Research article2019Peer reviewedOpen access
An integrated assessment of nitrogen source, transformation and fate within an intensive dairy system to inform management change
Clagnan, Elisa; Thornton, Steven F.; Rolfe, Stephen A.; Wells, Naomi S.; Knoeller, Kay; Murphy, John; Tuohy, Patrick; Daly, Karen; Healy, Mark G.; Ezzati, Golnaz; von Chamier, Julia; Fenton, Owen
Abstract
From an environmental perspective optimised dairy systems, which follow current regulations, still have low nitrogen (N) use efficiency, high N surplus (kg N ha(-1)) and enable ad-hoc delivery of direct and indirect reactive N losses to water and the atmosphere. The objective of the present study was to divide an intensive dairy farm into N attenuation capacity areas based on this ad-hoc delivery. Historical and current spatial and temporal multi-level data sets (stable isotope and dissolved gas) were combined and interpreted. Results showed that the farm had four distinct attenuation areas: high N attenuation: characterised by ammonium-N (NH4+-N) below 0.23 mg NH4+-N l(-1) and nitrate (NO3--N) below 5.65 mg NO3--Nr l(-1) in surface, drainage and groundwater, located on imperfectly to moderately-well drained soils with high denitrification potential and low nitrous oxide (N2O) emissions (ay. 0.0032 mg N2O-N l(-1)); moderate N attenuation: characterised by low NO3--N concentration in drainage water but high N2O production (0.0317 mg N2O-N l(-1)) and denitrification potential lower than group 1 (av. delta N-15-NO3-: 16.4 parts per thousand, av. delta O-18-NO3-: 9.2 parts per thousand), on well to moderately drained soils; low N attenuation-area 1: characterised by high NO3--N (ay. 6.90 mg NO3--N l(-1)) in drainage water from well to moderately-well drained soils, with low denitrification potential (av. delta N-15-NO3-: 9.5 parts per thousand, av. delta O-18-NO3-: 5.9 parts per thousand) and high N2O emissions (0.0319 mg N2O l(-1)); and low N attenuation-area 2: characterised by high NH4+-N (av. 3.93 mg NH4+-N l(-1) and high N2O emissions (av. 0.0521 mg N2O l(-1)) from well to imperfectly drained soil. N loads on site should be moved away from low attenuation areas and emissions to air and water should be assessed.
Published in
PLoS ONE
2019, Volume: 14, number: 7, article number: e0219479
Publisher: PUBLIC LIBRARY SCIENCE
UKÄ Subject classification
Agricultural Science
Publication identifier
DOI: https://doi.org/10.1371/journal.pone.0219479
Permanent link to this page (URI)
https://res.slu.se/id/publ/113721