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United States Department of Agriculture

Agricultural Research Service

Research Project: SOIL RESOURCE EVALUATION OF MANAGEMENT SYSTEMS TO ENHANCE AGROECOSYSTEM SUSTAINABILITY

Location: Northern Great Plains Research Laboratory

Title: Effects of Normal and Altered Cattle Urine on Short-term Greenhouse Gas Flux from Mixed-Grass Prairie in the northern Great Plains

Authors
item Liebig, Mark
item Kronberg, Scott
item Gross, Jason

Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 22, 2007
Publication Date: November 22, 2007
Citation: Liebig, M.A., Kronberg, S.L., Gross, J.R. 2008. Effects of Normal and Altered Cattle Urine on Short-term Greenhouse Gas Flux from Mixed-Grass Prairie in the northern Great Plains. Agric. Ecosys. Environ. 125:57-64.

Interpretive Summary: Globally, the livestock sector produces approximately 18% of total greenhouse gas emissions, of which the most important sources are nitrous oxide and methane from animals and their excreta. Urine patches in pastures and grazing lands, in particular, represent a significant potential source of greenhouse gases due to carbon and nitrogen contained in urine. Ingestion of small amounts of naturally-occurring tannins by livestock has been found to reduce nitrogen concentration in urine without negatively affecting animal performance. Given this context, a study was conducted to quantify the effects of cattle urine and urine from cattle that had ingested water containing condensed tannin on greenhouse gas flux under field conditions. For purposes of comparison, greenhouse gas flux was also evaluated from treatments including ammonium nitrate in solution and a no application control. Over the course of the six week study, carbon dioxide emission was greatest from normal urine and least from the control, with intermediate fluxes for the tannin urine and ammonium nitrate treatments. Uptake of methane was over 40% less within the tannin urine treatment as compared to normal urine, and may have been repressed by the capacity of tannin to bind specific enzymes responsible for methane oxidation. Though the tannin urine treatment possessed 34% less N than normal cattle urine, cumulative nitrous oxide emission between the treatments did not differ. Results from this study suggest the use of condensed tannin as a dietary amendment for livestock does not yield greenhouse gas mitigation benefits in the short-term.

Technical Abstract: Use of dietary amendments to reduce nitrogen (N) in excreta represents a possible strategy to decrease greenhouse gas (GHG) emissions from livestock. In this regard, ingestion of small amounts of condensed quebracho tannin has been found to reduce N concentration in livestock urine. In this study, we sought to quantify the effects of tannin-affected cattle urine, normal cattle urine, and ammonium nitrate in solution on greenhouse gas flux. Carbon dioxide, methane, and nitrous oxide flux was measured using static chamber methodology from the three N treatments and a no application control over a six-week period in a mixed grass prairie. Average carbon dioxide emission was greatest from normal urine (335 mg C/sq. m/hr) and least from the control (229 mg C/sq. m/hr), with intermediate fluxes for the tannin urine and ammonium nitrate treatments (290 and 286 mg C/sq. m/hr, respectively). Methane uptake was prevalent throughout the study, as soil conditions were predominantly warm and dry. Uptake of methane was greatest within the control (-30 ug C/sq. m/hr) and least in the tannin urine treatment (-12 ug C/sq. m/hr). Uptake of methane was over 40% less within the tannin urine treatment as compared to normal urine, and may have been repressed by the capacity of tannin to bind monooxygenases responsible for methane oxidation. Average nitrous oxide emission from ammonium nitrate solution was more than twice that of all other treatments. Though the tannin urine treatment possessed 34% less N than normal cattle urine, cumulative nitrous oxide emission between the treatments did not differ. Results from this study suggest the use of condensed quebracho tannin as a dietary amendment for livestock does not yield GHG mitigation benefits in the short-term. [GRACEnet Publication]

Last Modified: 10/1/2014
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