Impact of NO 3 leaching abatement measures on N 2 O and CH 4 emissions from a UK dairy system A. del Prado * , L. Cardenas, D. Scholefield Institute of Grassland and Environmental Research, North Wyke, Okehampton, UK Abstract. We describe a new farm scale model to optimize management of UK dairy farming systems in order to meet environmental and economic targets. The effect of abatement measures for nitrate (NO 3 ) leaching on the emissions of nitrous oxide (N 2 O) and methane (CH 4 ) and the economic output of a dairy farm was investigated using this model. The model is a useful tool to evaluate potential pollution swapping when applying abatement measures. D 2006 Elsevier B.V. All rights reserved. Keywords: Nitrate; Nitrous oxide; Methane; Modeling; Optimization 1. Introduction Dairy farming has been identified as a significant contributor to climate change (N 2 O and CH 4 ), acid rain (NH 3 and NO x ) and water eutrophication (NO 3 and P). Several studies have formulated abatement strategies and evaluated their economical cost in the UK for single pollutants such as: (i) greenhouse gases [1], (ii) P [2], (iii) nitrate [3] or a more recent approach in The Netherlands integrating multiple pollutants (N 2 O, CH 4 and NH 3 ) [4]. However, due to the multiple interactions that occur in this system, there is still a need for more integrated approaches that could analyse pollution swapping and the effect on the economic outputs of the farm. The objective of this study is to investigate the effect of NO 3 leaching abatement measures on the emission of N 2 O and CH 4 from a dairy farm. 2. Materials and methods A new farm model has been developed as part of a complex modeling framework. This model, among other things, is capable of simulating and optimizing the effect of different 0531-5131/ D 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.ics.2006.01.079 * Corresponding author. E-mail address: Agustin.del _ Prado@bbsrc.ac.uk (A. del Prado). International Congress Series 1293 (2006) 359 – 362 www.ics-elsevier.com