Household biochar production and use by smallholder farmers in Kenya

About 40% of the world population lack access to clean cooking fuels. In rural sub-Saharan Africa the majority of people prepare their meals with firewood on open three stone fires. Biochar-producing microgasification cookstoves provide an opportunity to reduce fuel consumption and reduce the indoor air pollution in the cooking area, while use of biochar in soils sequesters carbon and increases agricultural yields, thereby improving livelihoods, especially for women. This paper presents findings from transdisciplinary research that started with long-term biochar field trials established in 2006. During recent years this research has involved 150 farming households at 3 locations in Kenya that produce biochar in locally manufactured GASTOV Top-lit Updraft (TLUD) gasifier cookstoves and use the biochar in their own fields. Fuel use, indoor concentrations of CO, CO2 and PM2.5 in cooking areas, and biochar production potential was measured in 75 households during cooking of a common Kenyan meal. The produced biochar was used in field trials with maize (Zea mays) and kale (Brassica oleracea) comparing biochar to normal farming practices, at biochar doses of 1-10 t ha-1. Findings from one of the sites, in Kwale County, show that for cooking a meal, on average 18 % of fuel was saved compared to the three stone open fire. In addition, 200 g biochar were produced which corresponded to 16.5% of the biomass used. Concentrations of CO and PM2.5 were reduced by 57 and 79 %, respectively. Fuel use was dominated by the wood types neem (Azadirachta indica) and casuarina (Casuarina equisetifolia), but a large variety of wood types were used by the households. Yield increases of maize in Kwale correlated positively with biochar dose. For the 20 farmers that finalized the trials in the first season, yields increased from 0.9 Mg ha-1 in the control plot to 4.4 Mg ha-1 in average in the biochar-amended plots. In addition to presentation of data on biochar production, we present data on biochar quality and use from all three sites. Implications and prerequisites for long-term success and upscaling will be discussed. This research contributes to knowledge on adoption of improved cookstoves by investigating how biochar production can be an additional incentive for cookstove uptake. Furthermore, it contributes to the understanding of biochar production potential in African rural areas. This case study shows that biochar systems in rural Africa can contribute to climate change mitigation. Biochar technology can at the same time help to solve the problems with energy and food security that farmers are facing, and thereby contribute to sustainable development

Socioeconomic Obstacles to Establishing a Participatory Plant Breeding Program for Organic Growers in the United States

Proponents of participatory plant breeding (PPB) contend that it is more conducive to promoting agricultural biodiversity than conventional plant breeding. The argument is that conventional plant breeding tends to produce crops for homogenous environments, while PPB tends to be directed at meeting the diverse environmental conditions of the farmers participating in a breeding program. Social scientific research is needed to highlight the complex socioeconomic factors that inhibit efforts to initiate PPB programs. To contribute, we offer a case study of a participatory organic seed production project that involved a university breeding program, commercial organic seed dealers, and organic farmers in the Northeastern United States. We demonstrate that, although PPB may indeed promote agricultural biodiversity, several socioeconomic obstacles must be overcome to establish such a program.agricultural biodiversity; socioeconomic context; plant breeding

Making it to the PhD: Gender and student performance in sub-Saharan Africa.

Women's underrepresentation in science, technology, engineering, and mathematics (STEM) impedes progress in solving Africa's complex development problems. As in other regions, women's participation in STEM drops progressively moving up the education and career ladder, with women currently constituting 30% of Africa's STEM researchers. This study elucidates gender-based differences in PhD performance using new survey data from 227 alumni of STEM PhD programs in 17 African countries. We find that, compared to their male counterparts, sampled women had about one less paper accepted for publication during their doctoral studies and took about half a year longer to finish their PhD training. Negative binomial regression models provide insights on the observed differences in women's and men's PhD performance. Results indicate that the correlates of publication productivity and time to PhD completion are very similar for women and men, but some gender-based differences are observed. For publication output, we find that good supervision had a stronger impact for men than women; and getting married during the PhD reduced women's publication productivity but increased that of men. Becoming a parent during the PhD training was a key reason that women took longer to complete the PhD, according to our results. Findings suggest that having a female supervisor, attending an institution with gender policies in place, and pursuing the PhD in a department where sexual harassment by faculty was perceived as uncommon were enabling factors for women's timely completion of their doctoral studies. Two priority interventions emerge from this study: (1) family-friendly policies and facilities that are supportive of women's roles as wives and mothers and (2) fostering broader linkages and networks for women in STEM, including ensuring mentoring and supervisory support that is tailored to their specific needs and circumstances

Understanding users' needs is important for the adoption of cleaner biomass cook stoves

elwood is the main source of cooking and heating energy for households in rural sub-Saharan Africa. Unfortunately, most of these households use inefficient biomass cook stoves, leading to consumption of more fuel and exposure to indoor air pollutants and associate health problems which disproportionately affect women and children. However, adoption of cleaner biomass cook stoves has remained low which could be associated to low understanding of users' needs and preferences among other factors. This study examined the performance and use of efficient gasifier cook stoves in the mid-lowlands, highlands and coastal regions of Kenya. Gasifier stoves that produce char (charcoal when used fuel or biochar when used for soil amendment) while cooking were issued to 150 households for free and their performance in fuel use and household air pollution in real life assessed among 50% of the households using participatory cooking tests. Further uptake surveys were carried out after 2–3 months about one year after gasifier cook stoves were issued. The gasifier performs better than three-stone open fire as it reduces fuel use by 51% and 28% when char is considered as fuel and biochar for soil amendment respectively. The new stove reduces concentration of PM2.5 and CO by 90% and 73% respectively. The results showed that after 2-3 months, 86%, 96% and 100% (average 94%) of households were using the stove though at varying frequencies of 4, 9 and 7 (average 7) times per week in Embu, Kwale and Siaya respectively. The use of the new stove was alongside their traditional stoves a common practice known as stove stacking. The gasifier was mainly used to cook foods that required a short cooking time and many preferred to use it to cook dinner. After about one year, 38%, 100 % and 88% (average 75%) of households were using it 3, 2 and 5 (average 3) times per week in Embu, Kwale and Siaya respectively while stove stacking. The surveys showed that the users liked the gasifier because it saves fuel, produce char used as charcoal providing fuel for other purposes such as ironing clothes and heating space, cook well and burn longer with less smoke and is easy to harvest and cool the char produced. However, despite the positive characteristics the users found it difficult to light from the top, chop wood into required sizes and reload the stove when fuel charred before the food got ready. To meet their cooking and heating needs, households continued to use the traditional three-stone and added the new stove. Users’ needs and preferences need to be understood and considered in the development of cleaner cooking biomass stoves for enhanced adoption and realization of the associated benefit

Use of Biochar-Producing Gasifier Cookstove Improves Energy Use Efficiency and Indoor Air Quality in Rural Households

Biomass fuels dominate the household energy mix in sub-Saharan Africa. Much of it is used inefficiently in poorly ventilated kitchens resulting in indoor air pollution and consumption of large amounts of wood fuel. Micro-gasification cookstoves can improve fuel use efficiency and reduce indoor air pollution while producing char as a by-product. This study monitored real-time concentrations of carbon monoxide (CO), carbon dioxide (CO2) and fine particulate matter (PM2.5), and amount of firewood used when households were cooking dinner. Twenty-five households used the gasifier cookstove to cook and five repeated the same test with three-stone open fire on a different date. With the gasifier, the average corresponding dinner time CO, CO2, and PM2.5 concentrations were reduced by 57%, 41%, and 79% respectively compared to three-stone open fire. The gasifier had average biomass-to-char conversion efficiency of 16.6%. If the produced char is used as fuel, households could save 32% of fuel compared to use of three-stone open fire and 18% when char is used as biochar, for instance. Adoption of the gasifier can help to reduce the need for firewood collection, hence reducing impacts on the environment while saving on the amount of time and money spent on cooking fuel

Implications on Livelihoods and the Environment of Uptake of Gasifier Cook Stoves among Kenya’s Rural Households

A majority of people in developing countries use biomass energy for cooking and heating due to its affordability, accessibility and convenience. However, unsustainable biomass use leads to forest degradation and climate change. Therefore, this study was carried out in Kwale County, Kenya, on the use of a biochar-producing gasifier cook stove and implications of its uptake on livelihoods and the environment. Fifty households were trained and issued with a gasifier for free. After 2–3 months of gasifier use, a survey was conducted to investigate the implications of its uptake. The direct impacts included reduced fuel consumption by 38%, reduced time spent in firewood collection, reduced expenditure on cooking fuel, diversification of cooking fuels, improved kitchen conditions and reduced time spent on cooking. The potential benefits included income generation, increased food production, reduced impacts on environment and climate change and reduced health problems. Improved biomass cook stoves can alleviate problems with current cooking methods, which include inefficient fuel use, health issues caused by smoke, and environmental problems. These benefits could contribute to development through alleviating poverty and hunger, promoting gender equality, enhancing good health and sustainable ecosystems and mitigating climate change. The study recommends the promotion of cleaner cooking stoves, particularly gasifiers, among households in rural areas while paying attention to user needs and preferences

Cleaner cooking while producing biochar: factors affecting adoption of gasifier cookstoves in rural areas

A majority of households in developing countries use biomass energy for cooking and heating due to its affordability and accessibility. However, unsustainable biomass use leads to deforestation, environmental degradation and climate change. The pollution from open burning of biomass is a major health concern especially for women and children as they spend a lot of time in the kitchen. Biochar-producing gasifier cookstoves offer an opportunity to address many of these problems, while also producing biochar, which can be used as a soil amendment. A study was carried out in order to investigate factors influencing the adoption of these cookstoves in three sites in Kenya (Kwale, Embu and Siaya). After an introductory training, 150 households received cookstoves and were asked to use them to produce biochar for upcoming field experiments. User experiences were collected throughsurveys after 2-3 months and about 2 years, and at workshops. The main benefits of the cookstove identified by the users were fuel saving with significant impacts on household economies, reduced smoke and production of biochar for either cooking or soil amendment. Challenges were related to lighting, a need to refill the fuel canister, fuel preparation and different suitability for different typesof meals and meal sizes. The gasifier use frequency and biochar production rates differed between the sites, which had different climate, socio-economic conditions and fuel accessibility. The results will be of relevance for inclusion of user participation in cookstove designing and performance assessment as well as for stakeholders involved in marketing. They can also give guidance on therelevance of gasifier cookstoves for production of biochar for use on farms

Quality of charcoal produced using micro gasification and how the new cook stove works in rural Kenya

Wood based energy is the main source of cooking and heating fuel in Sub-Saharan Africa. Its use rises as the population increases. Inefficient cook stoves result in fuel wastage and health issues associated with smoke in the kitchen. As users are poor women, they tend not to be consulted on cook stove development, hence the need for participatory development of efficient woodfuel cooking systems. This paper presents the findings of a study carried out in Embu, Kenya to assess energy use efficiency and concentrations of carbon monoxide and fine particulate matter from charcoal produced using gasifier cook stoves, compared to conventional wood charcoal. Charcoal made from Grevillea robusta prunings, Zea mays cob (maize cob) and Cocos nucifera (coconut shells) had calorific values of 26.5 kJ g−1, 28.7 kJ g−1 and 31.7 kJ g−1 respectively, which are comparable to conventional wood charcoal with calorific values of 33.1 kJ g−1. Cooking with firewood in a gasifier cook stove and use of the resultant charcoal as by-product to cook another meal in a conventional charcoal stove saved 41% of the amount of fuel compared to cooking with firewood in the traditional three stone open fire. Cooking with firewood based on G. robusta prunings in the traditional open fire resulted in a concentration of fine particulate matter of 2600 μg m−3, which is more than 100 times greater than from cooking with charcoal made from G. robusta prunings in a gasifier. Thirty five percent of households used the gasifier for cooking dinner and lunch, and cooks preferred using it for food that took a short time to prepare. Although the gasifier cook stove is energy and emission efficient there is a need for it to be developed further to better suit local cooking preferences. The energy transition in Africa will have to include cleaner and more sustainable wood based cooking systems