Fourth Working Session of the International Network of Soil Information Institutions (INSII) 6-8 November 2018 | FAO HQ – German Room, Rome, Italy

1. IUSS WG Global Soil Map & GloSIS
Fine Resolution Soil Grid
Specifications
Dominique Arrouays (FR), Pierre Roudier (NZL),
Zamir Libohova (USA), Titia Mulder (NL)

2. What for? What were the initial aims?
Dealing with global issues requires global data and
assessment – Taking action requires local knowledge
=> Deliver a free-downloadable digital database on soil
attributes at a 3-arcsec x 3 arc sec (~90-m) scale all over
the world, with uncertainties

3. GlobalSoilMap Specifications
The specifications have been the first internationally
agreed specifications on digital soil mapping.
They explain WHICH products we want to achieve.
OPTIONS are provided in the specifications
=> Try to do the best with what we have!
Estimates of UNCERTAINTY are a key product, there is
still a lot of work to do on this

4. GlobalSoilMap products
Specifications Conferences – Books Highly cited papers
Scientific
Progress
Numerous Databases!

5. IUSS GlobalSoilMap WG –
The reason why
A fantastic opportunity : mechanisms for delivery +
R&D support
Support the production, based on ‘bottom-up’
approaches where possible
Review specifications – Ensure a link with GSP Pillar 4
fine grids.

6. IUSS GlobalSoilMap WG –
The reason why
Scientific products (reviews, methodological
advances)
• Deal with scientific issues (uncertainty, methods,
merging predictions)
• Coordinate the organization of the GlobalSoilMap
workshops/conferences
Report to IUSS on GlobalSoilMap achievements

7. Origin of people having officially supported
the proposal for a IUSS WG Global Soil Map
+ International Organizations : ISRIC, JRC, CGIAR
In the proposal
Late response
+ ISRIC, JRC, CGIAR
The door is open: feel free to join!

8. Pivotal Moments
GlobalSoilMap and Soil Science from 2016
to now
2016 – IUSS endorses the GlobalSoilMap
WG
2017 – A review paper on soil data rescue
involving 89 co-authors is published
2017 – The GlobalSoilMap specifications
are adopted by The Global Soil Partnership,
Pillar 4 for delivering a fine grid of soil
attributes
2017 – The 2nd GlobalSoilMap Conference,
(Moscow) proceedings are published
Arrouays et al.,
2017
Arrouays et al.,
2017

9. IUSS GlobalSoilMap WG – What next?
Review/ Update specifications – Establish a small group
• A list of volunteers was established during the World
Congress Soil Science (Brazil, 2018). A large part of them are
involved in both GSM and GSP activities
Activities
• Organize a dedicated conference merging Digital Soil
Mapping and Global Soil Map IUSS WG (Chile, 2019)
• Edit books/special issues/write papers
Formalize a link with GSP pillar 4 and INSII

10. Why should we strengthen the link between
GobalSoilMap WG and the INSII and the Pillar 4 WG
of the Global Partnership?
• The operational objectives are the same (deliver fine
grids of soil properties)
• We should avoid delivering contradictory/ diverging
products
• Win-win: The INSII and P4WG can benefit from the
IUSS WG methodological advances, the IUSS WG can
benefit from the visibility of GSP products

11. IUSS GlobalSoilMap WG
• Help P4WG to draft specifications for new products
asked to countries
• Act as a R&D WG helping to improve methods for
bottom-up mapping and further harmonization
• Improve methods for uncertainty assessment and
mapping and transfer them to INSII and P4WG of
the GSP
• IUSS WG can help training and capacity building

12. Why should we strengthen the link
We have a global consensus about the specifications for
gridded soil information products. We should consolidate it.
We have a unique opportunity to have both:
The IUSS WG on GlobalSoilMap supporting considerable
progress on DSM methodology and on improving the
specifications
The Global Soil Partnership which provides an efficient
policy mechanism to engage countries to deliver products
Win-win: The INSII and P4WG can benefit from the
IUSS WG methodological advances, the IUSS WG
can benefit from the visibility of GSP products

13. We should not miss this unique opportunity; it
would be a terrible error for the future of our
soils and for the world safety!

14. What does GobalSoilMap WG propose
to the INSII and the Pillar 4 WG of the
Global Partnership?
To have a representative of the IUSS WG invited to INSII
and P4WG meetings
This representative would be nominated by the IUSS WG
on an ad hoc basis, depending on the topic
The IUSS WG proposes to contribute to the writing the
specifications/cooking books of future products asked to
the countries by the GSP
The IUSS WG will propose its help for capacity
development and for developing new methods for
harmonization and for calculations of uncertainties

15. The motion the GlobalSoilMap WG proposes to the INSII and the Pillar 4 WG
The IUSS Working Group ‘Global Soil Map’ has been launched by the IUSS at the
end of 2016. It’s main aims are i) to update the specifications of the
GlobalSoilMap project for producing fine grids of soil properties, ii) to conduct
research activities about the methodologies to predict these properties, iii) to
provide assistance and training, iv) to report progress to the IUSS.
This WG has obvious links with the GSP Pillar 4 activities regarding the delivering
of fine grids of soil properties: i) the GSP plenary assembly endorsed the
GlobalSoilMap specifications; ii) the objective of delivering fine grids is the same.
To ensure coordination and to avoid overlapping or delivering of different
products in parallel, it is important that the activities of the GSP and of this WG
are strongly connected.
The IUSS WG ‘Global Soil Map’ asks if a representative of this WG can be
officially invited to the INSII and P4WG meetings. This representative could be
the chairman of the IUSS WG or a member of this WG, who will be nominated by
the WG on a case-by-case basis, depending on the topics.
Conversely, the IUSS WG ‘Global Soil Map’ proposes to invite a representative of
the GSP P4WG at each of its meetings.

17. • Mandatory but not limitative:
• Clay, silt, sand, coarse elements
• SOC
• pH
• CEC
• Total depth
• Effective depth to rooting
• Bulk density of fine earth
• Bulk density
• Available Water Capacity
• Potential other variates often cited : electrical conductivity, phosphorus, diagnostic
properties/horizons, soil type in WRB or ST.
• Predictions of mean values + uncertainties, on standard depths
Mandatory attributes

18. Uncertainties, the reason why:
1. Inform the users (confidence).
2. Allow modelers to take it into account
3. Show areas with large uncertainties and provide
information on where supplementary data should be
collected.

19. Which soil data are available?
Define an area of interest
Detailed soil maps
with legends
-Spatially weighted mean
-Spatial disaggregation
Extrapolation from
reference areas
Spatially weighted mean
Full Cover? Homosoil
Detailed soil maps
with legends
and Soil Point data
Soil Point data No data
NoYes
scorpan
kriging
Assemble environmental covariates
Soil maps:
-Spatially weighted mean
-Spatial disaggregation
Soil data:
- scorpan kriging
Extrapolation from
reference areas:
-Soil maps
-Soil point data
Full Cover?
NoYes
Assign quality of soil data and coverage in the covariate space
Choose your Digital Soil
Mapping method
depending on the data
you have…
Minasny & McBratney, 2010
Increasing uncertainty in prediction
(depends on the quality of data and complexity of soil cover )

20. Bottom-up vs Top-down
Bottom-up Top-down
Merge