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

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

[1]  Awwa,et al.  Standard Methods for the examination of water and wastewater , 1999 .

[2]  J. T. Douglas,et al.  Parameter selection and testing the soil water model SOIL , 1997 .

[3]  D. Powlson,et al.  Nitrogen Mineralization in Temperate Agricultural Soils: Processes and Measurement , 1996 .

[4]  B. E. Ruz-Jerez,et al.  A comparison of nitrate leaching under clover-based pastures and nitrogen-fertilized grass grazed by sheep , 1995, The Journal of Agricultural Science.

[5]  W. Wielemaker Soil science: methods and application (review). , 1995 .

[6]  S. Cuttle,et al.  Clover and fertiliser based strategies to limit nitrate leaching in conventional agriculture - relevance of research to organic farming systems , 1995 .

[7]  I. S. Kristensen,et al.  A Simple Model for Estimation of Atmospherically-Derived Nitrogen in Grass-Clover Systems , 1995 .

[8]  Lloyd B. Owens,et al.  Groundwater nitrate levels under fertilized grass and grass-legume pastures , 1994 .

[9]  R. H. Fox,et al.  Nitrate Leaching from Nitrogen-Fertilized and Manured Corn Measured with Zero-Tension Pan Lysimeters , 1994 .

[10]  S. Trudgill Farming, fertilizers and the nitrate problem: Addiscott, T.M., Whitmore, A.P. and Powlson, D.S. Wallingford: CAB International, 1991. 176pp. £13.50 paperback , 1993 .

[11]  S. Cuttle,et al.  Nitrate leaching from sheep-grazed grass/clover and fertilized grass pastures , 1992, The Journal of Agricultural Science.

[12]  A. Heathwaite,et al.  Soil nitrate sources and nitrate leaching losses, Slapton, South Devon , 1991 .

[13]  R. J. Orr,et al.  Uptake, cycling and fate of nitrogen in grass-clover swards continuously grazed by sheep , 1991, The Journal of Agricultural Science.

[14]  R. Lowrance Management Systems to Reduce Impact of Nitrates , 1991 .

[15]  J. Seager,et al.  The impact of intensive dairy farming activities on river quality : the eastern Cleddau catchment study , 1990 .

[16]  D. Walling,et al.  Stream nitrate levels in a small catchment in South West England over a period of 15 years (1970-1985) , 1988 .

[17]  Tim Burt,et al.  Temporal and spatial patterns of nitrate losses from an agricultural catchment , 1987 .

[18]  C. Jordan,et al.  Factors affecting leaching of nutrients from an intensively managed grassland in county Antrim, Northern Ireland , 1985 .

[19]  E. A. Garwood,et al.  Nitrate leaching from grassland , 1984, Nature.

[20]  D. Barraclough,et al.  Fate of fertilizer nitrogen applied to grassland. I. Field leaching results , 1983 .

[21]  A. J. Talman,et al.  A device for recording fluctuating water levels , 1983 .

[22]  M. R. Evans,et al.  Aerobic treatment of beef cattle and poultry waste compared with the treatment of piggery waste , 1980 .

[23]  C. P. Webster,et al.  A lysimeter study using nitrogen-15 on the uptake of fertilizer nitrogen by perennial ryegrass swards and losses by leaching. , 1980 .

[24]  C. I. Rich Soil Chemical Analysis , 1958 .