Niels H. Batjes

TL;DR: In this article, a discrepancy of approximately 350 × 1015 g (or Pg) of C in two recent estimates of soil carbon reserves worldwide is evaluated using the geo-referenced database developed for the World Inventory of Soil Emission Potentials (WISE) project.

TL;DR: Improvements in the relative accuracy considering the amount of variation explained, in comparison to the previous version of SoilGrids at 1 km spatial resolution, range from 60 to 230%.

Abstract: METIS-ID: 167825 The Harmonized World Soil Database is a 30 arc-second raster database with over 15000 different soil mapping units that combines existing regional and national updates of soil information worldwide (SOTER, ESD, Soil Map of China, ISRIC-WISE) with the information contained within the 1:5 000 000 scale FAO-UNESCO Soil Map of the World (FAO, 1971-1981). The resulting raster database consists of ... 21600 rows and 43200 columns, which are linked to harmonized soil property data. The use of a standardized structure allows for the linkage of the attribute data with the raster map to display or query the composition in terms of soil units and the characterization of selected soil parameters (organic Carbon, pH, water storage capacity, soil depth, cation exchange capacity of the soil and the clay fraction, total exchangeable nutrients, lime and gypsum contents, sodium exchange percentage, salinity, textural class and granulometry). Reliability of the information contained in the database is variable: the parts of the database that still make use of the Soil Map of the World such as North America, Australia, West Africa and South Asia are considered less reliable, while most of the areas covered by SOTER databases are considered to have the highest reliability (Southern Africa, Latin America and the Caribbean, Central and Eastern Europe). Further expansion and update of the HWSD is foreseen for the near future, notably with the excellent databases held in the USA (Natural Resources Conservation Service US General Soil Map, STATSGO), Canada (Agriculture and AgriFood Canada: The National Soil Database NSDB), and Australia (CSIRO, ACLEP, Nnatural Heritage Trust and National Land and Water Resources Audit: ASRIS), and with the recently released SOTER database for Central Africa (FAO/ISRIC/Univ. Gent, 2007)

TL;DR: SoilGrids1km provides an initial set of examples of soil spatial data for input into global models at a resolution and consistency not previously available and results of regression modeling indicate that the most useful covariates for modeling soils at the global scale are climatic and biomass indices, lithology, and taxonomic mapping units derived from conventional soil survey.

TL;DR: In this article, the influence of various factors regulating emissions from mineral soils was assessed using 846 N2O emission measurements in agricultural fields and 99 measurements for NO emissions, and the available data can be used to develop simple models based on the major regulating factors which describe the spatial variability of emissions of N 2O and NO with less uncertainty than emission factor approaches based on country N inputs.