Biogas Plant for Smallholder Farmers in Ethiopia
Showcased by Award-Winning Team for Sustainable Development
plants provide organic fertilizer and sustainable energy to increase crop yield
and supply households with clean safe energy
Sue Edwards with Fentaw
Ejigu and Hailu Araya from Institute of Sustainable Development
Please circulate widely and repost, but you must give the URL of the original and preserve all the links back to articles on our website
Announcing a new Report from ISIS. The most complete up-to-date summary of the dangers of GM agriculture in 52 pages. Buy Now, or download here
Anaerobic digestion can provide both
energy and food security for small productive farms while mitigating greenhouse
emissions, as ISIS has been stressing for many years (see  Sustainable
Agriculture and Off-Grid Renewable Energy, SiS 51). It is now
showcased by Institute of Sustainable Development based in Addis Ababa, which
has won the 2011 Gothenburg Award for Sustainable Development jointly with Kofi
Annan, former Secretary General of the United Nations . The prize of one
million Swedish Krona is shared equally between the winners.
Ethiopia is a
mountainous country in the Horn of Africa with over 45 percent of the land more
than 1 500 metres above sea level. That is where the majority of the
population, particularly smallholder farmers, live. They practice mixed
farming, combining arable crops with livestock
Livestock play a pivotal
role in smallholder farming, providing draught power for ploughing fields, dung
for fertilizing the soil and for cooking alongside fuel wood. Livestock also
provide a cash reserve by supplying meat and milk to the urban population.
However, due to poorly managed grazing, deforestation, and climate change,
farmers are facing land degradation from the loss of soil and nutrient
depletion. To make things worse, families live with indoor air pollution cooking
with dung and biomass on inefficient fires, and water pollution from poor or
non-existent sanitation. These factors severely undermine the health and
productive capacity of the farming households, particularly women and children.
The National Biogas Programme for Ethiopia (NBPE)
The NBPE is a project developed by the Ethiopian
Government and SNV (The Netherlands Development Organization) with the support
of HIVOS, a Dutch international development funding organisation; its
coordination office is in the Ministry of Water and Energy. The project aims to
help 14 000 Ethiopian smallholder farming families install and manage anaerobic
digester plants, to provide them with an alternative, renewable, clean, and
safe energy (biogas, 60 % methane) for cooking and lighting, as well as a
readily available organic fertilizer (bioslurry) to improve crop yields.
Households are also encouraged to attach a toilet to the biogas digester to
The NBPE is working in
the four main crop growing regions of the country: Amhara, Oromiya, Southern
Nations, Nationalities and Peoples (SNNP), and Tigray Regional States. The first biogas digester plants were built in 2009. By the end of August 2011, 1 634
biogas digesters were installed and working.
In the latter part of
2009, the Institute for Sustainable Development (ISD) based in Addis Ababa was invited to be a partner in the NBPE with special responsibilities for the
effective and efficient use of the ‘bioslurry’ residue of biogas production.
ISD has pioneered the use of compost with smallholder farmers in Ethiopia, and understands ecological organic agriculture well (see  Greening Ethiopia for Food Security
& End to Poverty, SiS 37.
Impacts of bioslurry compost on crop yields
In Ethiopia, the average cultivated area per
household is 0.96 ha and the average yield of cereals is below 2 000 kg/ha.
Food security is thus an over-riding concern for nearly 40 percent of
smallholder farming families. Use of chemical fertilizers is very low;
consequently there is an opportunity for good quality organic
fertilizers to help farmers increase their productivity.
ISD has developed a
method to record crop yields from farmers’ fields (see  The Tigray Project, SiS 23).
When the crop is mature, the farmer and his/her development agent harvest three
one-metre squares from a field. The crop is threshed (the process of loosening
the edible part of the grain from the chaff), the grain and straw is weighed,
and then returned to the farmer with the development agent recording the yield
data, the farmer's name, the crop and the input used. The straw is important
because this is the main source of animal feed during the long dry season.
Samples of the same crop are taken from good, average, and poorer fields. The
inputs are bioslurry compost, no input (check) and chemical fertilizer (mostly
urea) if the farmer so chooses.
The 2010 cropping season
provided the first opportunity to find out if the use of bioslurry compost
could improve crop yields in both grain and straw.
Yield Data from Tigray
The NBPE pilot woredas (districts) and villages
from Tigray in 2010 were Hintalo Wejerat, villages Adi Gudum and Waza, and
Ofla, villages Hashenge and Mankere. The data were taken from fields growing
either wheat or barley, as these are the dominant crops in the villages. The
climate in Hintalo Wejerat is semi-arid and the soils are thin and stony.
Rainfall in the Ofla area is higher, soils are deeper, and farmers have become
used to some chemical fertilizer.
Tables 1 and 2 give the
grain and straw averaged yields converted to kilograms per hectare for wheat
and barley from Adi Gudum in 2010.
Table 1 : Grain and
straw yield of wheat in Adi Gudum, Hintalo Wejerat, 2010
Average grain g/plot
Average straw g/plot
Grain average kg/ha
Straw average kg/ha
Grain increase over check
Table 2 : Grain and straw yield of barley in Adi
Gudum, Hintalo Wejerat, 2010
Average grain g/plot
Average straw g/plot
Grain average kg/ha
Straw average kg/ha
Grain increase over check
The response to bioslurry compost application
was large: the average yield of wheat grain increased by 64 %, while that of
barley grain increased by 72 % over check. Even the farmers with poorer fields
benefitted from the use of bioslurry. For wheat, the average yield for a poor
field more than doubled from 1170 to 2450 kg/ha, while that for barley
increased from 1150 to 2270 kg/ha.
In the village of Waza, farmers growing barley had included the use of chemical fertilizer in their
treatments. The results are presented in Figure 1.
Figure 1 Yields of barley from bioslurry
compost, chemical fertilizer and no input (check) in Waza, Hintalo Wejerat,
As can be seen, bioslurry
compost or chemical fertilizer almost doubled the yield of grain compared to
check. Furthermore, the use of bioslurry was as effective, or slightly more so
than chemical fertilizers. The impact on straw yield was smaller, indicating
that improving the supply of nutrients to the crop resulted in a higher
increase in the production of grain.
In Ofla, the bioslurry
development agents focused on collecting crop yield data from farmers growing
wheat. In Mankere, six farmers who had used all three treatments, compost,
chemical fertilizer and check cooperated with the development agent who took
data from a total of 541 m2 plots. The average grain yields were 4 500
kg/ha from the use of bioslurry, 4 600 kg/ha from chemical fertilizer and 3 600
kg/ha from check. In Hashengi, farmers were using an improved wheat variety,
HAR 1685. The average grain yields were 4600 kg/ha from both the check and
bioslurry, and 5300 kg/ha from the use of chemical fertilizer.
These data show that
applying bioslurry and using chemical fertilizer both increase yields,
significantly in Hintalo Wejerat. Chemical fertilizer only gave a higher yield
where the farmers were using an improved variety of wheat that probably responded specifically to chemical input.
In September 2010, the government launched a
five-year Growth and Transformation Plan (GTP). Agriculture is the major source
of economic growth, while particular focus is given to empowering women and
youth and ensuring their benefits. The making and use of organic fertilizers,
particularly compost, is incorporated as part of the agricultural extension
package. The importance of compost in sequestering carbon in the soil is
recognized as one of the means to mitigate and adapt to the challenge of
The NBPE has the
potential to contribute significantly to the target set for the use of compost
and to improve food security by 2015 in Ethiopia.
Biogas plants provide an alternative
form of safer, cleaner energy to homes as well as organic compost to farms. The
first data from field studies are showing improvements in crop yields
equivalent in most cases, to chemical fertilizers.
The authors are from Institute for Sustainable
Development, PO Box 171, code 1110, Addis Ababa, Ethiopia: email@example.com
Winners of the twelfth Gothenburg Award for Sustainable Development. Kofi Annan
shares the award with food supply project Tigray in Ethiopia”. Press Release,
Gothenbur 29 August 2011, http://www.isd.org.et/images/Other%20Publications/Gothenburg%20Award%20Press%20Release.pdf
Kaviraj Comment left 7th December 2011 16:04:34 How high is the cost of building a bio-fuel plant like that?
I am going back to Haiti in January, to start an agrohomoeopathy project in Haiti to enable at least subsistence farming.
I have been thinking about cheap ways to generate power and bio-gas is one of them. There are also cheap solar panels and less cheap wind generators as for instance used on river barges.
Moreover, a bio-gas plant fits in better with what we are trying to achieve, since the conditions in Haiti are similar to Ethiopia. Scarcity of water, little topsoil and small yields.
I would be delighted to hear the cost per unit and the yield in bio-fuel.
mae-wan Comment left 7th December 2011 16:04:08 Kaviraj, good idea! Note this is not a biofuel plant in the ordinary sense, especially not one that uses energy crops. It is strictly one that uses wastes. The cost will vary according to size. But you might like to read the ISIS article Biogas for China's Socialist Countryside here: http://www.i-sis.org.uk/biogasForChina.php
Luc Christiaensen Comment left 8th August 2012 16:04:40 Reassuring to see that smallholder biogas is also taking hold with success in Ethiopia. The article highlights the positive effects of the use of the bioslurry. This is to be expected in a country where chemical fertilizer use remains very low and soil degradation poses a major challenge. What about the other potential benefits of smallholder gas as well as the durability of the project? What about disadoption due to technical factors? The latest signs of China's experience seems encouraging (http://www-wds.worldbank.org/external/default/WDSContentServer/IW3P/IB/2012/06/20/000158349_20120620092111/Rendered/PDF/WPS6102.pdf), even though China also seems to have given a go at it several times before smallholder biogas really took hold. It will be important to learn from this experience. I trust a rigorous impact evaluation scheme has been put in place and look forward to learning more about Ethiopia's experience with smallholder biogas.