ETH-Soil
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How soil affects food security
Arable soils in Ethiopia are among the oldest on the African continent. Over the centuries, they have been severely degraded by natural and man-made causes. Particular deficiencies exist in key nutrients such as nitrogen, phosphorus and potassium, while soil organic matter levels remain critically depleted. Low organic inputs and rapid biological decomposition under tropical conditions, combined with erratic rainfall and extreme weather events, further contribute to nutrient depletion and soil health problems. Meanwhile, fertiliser use remains limited, particularly due to the ongoing global fertiliser crisis, which has led to shortages and price increases for synthetic fertilisers, placing them beyond the reach of many smallholder farmers. As a result, grain yields remain modest, with a national average of 2.6 t/ha – far below countries such as Germany, which produced around 7 t/ha in 2024. Despite these challenging conditions, about 80% of Ethiopia’s population depend on agriculture and livestock for their livelihoods. Improving soil health is therefore crucial for enhancing food security, productivity, and rural incomes.
Caring for soil is caring for life.
To tackle these issues, governmental and academic bodies in Ethiopia are working together on the research and improvement of soil health. ETH-Soil is part of this movement for healthy soils and food security, because caring for soil is caring for life.
Combatting hunger by improving soils
ETH-Soil is tackling food insecurity at its roots by improving degraded soils. We work for and with smallholder farmers with low incomes in Ethiopia's rural regions who are often threatened by food insecurity.
Together with our project partners, we test our agricultural transformation concept in three pilot districts in the Oromia region and two pilot districts in the Sidama region. Those districts are building on areas of agricultural transformation coordinated by the Bureau of Agriculture (BoA) as well as the Integrated Soil Fertility Management (ISFM+) and Prosilience Projects implemented by GIZ.
Furthermore, ETH-Soil is part of an ecosystem of national and international projects for agricultural transformation consisting of the Ministry of Agriculture's Ethiopia Food Systems Resilience Program, the TRANSFORM project (IFDC) and Soil Matters project (GIZ).
Key to our approach is the application of biochar-based organic fertilisers that are created from agricultural residues and biogenic household wastes as well as digestate from biogas production and thereby closing the nutrient cycle.
The project is running from 2021 to 2026.
Learn more about our pilot districts
The ETH-Soil approach is being tested in five pilot districts in Oromia and Sidama
Transformation concept
ETH-Soil contributes to improved soils, food security and clean energy for food security by building capacities in four areas:
Biochar production
Biochar production
What is biochar?
Biochar is a carbon-rich biogenic material that is produced from agricultural residues by the process of pyrolysis, the thermo-chemical conversion in absence of oxygen. The feedstock is charred in temperatures ranging between 300°C and 1000°C. The created pyrogas is burned and thereby continues the pyrolysis process.
Biochar has a porous structure which serves as habitat for microbes and increases the water holding capacity of soils. Nutrients attach to the functional groups of the biochar matrix creating an additional nutrient storage. These characteristics make it suitable as a soil amendment. When combined with nutrient-rich matters such as compost, manure or digestate from biogas plants, a potent organic fertiliser is created.
Biochar production
Biochar production in Asella, Ethiopia
As part of the project, DBFZ pyrolysis experts worked together with colleagues from Jimma University and Oromia Agricultural Research Institute to construct Kon-Tiki kilns (pictured on the left). With these devices, over 100 tons of biochar were produced from local biomasses in 2024, aiming at 500 tons by 2026.
Kon-Tiki kilns - especially soil pit Kon-Tikis - are low in cost and can be easily maintained which makes them viable for the use by smallholder farmers. By following some basic guidelines during operation the farmers ensure high quality of the resulting biochar making it safe for soil application.
Innovation for efficient resource use - Kenna Stove
Currently used wood burning stoves will be replaced by biochar producing pyrolysis and hybrid biogas cookstoves.
During the Kon-Tiki process, a lot of heat is produced but not easily utilsed. This is why ETH-Soil developes large-scale cookstoves which can be used for the preparation of large portions of food and simultaneous biochar production: the Kenna Cookstove. Based on a prototype created by DBFZ researchers, project partners at Jimma University develop a version for local resources as well as a hybrid version for biogas operation once the pyrolysis process is completed.
In the future, the Kenna cookstove is intended for commercial applications in Ethiopia and beyond. Potential uses include both canteens and restaurants as well as food-processing and other applications with high heat demands. The hybrid version shall serve the campus canteen at Jimma Institute of Technology where a new research and training biogas plant is being built. Read more
Biochar applied to the soil acts a carbon sink
How biochar benefits the climate
Producing biochar from agricultural residues and applying it to the soil creates a long-term carbon sink:
Plants absorb CO₂ from the atmosphere, and through pyrolysis this carbon is converted into a stable form. Once incorporated into the soil, it remains stored for centuries instead of being released back into the atmosphere through natural decomposition. Because of this long-term storage, biochar production can be certified as a carbon sink. Subsequently, companies or individuals from around the world can offset their hard-to-abate CO2 emissions by purchasing these certificates.
Not only the climate benefits from carbon sinks, producers do, too: C-Sink Certification generates an additional source of income for farmers. This is why ETH-Soil supports the implementation of the Global Artisan C-Sink Certification Scheme in Ethiopia which is tailored to small-scale biochar production by smallholder farmers.
Biochar-based fertilisers
Biochar-based fertilisers
BBF, abbr. for biochar-based fertiliser
of BBF applied by 450 smallholder farmers by 2026.
of degraded smallholder farmland treated with BBF by 2026
Building on existing scientific and methodological expertise, ETH-Soil develops technology and knowledge on the production of biochar-based fertilisers (BBF) from residues both on large scale and household level. Agricultural and other biogenic residues are the main ingredients for these fertilisers.
Nutrient-poor residues can be converted into biochar as the base of the fertiliser which is subsequently loaded with nutrients through the combination with (vermi-)compost, manure or digestate from biogas plants.
The biomasses used for these fertilisers are low in cost and locally available. This enables smallholder farmers to find sustainable solutions for their soils independently from the global fertiliser market and to close the nutrient cycle.
Biochar-based fertiliser ready for soil application
Plotted test fields in Hawassa
Test field in Dilla
Girma Seldegoma is a smallholder farmer participating in fields trials with BBF
Building an evidence base
Transforming agricultural practices is a challenging task that requires a solid evidence base, cooperation with agricultural bureaus and a clear focus on the farmers' participation.
The development of fertiliser recipes is accompanied by field trials and soil monitoring to provide the scientific base for their effectiveness for both crops and soil. This crucial work is conducted by researchers in Ethiopia who received grants from two calls for research proposals. You can learn more about them in the list below.
ETH-Soil funded research
Centering smallholder farmers
Smallholder farmers are an important part of ETH-Soil research
BBF can help smallholder farmers gain independence from expensive imported mineral fertilisers. To strengthen their capacities, the agricultural extension services in Oromia and Sidama use ETH-Soil training materials to raise awareness among smallholder farmers for the benefits of BBF production and application. During field demonstrations, farmers gain first-hand experience on what BBF can achieve.
However, farmers are agricultural experts in their own fields and can help to develop suitable solutions for their specific soil-health challenges. For this reason, the research funded under the second ETH-Soil call applied farmer-participatory methods to co-create, apply, and evaluate BBF.
Yield improvements compared to mineral fertiliser in trials on smallholder farmers' land in Oromia
Advantages of biochar-based fertiliser
In pot experiments and field trials, the researchers and participating farmers found positive effects of biochar-based fertilisers on degraded soils compared to their current practice. The most apparent improvements were increased crop growth and crop yields, which can be traced back to:
A farmer is monitoring his crop growth to evaluate the effect of the biochar-based fertiliser
- increased pH-value in acidic soils
- increased soil porosity and decreased bulk density
- increased content of plant available nutrients (phosphor and nitrogen), cation-exchange capacity as well as soil organic carbon content
In the long term, BBF can revitalise degraded soils through improvements of their physical, chemical and biological properties. Moreover, nutrients are being recycled and emissions reduced.
Learn more The first results from ETH-Soil research have been published in peer-reviewed papers:
Qualification of biogas experts
Circular solutions for clean energy
Qualification of biogas experts
Launching a new biogas programme at Jimma University
Students of the new biogas and biomass technology specialisation at JIT
Jimma University is a center for research and innovation in Oromia. In accordance with the Ethiopian National Biogas Programme, Jimma Institute of Technology (JIT) launched the new specialisation "Applied biogas and biomass technology" within the Master's programme "Sustainable Energy Engineering". The curriculum was developed in cooperation with DBFZ biogas experts.
During four semesters, the students will gain theoretical and practical knowledge of the planning, construction and operation of biogas plants, their feedstocks and sustainable use of digestate, a by-product of the biogas process. In the first cohort of 2024, 14 students receive an ETH-Soil funded scholarship.
In the news Ethiopian national TV channel EBC visited Jimma University and reported on the new programme.
Constructing a biogas plant and laboratory at Jimma University
Canteen food waste will serve as feedstock for the biogas plant
ETH-Soil and Jimma University are working together with Awite and AD Solutions for the construction of a modern biogas plant with a daily capacity of 2 tons of feedstock and a biogas laboratory with 10 work stations for training and research purposes. The close proximity of the units enables interaction and synergistic effects between science and practice.
Biogas plant with laboratory at Jimma Institute of Technology
Biogas plant
- Kitchen scraps and food wastes from the nearby university canteen will serve as feedstock using the University's existing waste logistic concept. To date, they are unused and deposed of in landfills emitting greenhouse gases.
- The produced biogas - provided via direct gas supply line - replaces woody fuels in the canteen which lowers costs and emissions.
- Digestate, the byproduct of the biogas production, can be applied as fertiliser, e.g. to close-by testing fields of the College of Agriculture.
Biogas laboratory
- The entire biogas process will be represented in the laboratory: preparation and characterisation of the substrate, determination of methane yield according to industry standards (VDI 4630), and practical tests with 6 continuous stirred-tank reactors.
- Based on the modular design, it can be easily adapted for future research projects.
- A photovoltaic and battery system ensures continuous operation even through power outages.
Low-emission off-grid cooking
Low-emission off-grid cooking
Many Ethiopian households, especially in rural areas, are cooking on traditional three-stone fires which pose serious health risks for the cook and their household members. Women - who are most often responsible for cooking - and small children are particularly vulnerable to the dangers of air pollution and injuries caused by the open fire.
One of ETH-Soils's goal is to provide clean and sustainable cooking energy for rural households while simultaneously producing biochar. This provides access to clean and cheap energy, improves health and contributes to gender equality. The use of agricultural residues furthermore relieves the pressure on forests as energy source.
Developing an improved cookstove
The cookstove prototype was developed at DBFZ
The cookstove is tested in a pilot user study in Oromia
Based on the needs of rural households in Ethiopia, researchers at DBFZ developed a low-emission and high efficiency cookstove model.
By employing clay as building material and biogenic residues as fuel, the ETH-Soil cookstove uses readily available, cheap resources to work towards healthy and climate-friendly technologies. The TLUD principle (top lit updraft) enables low-emission heat production through pyrolysis of various biomasses which can reduce deforestation. The resulting biochar can be used for the production of biochar-based biofertilisers.
After successful tests in the lab, the cookstove will be evaluated by the target group, registered with the Ministry of Water and Energy and finally produced and sold by small businesses in Ethiopia. The retail price will be low and spare parts easily available to ensure wide access and a long life cycle.
By the end of the project, 450 clay-based pyrolysis cookstoves will be produced and used in Ethiopia.
About us
Learn more about our project partners
ETH-Soil is a project by DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH (German Institute for biomass research), based in Leipzig, Germany. Together with our colleagues and partners in Ethiopia, we work towards a sustainable future with healthy soils, a climate resilient circular economy and food security for everyone.
ETH-Soil is funded by the Federal Ministry for Economic Cooperation and Development.
1st Soil Symposium 2023 in Addis Ababa
ETH-Soil project flyer in Oromiff
Lab course for soil analysis at Jimma University
KoBo-Toolbox training in Jimma
ETH-Soil Word Café of the Leipzig project team
2nd Soil Symposium 2024 in Addis Ababa
3rd Soil Symposium 2025 in Adama