Tillage, Compaction and Wetting Effects on NO3, N2O and N-2 Losses

Denitrification is sensitive to changes in soil physical properties that affect solute transport, air content and gas diffusion. Using lysimeters, containing intact soil from intensively tilled (IT) and no-tilled (NT) soil used to grow forage crops, we examined how simulated animal treading at different moisture contents (above and below field capacity; >FC and FC greatly increased denitrification, especially from IT soil and produced the greatest amount of N2 (64kg N ha–1), N2O (8.2kg N ha–1), as well as the lowest N2O to N2O+N2 ratio (0.08) and NO3 leaching (136kg N ha–1 below 30cm). In both the uncompacted or compacted soils FC. Treading at