In an earlier paper we presented data from an experiment in which nitrogen-15-labelled fertilizer was applied in spring to barley on the Rothamsted long-term Spring Barley Experiment, at rates of 48, 96 or 144 kg N ha−1. A substantial proportion (between 28 and 39%) of this 15N remained in the soil (0–70 cm) and stubble at harvest, mostly in organic form. The present paper follows the fate of this `residual' 15N over the following 2 years. Small amounts of `residual' 15N were recovered in the following two spring barley crops; 8% in the first and 3% in the second. The overall loss of `residual' 15N (i.e. `residual' 15N not recovered in crops and soil to a depth of 70 cm) over the 2 years was 23%. This is equivalent to just 8% of the total 15N originally applied. There was surprisingly little difference in the behaviour of the `residual' 15N in soils containing very different quantities of soil organic matter.