Data from: Sensitivity of global soil carbon stocks to combined nutrient enrichment

Soil stores approximately twice as much carbon as the atmosphere and
fluctuations in the size of the soil carbon pool directly influence
climate conditions. We used the Nutrient Network global change experiment
to examine how anthropogenic nutrient enrichment might influence grassland
soil carbon storage at a global scale. In isolation, enrichment of
nitrogen and phosphorous had minimal impacts on soil carbon storage.
However, when these nutrients were added in combination with potassium and
micronutrients, soil carbon stocks changed considerably, with an average
increase of 0.04 KgCm−2 year−1 (standard deviation 0.18 KgCm−2 year−1).
These effects did not correlate with changes in primary productivity,
suggesting that soil carbon decomposition may have been restricted.
Although nutrient enrichment caused soil carbon gains most dry, sandy
regions, considerable absolute losses of soil carbon may occur in
high‐latitude regions that store the majority of the world's soil
carbon. These mechanistic insights into the sensitivity of grassland
carbon stocks to nutrient enrichment can facilitate biochemical modelling
efforts to project carbon cycling under future climate scenarios.