Fertilizer effects on soil nutrients.

Effect of fertilizer treatments on soil concentrations of nitrate (a), ammonium (b), total-N (as calculated sum of nitrate- and ammonium-N; c), Bray-I P (d) and soil pH (e) (in mg/kg—y-axis) over time after application at high rate (equivalent to 120 kg N ha-1). Error bars above individual graphs represent significance between treatments (standard error of means; s.e.m.) at 95% confidence level for each sampling time (weeks 4, 7, 13, 17 and 22).