Digital soil maps of soil organic carbon (SOC) sequestration potential resulting from hypothetical increases in long-term vegetation cover are presented at 100-m resolution across NSW. This increase could be achieved by strategies such as revegetation, grazing management or crop residue management. By applying a 10% relative increase in vegetation cover, a mean state-wide potential increase of 5.4 t/ha over the 0-30 cm depth interval was modelled. Assuming a 20-year period of re-equilibration, this equates to an average SOC increase of 0.27 t/ha/yr.
Maps and data are also derived using a 10% absolute increase in vegetation cover and a maximum potential increase in vegetation cover, being that of geographically equivalent nature reserves. The outputs can be used to identify locations of highest sequestration potential and thereby help prioritise areas and inform decisions on sequestration programs. They can provide approximate estimates of equivalent CO2 emissions avoided within the soil from these vegetation cover increases. The results could encourage formal incorporation of soil carbon sequestration in programs under Australia’s Emission Reduction Fund.
The work was undertaken as part of the NSW Government's Primary Industries Productivity and Abatement Program (PIPAP). Methods and results are fully reported in Gray et al. (2021) as provided here.