Ammonia and Nitrous Oxide Emissions after Landspreading of Slurry as Influenced by Application Technique and Dry Matter‐Reduction. II. Short Term Nitrous Oxide Emissions

Abstract

Summary -ZusammenfassungStrategies reducing NH, volatilisation from slurry include separation of slurry, special application techniques and additives. We studied the impact of manure separation and application technique on N20 release after manure application. Untreated and separated cattle slurry (dry matter content of 7.1% and 4.4%. respectively) was applied to winter wheat using broadcast and banded application and injection.The N20 emissions were measured at high frequency for 14 to 20 days after slurry treatment by the closed chamber method. Manured plots showed significantly higher N20 emissions than the control plots but neither dry matter reduction of slurry nor application technique significantly influenced the N20 emissions. The variability of N2O emission was influenced by the application technique and increased in the order: banded application -injection -broadcast application. There was no correlation between NH3 losses from applied slurry and N20 emissions. Thus reducing ammonia volatilisation will not necessarily increase N20 emissions.

Inclusion of the variability of diffuse pollutions in LCA for agriculture: the case of slurry application techniques

“…The effect of injection was equivocal, k N2O,INJ ranging between 0.33 and 3.95 (MAD ¼ 1.25) with three values out of eight below 1. Some authors found that injection had no effect on N 2 O emissions (Weslien et al, 1998;Clemens et al, 1997;Sommer et al, 1996), while others found an important effect of the mode of application (Dosch and Gutser, 1996;Wulf et al, 2002a,b;Velthof et al, 2003;Flessa and Beese, 2000). The variability of the effect of the application technique on N 2 O emissions is probably due to several factors interacting (Velthof et al, 2003).…”

“…In this study, as environmental impacts mainly originated from N losses, the question addressed was whether application techniques designed to reduce NH 3 losses had resulted in greater losses of N via other pathways. This question has been addressed in different papers, including those used to calculate the k N,Tech (Dosch and Gutser, 1996;Misselbrook et al, 2006;Weslien et al, 1998;Rodhe et al, 2006;Clemens et al, 1997); A thorough analysis of these data revealed contradictory conclusions regarding the effect of injection on N 2 O emissions: some authors found no effect of injection on N 2 O emissions compared to band spreading whereas others found that injection increased N 2 O emissions from two to four times (see Section 3.1.2).…”

“…(Hansen et al, 2003;Huijsmans et al, 2003;Dosch and Gutser, 1996;Smith et al, 2000;Misselbrook et al, 2006;Wulf et al, 2002a,b;Weslien et al, 1998;Søgaard et al, 2002;Velthof et al, 2003;Clemens et al, 1997;Vandre et al, 1997;Rodhe et al, 1995;Svensson, 1994;Sommer et al, 1996;Flessa and Beese, 2000). N 2 O fluxes measured in these experiments are considered to be ''direct emissions'' (noted N 2 O d ), i.e.…”

“…The analysis was also restricted to experiments where N losses could be expressed as a percentage of losses for band spreading, which was chosen as the reference technique, for it was the most represented in the reviewed studies. Finally, data from seven studies were used to calculate the relative loss factors (Dosch and Gutser, 1996;Smith et al, 2000;Wulf et al, 2002a,b;Weslien et al, 1998;Clemens et al, 1997;Vandre et al, 1997;Rodhe et al, 1995). They are noted k N,Tech , where N designates the emission (NH 3 or N 2 O d ) and Tech designates the application technique (BAND, BROAD, HARR, INJ) respectively.…”

Soil, slurry and application effects on greenhouse gas emissions

“…Soil N 2 O emissions originate mainly from microbial processes such as nitrification and denitrification (Clemens et al 1997). These processes depend on soil moisture, temperature, texture, mineral N and organic carbon (C) content.…”