Testing the efficacy of on-farm pollution mitigation measures in agricultural catchments in England

Many rivers across England and Wales are experiencing excessive inputs of nutrients, faecal waste and sediment from agricultural land. Despite the resulting environmental impacts, population growth is renewing focus on the intensification of agricultural production to improve food security. As a result, balancing agricultural productivity with resource protection is high on the political agenda, and the need to assemble improved information on the efficacy of targeted on-farm pollution mitigation measures is key to informing the debate on production versus environmental burden. In England, Demonstration Test Catchments (DTCs) have been established as sentinel, landscape scale experimental facilities for assessing ways to mitigate the problems associated with agricultural pollution of watercourses. As part of the Hampshire Avon/Tamar DTC programme, a research studentship has been used to compile a toolkit of methods, including pollutant source fingerprinting, for testing the effectiveness of on-farm pollution control measures. These measures include: stream bank fencing, riparian buffer strips, ponds and wetlands, farm track re-surfacing, improved slurry stores, and the installation of swales. The toolkit aims to be sustainable, affordable, effective and replicable. This contribution provides a case study of findings and will present data from one experimental on-farm site, following 18 months of intensive monitoring and sampling. The data streams are used to assess the effectiveness of existing mitigation options, as well as providing suggestions for refining those in situ to improve performance.