1.2 Detalhes do contato das pessoas capacitadas e instituições envolvidas na avaliação e documentação da tecnologia

Nome da(s) instituição(ões) que facilitou(ram) a documentação/ avaliação da Tecnologia (se relevante)

Nome da(s) instituição(ões) que facilitou(ram) a documentação/ avaliação da Tecnologia (se relevante)

1.3 Condições em relação ao uso da informação documentada através de WOCAT

O/a compilador/a e a(s) pessoa(s) capacitada(s) aceitam as condições relativas ao uso de dados documentados através da WOCAT:

Sim

1.4 Declaração de sustentabilidade da tecnologia descrita

A tecnologia descrita aqui é problemática em relação a degradação da terra de forma que não pode ser declarada uma tecnologia de gestão sustentável de terra?

Não

2.1 Descrição curta da tecnologia

Definição da tecnologia:

Rice husks as well as empty seeds are pyrolised and used as a soil amendment in the rice seed beds and the vegetable gardens.

2.2 Descrição detalhada da tecnologia

Descrição:

Biochar is the residue left after the pyrolysis of any organic matter and is used as a soil amendment. Pyrolysis occurs when the organic matter is heated in anaerobic conditions, which is usually done in specially designed kilns. Sometimes it is also made in a conventional fire, which is extinguished before the char turns to ash. Agricultural wastes like rice husks or unfilled grains are mainly used. Biochar can have many positive effects on the soil and plants:
-It buffers the pH, and has usually a high pH due to theash content.
-Due to its porous structure, it holds water and serves as refuge for microorganisms.
-It absorbs and adsorbs nutrients, both cations and anions. They are available for the plant roots.
-It can increase the resistance of plants to diseases.
Due to all these effects, the increased yields are higher than those that can be achieved only through the nutrients contained in the Biochar itself. Biochar is and was used in many parts of the world as soil amendment, with some benefits persisting for centuries. In Cambodia it was used during the Pol Pot regime to reduce the smell of the human faeces that were used on the fields due to a lack of other fertilizers. Today research in the Biochar domain is increasing, especially since the discovery of the man-made terra preta soils in South America.

Biochar is mainly used to increase the fertility, water holding capacity and carbon content of the soil. The fact that the benefits of Biochar addition to the soil remain for several years, unlike chemical fertilizers, makes it attractive to farmers. Other purposes, like the increased resistance of plants to diseases and buffering of nutrients are also of importance.

Biochar was introduced or reintroduced trough different NGOs, JICA (Japanese International Cooperation Agency) in this case study. Because of knowledge exchange between farmers, a rice husk char/ash mix, as residue from the pottery baking, was used already in 2011. In 2013 JICA borrowed a Biochar kiln to the local farmer self-help group with a training, so they could produce Biochar by themselves. The inner part of the kiln (cf. technical drawing) is filled with wood and lit. It is then put into an empty oil barrel, which is filled with rice husks. The heat pyrolyses the husks from the bottom to the top of the barrel, and the gases are burned in the inner part of the kiln and the chimney. Just before the upper part is pyrolysed, the husks are extinguished. There is a weight loss of about 50 to 60 % caused by this process. The Biochar is added to the fields after ploughing, and the fields are harrowed. In this case study, Biochar is used both in rice seed beds and in a vegetable patch. Concentrations of 0.5 kg/m2 are used in the rice seed bed, and 2.5 kg for the vegetables. Due to the little available quantities of husks, Biochar is not applied to the field yet. The use of Biochar is spreading quickly from farm to farm

The analysed area is flat (slope < 2%), with a tropical climate (dry season from November to May and wet season from June to October), and the soils are mostly sandy or loamy. The soil has a low fertility, contains little organic matter, and acidifies. The area has been deforested a long time ago, and the groundwater table is rather high (1-2 m during the dry season, on the surface during wet season).
Due to climate change, farmers notice more erratic rainfall, temperature rises and more recurrent droughts. Rice is the predominant crop grown in the area, since it serves as staple food (mix subsistence and commercial activities). Cattle are usually grazing on the fields after the harvest, without much control. Thus the cattle grazes too often and too much on the same spot, leading to degradation.
The increasing migration rate (the young generation leaves the villages to work in the cities, garment industry or abroad) results in a decrease of available labour force in the area which has detrimental effects on the agricultural activities. Furthermore, the civil war in the 1970s (Khmer Rouge) led to the loss of agricultural knowledge. Several NGOs are trying to re-establish the knowledge.

2.3 Fotos da tecnologia

2.5 País/região/locais onde a tecnologia foi aplicada e que estão cobertos nesta avaliação

País:

Camboja

Região/Estado/Província:

Kampong Chhnang

Especificação adicional de localização:

Kraing Leav

Especifique a difusão da tecnologia:

• Uniformemente difundida numa área

Se a área precisa não for conhecida, indicar a área aproximada coberta:

• 0,1-1 km2

Comentários:

Area unknown and rapidly spreading.

Map

×

2.6 Data da implementação

Caso o ano exato seja desconhecido, indique a data aproximada:

• menos de 10 anos atrás (recentemente)

2.7 Introdução da tecnologia

Especifique como a tecnologia foi introduzida:

• através de projetos/intervenções externas

Comentários (tipos de projeto, etc.):

It was introduced in 2010 by JICA, the Japanese International Cooperation Agency.

3.1 Principal/principais finalidade(s) da tecnologia

• Melhora a produção

3.2 Tipo(s) atualizado(s) de uso da terra onde a tecnologia foi aplicada

Terra de cultivo

• Cultura anual

Cultivo anual - Especificar culturas:

• legumes - outros
• vegetais - vegetais de folhas (saladas, couve, espinafre, outros)
• legumes - raízes (cenouras, cebolas, beterraba, outros)
• legumes - melão, abóbora ou aboborinha

• rice, cucumber

Número de estações de cultivo por ano:

• 1

Especifique:

Longest growing period in days: 210, Longest growing period from month to month: June-December

Comentários:

Major land use problems (compiler’s opinion): Soil fertility decline, water availability
Major land use problems (land users’ perception): Water availability. Interestingly the farmer says that soil fertility is not a problem, as the farmers know about the use of compost. The compost application is the problem.
Livestock is grazing on crop residues

In the vegetable patch the farmer plants cucumber, pumpkin, onion, watermelon and leaf vegetables in the early wet season, before planting rice.

3.4 Abastecimento de água

Abastecimento de água para a terra na qual a tecnologia é aplicada:

• Misto de precipitação natural-irrigado

3.5 Grupo de GST ao qual pertence a tecnologia

• Gestão integrada de fertilidade do solo

3.6 Medidas de GST contendo a tecnologia

Medidas agronômicas

• A2: Matéria orgânica/fertilidade do solo

3.7 Principais tipos de degradação da terra abordados pela tecnologia

Deteriorização química do solo

• Cn: declínio de fertilidade e teor reduzido de matéria orgânica (não causado pela erosão)
• Ca: acidificação

Degradação da água

• Ha: aridificação

Comentários:

Main causes of degradation: soil management (Ploughing and bare soil during dry season.), labour availability (Farmers go to work in the garment industry, in construction, or sell their labor elsewhere.)
Secondary causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (Deforestation happened many years ago.), overgrazing (Uncontrolled grazing during dry season.), change in temperature (More hot days according to UNDP and farmers.)

3.8 Redução, prevenção ou recuperação da degradação do solo

Especifique o objetivo da tecnologia em relação a degradação da terra:

• Reduzir a degradação do solo

4.1 Desenho técnico da tecnologia

Especificações técnicas (relacionada ao desenho técnico):

Biochar kiln. In the inner part, the combustion chamber, a wooden fire is lit. The burning chamber is then placed in the oil barrel, which is filled with rice husks. The heat pyrolyses the husks, the gas burn in the chamber and chimney. When pyrolysis is almost completed, the char is extinguished.
Kampong Chhnang
Date: 2014

Technical knowledge required for field staff / advisors: high
Technical knowledge required for land users: moderate (When farmers only buy Biochar the required technical knowledge is low.)
Main technical functions: increase in organic matter, increase in nutrient availability (supply, recycling,…)
Secondary technical functions: improvement of surface structure (crusting, sealing), improvement of topsoil structure (compaction)

Manure / compost / residues
Material/ species: Rice husk Biochar (together with compost, which he already did before)
Quantity/ density: 0.5-2.5
Remarks: Entity: kg/m^2. Distributing on fields and harrowing.

Autor:

Stefan Graf, Switzerland

4.2 Informação geral em relação ao cálculo de entradas e custos

Outro/moeda nacional (especifique):

Riels

Se for relevante, indique a taxa de câmbio do USD para moeda local (por exemplo, 1 USD = 79,9 Real): 1 USD =:

4000,0

4.3 Atividades de implantação

4.4 Custos e entradas necessárias para a implantação

4.5 Atividades recorrentes/manutenção

4.6 Custos e entradas necessárias pata a manutenção/atividades recorrentes (por ano)

Comentários:

The costs are indicated per unit; a unit is one biochar kiln used on 1 a. The costs were calculated in 2014 for the vegetable beds, where the farmer uses around 2.5 kg/m2. He also uses Biochar on the rice seedling bed, with concentrations of around 0.5 kg/m2, 5 times less than in the vegetable patch. In the vegetable patch the farmer plants cucumber, pumpkin, onion, watermelon and leaf vegetables in the early wet season, before planting rice.

4.7 Fatores mais importantes que afetam os custos

Descreva os fatores mais determinantes que afetam os custos:

The factors affecting the cost the most are the biochar kiln, and the amount of added Biochar.

5.1 Clima

5.2 Topografia

5.3 Solos

5.4 Disponibilidade e qualidade de água

5.5 Biodiversidade

5.6 Características dos usuários da terra que utilizam a tecnologia

Indique outras características relevantes dos usuários da terra:

Land users applying the Technology are mainly common / average land users
Population density: 10-50 persons/km2
Annual population growth: 0.5% - 1%
Off-farm income specification: handicraft, remittances and factory work

5.7 Área média de terrenos utilizados pelos usuários de terrenos que aplicam a Tecnologia

5.8 Propriedade de terra, direitos de uso da terra e de uso da água

Propriedade da terra:

• Comunitário/rural
• Indivíduo, não intitulado

Direitos do uso da terra:

• Comunitário (organizado)
• Indivíduo

Direitos do uso da água:

• Acesso livre (não organizado)

Comentários:

Land users have a title that is not recognized by the state.

5.9 Acesso a serviços e infraestrutura

6.1 Impactos no local mostrados pela tecnologia

Impactos socioeconômicos

Produção

Renda e custos

Impactos socioculturais

Impactos ecológicos

Solo

Biodiversidade: vegetação, animais

6.3 Exposição e sensibilidade da tecnologia às mudanças climáticas graduais e extremos/desastres relacionados ao clima (conforme o ponto de vista dos usuários da terra)

Mudança climática gradual

Mudança climática gradual

Extremos (desastres) relacionados ao clima

Desastres meteorológicos

Desastres climatológicos

Desastres hidrológicos

Outras consequências relacionadas ao clima

Outras consequências relacionadas ao clima

6.4 Análise do custo-benefício

Como os benefícios se comparam aos custos de implantação (do ponto de vista dos usuários da terra)?

Como os benefícios se comparam aos custos recorrentes/de manutenção(do ponto de vista dos usuários da terra)?

Comentários:

The costs for the pyrolysis kiln were not borne by the land user. But as the farmer of this case study wants to build an own kiln as soon as the NGO needs it again, it is positive.

6.5 Adoção da tecnologia

Comentários:

100% of land user families have adopted the Technology with external material support
100 land user families have adopted the Technology with external material support
Considering only the farmers applying the technology with this stove. Other farmers buy Biochar, or burn the rice husks and extinguish them. But those farmers are nearly impossible to quantify as it changes quickly. The support was the kiln, which is only a small part of the costs.
Considering only the farmers applying the technology with this stove. Other farmers buy Biochar, or burn the rice husks and extinguish them. But those farmers are nearly impossible to quantify as it changes quickly.
In another area of Cambodia where the Ministry of Agriculture, Forestry and Fisheries (MAFF) is doing Biochar research, there was such a strong adoption of Biochar use that there are no more control areas. In Kampong Chhnang, the use of Biochar starts to spread now.

6.7 Pontos fortes/vantagens/oportunidades da tecnologia

6.8 Pontos fracos, desvantagens/riscos da tecnologia e formas de superá-los

7.1 Métodos/fontes de informação

7.2 Referências às publicações disponíveis

Título, autor, ano, ISBN:

Ithaka Journal

Disponível de onde? Custos?

www.ithaka-institut.org

Título, autor, ano, ISBN:

Biochar foundation

Disponível de onde? Custos?

www.britishbiocharfoundation.org