This study assessed the potential contributions of improved cookstoves in enhancing organic fertilizer availability for application to farmland, greenhouse gas emission mitigation and improvement of household finances using the Kitchen Performance Test and Controlled Cooking Test. Substitution of a three-stone open fire with improved cookstoves significantly (p<0.01) improved fuel use efficiency by 54% (highest) for the mirt stove together with biogas and 32% (lowest) for the mud stove without biogas. The greenhouse gas emission reductions in carbon dioxide equivalents were 4534(±32) kg y -1 , 6370(±42) kg y -1 , 6953(±51) kg y -1 , 7661(±43) kg y -1 for the mud stove, mirt stove, mud stove with biogas and mirt stove with biogas respectively. The average financial savings from the sale of surplus biomass fuel for the improved cookstoves were higher than the summed financial savings from substitution of commercial fertilizer, generation of carbon finance and replacement of kerosene for lighting. This explains why households usually prefer to sell surplus biomass fuels instead of using them as organic fertilizers. This finding suggests that wide scale adoption of fuel- efficient solid biomass stoves can contribute to the financial security of households, and may help to reduce deforestation, but will do little to increase the fertility of soils. By contrast, including biogas stoves will help to improve soil fertility by retaining at least some of the carbon and nutrients in bioslurry that will then be applied to the soil.
Bibliographical noteThe authors are grateful to the participating households in stove performance test and end-users’ stove satisfaction survey without whose assistance the accomplishment of the research undertaking could have been possible. We would like to give our deep gratitude to the African Union Commission (AUC) for funding the installation of biogas digesters and mirt stoves in Kumbursa Village as part of Afriflame project under the adaptation of small-scale biogas digesters for use in rural households in Sub-Saharan Africa. The assistance from Green Heat- Uganda in installing biogas digesters in Kumbursa Village is appreciated. Finally, we are thankful to the staff of Debrezeit Agricultural Research Center for analyzing the nutrient contents of dung cake, crop residues and bioslurry samples.
- Controlled Cooking Test, Cookstove
- Fuel saving efficiency
- greenhouse gases
- Kitchen Performance Test