Track 2-11: Plant Nutrition and Nutrient Cycling
Description
Agricultural activities are the major cause of non-point pollution. Mechanization of agriculture, artificial fertilizer use and overall intensification of farming has played a major role in the increased incidence of pollution by agricultural activities. Carton et al. (2006) reported the effects of agricultural practices on nitrate leaching from an intensively managed dairy farm and showed that mean concentrations of nitrate nitrogen in the groundwater beneath the farm during the two monitoring years exceeded the maximum admissible concentration (MAC) for drinking water. While average nitrate nitrogen concentration in soil water were less than MAC, there was a trend for increased nitrogen loading to result in elevated concentrations of nitrate nitrogen in soil water and ground water. Grassland devoted to 90% of agricultural land in Ireland, almost all fertilizer and animal manures is surface applied, with little incorporation through the soil. This means that most fertilizer and manure tends to accumulate in the top few centimeters of soil, so that this layer can become saturated or nearly saturated with organic compounds in specific nitrate. During rainfall events, water that runs over or infiltrates through this enriched surface soil can carry significant amounts of nitrate with it. This, in turn, can enrich surface water and contribute to eutrophication (Tunney et al. 2000).
According to the Environmental Protection Agency (Lucey 2005), eutrophication of inland waters is the main environmental issue in Ireland. A chemical analysis of water samples from a ground water well in Skeagh yard nearby the Hill Field in the UCD Research Farm showed high nitrate concentration of 55 mg NO3/L which exceeded the EU drinking water standards (Hart pers comm). The Hill Field at the UCD Research Farm was chosen as being representative of good versatile land, with undulating topography, on which moderate to intensive farming is practised in the drier rainfall areas of Ireland. Historically the field was included in the tillage rotation of the farm, but it has been in permanent grass for the last 25 years.
Included in
Leaching of Nitrate from a Grassland Field
Agricultural activities are the major cause of non-point pollution. Mechanization of agriculture, artificial fertilizer use and overall intensification of farming has played a major role in the increased incidence of pollution by agricultural activities. Carton et al. (2006) reported the effects of agricultural practices on nitrate leaching from an intensively managed dairy farm and showed that mean concentrations of nitrate nitrogen in the groundwater beneath the farm during the two monitoring years exceeded the maximum admissible concentration (MAC) for drinking water. While average nitrate nitrogen concentration in soil water were less than MAC, there was a trend for increased nitrogen loading to result in elevated concentrations of nitrate nitrogen in soil water and ground water. Grassland devoted to 90% of agricultural land in Ireland, almost all fertilizer and animal manures is surface applied, with little incorporation through the soil. This means that most fertilizer and manure tends to accumulate in the top few centimeters of soil, so that this layer can become saturated or nearly saturated with organic compounds in specific nitrate. During rainfall events, water that runs over or infiltrates through this enriched surface soil can carry significant amounts of nitrate with it. This, in turn, can enrich surface water and contribute to eutrophication (Tunney et al. 2000).
According to the Environmental Protection Agency (Lucey 2005), eutrophication of inland waters is the main environmental issue in Ireland. A chemical analysis of water samples from a ground water well in Skeagh yard nearby the Hill Field in the UCD Research Farm showed high nitrate concentration of 55 mg NO3/L which exceeded the EU drinking water standards (Hart pers comm). The Hill Field at the UCD Research Farm was chosen as being representative of good versatile land, with undulating topography, on which moderate to intensive farming is practised in the drier rainfall areas of Ireland. Historically the field was included in the tillage rotation of the farm, but it has been in permanent grass for the last 25 years.
