This data set contains terrestrial fluxes of N2O from an intensively managed grazed grassland in Scotland measured using eddy covariance and chamber methods . The effect of a tillage event and two nitrogen fertilizer applications were investigated by comparing N2O fluxes from two adjacent intensively managed grazed grasslands , one of which was tilled. An eddy covariance system mounted at 2.4 m was used to measure fluxes of N2O, H2O and CO2 using a quantum cascade laser (QCL) gas analyser. Flux measurements were made over a six month period starting at the end of March, 2012. Chamber measurements were also made using both static and dynamic chambers. The data was collected as part of the GHG Platform project AC0116 funded by DEFRA.