Abstract
The overall aim of this project is to review recent research on practices for managing soil organic matter (SOM) in agriculture and to identify best practices for recommendation in England. SOM is fundamental to the maintenance of soil fertility and function, as well as being an important carbon store. However, there is some evidence that soils in the UK may be losing SOM/carbon, probably as a consequence of land use change, particularly drainage of peat soils and a legacy of ploughing out grasslands, and this could have implications for climate change. Protecting and enhancing SOM levels will have beneficial effects for overall soil quality/fertility, carbon storage and erosion control. A key objective of the Draft Defra Soil Strategy (priority area 2) is to "reduce the rate of soil organic matter decline and protect habitats based on organic soils, such as peat bogs, to maintain our carbon stores and soil quality" (Defra, 2008). Moreover, the Sustainable Farming and Food Strategy has a target "to halt the decline in soil organic matter in vulnerable agricultural soils by 2025, whilst maintaining as a minimum, the soil organic matter of other agricultural soils, taking into account the impacts of climate change" (Defra, 2002). In a recent review of the Environmental Stewardship Scheme "providing and protecting carbon storage" was also identified as a key means by which agriculture and land management could contribute to climate change mitigation. This project will review and synthesise recent research on practices for managing SOM in agriculture, in order to distill best practice for inclusion in revised soil management guidance. Using results from recent research, as well as expert advice, the project will consider which practices are most appropriate for both 'upland' (above the intake wall) and 'lowland' agriculture in England, taking into account variations in soil type, agricultural systems and cropping/land use. Any potential negative environmental and economic impacts of each practice identified will also be considered and highlighted. Additionally, the potential carbon storage achievable with each management option will be quantified and contextualised in relation to 'benchmark' SOM management ranges or 'envelopes of normality' for different soil/land use and rainfall areas. As well as identifying best practice, the project will explore how this can be translated into advice for farmers and land managers, and incorporated into current Cross Compliance Guidance for Soil Management or via incentivised Environmental Stewardship.
United Kingdom