Biochar produced in cookstoves has the potential to contribute to negative carbon emissions through sequestration of biomass carbon while also providing other benefits for sustainable development, including provision of clean renewable energy and increased yields in tropical agriculture. The aim of the reported research was to estimate effects on food production, household energy access and life cycle climate impact from introduction of biochar-producing cookstoves on smallholder farms in Kenya. Participatory research on biochar production and use was undertaken with 150 Kenyan smallholder farming households. Gasifier cookstove functionality, fuel efficiency and emissions were measured, as well as biochar effects on agricultural yields after application to soil. Cookstoves provided benefits through reduced smoke, fuel wood savings and char production, but challenges were found related to labour for fuel preparation, lighting and refilling. On-farm trials with varying rates of biochar inputs, in combination with and without mineral fertilizers, have led to a sustained increase of maize yields following one-time application. The climate impact in a life cycle perspective was considerably lower for the system with cookstove production of biochar and use of biochar in agriculture than for current cooking practices. Climate benefits from biochar production and use are thus possible on smallholder farms in sub-Saharan Africa, through reduced use of biomass in cooking, reduced emissions of products of incomplete combustion and sequestration of stable biochar carbon in soils. Biochar-producing cookstoves can be implemented as a climate change mitigation method in rural sub-Saharan Africa. Successful implementation will require changes in cooking systems including fuel supply, as well as farming systems, which, in turn, requires an understanding of local socio-cultural conditions, including power relations and gender aspects.

炉灶中产生的生物炭有可能通过隔离生物质碳而导致负碳排放，同时还为可持续发展提供其他好处，包括提供清洁的可再生能源和热带农业增产。所报告研究的目的是估计在肯尼亚的小农户农场使用生物炭生产的炊具对粮食生产，家庭能源获取和生命周期气候影响的影响。对150个肯尼亚小农户进行了生物炭生产和使用的参与性研究。测量了气化炉灶具的功能，燃料效率和排放量，以及施用到土壤后生物炭对农业产量的影响。炊具通过减少烟雾提供了好处，节省了燃柴并节省了焦炭，但发现与燃料准备，照明和加气相关的挑战。在农场进行不同生物炭投入量的试验，无论是否使用矿物肥料，一次施用后，玉米产量持续增加。从生命周期的角度来看，具有炉灶生产生物炭和在农业中使用生物炭的系统的气候影响要比当前的烹饪方法低得多。因此，在撒哈拉以南非洲的小农户农场上，通过减少使用生物质，减少不完全燃烧产物的排放以及将稳定的生物炭碳隔离在土壤中，可能会在撒哈拉以南非洲的小农农场中获得生物炭生产和使用所带来的气候效益。可以在撒哈拉以南非洲农村地区实施生产生物炭的炉灶作为缓解气候变化的方法。成功实施将需要改变包括燃料供应在内的烹饪系统以及耕作系统，而这又需要了解当地的社会文化条件，包括权力关系和性别方面。