I participated in the recently concluded inaugural Africa Climate Summit in September 2023 in Nairobi, and was fortunate to be part of several captivating talks and panel discussions. These discussions delved into essential topics concerning Africa such as reducing food loss and waste, financing climate adaptation for agriculture and food security, promoting eco-friendly jobs and skills, exploring new opportunities for clean technology aiding small and medium-sized enterprises (SMEs) in addressing climate challenges, empowering young women in the context of climate-smart agriculture, and recognizing Africa’s potential as a carbon remover.
Throughout these informative conversations, I contemplated which of these valuable insights I could impart to the farmers in remote villages across Kenya and inspire them towards implementation. During this contemplation, I met a gentleman representing organisations dedicated to encouraging farmers to harness the potential of biochar production from locally abundant waste materials. This encounter, I realised, held the promise of practical and actionable recommendations that could transform the lives of countless farmers in Africa. The idea of biochar production from readily available waste resources presented an opportunity for both the environment and the livelihoods of farmers across the continent.
As defined by Lehmann and Joseph (2015), biochar is carbonised biomass obtained from sustainable sources, sequestered in soils to enhance their agricultural and environmental value under present and future management. This distinguishes it from charcoal which is used for heat, filtering, iron-making, or as a colouring agent in industry or art. Biochar, a porous material, aids in retaining water and nutrients in the soil benefiting plant growth. Some studies have suggested it can sequester up to 50% of carbon.
It is stated that biomass contains approximately between 45% to 60% of carbon and about 35% to 40% of oxygen, the remaining elements being hydrogen, nitrogen, and small amounts of minerals. As the biomass deteriorates or is burned, a significant amount of carbon is released into the atmosphere which could negatively impact the climate, but this can be avoided if biochar is produced instead.
The historical roots of biochar usage run deep dating back to ancient civilizations. For instance, the Amazonians employed a technique called “terra preta” to improve soil fertility by adding biochar. Centuries later, these soils were even remarkably productive and fertile, demonstrating the long-lasting benefits of biochar. The term biochar was coined by environmentalist Peter Read in 2005.
Biochar is produced through the pyrolysis of organic materials such as wood, crop residues, and other biomass. Pyrolysis involves heating these materials in a low-oxygen environment, causing them to decompose without combustion. The result is a stable, carbon-rich material with a high surface area and porous structure. The versatility of biochar lies in its ability to be produced from various feedstocks. What is required is for one to dig a hole, the dimensions usually guided by an expert, and assemble a mixture of dry plants from sweetcorn stalks, coconut residues, animal manures, forestry wastes, food leftovers, weeds, and so on, which are then slowly burned. Biochar varies depending on the original material used as it would reflect the physical and chemical properties of the parent material. For example, biochar derived from trees is different from that of plants.
The benefits of biochar are numerous. It offers a sustainable way to convert organic waste into a valuable soil amendment; since biochar is alkaline it raises the soil pH to above grade 7. Further, when incorporated into the soil, biochar enhances water retention and drought mitigation, improving soil texture, nutrient availability and microbial activity, thus reducing the need for synthetic fertilisers and pesticides and promoting sustainable agriculture.
Biochar sequesters carbon in a stable form and mitigates carbon emissions, which at scale could reduce overall greenhouse gas emissions. A particularly interesting use case is the application of biochar in rice paddies; it has been noted to reduce methane emissions, a potent greenhouse gas.
Smallholder farmers in Kenya face numerous challenges such as limited resources, degraded soils, unpredictable weather patterns, and a lack of access to modern agricultural inputs. Biochar can play a crucial role in alleviating these issues. Promoting biochar among smallholder farmers in Kenya may come with challenges, such as lack of awareness, minimum start-up costs if any, and skepticism. However, with focused efforts, support, and collaboration these challenges can be overcome. One way to promote biochar use among farmers is through awareness creation, education and practical demonstrations on the benefits, peer-to-peer learning, workshops and demonstration farms. These farms would allow farmers to witness first-hand the positive impact on soil quality and crop yield. Through practical observation, skepticism on the benefits of biochar would be eliminated as the clear impact on soil quality and crop yield would be evident.
The production of biochar not only benefits farmers directly but also opens doors for them to sell to other farmers who may not be able to make biochar. Secondly, organisations buying carbon credits present a great opportunity for smallholder farmers to earn from sequestering carbon. Scaling this endeavour would require the involvement of local actors such as cooperatives, community based organisations, women groups, and government agencies, to address some of the soil infertility issues and increase adoption.
In conclusion, biochar holds the potential to significantly improve the livelihoods of smallholder farmers in Kenya while contributing to sustainable agriculture and climate change mitigation. Effective promotion, education, and local production are key strategies to unlock the benefits of biochar and ensure that smallholder farmers can reap the rewards of this innovative and sustainable agricultural practice. With concerted efforts and collaboration, Kenya’s smallholder farmers can embrace biochar and enjoy a greener and more prosperous future.