Abstract
Livestock manure contributes considerably to global emissions of ammonia ( NH 3 ) and greenhouse gases ( GHG ), especially methane ( CH 4 ) and nitrous oxide (N 2 O). Various measures have been developed to mitigate these emissions, but most of these focus on one specific gas and/or emission source. Here, we present a meta‐analysis and integrated assessment of the effects of mitigation measures on NH 3 , CH 4 and (direct and indirect) N 2 O emissions from the whole manure management chain. We analysed the effects of mitigation technologies on NH 3 , CH 4 and N 2 O emissions from individual sources statistically using results of 126 published studies. Whole‐chain effects on NH 3 and GHG emissions were assessed through scenario analysis. Significant NH 3 reduction efficiencies were observed for (i) housing via lowering the dietary crude protein ( CP ) content (24–65%, compared to the reference situation), for (ii) external slurry storages via acidification (83%) and covers of straw (78%) or artificial films (98%), for (iii) solid manure storages via compaction and covering (61%, compared to composting), and for (iv) manure application through band spreading (55%, compared to surface application), incorporation (70%) and injection (80%). Acidification decreased CH 4 emissions from stored slurry by 87%. Significant increases in N 2 O emissions were found for straw‐covered slurry storages (by two orders of magnitude) and manure injection (by 26–199%). These side‐effects of straw covers and slurry injection on N 2 O emission were relatively small when considering the total GHG emissions from the manure chain. Lowering the CP content of feed and acidifying slurry are strategies that consistently reduce NH 3 and GHG emissions in the whole chain. Other strategies may reduce emissions of a specific gas or emissions source, by which there is a risk of unwanted trade‐offs in the manure management chain. Proper farm‐scale combinations of mitigation measures are important to minimize impacts of livestock production on global emissions of NH 3 and GHG .