Functional Land Management for managing soil functions: a case-study of the trade-off between primary productivity and carbon storage in response to the intervention of drainage systems in Ireland

Globally, there is growing demand for increased agricultural outputs. At the same time, the agricultural industry is expected to meet increasingly stringent environmental targets. Thus, there is an urgent pres-sure on the soil resource to deliver multiple functions simultaneously. The Functional Land Management framework (Schulte et al., 2014) is a conceptual tool designed to support policy making to manage soilfunctions to meet these multiple demands. This paper provides a first example of a practical applicationof the Functional Land Management concept relevant to policy stakeholders. In this study we examine thetrade-offs, between the soil functions ‘primary productivity’ and ‘carbon cycling and storage’, in responseto the intervention of land drainage systems applied to ‘imperfectly’ and ‘poorly’ draining managed grass-lands in Ireland. These trade-offs are explored as a function of the nominal price of ‘Certified EmissionReductions’ or ‘carbon credits’. Also, these trade-offs are characterised spatially using ArcGIS to accountfor spatial variability in the supply of soil functions.To manage soil functions, it is essential to understand how individual soil functions are prioritised bythose that are responsible for the supply of soil functions – generally farmers and foresters, and thosewho frame demand for soil functions – policy makers. Here, in relation to these two soil functions, a gapexists in relation to this prioritisation between these two stakeholder groups. Currently, the prioritisationand incentivisation of these competing soil functions is primarily a function of CO2price. At currentCO2prices, the agronomic benefits outweigh the monetised environmental costs. The value of CO2losswould only exceed productivity gains at either higher CO2prices or at a reduced discount period rate.Finally, this study shows large geographic variation in the environmental cost: agronomic benefit ratio.Therein, the Functional Land Management framework can support the development of policies that aremore tailored to contrasting biophysical environments and are therefore more effective than ‘blanketapproaches’ allowing more specific and effective prioritisation of contrasting soil functions.© 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-NDlicense (http://creativecommons.org/licenses/by-nc-nd/4.0/).