Direct‐cut grass which has been heavily fertilized often produces silage with a poor fermentation. An investigation was carried out to study the effect of rate and timing of N applications to herbage intended for direct‐cut silage. A small but consistent increase in silage pH was recorded after high levels of N were applied 7–8 weeks before cutting. The application of additional N fertilizer 10–14 days before cutting the sward had an adverse effect on silage fermentation. Changes in herbage composition following different levels of applied N are o