tGrazing systems represent a substa

tGrazing systems represent a substantial percentage of the global anthropogenic flux of nitrous oxide(N2O) as a result of nitrogen addition to the soil. The pool of available carbon that is added to the soilfrom livestock excreta also provides substrate for the production of carbon dioxide (CO2) and methane(CH4) by soil microorganisms. A study into the production and emission of CO2, CH4and N2O from cattleurine amended pasture was carried out on the Somerset Levels and Moors, UK over a three-month period.Urine-amended plots (50 g N m−2) were compared to control plots to which only water (12 mg N m−2)was applied. CO2emission peaked at 5200 mg CO2m−2d−1directly after application. CH4flux decreasedto − 2000 g CH4m−2d−1two days after application; however, net CH4flux was positive from urinetreated plots and negative from control plots. N2O emission peaked at 88 mg N2O m−2d−112 days afterapplication. Subsurface CH4and N2O concentrations were higher in the urine treated plots than thecontrols. There was no effect of treatment on subsurface CO2concentrations. Subsurface N2O peaked at500 ppm 12 days after and 1200 ppm 56 days after application. Subsurface NO3−concentration peakedat approximately 300 mg N kg dry soil−112 days after application. Results indicate that denitrification isthe key driver for N2O release in peatlands and that this production is strongly related to rainfall eventsand water-table movement. N2O production at depth continued long after emissions were detected atthe surface. Further understanding of the interaction between subsurface gas concentrations, surfaceemissions and soil hydrological conditions is required to successfully predict greenhouse gas productionand emission.

tGrazing systems represent a substantial percentage of the global anthropogenic flux of nitrous oxide (N2O) as a result of nitrogen addition to the soil. The pool of available carbon that is added to the soilfrom livestock excreta also provides substrate for the production of carbon dioxide (CO2) and methane (CH4) by soil microorganisms. A study into the production and emission of CO2, CH4and N2O from cattleurine amended pasture was carried out on the Somerset Levels and Moors, UK over a three-month period.Urine-amended plots (50 g N m-2) were compared to control. plots to which only water (12 mg N m-2) was applied. CO2emission peaked at 5200 mg CO2m-2d-1directly after application. CH4flux decreasedto -2000? G CH4m-2d-1two days after application; however, net CH4flux was positive from urinetreated plots and negative from control plots. N2O emission peaked at 88 mg N2O m-2d-112 days afterapplication. Subsurface CH4and N2O concentrations were higher in the urine treated plots than thecontrols. There was no effect of treatment on subsurface CO2concentrations. Subsurface N2O peaked at500 ppm 12 days after and 1200 ppm 56 days after application. Subsurface NO3-concentration peakedat approximately 300 mg N kg dry soil-112 days after application. Results indicate that denitrification isthe key driver for N2O release in peatlands and that this production is strongly related to rainfall eventsand water-table movement. N2O production at depth continued long after emissions were detected atthe surface. Further understanding of the interaction between subsurface gas concentrations, surfaceemissions and soil hydrological conditions is required to successfully predict greenhouse gas productionand emission.

TGrazing systems represent a substantial percentage of the global anthropogenic flux of nitrous oxide (N2O) as a result Of nitrogen addition to the soil. The pool of available carbon that is added to the soilfrom livestock excreta also provides Substrate for the production of carbon dioxide (CO2) and methane (CH4) by soil microorganisms. A study into the production And emission, of CO2CH4and N2O from cattleurine amended pasture was carried out on the Somerset Levels and Moors UK over, a three-month period.Urine-amended Plots (50 g N m − 2) were compared to control plots to which only water (12 mg N m − 2) was applied. CO2emission peaked at 5200 mg CO2m − 2D − 1directly after application. CH4flux decreasedto − 2000  g CH4m − 2D − 1two days after, application; howeverNet CH4flux was positive from urinetreated plots and negative from control plots. N2O emission peaked at 88 mg N2O m − 2D − 112 Days afterapplication. Subsurface CH4and N2O concentrations were higher in the urine treated plots than thecontrols. There Was no effect of treatment on subsurface CO2concentrations. Subsurface N2O peaked at500 ppm 12 days after and 1200 ppm 56 days After applicationSubsurface NO3 − concentration peakedat approximately 300 mg N kg dry soil − 112 days after application. Results indicate That denitrification isthe key driver for N2O release in peatlands and that this production is strongly related to rainfall Eventsand water-table movement. N2O production at depth continued long after emissions were detected atthe surfaceFurther understanding of the interaction between subsurface gas concentrations surfaceemissions and, soil hydrological Conditions is required to successfully predict greenhouse gas productionand emission