Abstract: The measurement of nitrate and ammonium leaching varied with plant species and soil types. This study compared 2 methods of measuring nitrate and ammonium leaching （lysimeters versus ceramic suction cups） using 12 soil monolith lysimeters （50 cm diameter and 70 cm deep） containing 4 replicates of 3 contrasting New Zealand soils：Gorge silt loam，Mataura sandy loam （both stone-free soils） and Lismore stony silt loam. The ceramic suction cups were installed at 35 cm （top cups） and 60 cm （bottom cups） depths. Sprinkler irrigation applied on lysimeters to minimize the NO₃^--N content of drainage water close to 0 mg·L-1，before experiments starting. Urea solution was surface applied at 250 kg N·hm^-2，followed by regular weekly irrigation. Due to small variations in irrigation nozzle application rates，the actual 3 hour irrigation totals measured were 45 mm，57 mm and 56 mm for the Gorge，Mataura and Lismore soils，respectively. There were significant differences between the cumulative leaching loss measured in the lysimeter drainage and values estimated from the cups in the Gorge and Lismore soils. The cumulative leaching loss，measured from the top cups，bottom cups and lysimeter drainage，were 64，68 and 54 kg N·hm^-2 of nitrate and 0.43，0.49 and 0.43 kg N·hm^-2 of ammonium，respectively，in the Gorge soil；57，68 and 62 kg N·hm-2 of nitrate and 0.51，0.37 and 0.23 kg N·hm^-2 of ammonium，respectively，in the Mataura soil; and 61，103 and 99 kg N·hm^-2 of nitrate and 1.70，2.24 and 2.04 kg N·hm^-2 of ammonium，respectively，in the Lismore soil. It was concluded that suction cups were inappropriate for the determination of cumulative leaching in the structured Gorge soil and the Lismore soil，but ceramic cups could provide useful data on cumulative leaching in the Mataura sandy loam soil. The cumulative ammonium leaching accounted for 0.37%-2.93% of the cumulative nitrate leaching in different soil types，and ammonium leaching could be neglected in measuring of nitrogen leaching.

Key words: nitrate, ammonium, leaching, methods of measurement