Impact of slurry strip-till and surface slurry incorporation on NH3 and N2O emissions on different plot trials in Central Germany

Abstract

Greenhouse gases (GHG) cause damage to the biosphere and atmosphere, and essentially lead to a reduction in fertilization efficiency. Different slurry application techniques can influence the emission of GHG. In the years 2014 and 2015, two parallel trials (sites: Lückstedt and Kossebau) and one lysimeter trial (site: Falkenberg) were set up in Central Germany (federal state: Saxony-Anhalt) in order to investigate the influence of the slurry strip-till method on ammonia (NH3) and nitrous oxide (N2O) emissions when compared to surface slurry incorporation. The effect of the nitrification inhibitor (NI) (PIADIN®) on GHG emissions was also examined. NH3 was measured using a combination of passive samplers and the Dräger Tube method (DTM). N2O was measured using the closed chamber method (CCM) both in the maize row and in the interrow space. In the two years of the experiment, NH3volatilization fluctuated between 0.6 and 3.5kg NH3-N ha−1. In 2014, the slurry strip-till treatments in Lückstedt emitted significantly less NH3 than surface slurry incorporation. In 2015, at the Kossebau site NH3 volatilization was significantly lower in the treatments with NI than those with no NI. In both years, N2O emissions were between 0.5kg and 2kgN2O-Nha−1.In the lysimeter trial, in 2014 significantly higher N2O emissions were detected in the unfertilized control than in the fertilized treatments. In the plot trial in Kossebau, in 2015 significantly lower N2O emissions were recorded in the row than interrow. These differences are probably due to the uptake of mineral nitrogen by the plants in the row as a starting material for nitrification and denitrification. In Kossebau there were significant correlations between N2O emissions and soil temperature. As regards the slurry strip-till method, no significant reduction in N2O emissions was observed in comparison to surface slurry incorporation. The influence of the slurry strip-till method on NH3 and N2O emissions depends on annual weather conditions and it cannot generally be regarded as preferable to conventional, surface slurry incorporation.