1.2 Detalles de contacto de las personas de referencia e instituciones involucradas en la evaluación y la documentación de la Tecnología

Nombre de la(s) institución(es) que facilitaron la documentación/ evaluación de la Tecnología (si fuera relevante)

Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH (GIZ) - Alemania

1.3 Condiciones referidas al uso de datos documentados mediante WOCAT

El compilador y la/s persona(s) de referencia claves aceptan las condiciones acerca del uso de los datos documentados mediante WOCAT:

Sí

1.4 Declaración de la sostenibilidad de la Tecnología descrita

¿La Tecnología aquí descrita resulta problemática en relación a la degradación de la tierra, de tal forma que no puede considerársela una tecnología sostenible para el manejo de la tierra?

No

2.1 Breve descripción de la Tecnología

Definición de la Tecnología:

Application of biochar to soils in the tropics / sub-tropics improves their ability to store and supply nutrients and water for crop growth, thereby enhancing yields and food security. At the same time, biochar holds carbon in soils for extended time periods, which makes it an agricultural practice that contributes to climate change mitigation.

2.2 Descripción detallada de la Tecnología

Descripción:

Biochar is carbonised organic material that is produced through pyrolysis, that is thermal conversion under low or no oxygen. The biochar is used as an amendment to farmland for ameliorating soil properties. Owing to the great number of micropores and charges on biochar, its application to soil boosts water and nutrient storage, and their delivery to crops. Biochar also helps neutralise acidity in soils, replacing the need for lime. All these positive effects make it ideally suited for acid, nutrient-poor soils in tropical/ sub-tropical regions. Even at low rates of 1 or 2 tonnes per hectare, biochar significantly increases crop production. Biochar hardly decomposes in soils, causing positive effects to last for several years without repeat application. This also provides very stable carbon storage on farms which helps mitigate climate change. Its stability also allows farmers to gradually add biochar to the entire farm, thereby increasing their food self-sufficiency and incomes.
Biochar itself is not a fertilizer, but a soil rejuvenating agent. Therefore, farmers must apply essential nutrients through synthetic or organic inputs to reap the full yield potential and maintain soil fertility. Yet, when biochar is combined with fertilizers, about 40% - 70% nitrogen and phosphorus can be saved over multiple seasons while maintaining the same productivity. Biochar is a promising solution to address low response of crops to fertilizer addition in tropical soils and to alleviate the impact of input price hikes and supply disruptions.
In the study presented here, farmers produced biochar as a residue from small gasifier stoves during daily cooking. These systems are highly energy efficient and reduce the consumption of firewood while improving indoor air quality, which, alongside crop yield gains from biochar, is perceived positively by farmers. The specific design of gasifier stoves requires them to be well-packed with appropriately sized tree prunings or maize stems. For larger meals it requires a refill, which users find less convenient than their traditional open combustion fires. Life-cycle assessment shows that households significantly reduce greenhouse gas emissions with the gasifier stoves when biochar is applied to the farm. For the field trials with maize and kale in this study, farmers applied their usual rates of inorganic fertilizers, animal manure, or a combination of both. Results from this multi-locational participatory assessment showed that maize grain yield increased by 0.2 - 0.7 tonnes per hectare for every tonne of home-made biochar that was added to the field.
One household can produce 300 kg biochar per year by cooking on the gasifier stove. With this amount a biochar dosage of 1.5 t/ha can be realized on an area of 0.2 ha per year. If biochar is not spread evenly, but along seed rows, its effective dosage can be increased. As the gasifier stove can be operated for 2-3 years, it is assumed that the costs of 50 USD, which are needed to purchase one gasifier, are good to equip 1 ha of land with an amount of biochar that results in increased crop yields.

2.3 Fotografías de la Tecnología

2.5 País/ región/ lugares donde la Tecnología fue aplicada y que se hallan comprendidos por esta evaluación

2.6 Fecha de la implementación

Indique año de implementación:

2016

2.7 Introducción de la Tecnología

Especifique cómo se introdujo la Tecnología:

• durante experimentos/ investigación

Comentarios (tipo de proyecto, etc.):

IITA (International Institute of Tropical Agriculture) started a long-term field trial in 2006, in which crop and soil properties were monitored following one initial biochar application of 100 t/ha. ICRAF investigated the charcoal value chain in Kenya and, among others, promoted cooking stoves which were more efficient than the traditionally used open fires. Those stoves run on pyrolysis, which provides heat for cooking and charcoal as a residual. That charcoal can be used for cooking so that the initial biomass is used more efficiently as an energy source. Or, alternatively, the residual charcoal is used as biochar to improve the farmers' soils.
This combination of cooking and biochar production and application to soils began in 2016 as participatory research.

3.1 Propósito(s) principal(es) de la Tecnología MST

• mejorar la producción
• adaptarse al cambio climático/ extremos climáticos y sus impactos
• mitigar cambio climático y sus impactos
• crear impacto económico benéfico
• crear impacto social benéfico

3.2 Tipo(s) actuales de uso de la tierra donde se aplica la Tecnología

Mezcla de tipos de uso de tierras dentro de la misma unidad de tierras: :

No

3.3 ¿Cambió el uso de tierras debido a la implementación de la Tecnología?

¿Cambió el uso de tierras debido a la implementación de la Tecnología?

• No (Continúe con la pregunta 3.4)

3.4 Provisión de agua

Provisión de agua para la tierra donde se aplica la Tecnología:

• de secano

3.5 Grupo MST al que pertenece la Tecnología

• manejo integrado de la fertilidad del suelo

3.6 Medidas MST que componen la Tecnología

3.7 Principales tipos de degradación del suelo encarados con la Tecnología

Comentarios:

Biochar increases the cation exchange capacity of soils and enhances the plant availability of phosphorus so that it contributes to soil fertility. Biochar increases the soil pH so that it treats acidification of soils. In the field of soil physical properties, biochar decreases the bulk density of soils and adds pore space to soils so that the infiltration into the soil and the usable field capacity of soils are increased. In this specific case, soil sealing and compaction do not play a role, but biochar can address those soil degradation issues.

3.8 Prevención, reducción o restauración de la degradación del suelo

Especifique la meta de la Tecnología con relación a la degradación de la tierra:

• reducir la degradación del suelo
• restaurar/ rehabilitar tierra severamente degradada

4.2 Información general sobre el cálculo de insumos y costos

Especifique cómo se calcularon los costos e insumos:

• por unidad de Tecnología

Especifique la moneda usada para calcular costos:

• USD

4.3 Actividades de establecimiento

	Actividad	Momento (estación)
1.	Biochar production	Year-round while using the gasifier cooking stove.
2.	Mixing biochar into the soil	During the normal time of field preparation for and planting of the next crop
3.	Proceed with normal cropping activities

Comentarios:

This SLM technique adds biochar to the ongoing cropping activities. So, the choice of crops, soil preparation, planting, inputs, and harvest do not change after biochar application. The biochar is sourced from so-called gasifier cooking stoves, which are stoves that perform through pyrolysis. The excess energy of that pyrolysis is used for cooking, while the residual char is applied as biochar to the farmers' field. Char (biochar) is produced during every cooking activity, collected, and finally applied. Most household in the project regions use open three-stone fires for cooking followed by charcoal. Adoption of the gasifier stoves is a shift away from the open fires and charcoal.

4.4 Costos e insumos necesarios para el establecimiento

	Especifique insumo	Unidad	Cantidad	Costos por unidad	Costos totales por insumo	% de los costos cubiertos por los usuarios de las tierras
Mano de obra	gasifier cooking stove		1,0	50,0	50,0
Costos totales para establecer la Tecnología					50,0
Costos totales para establecer la Tecnología en USD					50,0

Comentarios:

As costs we only listed the 50 USD per gasifier cooking stove. As the other farm operations do not change, no further costs for plant materials or fertilizers or other were listed, because those inputs do not change solely due to the use of biochar from the gasifier stoves.
One household can produce 300 kg biochar per year by cooking on the gasifier stove. With this amount a biochar dosage of 1.5 t/ha can be realized on an area of 0.2 ha per year. If biochar is not spread evenly, but along seed rows, its effective dosage can be increased. As the gasifier stove can be operated for 2-3 years, it is assumed that the costs of 50 USD are good to equip 1 ha of land with an amount of biochar that results in increased crop yields.

4.5 Actividades de establecimiento/ recurrentes

	Actividad	Momento/ frequencia
1.	Replace the gasifier cooking stove	every three years

Comentarios:

Once biochar has been applied into a given soil, it sits there in the soil and does not require further maintenance. The farming activities and their associated labor remain unchanged compared to the the time before biochar application.

4.6 Costos e insumos necesarios para actividades de mantenimiento/ recurrentes (por año)

	Especifique insumo	Unidad	Cantidad	Costos por unidad	Costos totales por insumo	% de los costos cubiertos por los usuarios de las tierras
Equipo	gasifier cooking stove	1	0,33	50,0	16,5	100,0
Indique los costos totales para mantenecer la Tecnología					16,5
Costos totales para mantener la Tecnología en USD					16,5

Comentarios:

The depreciation of the gasifier cooking stove and the need to replace it every three years is included here unde rrecurrent costs.

4.7 Factores más determinantes que afectan los costos:

Describa los factores más determinantes que afectan los costos:

Purchase price of the gasifier stove. Opportunity cost for collection and pre-processing of tree prunings and crop residues for the stove.

5.1 Clima

5.2 Topografía

Indique si la Tecnología se aplica específicamente en:

• no relevante

Comentarios y especificaciones adicionales sobre topografía :

Kwale: 328 m a.s.l.
Embu: 1350 m a.s.l.

5.3 Suelos

Si se halla disponible, adjunte una descripción completa de los suelos o especifique la información disponible, por ej., tipo de suelo, pH/ acidez de suelo, capacidad de intercambio catiónico, nitrógeno, salinidad, etc. :

The following information are available for two field plots out of the three counties:
Embu County: pH(H2O) - 5.01, SOC - 2.01%, sand - 21%, clay - 43.5%
Siaya County: pH(H2O) - 5.25, SOC - 1.56%, sand - 22.4%, clay - 60.1%

5.4 Disponibilidad y calidad de agua

5.6 Las características de los usuarios de la tierra que aplican la Tecnología

Indique otras características relevantes de los usuarios de las tierras:

Women and children operate the gasifier stove and therefore produce the biochar. In the field it is mainly men who mix the biochar into the soil and perform other farm operations.

5.7 Área promedio de la tierra usada por usuarios de tierra que aplican la Tecnología

5.8 Tenencia de tierra, uso de tierra y derechos de uso de agua

Tenencia de tierra:

• individual, sin título
• individual, con título

Derechos de uso de tierra:

• individual

Derechos de uso de agua:

• acceso abierto (no organizado)

¿Los derechos del uso de la tierra se basan en un sistema legal tradicional?

Sí

5.9 Acceso a servicios e infraestructura

6.1 Impactos in situ demostrados por la Tecnología

Impactos socioeconómicos

Producción

Ingreso y costos

Impactos ecológicos

Reducción de riesgos de desastres y riesgos climáticos

6.2 Impactos fuera del sitio demostrados por la Tecnología

6.4 Análisis costo-beneficio

¿Cómo se comparan los beneficios con los costos de establecimiento (desde la perspectiva de los usuarios de tierra)?

¿Cómo se comparan los beneficios con los costos de mantenimiento/ recurrentes (desde la perspectiva de los usuarios de tierra)?

Comentarios:

The main benefits from this SLM technology from the land users' perspective are increased crop yields, reduced need to collect fuel wood, and improved indoor ambient air quality. The latter two benefits materialize immediately, onec the gasifier is used. The crop yields increase during the season that follows the biochar application, which is a short-term benefit. These benefits justify the establishment costs, which in fact are the costs to purchase the gasifier.
On a long-term perspective, the effect to improve the soil, which leads to crop yield increases, remains, because biochar is stable in soils ove rlong time periods. Particularly positive is that there are no maintenence costs to keep the biochar in the soil.

6.5 Adopción de la Tecnología

• casos individuales / experimentales

De todos quienes adoptaron la Tecnología, ¿cuántos lo hicieron espontáneamente, por ej. sin recibir nada de incentivos/ materiales:

• 0-10%

6.6 Adaptación

¿La tecnología fue modificada recientemente para adaptarse a las condiciones cambiantes?

No

6.7 Fuerzas/ ventajas/ oportunidades de la Tecnología

Fuerzas/ ventajas/ oportunidades desde la perspectiva del usuario de la tierra
Most land users stated to have observed positive impacts on soil health and improvement of soil fertility. Additionally, about 25% of the land users specifically mentioned that the moisture retention in the soil improved after biochar application. Some land users experienced lower costs for fertilizers.
Most land users found the small top-lit updraft cooking stoves are easy to use, though being more suitable for food with short cooking time. All land users stated that the gasifier cooking stoves were cleaner than the traditional open fires and charcoal stoves, since the gasifiers produced less smoke, less soot, and fewer ashes. Some land users responded even that the gasifiers were less harmful to cooking utensils and food tasted better (less smoky). The gasifier stove was preferred by land users because it takes less fuel and therefore saves time to collect fire wood and household expenditures. This was particularly viewed positively by women. The residual char also can be used as an energy source. Some land users saw sales of charcoal as potential additional income.
In total, the package of using gasifier stoves for cooking and applying the residual biochar to soils was seen as beneficial by most land users, because it saved costs and efforts on the side of cooking and increased crop yields and income.

Fuerzas/ ventajas/ oportunidades desde la perspectiva del compilador o de otra persona de referencia clave

Biochar improves soil properties which intensifies crop production. Even a small amount of biochar added to the soil has a long-lasting positive effect on yields. The effect of a one-time biochar application lasts for decades. Therefore, if soils are enriched with biochar by repeatedly adding low quantities, its benefits to land users accumulate over time. Biochar increases the cation exchange capacity, pH, and phosphorus availability of soils, which are key constraints to in many farming systems across tropical Africa. Non-responsive soils are turned into soils that respond to fertilizer application.

6.8 Debilidades/ desventajas/ riesgos de la Tecnología y formas de sobreponerse a ellos

Debilidades/ desventajas/ riesgos desde la perspectiva del usuario de la tierra	¿Cómo sobreponerse a ellas?
Half of the respondents stated the production of biochar was time consuming due to the process of cutting the feedstock in suitable sizes, as needed for the gasifier stove.	Chopped firewood for the gasifier could become a source of income for youth.

Debilidades/ desventajas/ riesgos desde la perspectiva del compilador o de otra persona de referencia clave	¿Cómo sobreponerse a ellas?
Gasifiers may emit more methane than technologically more advanced pyrolysis units.	Improve the gasifier utility with a shift to the latest mobile or decentralized technologies that produce syngas, green hydrogen or electricity that can be used for cooking.
Deploying gasifier and biochar at large scale without regulations poses a risk of unsustainable rates of tree clearing and residue removal.	Follow rules such as EBC and only use on-farm or residual biomass.

7.1 Métodos/ fuentes de información

7.2 Vínculos a las publicaciones disponibles

Título, autor, año, ISBN:

Biochar from cooking stoves reduces greenhouse gas emissions from smallholder farms in Africa; Sundberg et al., 2020

¿Dónde se halla disponible? ¿Costo?

https://link.springer.com/article/10.1007/s11027-020-09920-7, open access

Título, autor, año, ISBN:

Use of Biochar-Producing Gasifier Cookstove Improves Energy Use Efficiency and Indoor Air Quality in Rural Households; Gitau et al., 2019

¿Dónde se halla disponible? ¿Costo?

https://www.mdpi.com/1996-1073/12/22/4285, open access

Título, autor, año, ISBN:

Implications on Livelihoods and the Environment of Uptake of Gasifier Cook Stoves among Kenya’s Rural Households; Gitau et al., 2019

¿Dónde se halla disponible? ¿Costo?

https://www.mdpi.com/2076-3417/9/6/1205/pdf, open access

Título, autor, año, ISBN:

Factors influencing the adoption of biochar-producing gasifier cookstoves by households in rural Kenya; Gitau et al., 2019

¿Dónde se halla disponible? ¿Costo?

https://www.sciencedirect.com/science/article/pii/S0973082618308913, open access

Título, autor, año, ISBN:

Soils, sinks, and smallholder farmers: Examining the benefits of biochar energy transitions in Kenya; Mahmood et al., 2021

¿Dónde se halla disponible? ¿Costo?

https://reader.elsevier.com/reader/sd/pii/S2214629621001262?token=D446F30FC8FDAEC80F73AE31BBFEA69E754E2F9EB21A9605CC6D04A2FE0FCD39182848F88AC6D17BF7D12B8EEED7BD9E&originRegion=eu-west-1&originCreation=20210415190025, open access

Título, autor, año, ISBN:

Gasifier as a cleaner cooking system in rural Kenya; Njenga et al., 2016

¿Dónde se halla disponible? ¿Costo?

https://www.sciencedirect.com/science/article/abs/pii/S0959652616000743?via%3Dihub, access at no costs through limited number of institutions

Título, autor, año, ISBN:

Biochar addition persistently increased soil fertility and yields in maizesoybean rotations over 10 years in sub-humid regions of Kenya; Kätterer et al., 2019

¿Dónde se halla disponible? ¿Costo?

https://www.sciencedirect.com/science/article/pii/S0378429018318938?via%3Dihub, open access

Título, autor, año, ISBN:

sMaize grain yield responses to realistic biochar application rates on smallholder farms in Kenya, Kätterer et al., 2022

¿Dónde se halla disponible? ¿Costo?

https://link.springer.com/article/10.1007/s13593-022-00793-5, open access

7.3 Vínculos a la información relevante disponible en línea

Título/ descripción:

Biochar stoves for socio-ecological resilience: Lessons from small-scale farms in rural Kenya / Report by ICRAF

URL:

http://apps.worldagroforestry.org/downloads/Publications/PDFS/PB20040.pdf