N-leaching in hill country; farmer led research.

there is scant information on nitrate-N leaching in East Coast hill country. Castlepoint Station, a focus farm in the Wise Use of fertiliser Nitrogen (N) project and in the face of potential restrictions on fertiliser N use, ran a 3 year trial focused on the impacts of N fertiliser on pasture and animal production as well as nitrate leaching. the paddock-scale trial was run by the focus farm community group, a farm consultant, and representatives from the regional Council and Agresearch. fertiliser N (0, 60 and 120 kg N/ha) (0N, 60N and 120N, respectively) was applied as urea annually in early August. twinning ewes were stocked at rates modelled by farmax for poor pasture growth. Young cattle were added to maintain pasture control in the event of an average or favourable growing season. Application of fertiliser N increased pasture and animal production for both of the rates used. the 3 year mean annual amount of nitrate-N leached from the 120N treatment was 3x that from the 0N treatment and 2x that from the 60N treatment (P 0.05). Early August application of fertiliser of 60N had no significant impact on annual nitrate-N leaching in this East Coast hill environment. research initiated and led by farmers successfully contributed to increased understanding of management impacts on nitrate-N leaching losses in East Coast hill country. implications for on-farm research are discussed.