Functional land management for managing soil functions – the trade-off between primary productivity and carbon storage

This research provides a first example of a practical application of the concept relevant to policy stakeholders, wherein the trade-off between two soil functions – ‘primary productivity’ and ‘carbon cycling and storage’ is assessed. This is measured in response to the intervention of land drainage systems applied to poorly and imperfectly draining managed grasslands in Ireland. This trade-off is examined spatially using integrated mapping within ArcGIS. National level datasets on land use were combined with an indicative drainage map. Drainage class was used as the dominant classifier for soil types. This allowed both the spatial heterogeneity of soil in terms of biophysical constraints/endowments and their complex interaction with land use to be mapped at a national level. Outputs from DNDC biogeochemical modelling based on Irish Soil Information System Data were used to develop an indicative soil organic carbon loss map used to derive the associated CO2 loss. Application of the Hybrid Soil Moisture Deficit model was used to determine the impact of drainage on productivity to compute the decreased number of days at which soils are untrafficable and this data was used to develop a productivity difference map.