Author
Selbie, Diana R.Lanigan, Gary
Laughlin, Ronald J.
Di, H.J.
Moir, James L.
Cameron, K.C.
Clough, Timothy J.
Watson, C. J.
Grant, Jim
Somers, Cathal
Richards, Karl G.
Keyword
co-denitrificationDi-nitrogen (N2) emissions
Pasture-based livestock systems
N2 production pathway
N budgets
Nitrogen use efficiency
Date
30/11/2015
Metadata
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Selbie D.R., Lanigan G.J., Laughlin R.J., Di H.J., Moir J.L., Cameron K.C., Clough T.J., Watson C.J., Grant J., Sommers C. & Richards K.G. (2015) Confirmation of co-denitrification in grazed grassland, Nature Scientific Reports 5:17361 1-5 | DOI: 10.1038/srep17361Abstract
Pasture-based livestock systems are often associated with losses of reactive forms of nitrogen (N) to the environment. Research has focused on losses to air and water due to the health, economic and environmental impacts of reactive N. Di-nitrogen (N2) emissions are still poorly characterized, both in terms of the processes involved and their magnitude, due to financial and methodological constraints. Relatively few studies have focused on quantifying N2 losses in vivo and fewer still have examined the relative contribution of the different N2 emission processes, particularly in grazed pastures. We used a combination of a high 15N isotopic enrichment of applied N with a high precision of determination of 15N isotopic enrichment by isotope-ratio mass spectrometry to measure N2 emissions in the field. We report that 55.8 g N m−2 (95%, CI 38 to 77 g m−2) was emitted as N2 by the process of co-denitrification in pastoral soils over 123 days following urine deposition (100 g N m−2), compared to only 1.1 g N m−2 (0.4 to 2.8 g m−2) from denitrification. This study provides strong evidence for co-denitrification as a major N2 production pathway, which has significant implications for understanding the N budgets of pastoral ecosystems.Funder
Department of Agriculture, Food and the Marine, Ireland; Teagasc Walsh Fellowship ProgrammeGrant Number
RSF 07536ae974a485f413a2113503eed53cd6c53
http://dx.doi.org/10.1038/srep17361