Presented by Rattan Lal at the seminar Save our Soils on May 20, Malmö, Sweden. Read more here: http://www.siani.se/event/SOSsoil

1. Six Feet Under
Rattan Lal
Carbon Management and Sequestration Center
The Ohio State University
Columbus, OH 43210 USA

2. 2
Carbon Management and
Sequestration Center
Population
Energy use
Deforestation
CO2 Emissions
Land Degradation
Desertification
Water use
8000
BC
N
1750 1850 1950 2000
Time
HumanImpact
The answer lies in soils.
Soil Matters

3. 3
Carbon Management and
Sequestration Center
Soil is an organic-carbon
mediated realm in which
solid, liquid, gas and
biology all interact from a
scale of nanometer to
landscape.
The Living Soil
The weight of live organisms
in arable land is 5 t/ha

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Carbon Management and
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• A spade of rich garden soil
may harbor more species
than the entire Amazon
nurtures above ground
• A teaspoon of productive
soil contains 100 million to
1 billion micro-organisms
(Dunne 2009)
Soil is Life

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Carbon Management and
Sequestration Center
I = P x A x T
P = Population
A = Affluence
T = Technology
Over the last
10,000 years, the
number of humans
has increased about
a thousand-fold from
2- 20 million to
7.3 billion.
1.0
1800
1.3
1850
1.7
1900 1.8
1910 1.9
1920
2.1
1930
2.3
1940
2.5
1950
3.0
1960
3.7
1970
4.4
19805.3
1990
6.1
2000
7.0
2011
7.5
2020
8.1
2030
8.6
2040
9.6
2050
11
2100
The
Anthropogenic
Driver

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Carbon Management and
Sequestration Center
Causes or Activities
 Deforestation
 Land Use Conversion
 Extractive Farming
 Inappropriate Irrigation
 Excessive Plowing
 Soil, Crop, Animal
Management
Processes or
Mechanisms
 Erosion
 Salinization
 Nutrient Depletion
 Acidification
 Species Extinction
Factors or Agents
 Climate
 Physiography
 Land forms
 Socio-economic,
Ethnic/Cultural Setting
Soil
Degradation
Anthropogenic &
Natural
Perturbations
Biophysical &
Socioeconomic
Interactions
Climate-Soil-Biotic
Interactions
Processes, Factors, and Causes of Soil Degradation

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Carbon Management and
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Resilience of Soil-Ecological Systems
It has multiple regimes (stable states) which are separated by thresholds
Thresholds
Critical
Threshold
The
current
state of
the
system
Possible states in which the
system can still have the
same function
Irreversible
Degradation
Resilience

8. 8
Carbon Management and
Sequestration Center
Threshold/Critical Level
Threshold/Critical Level/Tipping Point: Soil processes and
properties have threshold levels (1.1% SOC concentration
in soils of the tropics). Beyond threshold level, there is a
drastic regime change.

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Carbon Management and
Sequestration Center
Types of Soil Degradation
Anthropogenic Natural
Land Misuse &
Soil Mismanagement
Climate Change &
Related Factors
Crusting,
Sealing
Compaction
Runoff and
Erosion
Endangered
or Extinct Soil
Un-optimal
Soil
Temperature
Inhibited
Aeration
Desertification
Physical
Degradati
on
Acidification
Salinization
Decline in
CEC,
Nutrient
Depletion
Elemental
Imbalance
Leaching
Pollution/
Contaminati
on
Chemical
Degradation
Loss of Soil
Biodiversity
Soil-Borne
Pathogens
Decline in
Soil Organic
Matter
Emissions of
Greenhouse
Gases
Loss of Soil
C Sink
Capacity
Biological
Degradation
Decline in Soil Quality
DeclineinEcosystemServices
ReductioninNatureConservancy
Disruption in
Nutrient
Cycling
Perturbations
of the
Hydrological
CycleDecline in Net
Biome
Productivity
Loss of
Nutrients &
Carbon
Decline in
Use Efficiency
of Inputs
Ecological
Degradation
Inhibited
Denaturing of
Pollutants
Lal (2015)

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Carbon Management and
Sequestration Center
DeclineinResilienceandQualityof
SoilandEnvironment
Decline in SOC Pool
Reduction in Soil
Biodiversity
 Crusting Compaction
 Increase in Runoff
 Accelerated Erosion
Loss of Nutrients,
C and Water from Ecosystem
Degradation of Soil
Structure
Decline in soil and environment quality, and increase
in risks of social unrest and political instability
Extractive Farming
 Indiscriminate plowing
 Residue removal
 Negative SOC Budget
 Negative Nutrient Budget
 Decrease in Use Efficiency
 Loss of Soil Resilience
 Decrease in ecosystem services
Lal (2015)

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Carbon Management and
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The Gullied Land In West Africa
DesperatenessDesperateness
Increase in erosion risks between 1980s and 2090:Increase in erosion risks between 1980s and 2090:
Africa….+36%Africa….+36%
World....+14%World....+14%
15001500 xx 11001515
CC
1.11.1 xx 10101515
g/g/yyrr
5.75.7 xx 10101515
g/g/yyrr CC
3.993.99 xx 10101515
g/g/yyrr
0.570.57 xx 10101515
g/g/yyrr
decompositiondecomposition
and emission toand emission to
the atmospherethe atmosphere
Stored within theStored within the
terrestrial ecosystemterrestrial ecosystem
Displaced due to erosionDisplaced due to erosion
TransportedTransported
to the oceanto the ocean
In world soilIn world soil

12. 12
Carbon Management and
Sequestration CenterChief Seattle’s Letter to President
Washington
• We are part of the earth, and it is part
of us. The bear, the deer, the great
eagle, these are our brothers.
• The rivers are our brother, they quench
our thirst.
• The earth does not belong to the man,
man belongs to the earth.
• How can you buy or sell the sky? The
land?

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Carbon Management and
Sequestration Center
Biota
620 Pg
Atmosphere
840 Pg
+4.0 Pg/yr
Soils (3-m)
4,000 Pg
Ocean
42,000 Pg + 2.3 Pg/yr
(i) Surface layer: 670 Pg
(ii) Deep layer: 36,730 Pg
(iii) Total organic: 1,000 Pg
Fossil Fuels
4,130 Pg
(i) Coal: 3,510 Pg
(ii) Oil: 230 Pg
(iii) Gas: 140 Pg
(iv) Other: 250 Pg
90Gt/yr
MRT = 5Yr
MRT = 25Yr
Mean Residence Time (MRT) = 400Yr
MRT = 6Yr
92.3Pg/yr
The Short-Term Global Carbon Cycle

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Carbon Management and
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• Gross Primary Productivity (GPP) = 123 Gt C/yr
• Net Primary Productivity (NPP) = 63 Gt C/yr
• Net Ecosystem Productivity (NEP) = 10 Gt C/yr
• Net Biome Productivity (NBP) = 3 Gt C/yr
“If we control what plants do with carbon, the fate of CO2 in the
atmosphere is in our hands”
-Freman Dyson (2008), BioScience (10/10)
Only 0.05% of the 3800 zettajoules (1021
J) of solar energy
is absorbed annually as GPP
Biosequestration of Atmospheric CO2

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Carbon Management and
Sequestration Center
Strengthening of
Elemental and H2O
Cycling
Soil and Water
Conservation
 Improvements in Rhizospheric Processes
 Increase in Net Biome Productivity
Increase in Soil Biodiversity
 Earthworm Activity
 MBC
 Increase in SOC Pool
 Improvement in Aggregation
Restoration of soil and environment quality,
improvement in soil resilience and increase in social
and political stability
Conversion to CA
 Residue Retention
 Cover Cropping
 INM
 Tillage Elimination
 Increase in Use Efficiency of Input
 Increase in Ecosystem services
Lal (2015)

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Carbon Management and
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Sustainable
Agriculture
(116-27 BC)
Agricultura “est scientia,
quae sint in quoque agro
serenda ac facienda,
quo terra, (that the land)
maximos (the highest)
perpetetuo (in perpetiuty)
reddat fructus” (yields)
Marcus
Terentius Varro
Rerum
Rusticarum
Ribri III
(Agricultural topics
in
3 books)

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Carbon Management and
Sequestration Center
“When we try to pick out anything by itself,
we find it hitched to everything else in the universe.”
John Muir
(Naturalist)

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Carbon Management and
Sequestration Center
Accelerated erosion
Innovative
Technology II
Innovative
Technology I
Subsistence
farming, none or
low off-farm input
soil degradation
New
equilibrium
Adoption of
RMPs
Time (Yrs)
Lal, 2004
80
100
20
40 60 80 100 120 140 160
40
60
20
RelativeSoilCPool
0
Maximum
Potential
Rate
ΔY
ΔX
Attainable
Potential
CSinkCapacity
Δt
•NT
•INM & NUE
•Cover Crops
•Biochar
•Agroforestry
•Desert. Control
• Afforestation
• Pasture Mgmt
•H2O harv., DSI
MRT =
Pool
Flux
Soil C Sequestration

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Carbon Management and
Sequestration Center
Sustainable Soil Management
• Replace what is removed,
• Respond wisely to what is changed, and
• Predict what will happen from anthropogenic
and natural perturbations
•Enhance soil resilience

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Carbon Management and
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Disease-
Suppressive soil
High Soil
Biodiversity
Improved
Varieties
Complex
Rotations
Conservation Agriculture System
Mulch Cover cropNo-till
MycorrhizaeMycorrhizae
RhizobiumRhizobium
Integrated Nutrient
Management

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Carbon Management and
Sequestration Center
Corn with no residue. Corn with 100% residue
Drought of 2012
Climate-Resilient Soil

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Carbon Management and
Sequestration Center
““Soil biota is the bioengine of the Earth”Soil biota is the bioengine of the Earth”
There is no such thing as a free biofuel fromThere is no such thing as a free biofuel from
crop residues.crop residues.
There is no such thing as a free biofuel fromThere is no such thing as a free biofuel from
crop residues.crop residues.
Economics of Residue Removal for Biofuel

23. 23
Carbon Management and
Sequestration CenterProperties of Agroecosystems
1) Productivity : Total output
2) Stability : Consistency of production
3) Equitability : Fair allocation for all inhabitants
of Earth
4) Autonomy : Self-sufficiency
5) Sustainability : Forever
6) Efficiency (Eco) : Producing more with less
All of these properties depend on soil carbon
pool

24. 24
Carbon Management and
Sequestration Center
• Total SOC pool to 2-m depth = 2400 Pg
• Increasing SOC pool by 1% = 24 Pg
• 1 Pg = 0.47 ppm
C sink capacity for every 1% increment ≈ 11 ppm
Capacity of Soil Carbon Sink

25. 25
Carbon Management and
Sequestration Center
Sustainable
Soil
Management
1.
Causes
of Soil
Degradation
• The biophysical process of soil degradation is driven by economic, social
and political forces.
• Vulnerability to degradation depends on “how” rather than “what” is grown.
2. Soil
Stewardship
& Human
Suffering 3.
Nutrient,
Carbon, &
Water Bank
4.
Marginality
Principle
5. Organic
vs. Inorganic
Nutrients6.
Soil Carbon
&
GHG Effect
8. Soil as
Sink for
Atmospheric
CO2 7.
Soil
vs.
Germplasm
9. Engine
of Economic
Development
10. Traditional
Knowledge &
Modern
Innovations
• When people are poverty stricken, desperate and starving, they
pass on their sufferings to the land.
• It is not possible to take more out of a soil than what is put in it
without degrading its quality.
• Only by replacing what is taken can a soil be kept fertile,
productive, and responsive to inputs.
• Marginal soils cultivated with marginal inputs produce
marginal yields and support marginal living.
•Recycling is a good strategy especially when there is something to
recycle.

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Carbon Management and
Sequestration Center
en.wikipedia.orgwww.worldwildlife.org
www.seeturtles.org
HANDOUT / Reuters
Soil: the Global Icon