Abstract Lysimeters consisting of intact soil cores, including field- and ground-layer vegetation, from a sandy podzol were treated with irrigation water, H 2SO 4 or NPK and combinations thereof. The acid and fertilizer applications corresponded to 100 kg H 2SO 4 per ha annually and a total of 360 kg N per ha, respectively. Precipitation and leachates from the lysimeters were analyzed for main chemical constituents during a 6-year-period. There-after the experiment was terminated and the cores were fractionated into appropriate vegetation and soil strata. Chemical analyses of the soil revealed a significant increase of exchangeable aluminium in the B- and B/C-horizons due to H 2SO 4 application, accompanied by a decrease of magnesium in the same horizons. The fertilizer caused a net depletion of magnesium in the B- and B/C-horizons mainly due to high levels of replacing cations other than magnesium and correspondingly high levels of mobile anions. Budget calc.ulations indicated increased weathering of magnesium and calciu acid treatment. There were also indications of a calcium adsorption from the irrigation water. H + activity estimated from pH measuremetns in 0.001 M CaCl 2, had increased in the A 0-horizon, in lysimeters treated with sulphuric acid, probably an effect of aluminium hydrolysis. There was a slight in activity in the A 0-horizon of the fertilized lysimeters.