Nitrous oxide and methane fluxes from urine and dung deposited on Kenyan pastures
Livestock keeping is ubiquitous in tropical Africa. Urine and dung from livestock release greenhouse gases (GHGs), such as nitrous oxide (N2O) and methane (CH4), to the atmosphere. However, the extent of GHG’s impact is uncertain due to the lack of in situ measurements in the region. Here we measure...
| Autores principales: | , , , , |
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| Formato: | Journal Article |
| Lenguaje: | Inglés |
| Publicado: |
Wiley
2017
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| Materias: | |
| Acceso en línea: | https://hdl.handle.net/10568/82560 |
| _version_ | 1855538217241018368 |
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| author | Tully, Katherine L. Abwanda, Sheila O. Thiong'o, Margaret Mutuo, Paul M. Rosenstock, Todd S. |
| author_browse | Abwanda, Sheila O. Mutuo, Paul M. Rosenstock, Todd S. Thiong'o, Margaret Tully, Katherine L. |
| author_facet | Tully, Katherine L. Abwanda, Sheila O. Thiong'o, Margaret Mutuo, Paul M. Rosenstock, Todd S. |
| author_sort | Tully, Katherine L. |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Livestock keeping is ubiquitous in tropical Africa. Urine and dung from livestock release greenhouse gases (GHGs), such as nitrous oxide (N2O) and methane (CH4), to the atmosphere. However, the extent of GHG’s impact is uncertain due to the lack of in situ measurements in the region. Here we measured N2O and CH4 emissions from cow urine and dung depositions in two Kenyan pastures that received different amounts of rainfall using static chambers across wet and dry seasons. Cumulative N2O emissions were greater under dung+urine and urine-only patches (P < 0.0001), more than three times higher in the wet compared with the dry season (P < 0.0001), and higher in the farm receiving higher rainfall overall (P < 0.0001). Cumulative CH4 emissions differed across treatments (P = 0.012), driven primarily by soil CH4 uptake from the urine-only treatment. Cumulative N2O emissions were positively related to N input rate in excreta. However, the relationship was linear during the dry season (r2 = 0.99; P = 0.001) and exponential during the wet season (r2 = 0.99; P < 0.0001). Nitrous oxide emission factors were 0.05% (dry season) and 0.18% (wet season) of N in urine and dung+urine, which is less than 10% of the IPCC Default Tier 1 emission factor of 2%. We predict that emissions from cattle urine in Kenya are approximately 1.7 Gg N2O–N yr−1 (FAO estimates 11.9 Gg N2O–N yr−1). Our findings suggest that current estimates may overestimate the contribution of excreta to national GHG emissions and that emission factors from urine and dung need to account for agroecosystems with distinct wet and dry seasons. |
| format | Journal Article |
| id | CGSpace82560 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2017 |
| publishDateRange | 2017 |
| publishDateSort | 2017 |
| publisher | Wiley |
| publisherStr | Wiley |
| record_format | dspace |
| spelling | CGSpace825602025-02-20T11:27:48Z Nitrous oxide and methane fluxes from urine and dung deposited on Kenyan pastures Tully, Katherine L. Abwanda, Sheila O. Thiong'o, Margaret Mutuo, Paul M. Rosenstock, Todd S. greenhouse gases livestock pasture food security climate change agriculture Livestock keeping is ubiquitous in tropical Africa. Urine and dung from livestock release greenhouse gases (GHGs), such as nitrous oxide (N2O) and methane (CH4), to the atmosphere. However, the extent of GHG’s impact is uncertain due to the lack of in situ measurements in the region. Here we measured N2O and CH4 emissions from cow urine and dung depositions in two Kenyan pastures that received different amounts of rainfall using static chambers across wet and dry seasons. Cumulative N2O emissions were greater under dung+urine and urine-only patches (P < 0.0001), more than three times higher in the wet compared with the dry season (P < 0.0001), and higher in the farm receiving higher rainfall overall (P < 0.0001). Cumulative CH4 emissions differed across treatments (P = 0.012), driven primarily by soil CH4 uptake from the urine-only treatment. Cumulative N2O emissions were positively related to N input rate in excreta. However, the relationship was linear during the dry season (r2 = 0.99; P = 0.001) and exponential during the wet season (r2 = 0.99; P < 0.0001). Nitrous oxide emission factors were 0.05% (dry season) and 0.18% (wet season) of N in urine and dung+urine, which is less than 10% of the IPCC Default Tier 1 emission factor of 2%. We predict that emissions from cattle urine in Kenya are approximately 1.7 Gg N2O–N yr−1 (FAO estimates 11.9 Gg N2O–N yr−1). Our findings suggest that current estimates may overestimate the contribution of excreta to national GHG emissions and that emission factors from urine and dung need to account for agroecosystems with distinct wet and dry seasons. 2017-07 2017-06-22T14:31:40Z 2017-06-22T14:31:40Z Journal Article https://hdl.handle.net/10568/82560 en Limited Access Wiley Tully KL, Abwanda S, Thiong'o M, Mutuo PM, Rosenstock TS. 2017. Nitrous oxide and methane fluxes from urine and dung deposited on Kenyan pastures. Journal of Environmental Quality. |
| spellingShingle | greenhouse gases livestock pasture food security climate change agriculture Tully, Katherine L. Abwanda, Sheila O. Thiong'o, Margaret Mutuo, Paul M. Rosenstock, Todd S. Nitrous oxide and methane fluxes from urine and dung deposited on Kenyan pastures |
| title | Nitrous oxide and methane fluxes from urine and dung deposited on Kenyan pastures |
| title_full | Nitrous oxide and methane fluxes from urine and dung deposited on Kenyan pastures |
| title_fullStr | Nitrous oxide and methane fluxes from urine and dung deposited on Kenyan pastures |
| title_full_unstemmed | Nitrous oxide and methane fluxes from urine and dung deposited on Kenyan pastures |
| title_short | Nitrous oxide and methane fluxes from urine and dung deposited on Kenyan pastures |
| title_sort | nitrous oxide and methane fluxes from urine and dung deposited on kenyan pastures |
| topic | greenhouse gases livestock pasture food security climate change agriculture |
| url | https://hdl.handle.net/10568/82560 |
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