This study evaluated the effect of grassland renovation on soil total N, soluble N, N leaching to groundwater and nitrous oxide (N2O) fluxes from poorly drained clay loam soils on a dairy farm in Ireland. The experimental area was divided into six blocks. In June 2008, one paddock in each block was ploughed and reseeded, and subsequently compared with a permanent grassland paddock. Nitrogen in groundwater was determined in a dense network of piezometers. Soil total N along with soluble N assessed in KCl extracts were determined at three depths to 0.9 m. The N2O fluxes were measured using the static chamber technique. Renovation decreased topsoil total N and soluble organic N (P 3 t N ha(-1)), the proportion lost via N leaching and N2O emissions was unsubstantial (27.11 kg N ha(-1) y(-1)) and represented only 4.8 and 0.49 % of the N input to renovated grassland, respectively. This was likely a result of soil inherent properties and anoxic status of the soils, which likely promoted complete denitrification. Since this study was a single site study and the measurements started only months after the renovation and were relatively short term, there is some uncertainty in the results.
