There is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international ‘4p1000’ initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long‐term experiments and space‐for‐time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils.

/pdf/how-to-measure-report-and-verify-soil-carbon-change-to-kt0ntktouo.pdf

How to measure, report and verify soil carbon change to realize the potential of soil carbon sequestration for atmospheric greenhouse gas removal.

Convolutional neural network for simultaneous prediction of several soil properties using visible/near-infrared, mid-infrared, and their combined spectra

Using deep learning to predict soil properties from regional spectral data

. The World Soil Information Service (WoSIS) provides
quality-assessed and standardised soil profile data to support digital soil
mapping and environmental applications at broadscale levels. Since the
release of the first “WoSIS snapshot”, in July 2016, many new soil data were
shared with us, registered in the ISRIC data repository and subsequently
standardised in accordance with the licences specified by the data
providers. Soil profile data managed in WoSIS were contributed by a wide
range of data providers; therefore, special attention was paid to measures
for soil data quality and the standardisation of soil property definitions,
soil property values (and units of measurement) and soil analytical method
descriptions. We presently consider the following soil chemical properties:
organic carbon, total carbon, total carbonate equivalent, total nitrogen,
phosphorus (extractable P, total P and P retention), soil pH, cation
exchange capacity and electrical conductivity. We also consider the following physical properties:
soil texture (sand, silt, and clay), bulk density, coarse fragments and
water retention. Both of these sets of properties are grouped according to analytical procedures that are
operationally comparable. Further, for each profile we provide the original
soil classification (FAO, WRB, USDA), version and horizon designations,
insofar as these have been specified in the source databases. Measures for
geographical accuracy (i.e. location) of the point data, as well as a first
approximation for the uncertainty associated with the operationally defined
analytical methods, are presented for possible consideration in digital soil
mapping and subsequent earth system modelling. The latest (dynamic) set of
quality-assessed and standardised data, called “wosis_latest”, is freely accessible via an OGC-compliant WFS (web feature
service). For consistent referencing, we also provide time-specific static
“snapshots”. The present snapshot (September 2019) is comprised of 196 498
geo-referenced profiles originating from 173 countries. They represent over
832 000 soil layers (or horizons) and over 5.8 million records. The actual
number of observations for each property varies (greatly) between profiles
and with depth, generally depending on the objectives of the initial
soil sampling programmes. In the coming years, we aim to fill gradually gaps
in the geographic distribution and soil property data themselves, this
subject to the sharing of a wider selection of soil profile data for so far
under-represented areas and properties by our existing and prospective
partners. Part of this work is foreseen in conjunction within the Global
Soil Information System (GloSIS) being developed by the Global Soil
Partnership (GSP). The “WoSIS snapshot – September 2019” is archived and
freely accessible at https://doi.org/10.17027/isric-wdcsoils.20190901 
(Batjes et al., 2019).

/pdf/standardised-soil-profile-data-to-support-global-mapping-and-x02esfqak0.pdf

Standardised soil profile data to support global mapping and modelling (WoSIS snapshot 2019)

A systematic study on the application of scatter-corrective and spectral-derivative preprocessing for multivariate prediction of soil organic carbon by Vis-NIR spectra

/pdf/a-global-spectral-library-to-characterize-the-world-s-soil-3i27xq6dx0.pdf

P. Sanborn

Papers

A global spectral library to characterize the world’s soil