Abstract
The Soil Strategy for England, Safeguarding our Soils (Defra, 2009) aims to better protect and enhance England’s soils and to safeguard and optimise their ability to provide essential services for this and future generations. The strategy stresses the importance of developing an evidence-base as to the impact of climate change on soils. This strategy was further emphasised in 2010 with the release of Defra’s climate change plan (Defra 2010) which identifies key areas for adaptation to climate. The Land Use Climate Change Report to the Welsh Assembly Government (Welsh Assembly, 2010) presents five scenarios for reducing emissions to address the challenges of a changing climate. Potential impacts of a changing climate in Wales are highlighted, including increased average annual temperatures, increased winter and reduced summer rainfall patterns and a rising sea level of approximately 20cm by 2050. Climate change will have impose both direct and indirect impacts on the soil resource through changes in temperature and rainfall patterns as well as changes in cropping and agricultural management practices. The new UK Climate Projections (UKCP09) now provide an opportunity to examine the nature and scale of this impact on the soils of England and Wales. This research serves to underpin the evidence base as to how the ability of soil to support agricultural productivity is likely to be impacted, and as to how soil management practices are likely to have to change to adapt to climate-induced changes. Agricultural capability of soils is assessed currently through the application of the Agricultural Land Classification (ALC) revised guidelines (MAFF, 1988). ALC is based on the long-term physical limitations of land for agricultural use, assessed currently using prevailing climate, site and soil characteristics, with the important interactions between these being used to determine the eventual classification. As the classification makes use of climate data there is an important potential now to recalculate site grading on the basis of potential future climatic scenarios, thus allowing the impact of climate change on the patterns and distribution of land in different ALC grades to be estimated. The ALC system was first introduced in 1966, with maps being produced on a scale of one inch to one mile (1:63,360) in the period 1967-1974. The current ALC (MAFF, 1988) mainly uses the climatic data from 1941-1970, although for temperature inputs data for 1961-80 are also used. This proposed project will extend the ALC methodology to combine the latest UK Climate Projections (UKCP09) with the existing soil and site data from the National Soil Inventory (NSI), to generate projections of possible future distribution of all ALC grades and to identify the best and most versatile land (BMV), being Grades 1, 2 and 3a. The ALC methodology relies on 9 climatic variables: Annual Average Rainfall (AAR); Annual Summer Rainfall (ASR); Accumulated Temperature above 0° from January to June (AT0); Accumulated Temperature above 0° from April to September (ATS); Moisture Deficit for Wheat and Potatoes (MDMWHT, MDMPOT); and the Duration of Field Capacity (FCD). These variables will be recalculated using appropriate future scenarios and the resulting patterns interacted with the soil and site information. References Defra (2009) Safeguarding our Soils – A Strategy for England. Published September, 2009. [Accessed at http://www.defra.gov.uk/environment/quality/land/soil/sap/index.htm] Defra (2010) Defra's Climate Change Plan 2010, Department of the Environment, Food and Rural Affairs, London [Accessed at http://www.defra.gov.uk/environment/climate/index.htm] UKCP09. [Accessed at http://ukclimateprojections.defra.gov.uk/ and http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=163] Welsh Assembly (2010) The Land Use Climate Change Report to the Welsh Assembly Government. [Accessed at http://cymru.gov.uk/topics/environmentcountryside/farmingandcountryside/farming/ landuseclimatechangegroup/landuseclimatechangereport/?lang=en&ts=3]
United Kingdom