Nitrous oxide emission factors for cattle dung and urine deposited onto tropical pastures: A review of field-based studies

Livestock excreta on pastures is an important source of nitrous oxide (N 2 O) emissions, however studies measuring these emissions in tropical regions, particularly Africa, remain limited. Therefore we measured N O from different quantities dung patches during three observation periods (dry, wet and transition dry to season) volumes urine seasons. Dung did not stimulate soil any the periods, while application stimulated both seasons, with higher observed season. The EFs (0.00–0.03%) (0.04–0.40%) showed no detectable effects quantity or volume. We further synthesized observations other which indicated that were similar default values provided IPCC 2019 refinement (0.11% vs 0.07% for 0.41% 0.32% climates, 0.13% 0.65% 0.77% climates). However, sub-Saharan African (SSA) had consistently lower EFs, possibly due urine-N: dung-N ratio SSA compared suggesting may still overestimate SSA. Moreover, considering large variations summarized -0.01 1.77% 0.00 4.90% urine, more under diverse conditions across regions are recommended. • Excreta emission factors influenced by mass Soil type partitioning overlooked national inventories.