Adrian Collins, Head of Water Quality Science explains, using nitrate as an example, how modelling can help target management in catchments to reduce multiple pollutants.
Over the last 40 years, increasing nitrogen (N) applications have been made to agricultural land. As well as increasing productivity, this N has created serious water quality issues which need to be addressed. Understanding the origin and location of the nitrate loads is challenging but it is crucial in tackling the problem.
NEAP-N is a soil leaching model that has been developed over the last two decades by ADAS to predict the concentration of nitrate in water draining from agricultural land to surface and groundwater. The model takes into account climate, soil type, animal number and type, crop type and agricultural practice. It has been validated against detailed monitoring on a variety of commercial farms across England and Wales, as well as EA catchment monitoring data.
ADAS is now working with some water companies to use modelling, monitoring and practical knowledge to improve and target catchment management. This combination of approaches can be used to inform new management strategies, project the expected future responses or measure the current outcomes of mitigation schemes. The latter might include payment for ecosystem services.
ADAS’s NEAP-N model can be run using input land use data from 1970 to 2009, allowing users to develop a realistic historic picture of nitrate inputs from agriculture and the associated changes in farming practices and land use that have occurred over the past 40 years. Outputs can be broken down by agricultural sector.
For more information please contact Adrian Collins on 01902 693404 or email Adrian.Collins@adas.co.uk.