This document discusses plans for creating a Global Soil Organic Carbon Sequestration Potential (GSOCseq) map. It will use a country-driven approach with capacity development workshops to generate national maps of attainable SOC stocks under recommended land management practices. A three-phase process is outlined: 1) Develop technical specifications; 2) Conduct capacity building; 3) Update information and compile the global GSOCseq map. Modeling approaches at different levels are proposed depending on data availability and skills. The goal is to empower countries to estimate their own SOC sequestration potential to inform policies and actions.
2. SOC represents the largest C pool
contained in terrestrial ecosystems
Principal global carbon pools
3. SOM dynamics in Heilongjiang Province
Morrow Plots, Illinois
Clearing Prairies (natural grassland) for agriculture
Gollany et al, 2011
Ren et al, 2018
long-term rotations experiment in
Uruguay by the Century model
Climate change
• Carbon emissions from LULCC represent the second largest
anthropogenic source of carbon into the atmosphere
• This emissions are the most uncertain component of the global carbon
cycle.
Loss of SOC is
the second
biggest threat to
soil functions
6. Global Soil Organic Carbon Stocks on Croplands
Available maps about SOC sequestration
Fleskens et al, 2017
Zomer et al, 2017
7. Global SOC sequestration
potential
Available maps about SOC sequestration
Total biophysical mitigation potentials (all practices, all GHGs: Mt
CO2-eq. yrK1) for each region by 2030, showing mean estimates (B1
scenario shown though the pattern is similar for all SRES scenarios).
Global soil organic carbon restoration potential
Smith et al, 2008
Lal, 2004
9. Estimates of global SOC stocks from the literature through
time
Median across all estimates 1460.5 Pg C
Range 504–3000 Pg C
n = 27 studies
10. GSOCmap: the most recent global estimate
of global SOC stocks in the top 30 cm
Ground Data
Measurements
~1 Million
Global SOC
Stock
~680 Pg
Triggered further actions: Global Soil
SOC Sequestration Assessment
11. Why should we continue with this topic?
• There are high expectations on the world's soils to
contribute to climate change mitigation and adaptation.
• The United Nations Statistics Division (UNSD), defined
the bellow and aboveground SOC stocks as a universal
sub-indicator (15.3.1) to asses land degradation.
• Need to contribute to enhancement of soil productivity
and food security.
• There is a request from member countries to generate
updated information about the global potential of SOC
sequestration. GSOC17, 6th GSP Plenary Assembly/26th
COAG session.
• Empower countries to know and generate their own
information about their SOC sequestration potential.
12. Why should we continue with this topic?
• We approximately know the current SOC stocks
GSOCmap and is guiding policies (i.e. Black soils).
• We still do not know where there is potential for
sequestering SOC so that policies and actions by
countries are implemented.
13. Global assessment of soil organic carbon
sequestration potential (GSOCseq)
Objective
• Preparation of the GSOCseq map following a
country-driven approach including country
capacity development.
14. Global assessment of soil organic carbon
sequestration potential (GSOCseq)
Added value
• Country driven approach (bottom-up).
• Information will be generated by national experts.
• Information will be generated by the countries and for the
countries.
• Empowerment of the countries.
• Capacity development at national and regional level trough SOC
modeling and mapping workshops.
• Estimation of attainable SOC stocks for each context and
country.
15. Phases Activities Outputs
Phase 1
Preparation of
technical
specifications to
develop the GSOCseq
1. Preparation of concept note and
technical specifications (ITPS,
INSII)
2. Call for preparation of the map to
focal points
Technical
specifications
Phase 2
Capacity
development in SOC
modelling and
mapping
1. Preparation of a handbook
2. Tailored capacity development in
SOC modelling and mapping
3. Preparation and provision of
global datasets: official exchange
of edaphic-climatic data between
GSP-Secretariat and member
countries.
Handbook of SOC
sequestration
potential
mapping
Capacity building
in SOC modelling
at national and
regional levels
Phase 3
Update existing
information on global
SOC sequestration
potential
1. Preparation of national SOC
sequestration potential maps by
member countries
2. Delivery of national SOC
sequestration potential maps.
3. Quality assessment
4. Harmonization and compilation
of GSOCseq.
5. Final review by ITPS, IPCC and SPI-
UNCCD.
6. Launch during WSD19
National SOC
sequestration
potential maps
available.
Global soil
organic carbon
sequestration
potential map
launched.
16. Inspired in the Global Yield Gap
Atlas Project
http://www.yieldgap.org/gygamaps/app/index.
html
‘Gap’ approach
•National experts – bottom up
•Over 65 countries
•Over 25 publications. E.g.
Van Ittersum et al., 2013
Grassini et al 2015
Schills et al 2018
•Identyfing environments with greater
potential to increase production
•establishing priorities for research and public
policies among countries and within a country
17. Technical specifications
• Actual: present stocks in a specific edapho-climatic condition (country,
regional, sub-regional scale), up to a defined depth, under present LUM.
• Attainable: stocks for the same edapho-climatic conditions, under expert
recommended LUM to prevent soil degradation and improve soil carbon
sequestration, after a defined period of time.
• Native vegetation: assuming the system is in ‘equilibrium’ (under ‘pristine’
conditions )
• Saturation: ‘physical’ potential of a specific soil to sequester carbon.
“Soil Carbon Gaps
conceptual
framework”
18. • Level 1: Minimum data and technical capacity requirements.
‘Empirical’ Models: IPCC with national and regional data.
• Level 2: Intermediate data and technical capacity requirements.
‘Soil’ Models: Roth-C type
• Level 3: Maximum data and technical capacity requirements.
‘Ecosystem’ Models: CENTURY; DAY-CENT type.
• Level and methodology selection will depend on data
availability and technical capacity .
• Moving to a higher level should improve the accuracy of
the estimation and reduce uncertainties.
• Through capacity development we have the expectation
of aspiring to level two in all countries.
• We'll use level 1 when there's no country participation.
To estimate attainable SOC Stocks under recommended practices
in a 20 years period, a modeling approach is proposed:
19. Level 1 Empiric, Level 1 approach using global coefficients to
estimate attainable SOC stocks
Global coefficients
Prior to the use of any modeling approach, a ‘general’ empiric estimate of
attainable SOC stocks under ‘best’ practices may be performed as a guide
20. Level 1 ‘ IPCC with national data’ Approach, for the estimation
of Attainable SOC stocks under recommended practices
Attainable SOC 20y = SOC Ref x FLU x FMG x FI
This approach projects net stock changes of C over a given period of time
The role of soil organic carbon in global carbon cycles is receiving increasing attention both as a potentially large and uncertain source of CO2 emissions in response to predicted global temperature rises, and as a natural sink for carbon able to reduce atmospheric CO2.
Carbon emissions from land use and land cover change (LULCC) represent the second largest anthropogenic source of carbon into the atmosphere, and they are the most uncertain component of the global carbon cycle.
Hence, a need exists for improved understanding of soil carbon stocks, their distribution and likely impacts of management options on soil carbon emissions to improve models and policies.
The SOC sequestration is caused by those practices that add high amounts of biomass to the soil, cause minimal soil disturbance, conserve soil and water, improve soil structure, enhance activity and species diversity of soil fauna, and strengthen mechanisms of elemental cycling.
An extensive body of research has shown that land management practices can increase soil carbon stocks on agricultural lands with practices including: Cover cropping, addition of organic manures, conservation tillage, mulching, fertility management, agroforestry, and rotational grazing
We model the global SOC restoration potential in the top 30cm of soil as a full-scale SOC Restoration scenario by aggregating the effects of the most effective restoration category in each location.
SLM and reforestation practices can affect SOC in two ways: Restoring SOC and Preventing SOC loss
Establishing SOC restoration potential requires: i) restoration and prevention trend lines considering time after investment (literature review) ii) SOC restoration ceilings (S-World) iii) Current levels of soil loss and SOC loss (NDVI+S-World) iv) Classification of restoration measures and developing an allocation mechanism for these categories of restoration measures (WOCAT and data review)
We model the global SOC restoration potential in the top 30cm of soil as a full-scale SOC Restoration scenario by aggregating the effects of the most effective restoration category in each location.
SLM and reforestation practices can affect SOC in two ways: Restoring SOC and Preventing SOC loss
Establishing SOC restoration potential requires: i) restoration and prevention trend lines considering time after investment (literature review) ii) SOC restoration ceilings (S-World) iii) Current levels of soil loss and SOC loss (NDVI+S-World) iv) Classification of restoration measures and developing an allocation mechanism for these categories of restoration measures (WOCAT and data review)
CIRCASA (Coordination of International Research Cooperation on soil Carbon Sequestration in Agriculture) aims to develop international synergies concerning research and knowledge exchange in the field of carbon sequestration in agricultural soils at European Union and global levels, with active engagement of all relevant stakeholders.
The Verified Carbon Standard (VCS) Programme. There are several methodologies relevant for SOC management in agriculture and forestry. The Soil Carbon Quantification Methodology was approved since 2012. It supports sustainable methods of agriculture and other land use.
The OCCP is a voluntary program for the verification, certification, and registration of Oklahoma carbon offsets and avoided emissions from agriculture, forestry, and geologic sequestration. It provides project verification to approved aggregators and buyers of carbon offsets.
AFR100 (the African Forest Landscape Restoration Initiative) is a country-led effort to bring 100 million hectares of land in Africa into restoration by 2030.
SOC stocks are temporally and spatially variable which complicates sampling, measuring and monitoring SOC stocks. Countries place great emphasis on managing, increasing and monitoring SOC stocks for sustainable development, fostering adaptation to climate change, sustainable agriculture, and restoration of degraded soils. However, quantifying these benefits will not be possible unless changes in C stocks can be measured and monitored accurately and cost‐effectively.
Accurate SOC measurement and monitoring requires the establishment of baseline SOC stocks from which to measure future changes associated with environmental changes and management.
There is general agreement that the technical potential for sequestration of carbon in soil is significant, and some consensus on the magnitude of that potential.
First test round of the Global Soil Information System following a bottom-up approach.
First ever global soil organic carbon assessment done by a Country Driven Approach.
supports the national capacities to build their National Soil Information Systems.
has proven the feasibility of a distributed approach.
Triggered further actions: Global Soil Organic Carbon Sequestration Assessment, Global SOC Monitoring Network
SOC stocks are temporally and spatially variable which complicates sampling, measuring and monitoring SOC stocks. Countries place great emphasis on managing, increasing and monitoring SOC stocks for sustainable development, fostering adaptation to climate change, sustainable agriculture, and restoration of degraded soils. However, quantifying these benefits will not be possible unless changes in C stocks can be measured and monitored accurately and cost‐effectively. Accurate SOC measurement and monitoring requires the establishment of baseline SOC stocks from which to measure future changes associated with environmental changes and management.
There is general agreement that the technical potential for sequestration of carbon in soil is significant, and some consensus on the magnitude of that potential.
Black soils are of particular global importance because of their relevance to food security and climate change. Considering the great importance of these soils, it becomes crucial to promote their conservation and sustainable use and maintain their functioning in the longer term to keep them supporting food security while protecting the environment and mitigating climate change.
Considering the importance of soils with very high SOC content, the International Network of Black Soils (INBS) was launched during the Global Symposium on Soil Organic Carbon on 21-23 March 2017. The objective of the network is to foster technical cooperation among countries having these precious soils.
Objectives of the INBS
To provide a platform for countries with BS to discuss common issues related to the conservation and SM of BS.
To develop a report on the global status.
To foster collaboration among countries.
Identify relevant research gaps.
Platform for enhancing collaboration and synergies to move SSM forward and achieve implementation in black soil region countries of the world.
However, understanding the potential for sequestering SOC is still unknown.
Similarly, ‘Soil Carbon Gaps’ may be determined at a sub-regional, regional and country level, for different productive systems, by estimating the gap or difference between actual Soil Organic Carbon (SOC) stocks; attainable SOC stocks; and pristine (vegetation vegetation) or SOC Saturation Levels.
Estimating the gaps and rates of carbon sequestration in the different regions and countries will allow to identify conditions with faster rates and greater potential to accumulate SOC, and to establish priorities for research, policies and management decisions.
Although this last two SOC stocks may give an approximation of the maximum sequestration potential in some cases, it is clear that attaining pristine or saturation levels may be unrealistic in most productive systems (Wiesmeier et al., 2014).
Prior to the use of any modeling approach, a ‘general’ empiric estimate of attainable SOC stocks under ‘best’ practices may be performed as a guide, using global coefficients and functions from Minasny et al (2017) or Zommer et al (2017), and considering GSOC actual stocks as a baseline.
Abstract. Soil organic carbon is a highly variable soil property. In a soil profile, the concentration of organic carbon shows marked anisotropy. Many times, in the field soils are surveyed using morphological criteria. This means that different soil horizons are identified in the profiles at different depths for sampling purposes.
Taking into account that in national maps soil organic carbon contents must be obtained from the top 30 cm soil depth, we need to predict soil organic carbon contents from legacy data, usually including two fixed soil thickness that do not exactly match. It is not an easy task. Different models have5 been proposed to estimate the vertical variability that lo causes anisotropy of soil organic carbon. Soil organic carbon also varies with time, although at a slower rate.
This variation is related to changes in land use, management and input regimes. There are numerous models to estimate the variation of the soil organic carbon content with time. Soil organic carbon also varies in space, even between two proximal locations. In recent years, numerous digital soil map models appeared.
These models use the spatial variation of environmental properties and machine learning techniques to estimate the spatial variability of the soil property of interest.
In this paper, we combine three models to obtain the soil organic carbon map of Argentina from legacy data. Using the 5368 soil profiles in the Soil Information System of Argentina we applied a mass preserving spline to obtain the amount of soil organic carbon at a fixed depth of 0 to 30cm.
Then, we estimated the temporal variation at the profile locations by means of soil organic model for land use use changes (croplands) of 2006 IPCC Guidelines. A Tier 2 approach was applied because the country has its own soil carbon reference values and non-dimensional factors (FLU, FMG, FI) by15 regions.
Finally we applied a digital soil mapping technique to account for the spatial variability. Using this combination we obtained a map of the predicted soil organic carbon stock and a measurement of its uncertainty