.3 Monnier et al. (1976) Alfisol 0-5 33 22.6 11.0 Oorts (2006) & Oorts et al. (2007b)

Syria Inceptisol 0-10 10 17.5 11.0 Ryan (1998) Tunisia Isohumic

Fersialitic 0-20 0-20

4 4

27.5 22.4

24.1 15.5

Ben Moussa-Machraoui et al. (2010)

Morocco Calcixeroll 0-5 5 17.3 16.6 Mrabet (2008a) Calcixeroll 0-2.5 11 28.9 23.5 Mrabet et al. (2001)

Italy Cambisol 0-40 3 7.5 7.5 Borin et al. (1997)

Entisol 0-10 - 20.1 14.3 Basso et al. (2002)

Portugal Cambisol 0-20 3 14.82 12.94 Basch et al. (2008) Vertisol 0-10 - 25.3 19.1 Carvalho & Basch (1995)

Spain Xerocrept 0-5 18 22.5 15 Álvaro-Fuentes et al. (2008) Xerofluvent 0-5 15 18.81 8.8 Álvaro-Fuentes et al. (2008)

Calciorthid 0-5 16 13.7 8.7 Álvaro-Fuentes et al. (2008) Calcisol 0-5 7 12.55 10.17 Fernandez-Ugalde et al. (2009) Haploxeralf 0-5 14 11 7 Hernanz et al. (2002)

Haploxeralf 0-10 8 11.6 8.8 Medeiros et al. (1996) Xerofluvent 0-5 3 17.2 15.7 López-Garrido et al. (2009)

Temporal SOC dynamics from 2010 to 2100 for the different management scenarios

Alavaro-Funentes and Paustian, 2010

Re-building soil organic matter

Ogle et al., 2005

No-Till: CO2 emission!

Reicosky and Lindstrom, 1993

Reicosky

y = 0,0792x + 9,7647

R2 = 0,9698

0

30

60

90

120

150

180

0 250 500 750 1000 1250 1500 1750 2000

Severity of disturbance (cm2)

CE

R (

g C

O2 m

-2)

MP

SS

RM

MK

NT L128

Cumulative Carbon Dioxide Loss after 24 hours

Alvaro-Fuentes et al., 2007

No-Till: CO2 emission!

Akbolat et al., 2009

No-Till: CO2 emission!

Oorts et al., 2007

No-Till: CO2 emission!

Runoff projections with respect to climate change scenarios

Runoff reduction !

Jordán et al., 2010

Soil loss reductions!

Fleskens & Stroosnijder (2008) Portugal & Italie

Sediment loss reductions!

0 40 80 120

0

100

200

300

400

500

0 40 80 120

0

100

200

300

400

500

Y = X

0 40 80 120Sediments. Cover, g m-2

0

100

200

300

400

500

Se

dim

en

ts. T

illa

ge

, g

m-2

Y = 2X

In 80,3% of cases the relation

between N/C has been greater to 2

In 92,4% of cases the relation between N/C has been greater to 1

0 20 40 60 80 100Cover, %

0

20

40

60

80

100

Se

dim

en

t co

nce

ntr

atio

n, g

L-1

Tillage

Plant cover

Espejo-Pérez et al. 2006

Water capture & movement in soils with No-Tillage systems

.1Improved water entry in place of water runoff

.2Reduced water evaporation

.3Channels and macropore in

place of crust and slacking for improved water distribution

and movement in soil profile

.4Water storage for seasonal availability and use by crops

Ruan et al., 2001

NT vs CT for Cereals in Med-Basin

Yield variability vs climate!

yield CT = 0,0033 Rainfall + 1,4116

R2 = 0,1823

yield NT = 0,0028 Rainfall + 2,01

R2 = 0,1457

0

0,5

1

1,5

2

2,5

3

3,5

4

150 200 250 300 350 400 450 500

Rainfall (mm)

Gra

in Y

ield

(M

g/h

a)

No-tillage

Conventional Tillage

Mrabet, 2010

Yield Variability vs climate!

De Vita et al., 2007

Drought Management!

Water evaporation suppression or

water management with crop residues!

0

10

20

30

40

50

60

Cu

mu

lati

ve

so

il e

va

po

ra

tio

n (

mm

)

0 100 200 300 400 500

Cumulative potential evaporation (mm)

OD SW DP CH RT NT-0 NT-80

Mrabet, 1997

Seasonal Carry over of soil water to crop critical stages

Water

gain

No-till Residue Cover Suppression of Soil Water Evaporation

0

10

20

30

40

50

60

Cu

mu

lati

ve

So

il E

va

po

rati

on

(m

m)

0 100 200 300 400 500 Cumulative Potential Evaporation (mm)

0 50 60 80 100

No-till Residue Cover Percent

Mrabet (1997)

Water Conservation: securing water against drought

0

5

10

15

20

25

30

35

40

45

0 50 60 80 100

Residue cover under no-tillage

Tim

e t

o w

ilti

ng

po

int

(days)

0

5

10

15

20

25

30

35

40

Disk plow Stubble

Mulch

Chisel Rotary

tiller

Off-set

disk

No-tillage

w ith 60%

cover

Tillage System

Tim

e t

o w

ilti

ng

po

int

(days)

Keeping the soil moist longer as residue cover increase!

Halting evaporation process in semi-arid areas!

Mrabet, 1997

Precipitation storage efficiency

•Low and highly variable rainfall are major sources of risk for

farms of drylands!

•Precipitation storage efficiency increases as tillage intensity is

reduced during the summer fallow period.

•The increased soil water storage is a result of both maintained

crop residues at the surface and no-turing and mixing of the soil

moisture.

Conservation agriculture: mitigating climate change through

Drought

management

High reduction

in CO2

emission

High

environmental

resilience

Carbon

sequestration

Lets finish this talk with these important statements!

.1The fact is no one has ever advanced a scientific reason for plowing (Edward H.

Faulkner, 1943).

.2No-tillage systems are means for capturing the synergy between climate change

adaptation and mitigation and prevention of desertification (Virdin, 2001).

Transforming research efforts and development (farmers) achievement s on policy issues

Think Thank

To get all elites and leaders in research, development and education with international organisations and NGOs for the same objectives.

Lobbying

Transform weakness on strenghts to convince policy and industries.

« Climate change is a shared responsability and the future is no longer as it used to be »

Merci

“You’ve got to be very careful

if you don’t know where you’re going,

because you might not get there.”