135-11 Nitrous Oxide (N2O) Emissions From Soils Receiving Long-Term Applications of Liquid Swine Manure or Solid Cattle Manure.



Monday, October 17, 2011: 11:15 AM
Henry Gonzalez Convention Center, Room 218, Concourse Level

Richard Farrell1, Reynald L. Lemke2 and Jeff Schoenau2, (1)Soil Science, University of Saskatchewan, Saskatoon, SK, Canada
(2)Agriculture and Agri-Food Canada, Saskatoon, SK, Canada
Nitrous oxide (N2O) fluxes associated with the long-term manure and fertilizer application plots at Humboldt, SK were measured over a two year period from 2009 to 2010. Plots received either liquid swine manure (LSM), solid cattle manure (SCM), or banded urea. Gas fluxes were measured more frequently (1–2 times per week) at the start of the season (i.e., during spring thaw and following seeding) and less frequently (once every 2–3 weeks) at the end of the season. Gas fluxes also were measured 24–48 hours after any significant precipitation event during the sampling season. In addition, denitrification enzyme activity (DEA) was measured in spring, mid-summer and early fall.
Daily N2O fluxes were highly variable, but followed the general event based/background pattern; DEAs were significantly greater in the plots receiving the highest manure applications. In general, it was determined that (1) emission factors for the urea- and manure-amended plots were in the range (i.e., 0.2–1.0) normally associated with prairie agriculture; (2) N2O emissions from LSM-amended soils increase with increasing rate and intensity of the manure-N application; (3) long-term applications of manure-N can, at high application rates or following frequent manure applications, produce a ‘priming’ effect which may exacerbate N2O emissions if a more available form of N (e.g., urea fertilizer) is applied to the soil; and (4) the variable effects of the LSM and SCM on soil N2O emissions are a reflection of the variable compositions of the manures as well as interactions with soil environmental conditions and soil management practice.
See more from this Division: S06 Soil & Water Management & Conservation
See more from this Session: Agricultural Practices to Increase Nitrogen-Use Efficiency, Carbon Sequestration, and Greenhouse Gas Mitigation: I