1 ADAS Consulting Ltd., Gleadthorpe Research Centre, Meden Vale, Mansfield, Notts NG20 9PF. mark.shepherd@adas.co.uk; anne.bhogal@adas.co.uk 2 IOR Elm Farm Research Centre, Hamstead Marshall, Near Newbury, Berkshire, RG20 0HR. bruce.p@efrc.com; lois.p@efrc.com 3 ADAS Consulting Ltd., Terrington Research Centre, Terrington St Clement, Kings Lynn, Norfolk PE34 4PW. bill.cormack@adas.co.uk 4 Institute of Grassland and Environmental Research, Plas Gogerddan, Aberstwyth, SY23 3EB. steve.cuttle@bbsrc.ac.uk 5 Department for Environment, Food and Rural Affairs, Land Use and Rural Affairs Directorate General, Cromwell House, London, SW1P 3JH. peter.costigan@defra.gsi.gov.uk 6 Rural Development Service, Technical Advisory Unit, Defra, 4 Floor, Ergon House, 17 Smith Square, London, SW1P 3JR roger.j.unwin@defra.gsi.gov.uk

This project covered two separate activities, but both were examples of technology transfer, relating to organic farming: 1. Developing a science-based report, which covered an assessment of the environmental impacts of organic farming. Defra’s Action Plan to Develop Organic Food and Farming included as Annexe 3 an assessment of the environmental impacts of organic farming. This paper was prepared by a Subgroup of the Action Plan for Organic Farming. Its purpose was to summarise the Subgroup’s views of the likely comparative effects of organic and conventional farming on the environment. However, to be robust and defensible, the assessment needs to be supported by scientific data. Although the report was based on such an assessment, the scientific data were not summarised and this needed to be done. The objective of this part of the project was therefore to collate and publish on the Defra website the evidence that underpinned the overall conclusions. 2. Preparation of a booklet to provide guidelines for managing soil fertility in organic farming. Organic farming aims to create an economically and environmentally sustainable agriculture, with the emphasis placed on self-sustaining biological systems, rather than external inputs. Building soil fertility is central to this ethos. ‘Soil fertility’ can be considered as a measure of the soil’s ability to sustain satisfactory crop growth, both in the short- and longer-term, and it is determined by a set of interactions between the soil’s physical environment, chemical environment and biological activity. The aim of recent Defra-funded projects has been, therefore, to provide a better scientific understanding of ‘soil fertility’ under organic farming, in line with Defra’s policy objective of greater technical support to organic farming. The aim here was to prepare a booklet based on the findings of Defra-funded project OF0164 ‘Soil fertility in organically farmed soils’.