Effects of liming and local sediment amendment on millet production and soil N2O emission in western Kenya

Abstract Aim Soil acidification is a major constraint to agricultural productivity in East Africa. This study evaluated the effects of liming and local sediment amendments on millet production, soil properties, and soil N₂O emissions in western Kenya. Methods Field experiments with liming (Ca(OH)₂, 5 t ha⁻ 1 ) and local sediment amendments (1% and 3%) were conducted using a four-replicate block design. Soil properties, millet biomass and yield, and N₂O fluxes were measured. Results Liming significantly increased millet biomass and yield by raising soil pH, enhancing Ca availability, and reducing Al toxicity, while also resulting in the lowest N₂O emissions. In contrast, sediment amendments had only minor effects on soil chemistry and did not significantly improve yield or reduce N₂O fluxes compared to the control. Conclusion By improving soil properties as soil pH and nutrient availability, liming proved to be an effective strategy to increase millet production and reduce N 2 O emissions in acidic soils. In contrast, local sediment amendment offered moderate but persistent improvements in soil fertility, but did not increase millet yield significantly. These findings highlight liming as a key management practice for enhancing crop production while mitigating greenhouse gas emissions in acidified agricultural systems of East Africa.