Greenhouse gas emissions from sheep excreta deposited onto tropical pastures in Kenya ...

To improve the estimate of greenhouse gas emissions (GHG) from tropical rangelands in sub-Saharan Africa, we measured GHG emissions from sheep excreta over two periods of 51 days on a Kenya rangeland. In addition, we measured GHG emissions from potential hotspots in the landscape linked to sheep grazing: overnight enclosures (“bomas”), where sheep are kept at night to protect them from theft and predators, the areas surrounding sheep bomas, and areas surrounding watering troughs. Results showed a short pulse of CO$_2$ fluxes after sheep urine application and a rapid increase of CH$_4$ fluxes following sheep dung application in both rainy and dry season. However, only small increases of N$_2$O fluxes were observed after dung and urine applications compared to controls without excreta. Elevated N$_2$O fluxes mainly coincided with heavy rainfall. Overall, N$_2$O emission factors (EFs) did not vary across excreta type or seasons, but mean N$_2$O EFs for dung (0.01%) and urine patches (0.02%) were only one tenth ...