A comparative study of nitrate leaching from intensively managed monoculture grass and grass-clover pastures

摘要: Nitrate leaching losses from intensively managed monoculture grass and grass-clover pastures were measured during 1994-96 at a long-term experimental farm in south-west Scotland. Field-size lysimeter plots established 1993 on the existing silty clay loam non-calcareous gley. No fertilizer-N was applied to grass-clover, while fertilized with c.240 kg N ha-1 year-1, but both swards received 2-3 cattle slurry applications annually (120-390 total year-1). The supported cuts for silage conservation, grazed by dairy stocked sheep winter months. Initially, leachate nitrate concentrations considerably larger than those clover-based pasture, became similar time. annual (24-38 NO3-N ha-1) less that (30-45 ha-1), differences not large considering additional latter treatment. Results also suggested greater occur warmer, drier year, compared cooler, wetter regardless of source N-input.