Soil Carbon Pool As an Environmental Indicator

Carbon Management and Sequestration Center

Soil Carbon Pool as an Environmental Indicator

Rattan Lal Carbon Management and Sequestration Center The Ohio State University Columbus, OH 43210 USA

1 Carbon Management and Sequestration Center

SOIL: THE ESSENCE OF LIFE

“Hello there folks. Do you know who or what I am? I am the geomembrane of the Earth. I am your protective filter, your buffer, your mediator of energy, water, and biogeochemical compounds. I am your sustainer of productive life, your ultimate sources of elements, and the habitat for most biota. I am the foundation that supports you, the cradle of your myths, and the dust from which you will return. I am a soil”.

Richard Arnold (2005) Senior Soil Scientist

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SOIL

Soil is a 4-dimensional complex mixture of organic and mineral substances, with a hierarchy of pores containing dilute solution and gases at a wide range of energy potentials, comprising of diverse micro to macro organisms, and a medium for complex biochemical transformations which support plant growth and numerous ecosystem services.

Lal (2015)

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THE DIRT

"Dirt has no currency in western society, and has little impact on politicians. It comes under the journalist "MEGO" category… My Eyes Glaze Over.

Bar a few impressive dust storms, we care little of our soil. We do not relate what we eat in our home, buy in out supermarkets, or drink from our Starbucks to the soil. And yet, without soil, we become thirsty, hungry, and we die. Without soil, we become Mars, with no water, no atmosphere, and only relics of life, with at best distant stargazers trying to figure out the life that could have been."

Young and Crawford (2015) 4 Carbon Management and Sequestration Center

SCIENCE POLICY INTERPHASE

"So, before we examine what we need in terms of new seeds, new chemicals to add to the soil, and new technology platforms that need development, we need to urgently look at legal frameworks that protect our soil asset. So, our first challenge with any discipline, any agricultural framework, or any plant species, is to call on governments to implement legal strategies to secure and build our fertile soil reserves."

Young and Crawford (2015)

Especially so during the IYS-2015 5 Carbon Management and Sequestration Center

Mamani-Pati et al., 2014 6 Carbon Management and Sequestration Center

NATURAL ENVIRONMENT

• The aggregate of surrounding Physical Chemical things, conditions, or influences

Interaction • Surroundings

• Milieu

Biological • Context

• The style of a place

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INDICATOR

Latin verb “indicare” means to:

• Disclose • Point out • Announce • Estimate • Put a prince on • communicate

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INDICATOR

• It is a sign, signal or a message about the surroundings.

• It is an acceptable and simple yard stick about any parameter as a measure of the present state and of the future trends.

• It is a proxy regarding state of the things, resources, activities, etc.

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ENVIRONMENTAL INDICATOR

• It is a measure, quantitative or qualitative, of changes occurring in the environment, including trends overtime

• It is a quantifiable measure of the sate of the environment, and its impact on ecosystems.

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ENVIRONMENTAL INDICATOR

Ecosystem Economy

Human Well-being

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CHARACTERISTICS OF A GOOD INDICATOR

• Relevant • Simple • Reliable • User-driven • Repeatable • Policy-relevant • Accessible • Highly aggregated • Quantifiable • Credible • Scalable: local to national and global

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APPLICATION OF INDICATORS

• Assess trends • Compare scenarios • Monitor progress • Evaluate performance • Provide early warning • Assist in decision making • Identify knowledge gaps • Define researchable issues • Establish criteria for resource allocation • Measure impact

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GROUPING OF INDICATORS

Types of Environmental Indicators

State of the Environment Sustainability Environment Performance Indicators Indicators Indicators

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Environment INTERACTIVE Gaseous emissions Sea level rise Biodiversity INDICATORS Water quality Air quality Soil quality

Sustainability Human Well being Per capita CO2 Average age emission Education Types of Renewable vs. total energy consumed Diet quality Indicators Affluence Recycling of urban/ industrial/ ethnic/ Status of women and gender equity minority Resilience

Performance Trend in emissions Renewable resources vs. total resources Intensity of use

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SUSTAINABILITY INDICATORS

Well-being Sustainability Social

Economy

Environment

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HOLISTIC INDICATORS

Environment

Economy Society

Sustainability

Technology Performance Management

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SOIL CARBON AS AN ENVIRONMENTAL INDICATOR BECAUSE IT DETERMINES:

• Productivity • Erosion, degradation • Biodiversity • Water quality • Gaseous emission and air quality • Pollutant denaturing • Food and nutritional security • Plant, animal and human health • Ecosystem resilience • Sustainability

18 • Extractive Farming/Subsistence

• Depletion of SOC and Nutrients • Decline in Soil Structure

• Loss of Soil Resilience

• Decline in Ecosystem Functions and Services

• Loss of Soil biodiversity • Disruption of Key Processes

• Hunger • Malnutrition • Political Unrest • Civil Strife • War and insecurity Severe Degradation Carbon Management and Sequestration Center

THE LIVING SOIL

Soil is an organic- carbon mediated realm in which solid, liquid, gas and biology all interact from a scale of nanometer to landscape.

The weight of live organisms in arable land is 5 t/ha 20 Carbon Management and Sequestration Center

SOILS AND MEN (1938)

“SOM is one of our most important natural resources: its unwise exploitation has been devastating, and it must be given its proper place in any conservation policy as one of the major factors affecting crop production in the future.”

“A declining soil fertility, due to a lack of organic material, major elements, and trace minerals, is responsible for poor crops and in turn for poor people.”

“Health of our nation may be impossible to restore without first restoring the health of our soils.”

Albrecht, President SSSA (1938) 21 Carbon Management and Sequestration Center

AL-IKSEER (THE RECIPE)

“Soil organic matter has over the centuries been considered by many as an elixir of life. Ever since the dawn of history, some eight thousand and more years ago, man has appreciated the fact that dark soils, commonly found in river valleys and broad level plains, are usually productive soils. He also realized at a very early stage that color and productivity are commonly associated with organic matter derived chiefly from decaying plant materials”. ... Allison, 1973

22 Carbon Management and Sequestration Center Elemental Ratio Cereal Residues Humus NUTRIENTS REQUIRED TO CONVERT BIOMASS INTO SOC C:N 100 12 C:P 200 50 Crop Residues SOC C:S 500 70

Biochemical Transformations

+ (N, P, S etc.)

Elemental Ratio Cereal Residues SOC C:N 100 12 C:P 200 50 C:S 500 70

Straw photo: http://shannahatfield.com/2013/09/24/hay-vs- straw/ Humus photo: http://www.davecullen.com/ 23 forum/index.php?topic=26820.3285 Carbon Management and Sequestration Center

TRADING NUTRIENTS FOR CARBON

Sequestration of 10,000 kg of biomass C as SOC requires additional nutrients:

• 833 kg N 28,000 kg of C in residues • 200 kg P 62,000 kg of residues (oven dry) • 143 kg S

These ingredients will produce + 17,241 kg of humus

Recalculated from Himes, 1998. 24

Carbon Management and Sequestration Center

MRT OF SOIL ORGANIC CARBON

• MRT varies from a few seconds to a few millennia.

• It is only the SOC with a long MRT of decades to millennia that can mitigate the climate.

• It is the environmental and biological controls, rather than molecular structural properties (recalcitrance), which impact the MRT.

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MECHANISMS OF SOC PROTECTION

Protection Mechanism Component Chemical Silt + Clay Physical Micro-aggregates Biochemical Non-hydrolyzable C Unprotected POM in sand fraction

Six et al. (2002)

26 Carbon Management and Sequestration Center CLIMATE CHANGE WATER

RESOURCES - Migaon - Quality -Adaptaon - Quanty - Stabilizaon

THE ENGINE OF SOIL ECONOMIC QUALITY DEVELOPMENT (SOC)

BIODIVERSITY FOOD SECURITY - Above ground - Quanty - Below ground - Quality

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Innovative SOIL C SEQUESTRATION Technology II

Subsistence Innovative Technology I farming, none or New Adoption of 100 low off-farm input equilibrium RMPs soil degradation Maximum C C Sink Capacity Potential • Conservation 80 Agriculture Rate Attainable • Biochar ΔY Potential • Agroforestry • Desert. Control ΔX 60 • Afforestation • Pasture Mgmt

• H2O harv., DSI Δt • Farming 40 Accelerated erosion Systems

Relative Soil C Pool CPool RelativeSoil Pool MRT = 20 Flux

Lal, 2004 0 Time (Yrs) 28 20 40 60 80 100 120 140 160 Carbon Management and Sequestration Center

WORLD POPULATION (BILLIONS) 20 0.8 1 3 4 6 7.6 8 9.6 15

12 • Recarbon- TECHNOLOGICAL ization of the biosphere

(Mg/ha) (Mg/ha) NNOVATIONS 8 I • Nutrition-

• Sustainable sensitive Improved intensification agriculture 6 cultivars (SI) Biotech- • SI/ • Rhizospheric nology processes Restorative

RODUCTION Agriculture No-till

Micro-irrigation • Disease- P

farming suppressive • Soil-less soils 4 INM agriculture GMOs GMOs OOD

Perennial culture • Soil-less

IPM

F agriculture • Phytobiome management

Germplasm Carbon

• The nexus sequestration approach • Urban 1 • Phytobiome agriculture ELATIVE management R 0.8 • Animal Power • Space

Machinepower Fertilizers Conservationagriculture

GREEN REVOLUTION GREENREVOLUTION Precisionfarming Complexrotations

farming • Hand Tools • Rotations 1750 1850 1950 1975 2000 2015 2025 2050 YEAR 29 Carbon Management and Sequestration Center

TOWARDS C- NEUTRAL AGRICULTURE Chatting with plants through INM molecular- based No-till Farming signals

Soil biota and N, P, K, Zn, H2O ecosystems services

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Resilience of Soil-Ecological Systems

It has multiple regimes (stable states) which are separated by thresholds

Resilience Thresholds

Critical Threshold

The current state of Possible states in which the the system can still have the system same function Irreversible Degradation Regime Shift

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THRESHOLD/CRITICAL LEVEL

Threshold/Critical Level/Tipping Point: Soil processes and properties have threshold levels (~2.0% SOC concentration). Beyond threshold level, there is a drastic regime change.

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CRITICAL LEVEL OF SOC FOR WHEAT YIELD (Diaz-Zorita et al., 2002)

4000

3000 )

2000-1 Yield (kg Yield ha

1000

0 0 20 40 60 80 Soil Organic C (Mg ha-1) 33 Carbon Management and Sequestration Center

CROP YIELD INCREASE WITH INCREASE IN SOC BY 1 Mg C/Ha (LAL, 2005)

Crop Yield Increase (Kg/Ha/Mg C) Maize 100 - 300 Soybeans 20 - 50 Wheat 20 - 70 Rice 10 - 50 Sorghum 80 - 140 Millet 30 - 70 Beans 30 - 60

30-50 million tons/yr in developing countries

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SUSTAINABLE SOIL MANAGEMENT

• Replace what is removed,

• Respond wisely to what is changed, and

• Predict what will happen from anthropogenic and natural perturbations

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SOIL C AS AN INDICATOR OF ENVIRONMENT

There are numerous advantages:

1. It is a familiar property,

2. It involves direct measurement,

3. It can be measured in 4 dimensions (length, width, depth, time),

4. It lends itself to repeated measurements over the same site,

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SOIL C AS AN INDICATOR OF ENVIRONMENT (CONTINUED)

5. It is linked to ecosystem performance and services,

6. It is a key driver of soil formation,

7. It is important to soil fertility,

8. It has memory,

9. It has well defined properties,

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SOIL C AS AN INDICATOR OF ENVIRONMENT (CONTINUED)

10. It can be used in synergism with other indicators,

11. Its uncertainty can be quantified,

12. Its pathways across the landscape can be followed,

13. It is an important archive of paleo-environmental conditions.

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SOILS AND MEN (1938)

“A declining soil fertility, due to a lack of organic material, major elements, and trace minerals, is responsible for poor crops and in turn for poor people.”

“Health of our nation may be impossible to restore without first restoring the health of our soils.”

Albrecht, President SSSA (1938) 39 Carbon Management and Sequestration Center

AL-IKSEER (THE RECIPE)

40 Carbon Management and Sequestration Center

GLOBAL SOIL ORGANIC CARBON POOL 0-30cm DEPTH

Total Pool = 684-724 (704) Pg .... Batjes (1996) 0.4% Increase/yr = 2.8 Pg C/yr

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GLOBAL POTENTIAL OF TERRESTRIAL C SEQUESTRATION (Lal, 2010)

42 THE NPP OF A CORN FIELD IS 400 TIMESCarbon THE Management ANNUAL and Sequestration Center INCREASE IN ATMOSPHERIC C POOL

NPP

/y 2 yr 12.5 x 10-12 Pg C/ha/y

NBP≅3PgC/yrCO 2ppm + Pg C/ha per C/ha Pg -9 5 x 10

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THE TERRESTRIAL AND OCEANIC PROCESSES IMPACTING ATMOSPHERIC CHEMISTRY

Atmosphere 800 Pg (400 ppmv) + 4.3 Pg/yr (2.2 ppm/yr)

Land Fossil Fuel Ocean

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POTENTIAL MITIGATION STRATEGIES INVOLVING THE TERRESTRIAL BIOSPHERE

Terrestrial Biosphere

• Soil • Biota

Atmosphere Fossil Fuel Ocean

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Biosphere • Live Biomass • Detritus Material • Marine Biota • Green Roofs • Afforestation

Lithosphere Anthroposphere Byproducts of • Geologic sequestration Storing Biomass (CCS) • Houses, furniture, • Carbonation Biogenic timber processes Carbon • Carbonization • Weathering of • Landfills alumino-silicates • Artificial trees

Pedosphere • Land application of biomass-C (mulch, compost, manure, biochar) • Erosion control • Waste management • Producing technosols • Soil restoration 46 Carbon Management and Sequestration Center

TECHNICAL POTENTIAL OF CARBON SEQUESTRATION IN THE TERRESTRIAL

Technical Potential Activity (Pg C/yr) A. Soil • Cropland management 0.4-1.2 • Restoration of Salt-Affected Soils 0.3-0.7 • Desertification Control 0.2-0.7 Sub-total 0.9-2.6

B. Vegetation • Afforestation, Forest Succession, 1.2-1.4 Agroforestry, Peatland Restoration • Forest Plantations 0.2-0.5 • Savanna and Grassland Ecosystems 0.3-0.5 Sub-total 1.7-2.4

Grand Total 2.6-5.0 (3.8) 47 Carbon Management and Sequestration Center

4 FOR 1000 : A NEW PROGRAM FOR CARBON SEQUESTRATION IN AGRICULTURE

With soil C pool of 2400 Pg, 4/1000 = 9.6 Pg C

= 4.5 ppm CO2 Drawdown

• Reducing emissions in 2050 to half of 1990 levels in Europe

implies offsetting a total if 20 Pg CO2 (5.5 Pg C)

• Thus, 4 per 1000 initiative can be an important strategy to achieve this goal.

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SOIL CARBON AND ECOSYSTEM SERVICES

22 -- FoodFood SecuritySecurity

1- Global Soil C Pool

Lal (2012) 49 Carbon Management and Sequestration Center

SOIL: THE GLOBAL ICON

www.seeturtles.org HANDOUT / Reuters

Water Carbon Nitrogen Phosphorous Sulfur

Lal (2014) 50 www.worldwildlife.org en.wikipedia.org