Effect of Assisted Soil Infiltration on Emissions of Ammonia and Nitrous Oxide from Applied Dairy Slurry.

Bhandral, R.¹, *Bittman, S.¹, Kowalenko, G.¹, Hunt, D.E.¹, Bounaix, F.¹, Friesen, A.,¹ Buckley, K.² and Chantigny, M.³

AAFC Research Stations ¹Agassiz, ²Brandon and ³Sainte Foy*Corresponding Author

Low-cost technologies are needed to reduce emissions of both ammonia (NH₃) and nitrous oxide (N₂O) from field applied slurry manure. Removing solids from slurry makes the manure less viscous so it can better infiltrate the soil and reduces concentration of N and P allowing greater application rates by volume. This study was undertaken to assess the effects of assisting infiltration mechanically (by soil aerating) and solids removal (by settling/decanting) on emission of NH₃ and N₂O from spring, summer and autumn applied dairy slurry. Both methods were observed to enhance rate of infiltration into the soil. Mechanically assisted infiltration of manure reduced emissions of NH₃ during three seasons but decantation effect varied with season (reduced emission in fall and increased in summer). The two abatement techniques generally did not significantly affect N₂O emissions. Using both techniques, NH₃ emissions were reduced by 82% in autumn, 58% in spring and 34% summer. While decanting should help farmers reduce emissions and hauling costs, timing of manure application needs to be considered.