This presentation was presented during the 1 Parallel session on Theme 1, Monitoring, mapping, measuring, reporting and verification (MRV) of SOC, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Mr. Luuk Fleskens from Soil Physics and Land management Group – Wageningen University, in FAO Hq, Rome

1. A high-resolution spatially-explicit
methodology to assess global soil organic
carbon restoration potential
21 March 2017
Luuk Fleskens, Michel Bakkenes, Coen Ritsema, Ben ten
Brink, Klaas Oostindie, Gudrun Schwilch

2. Rationale
 Urgent need for spatial data to guide initiatives on
restoration and prevention of land degradation:
what practices are available, possible and feasible
in each location, and how do they perform?
 Much research exists on restoration opportunities,
but the bulk of it concentrates on local scales.
 A new approach is therefore much needed that,
based on the state of knowledge, enables a global
outlook on opportunities and challenges of SOC
restoration.

3. Methodology
We model the global SOC restoration potential in the top 30-
cm 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)

4. C Sequestration potential: restoration +
prevention of SOC losses

5. SLM effect on SOC – relation of SOC
increase with time
Literature review
Relationship between the
number of years and the
increase of Soil Organic
Carbon (SOC)(Mg/ha) for
those cases exhibiting a
sequestration rate greater or
equal than 0.25 Mg/ha, or
where the total SOC increase
is greater or equal than 7.5
Mg/ha
This function is used to map
C restoration potential

6. Current SOC levels, trend and potential
SOC content
30 arcsec (~1 km2) global datasets:
• Current soil organic carbon (SOC) content
Based on S-World; functional interpolation modelling
based on harmonised global soil profiles. Stoorvogel
et al. (2017a) Land Deg Dev in press)
• Current rate of soil degradation (SOC loss
and soil depth loss) Based on trend analysis
and projection of bias-corrected NDVI analysis.
Schut et al. (2015) PLOS One 10(10): e0138013
• Potential soil organic carbon (SOC)
content Based on S-World; analyses of soils
under natural land use classes and best possible
agricultural management given current land use.
Stoorvogel et al. Stoorvogel et al. (2017b) Land Deg
Dev in press)

7. SLM category types
WOCAT Broad
Categories
WOCAT
Sub-classifications
included)
Agronomic Cropping
management
Conservation
agriculture
Reduced tillage (44)
Soil improvement Manuring/composting Soil improvement (42)
Integrated soil fertility
management
Vegetative Cover crops Vegetative cover (33)
Cross-slope barriers
(vegetative)
Vegetative barriers (43)
Agroforestry Agroforestry (38)
Sustainable planted
forest management
Reforestation in
savannahs* (29)
Assisted natural
regeneration* (6)
Smallholder woodlots*
(6)
Forest plantations *(6)
Structural Water management Water harvesting Floodwater harvesting Water harvesting (36)
Macrocatchment
Microcatchment
Rooftop/courtyard
Irrigation Drip irrigation Irrigation (24)
Smallholder irrigation
management
Cross-slope barriers
(structural)
Terraces Terracing (29)
Bunds Bunds (45)
Gully rehabilitation Gully rehabilitation (26)
Management Grazing land
management
Integrated crop-
livestock management
Grazing land
management (39)
Pastoralism and
rangeland management
Forest management Sustainable forest
management in
drylands
Sustainable rainforest
management
Combination Miscellaneous Other Multi-faceted
intensification (19)Trends and
opportunities
Classification
used

8. SOC restoration potential per technology
category*
*Based on WOCAT expert opinion, assuming a 5-year assessment lag period
SOC Increase (%)
Soil loss reduction (%)

9. Applicability of SLM categories (examples)
Agroforestry
Terraces
Water harvesting
Bunds
Considering land use, slope, elevation, precipitation,
biome, soil depth, soil texture, population density,
distance to roads/ports/etc (at 1 km2 resolution)

10. Most effective restoration technology per
location/pixel

11. Soil organic carbon restoration potential
until 2050

12. SOC restoration potential 2050
Calculations based on following assumptions:
• Excludes conversion of any agricultural land to forest
• Considers only the top 30 cm of soil as responding to
management
Total global SOC restoration and prevention: 22 Gt C

13. Conclusions
1. We present a first, high resolution (30 arc second) and
spatial-explicit assessment of the global SOC
restoration potential.
2. A theoretical full-scale Restoration scenario considering
both restoration of historical and prevention of ongoing
SOC losses, amounts to 22 Gt by 2050.
3. Comparing our results to findings by others, the
potential contribution of SOC restoration to climate
change mitigation is low, mainly governed by SOC
ceilings associated to current land use.
4. A variety of restoration technologies can be deployed for
restoration. There are some interdependencies that
were not considered (e.g. use of compost/manure may
be limiting; livestock exclusion may lead to degradation
surrounding areas)