Loads of nutrients and faecal micro-organisms in surface runoff from perennial grass ley after slurry applications were studied at Jokioinen, SW Finland. The study comprised three parts: 1) slurry application in summer 1996 1997, 2) slurry application in summer and autumn 1998 2000, and 3) ploughing the ley in autumn 2000 and the residual effect of slurry on barley in summer 2001. Cattle slurry was either surface-applied or injected into the soil. Surface and subsurface waters were directed into a collector trench on each plot. Drainage water was not collected. Leaching of nutrients was estimated by measuring inorganic nitrogen and ammonium acetate extractable phosphorus (PAAAc) from soil at depths of between 0 and 1 metre. Ammonia (NH3) volatilisation from applied slurry was measured in the autumn of 1999 and 2000. The nutrient load in surface runoff was greatest after surface application of slurry in the autumn. The cumulative losses of total phosphorus (TP) and total nitrogen (TN) from surface application plots in 1998 to 2000 were 4.8 kg/ha and 11 kg/ha, respectively. Injection decreased TP and TN in runoff by an average of 48% and 40%, respectively. There were also high numbers of faecal micro-organisms in surface runoff from surface application plots. In the autumn, there were fewer faecal micro-organisms in the runoff from injected plots, but the microbes seemed to remain in the soil longer than in surface application plots. NH3 emissions were, on average, 26% of the ammoniacal N of surface applied slurry, but injection hindered them effectively. In October 1999, the PAAAc content was greatest (25.7 187 mg/kg) in the surface soil (0 2 cm) of surface application plots. In injection plots the highest PAAAc levels (25.6 43.6 mg/kg) were observed at a depth of 5 10 cm. Inorganic nitrogen increased in the injection plots in particular. In 2001, the different fertilisation practices (surface-spread slurry, injection of slurry, or inorganic fertiliser) had no residual effect on barley yield (4.5 t/ha).