Greenhouse Gas Fluxes from Selected Soil Fertility Management Practices in Humic Nitisols of Upper Eastern Kenya

Sustainability

Milka N. Kiboi¹  Felix K. Ngetich¹  Joseph M. Macharia²  Andreas Fliessbach³  Collins M. Musafiri⁴  Miriam W Githongo⁴  Anne Muriuki⁵ 

[1] Cortile Scientific Limited, P.O. Box 34991, Nairobi 00100, Kenya;Department of Geography, Kenyatta University, P.O. Box 43844, Nairobi 00100, Kenya;Department of Soil Sciences, Research Institute of Organic Agriculture (FIBL), Ackerstrasse 113, 5070 Frick, Switzerland;Department of Water and Agricultural Resource Management, University of Embu, P.O. Box 6, Embu 60100, Kenya;National Agriculture Research Laboratories, Kenya Agricultural and Livestock Research Organization, P.O. Box 14733, Nairobi 00800, Kenya;

关键词: emission factor;    greenhouse gas intensities;    global warming potential;    greenhouse gases;    carbon sequestration;   

DOI  :  10.3390/su14031938

来源: DOAJ

【 摘 要 】

We quantified the soil carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) fluxes of five soil fertility management practices (inorganic fertilizer (Mf), maize residue + inorganic fertilizer (RMf), maize residue + inorganic fertilizer + goat manure (RMfM), maize residue + tithonia diversifolia + goat manure (RTiM), and a control (CtC)) in Kenya’s central highlands using a static chamber method from March 2019 to March 2020. The cumulative annual soil CH₄ uptake ranged from −1.07 to −0.64 kg CH₄-C ha⁻¹ yr⁻¹, CO₂ emissions from 4.59 to 9.01 Mg CO₂-C ha⁻¹ yr⁻¹, and N₂O fluxes from 104 to 279 g N₂O-N ha⁻¹ yr⁻¹. The RTiM produced the highest CO₂ emissions (9.01 Mg CO₂-C ha⁻¹ yr⁻¹), carbon sequestration (3.99 Mg CO₂-eq ha⁻¹), yield-scaled N₂O emissions (YSE) (0.043 g N₂O-N kg⁻¹ grain yield), the lowest net global warming potential (net GWP) (−14.7 Mg CO₂-eq ha⁻¹) and greenhouse gas intensities (GHGI) (−2.81 Kg CO₂-eq kg⁻¹ grain yield). We observed average maize grain yields of 7.98 Mg ha⁻¹ yr⁻¹ under RMfM treatment. Integrating inorganic fertilizer and maize residue retention resulted in low emissions, increased soil organic carbon sequestration, and high maize yields.

【 授权许可】

Unknown