Agriculture is the backbone of Cameroon's economy. The population is growing and with it the increasing demand for food. Chemical pesticides and fertilizers have been produced to fight pests and improve on soil fertility respectively and increase agricultural output. These chemicals used in farms are, however, polluting groundwater, surface water, soils, reducing biodiversity and adversely affecting plant, animal and human health.
Poverty and unemployment has hit hard in the rural communities. Many peasant farmers live on less than a dollar per day. Population increase in the area has made land scarce and this is demonstrated by an upsurge in land conflicts. The vegetation in the North West Region is mostly grassland and the topography is hilly. This makes the soil fertility in the area fragile and the land is subject to soil erosion. Farmers used to increase soil fertility using chemical fertilizers, but prices of these has risen above the affordability of poor peasant farmers who are now searching for different methods of farming. Farmers in the area now put in a lot of effort to till the soil and improve on its fertility, but yields are usually poor due to poor farming techniques and poor pest management. The animals reared lack enough pasture to feed on and suffer from diseases. These farmers often work more than ten hours per day in scorching sunshine or continuous rainfall for less and less output, but still run short of food a few months after harvest. This means that agriculture is seen to be unprofitable.

Most of the North West Region, like other parts of Cameroon, lacks energy for cooking, heating and lighting. This is common in rural areas that are far away from the national electricity grid. The prices of fossil fuel have also risen and poor farmers can no longer meet their energy needs. This area is covered by small patches of forest found in some of its valleys. People walk long distances to fetch firewood from these areas for cooking and heating. This has resulted in deforestation. When this firewood is used for cooking, it produces smoke that causes indoor pollution and this has been responsible for a large number of respiratory diseases here and world wide as sited by the World Health Organisation. Those mostly affected are women and their children who spend much time in the kitchen preparing food for the family.
This report looks at biogas production as a solution to energy needs especially as many households around the SHUMAS Integrated Organic Farm Training Centre keep animals whose waste or dung can be used to provide raw material for the production of energy. The institutionalisation of integrated organic agriculture for peasant farmers is also a solution to increasing agricultural output and reduce many of the problems experienced by farmers. Comprehensive training in organic methods is provided at the Centre.

The Centre is also referred to as the SHUMAS Biofarm Centre [Not to be confused with biodynamic farming which is neither taught nor endorsed at the Centre]. The term reflects the important role played by the biogas digesters installed on the site for the provision of energy and organic fertilizers and pesticides..

This report presents activities carried out by trainees at the Centre in the months of August and September 2009. The training was carried out by Strategic Humanitarian Services (SHUMAS), a non profit organisation based in the North West Region of Cameroon with a head office in Bamenda. The report focuses on biogas production for cooking and heating and the use of its by-products for soil fertility improvement and pest control. The first part of the training period involved getting acquainted with SHUMAS's activities and reading more on biogas production for cooking and heating, and also on integrated organic farming. The second part involved practical training in these methods. Subsidiary activities included project writing, radio programmes and fully participating in project planning and implementation.

Training objectives
The objectives of this training were to know how:
· the biogas systems function to produce energy for cooking and heating;
· by-products from biogas production are used to improve soil fertility and fight pests;
· crop cultivation and reared animals can be improved without the use of chemicals in farms and how these organic techniques can benefit local peasant farmers;
· economic, food and environmental crises can be solved by integrated organic agriculture and biogas production.

Presentation of SHUMAS
Strategic Humanitarian Services (SHUMAS) created in 1993 as a local initiative was legalized in 1997. Its sphere of action is Cameroon with targeted groups being the rural population and the urban poor, including the disabled. Its goal is to improve lives, reduce poverty and empower people. Since its creation SHUMAS has tackled developmental issues in the country using its multi-complex or integrated approach. SHUMAS's approach is participatory and it works in collaboration with its target groups in project development, execution and monitoring, so that beneficiaries can gain full ownership after completion. This has proven to yield positive fruits as most communities involved have gained skills to initiate their own development activities. SHUMAS's range of intervention includes:

· Education
Education is vital and constitutes part of the development of a people. It has often been said that poverty of ideas is worst than poverty of material resources. SHUMAS intervenes in education by promoting appropriate education in rural areas of Cameroon and supporting government action by contributing to the achievement of the Millennium Development Goals. SHUMAS intervenes in the construction of classrooms, refurbishing of existing school structures, donation of didactic materials, construction of toilets, scholarship offers, teachers salaries support activities and provision of drinking water . Some of the achievements for 2008 were in Government School (G.S) Menjung in Boyo division of North West region where it constructed three large classrooms, a toilet and provided benches, tables and chairs to enhance education and constructed three large classrooms in Islamic Primary School (I.P.S) Bamali and a toilet. Potable water, benches, table and chairs were also supplied. This was done in partnership with Building Schools for Africa (BSFA) and Lambert Academy UK. Other schools that SHUMAS worked with included G.S Mbohkija, G.S Quebessi and Catholic School Golongui all in the North West region.

· Social welfare
This program promotes intervention that targets the most vulnerable population and people with disability. Persons with disability are often exposed to social stigmatization and mistreatment. SHUMAS intervenes by rehabilitating through socialisation and moral enhancement workshops, capacity building workshops, life skills training through attachment with trainers in Bamenda and provision of seed capital to trainees. Thanks to SHUMAS's intervention in collaboration with the beneficiaries, the following four disabled groups have been created and assisted: Bamenda Disabled Group under SHUMAS (BADIGUS), Kumbo Disabled Group under SHUMAS (KUDIGUS), Wum Disabled Group under SHUMAS (WUDIGUS) and Binka Disabled Group under SHUMAS (BINDI). SHUMAS also runs a rehabilitation centre in Bamenda where qualified people with disabilities train other people with disabilities in tailoring, hair dressing, handicraft work, traditional embroidery, shoe making and mending, etc.

· Environmental protection and management
The environment is a determining component of human life. Indiscriminate planting of eucalyptus trees on farm land and water catchments has over the years resulted in shortage of farmland and drying up of streams in the North West Region. Women have to walk long distances to find farms and water. SHUMAS has intervened by nursing thousands of agro forestry indigenous tree species and has cut down more than 1.5 mil mature eucalyptus trees to recover productive farmland, improve water catchments and carried out sustainable afforestation. The eucalyptus trees felled have been replaced by indigenous tree species. A school environmental programme has been another aspect of environmental protection and management. This programme has two main objectives; namely promoting sustainable environmental management through a practical education and enhancing rural primary education. SHUMAS, in collaboration with some beneficiaries, has helped pupils to learn how to cultivate crops and plant local trees that are highly needed. The proceeds from the sale of crops have been used to assist with teacher salaries and for acquiring didactic materials.

· Health, sanitation and water
Cameroon, situated in Central Africa, has an estimated population of 20,000,000, with 60% living in rural areas. Rural people have common problems like bad roads, poor sanitation, and lack of clean potable water. SHUMAS has intervened in collaboration with foreign partners to donate medical facilities to some health centres in the North West Region, specifically in Rohvitangtah community, Lui community, maternity in Oku and Kitiwum Integrated Village Health Centre, Bui division. It is also giving scholarship to young girls and boys from some rural areas to study nursing in St Louis clinic in Bamenda so that they will help their various communities to improve on their health conditions upon completion.
Water is a vital source for livelihood. The rural community suffers a lot from water related diseases. Most often water is obtained from streams, unprotected springs, lakes and rivers. This often causes water born diseases. SHUMAS has provided many water supplies to rural communities and the eucalyptus replacement project has enabled increased access to clean water by enabling water courses, water taps and springs to recover. The water supply projects have benefited 25 rural communities. SHUMAS's objective is to improve rural access to potable water and ensure good management of water and building sufficient standpipe taps as needed by the communities.

· Agriculture and womens' empowerment
Agriculture is the backbone of Cameroon's economy. The rural population accounts for 70% of the country's economy. Low crop and livestock yields are the result of declining soil fertility, poor seeds, poor farming techniques etc. SHUMAS has contributed greatly to the enhancement of sustainable farming by designing a project to promote integrated organic farming which has proven to be economically and environmentally profitable. It has also achieved much in crop production, animal production and infrastructure in the integrated organic farm. SHUMAS has also been working with women's groups in facilitating the marketing of farm products and capacity building of women on improved agricultural techniques. SHUMAS's intervention has resulted in an increase in production in rural agriculture. The SHUMAS truck has also played a significant role in assisting women farmers with transportation for marketing their products. This is because of the existing poor farm-to-market roads in these rural areas. This has improved rural peoples' standards of living and reduced poverty. SHUMAS has so far provided 40 cassava mills to some forty women's groups, 21 corn mills, 80 'push-push' trucks (hand carts) and numerous farming implements like hoes, cutlasses and wheelbarrows.

· Integrated organic agriculture
SHUMAS's integrated organic farm in Kumbo carries out crop production and animal rearing. The crops cultivated include beans, Solanum potatoes (commonly called Irish potatoes), maize and vegetable farming. The animals reared are cows, goats, sheep, rabbits, pigs and chickens (broilers and layers). Animal droppings are used to produce biogas for food preparation and heating of the poultry. The biogas by-product is used to improve soil fertility and fight pests in the various crop areas. The SHUMAS Biofarm Centre runs training programmes on organic farming for peasant farmers and their children to build their capacity on how to improve on farm yields without destroying the environment, biodiversity and the soil. Inorganic fertilizers and pesticides prices are high and it is difficult for poor peasant farmers to afford them. SHUMAS has developed this programme to solve the problem, improve on health and fight poverty through increases in food security and self reliant activities that provide employment.
Carrying out organic farming and working with these peasant farmers and their children through training programmes has enabled SHUMAS to gather much information on the problems faced in the field and successful local agricultural practices. SHUMAS has exploited this information to come up with better techniques to improve local organic farming methods.

SHUMAS organisational structure
SHUMAS is managed by a board of trustees which chooses the President and General Coordinator who works with SHUMAS partners. The General Coordinator is responsible for the day-to-day functioning of the office and makes sure that the running of the organisation is smooth. The Programme Coordinator is next to the General Coordinator and is responsible for coordinating SHUMAS's programmes in the four departments (technical, personnel management, project management and finance). These departments are headed by Heads of Departments. The technical department is made up of field technicians. The personnel department coordinates activities of secretaries, drivers, contract workers and guards. The project department head manages activities of volunteers, project officers, students on internship and field supervisors. Field supervisors control activities of field inspectors and extension staff.

SHUMAS planning, monitoring and evaluation
The planning, monitoring and evaluation of projects in SHUMAS is done by its staff in partnership with project stakeholders including the beneficiary population, funding institutions and traditional and statutory administrative authorities to ensure that projects pursue their goals and address upcoming challenges. The challenges and difficulties encountered in projects are handled by project staff on a daily basis as they execute the projects. On a weekly basis, all project staff hold staff meetings to search for the way forward and possible solutions to challenges. Any complaints and requests from beneficiary populations are also reviewed to see how SHUMAS can help them. To solve these unforeseen problems, beneficiaries are implicated fully in project development, implementation and monitoring. This promotes a sense of belonging, ownership, care and interest for the project.
During monthly meetings the project staff update the management of SHUMAS on the project's recorded successes, challenges faced and difficulties encountered during the project execution. This event is organised to share skills, knowledge and experience, and help assess the progress of project work so as to come up with new improved strategies and methods to overcome any identified obstacles. Evaluators from SHUMAS visit the field to evaluate each project to see what was successful and what failed in order to use the experience gained to prepare for better future project execution. Questionnaires are sometimes used to gather information from project stakeholders on what they think went well and what could be modified to improve on the project in the future. The process of planning, monitoring and evaluation has helped SHUMAS to grow and gain local, national and international recognition.

Organic agriculture in the Biofarm Centre
The Centre is situated at Bamdzeng, a small village community in Kumbo, Bui division of the North West Region of Cameroon. Kumbo is located at approximately 113km from Bamenda, the regional capital of North West Region and the distance between Kumbo central square and the Biofarm is approximately 30km.

SHUMAS organic agriculture rationale
SHUMAS's mission is "Improving lives, reducing poverty and empowering people so that they can meet their needs, without compromising posterity from meeting theirs". Chemical farming has proven dangerous to the environment. SHUMAS has worked with many rural communities in Bui Division and other parts of Cameroon and understands the problems of rural people well, especially on small household agriculture. It has carried out feasibility studies on problems faced by agriculture in Bui Division and other parts of Cameroon. SHUMAS has come to realise that farming is facing the following problems:
· Farming land is reducing as the population is increasing and demand for space for infrastructure is also increasing;
· Land in the North West Region is hilly and vegetation is savannah. This makes soils fragile and prone to erosion that reduces fertility;
· Chemical fertilizers are already so expensive and above the affordability of peasant farmers;
· Poverty is widespread in rural areas of the North West Region and peasant farmers are unable to meet their basic needs by practicing agriculture;
· Youths in rural areas are unemployed and do not see agriculture as a source of livelihood because they lack skills in sustainable agricultural methods that do not need external farm inputs. Hence there is a need for institutionalisation of a form of agriculture adapted to peasant farmers conditions and needs;
· Farmers suffer from hunger and malnutrition before the next harvest season because they sell their farm produce at low prices immediately they are harvested to settle debts incurred to buy fertilizers and meet their basic needs;
· Farmers put in a lot of effort to till the soil and improve on its fertility but realize very little farm produce due to poor farming techniques and poor pest management;
· The animals reared lack enough pasture to feed on and also suffer from diseases;
· Farmers have to work more than ten hours per day in scorching sunshine or continuous rainfall for less and less output, but still find themselves and their families held down by starvation just a few months after harvest;
· The rural poor population has no other means of livelihood and depend on agriculture that is proving unprofitable.

Organic agriculture programme conception and summary
Knowing all these problems faced by peasant farmers especially in the rural areas, SHUMAS came up with an alternative means of farming. This programme has been called "Integrated Organic Farming" involving crop production, animal rearing, pasture improvement, biogas production and agroforestry practices in an integrated manner. This programme has the following objectives:
· To provide alternative means of farming that is chemical fertilizer free and affordable by all peasant farmers. This is to tackle the prevailing high prices of chemical fertilizers and diminishing yields in peasant farms through the practice of organic farming;
· Provide a source of employment for youths and improve on the capacity of old farmers in crop cultivation and animal rearing through improved organic agricultural training;
· Protect the soil and biodiversity from harm by avoiding the use of chemical farm inputs like chemical pesticides and fertilizers;
· Fight poverty and the food crisis by increasing agricultural yields through organic farming techniques;
· Protect the soil from erosion through improved animal pasture to fight over-grazing, and encourage the practice of agroforestry.

This programme has been institutionalised into short and long term courses for peasant farmers and has also been serving as a demonstration centre. Farming activities carried out at the Biofarm Centre are the same as those carried out by peasant farmers, but in an improved manner using modern organic agricultural techniques. The Centre has researched common pests in the area and come up with natural pest management methods. It also practices agroforestry, natural soil improvement techniques and pasture improvement to increase farm output without using chemicals. SHUMAS also depends on the peasant farmers to know the problems they face in their farms where research is then carried out to arrive at solutions that are made available to them and popularised to improve on farm output. This is achieved through training courses and field action with farmers on their farms. The Biofarm Centre tailors these courses to meet the needs of farmers and solve agricultural challenges. The short courses are more specialised. The participants who have finished the course are expected to join SHUMAS in the field at their various destinations to show to the other farmers that organic agriculture is the solution to problems that plague agriculture in the rural areas. These participants are expected to be ambassadors of SHUMAS and as ambassadors they are to approach agriculture with the spirit of hard work, determination and positive thinking to improve on their living standards and protect the environment. They are expected to be models to their communities, showing that organic farming can end poverty, provide enough food and employment opportunities and promote environmental protection. SHUMAS has also come to realise that the work to be done by graduating participants will not go on without challenges and problems and has called on them to bring the challenges and problems they encounter back to the Centre and carry out research and come up with workable solutions that will make things work better. SHUMAS has made it clear that it depends on these challenges to develop a pragmatic organic agricultural course content that really reflects field realities and builds farmers' capacity to meet future challenges.
Peasant farmers, through these organic methods can also contribute to the fight against global climate change. Organic products have a high quality and improve on human health. SHUMAS hope also to see peasant farmers' health improve when they consume organic products. Increasing farm output of peasant farmers through organic farming will enable them to fight hunger, malnutrition and make poverty history through eating qualitative and quantitative farm outputs while selling excesses.

Crop production
The crops produced are beans, potatoes, coco yams, yams and vegetables. There is also a nursery for spices, vegetables and some fruit trees. Training is provided in vegetable cultivation and soil improvement techniques and the species of trees suitable for agroforestry.

The nursery for fruit trees, vegetables and spices

The animal dung from the piggery, small ruminants (goats, sheep, and rabbits) and fowl dropping are used directly in the crop fields to increase soil fertility and improve yields. Cow dung is used to produce biogas and its by-product in form of slurry is used directly in vegetable farms as a natural fertilizer.
Weeding in the lettuce farm Tephrosia for soil enrichment in the maize farm Compost manure

Another soil improvement technology used is agroforestry where some soil fertility improvement trees are planted in farms to increase crop yields. Trees include Tephrosia and Scrotin. Tephrosia enriches the soil with nitrogen needed by crops and leaves of Scrotin trees are very rich in soil nutrients and enrich the soil when they fall off from the trees. The Scrotin trees in the Biofarm have also been used as wind breaks, protecting crops.
The soil is also managed through the practice of mixed cropping. Beans are planted together with corn. Beans fix nitrogen in the soil through nodules found in their roots and corn uses the nitrogen to grow. Some compost manure is mixed with grass, animal dung, cattle urine and soil. This is prepared for the cultivation of vegetables during the dry season. This is a regular practice to teach course participants how to prepare compost manure.

Animal production
The Centre has a piggery, poultry (layers and broilers), cattle and small ruminants (goats, sheep and rabbits). These animals are reared for the following purposes:
· Training in animal rearing;
· Production of animal dung to be used as natural fertilizer;
· Production of animal dung as raw material for biogas production;
· Fattening for consumption and marketing;
· The use of cattle for ploughing.
The animal units are mainly focussed on dung production and pasture improvement. Fodder including Guatemala and Bracharia is spread on newly ploughed fields. Many reared animals in the region lack sufficient pasture for grazing despite the availability of large grazing fields. Many fields are covered with the bracken fern that prevents the growth of good pasture. SHUMAS embarked on improving pasture in its fields by planting Guatemala and Bracharia for its animals. Bracharia is harvested to feed pigs. A tractor is available for ploughing to supplement animal traction to relieve pressure on the animals when necessary. Farmers are copying these methods and the tractor is frequently rented out.

Guatemala crop planting for pasture improvement

The animal dung produced is used directly as fertilizer or passed through the biogas system to produce biogas and its byproduct used as natural fertilizer and natural pesticide. To maximize animal dung production, some animals are confined. Waste is collected from rabbits, birds and pigs. Cattle, goats and sheep are allowed to graze in the field during the day and in the evening they are enclosed for security reasons and also to make sure that their droppings (animal dung) during the night can be easily gathered. The place where cattle spend the night is cemented to make sure that their urine can be collected for it is very rich in nitrogen which is good as fertilizer when kept for about three weeks or used with compost.
Animals confined to collect waste for farm manure
The role of the gallery forest at the Biofarm
The Biofarm Centre has some patches of forests in valleys found on its land. These forests host a wide range of useful trees, plants and wildlife species and provide the following services:
· A source of beneficial insects. Honey bees and other insects found in these forests are involved in pollination for crop fertilisation;
· Bee farming for honey production is also practiced. Participants in training courses learn about bee farming;
· A beautiful scene or tourist site for both volunteers and visitors. This forest is rich in different types of trees;
· Sources of water that is used by the Centre for agriculture and drinking;
·A source of agro-forestry seeds (seeds that are important in soil fertility improvement) and seeds for trees that provide wind breaks, shade and pest control. Many of the forest trees and plants are very useful in agriculture. Seeds of certain trees are dried and nursed for planting in the crop fields. Many of the trees and plants enrich the soil with nitrogen. These forests are known to be a good seed bank for agroforestry;
· Serve as a wildlife refuge for many animals. SHUMAS decided to preserve all forest galleries found on its land. Unlike other forests in the vicinity that undergo destruction from bushfires, animal encroachment and exploitation for firewood, the forests at the Biofarm are free from these problems. Many animals have found refuge in them, especially in the dry season when bushfires are so common. The forests host some monkeys that are hardly seen but are noticed to be present only through the chewed remains of certain tree fruits known to be their favourites. Many animals in these forests can be heard chattering, mainly during the night.
Forest gallery
Capacity building
SHUMAS has institutionalised integrated organic agriculture by providing short and long term courses for peasant farmers and the public to improve their agricultural output and preserve the environment. The Centre has the following units: Crop production unit, Animal production unit, and Clean and Renewable energy unit. The courses carried out are both long and short term. The long term courses run for a period of 9 months and presently accommodate 35 trainees. These trainees are trained with the use of locally available materials which are affordable by all. The training cycle is 60% practical and 40% theory. These trainees are trained in soil conservation techniques, use of organic fertilizers, production of improved seedlings, renewable energy, animal and crop production, pasture improvement etc. After graduation, it is expected that the participants will be able to replicate the knowledge acquired when they return to their communities, hence fighting poverty and unemployment and fostering economic development in their various Divisions. SHUMAS expects these trained individuals to be models in their communities for other farmers to emulate.

Local farmers have been coming to the Centre to request information and training on how to grow potatoes, manage animals and plants, control animal pests and diseases, improve on animals' yields and know more about the biogas plant. SHUMAS has responded by organising shorter training courses to meet the specific needs of these local farmers in domains where demand has been high.
Course participants
Integrated organic farming
SHUMAS has been able to get energy for heating and cooking in the Centre from the practice of this type of agriculture. The animal dung produced has been used as natural fertilizer and also as raw material for the biogas plant to produce energy that is used for cooking and heating. The by-product from the biogas plant has been used as natural pesticide and fertilizer. The corn that is grown is used for preparing animal feed and also for consumption in the Centre. After corn harvest, the corn stems and leaves are gathered and preserved for consumption by the animals in the dry season when there is little pasture. Agroforestry techniques are used to improve soil fertility and ensure high crop yields. Tephrosia and Scrotin are seen all over the farm and play many roles in crop production. Tephrosia enriches the soil in nitrogen and Scrotin's leaves enrich the soil in nutrients, provide shading to crops and also serve as wind breaks. Bee farming is practiced in the gallery forests found in the valleys. This activity produces honey and the bees are useful insects to the Biofarm as they help in pollination. Improved pasture using Guatamala and Bracharia is planted in grazing fields. The slurry and other animal waste is used as fertilizer for animal fodder.

Biogas production rationale
The Biofarm Centre is located in an area where the population faces a lot of problems getting energy for cooking, heating and lighting. The area is far away from the national electricity grid. This area is covered by grass fields and has some small patches of forest found in some of its valleys. The peasant farmers have to move long distances to fetch firewood especially from these small patches of forest for cooking. This has caused deforestation in the area. When firewood is used for cooking it produces smoke that causes indoor pollution and this has been responsible for a large number of respiratory diseases world wide as sited by World Health Organization. Those most affected are women and their children who spend much time in the kitchen to prepare food for the family.
Prices of petroleum products are skyrocketing and rural people can no longer afford to use petroleum products like kerosene to meet their energy needs. SHUMAS was going to face the same problems in its Biofarm Centre. SHUMAS searched for an alternative solution to these problems by engaging in biogas energy production for cooking and heating. SHUMAS in collaboration with a research student from the University of Dschang, Cameroon, Tize Koda Joell, developed a biogas plant that has been producing biogas in the Centre. This biogas is used to prepare food for the staff and participants doing the nine month course. Some of this bio-energy is used for heating the poultry.
This biogas technology is suitable for the population around the Centre because every family around engages in animal rearing (sheep, goats, cattle), but lack energy to meet their various needs. The animal dung produced by these animals has not been properly put to use. The surrounding population needs to be trained in how to build and operate biogas plants.

Principles of biogas production
Biogas production is the creation of bio-fuel using the anaerobic decomposition of organic materials from plant or animal origin. Anaerobic decomposition of organic materials occurs when biodegradable matter from a living or once-living organism decays with the help of micro-organisms in an oxygen-free environment. Biogas is often celebrated by environmentalists for its relatively low carbon output. It can act as a substitute for fossil fuels as an energy source for heating, cooking and moving vehicles. Biogas production typically occurs in a biogas plant on a large or small scale, depending on the materials available and the quantity of gas needed.
A biogas plant has two principal components, a digester and a gas holder. The digester is an airtight container in which the organic waste is dumped and decomposes and the gas holder is a tank that harnesses the gases emitted by the slurry. Bacteria within the digester tank breaks down the waste and, as it decomposes, gases such as carbon monoxide, methane, hydrogen and nitrogen, are released.
Through a pressurized system, the gas holder conducts the flow of these gases upward into a hole in the drum of the holder. The hole is specially designed to allow gases to pass freely into the holder while preventing any gases from escaping back into the digester. When the gas is ready to be used, the gases are put in contact with oxygen in a controlled environment to create a combustion reaction. This combustion produces an energy source for such processes as heating, cooking and vehicle propulsion.

Biogas production can occur in different types of plants, depending on the amount of gas needed, the amount of waste at hand, and whether the digester is designed for batch feeding or continuous feeding. Batch feeding systems decompose mostly solid wastes that are added to the tank in instalments, while continuous feeding models feed mostly liquids to the digester. Biogas production can be achieved in above or below ground plants. Both models have advantages and disadvantages. An above ground biogas plant is easier to maintain and able to benefit from solar heating, but needs more care in construction. A below ground biogas plant is cheaper to construct and easier to feed, but more difficult to maintain.
Anaerobic digestion will occur best within a pH range of 6.8 to 8.0. The bacteria responsible for the anaerobic process require nitrogen and carbon elements, as do all living organisms, but they consume carbon roughly 30 times faster than nitrogen. Assuming all other conditions are favourable for biogas production, a carbon - nitrogen ratio of about 30:1 is ideal for the raw material fed into a biogas plant. A higher ratio will leave carbon still available after the nitrogen has been consumed, starving some of the bacteria of this element. These will in turn die, returning nitrogen to the mixture, but slowing the process.
Anaerobic breakdown of waste needs temperatures lying between 0°C and 69°C, but the action of the digesting bacteria will decrease sharply below 16°C. Production of gas is most rapid between 29°C and 41°C or between 49°C and 60°C. This is due to the fact that two different types of bacteria multiply best in these two different ranges, but the high temperature bacteria are much more sensitive to ambient influences. A temperature between 32°C and 35°C has proven most efficient for stable and continuous production of methane. Biogas produced outside this range will have a high percentage of carbon dioxide and other gases than within this range. Microbial diversity in biogas digesters is great and about seventeen fermentative bacterial species have been reported to play important roles in the production of biogas. Furthermore, it is the nature of the substrate that determines the type and extent of the fermentative bacteria present in the digester.

Systems intended for the digestion of liquid or suspended solid waste (cow manure is a typical example of this variety) are mostly filled or emptied using pumps and pipe work. A simpler version involves using gravity waste liquid or suspended organic solid waste fed to the tank and the digested slurry is allowed to overflow the tank. This has the advantage of being able to consume more solid matter as well, such as chopped vegetable waste, which would block a pump very quickly. This provides extra carbon to the system and raises the efficiency. Cow manure is very nitrogen rich and is improved by the addition of vegetable matter.
Biogas production is often preferred to fossil fuel energy sources, such as oil or coal, for environmental and economic reasons. The rising concentration of carbon, a greenhouse gas, in the atmosphere has become a central issue in the problem of global warming. Though both biogas and fossil fuels emit carbon, fossil fuels release carbon that has been buried for many years in ancient biomass and eventually removed from the carbon cycle. Carbon released during biogas production and use has been stored in the form of organic matter only recently and is still part of the cycle. Therefore it does not cause as much carbon concentration in the atmosphere.
Proponents of biogas production also prefer biogas to fossil fuels because it is a low cost, renewable source of energy, and it uses waste materials. Biogas production can take place on a small scale and this makes it a viable option for many regions of developing nations. Critics of biogas argue that food crops grown for the purposes of biogas production will create a global food shortage. However this criticism usually relates to the use of crop land to grow biofuels such as jatropha and palm oil. In many regions of the world tropical forest has been cleared to grow palm oil as a cash crop for both processed food and fuel. In addition to deforestation this may also cause water pollution, soil erosion and have a negative impact on oil producing nations. In some cases, especially in the USA, food crops have been grown to provide ethanol as a transport fuel. SHUMAS is using animal waste and not food to produce biogas

The Biofarm biogas production process
Activities in the biogas plant of the Centre are carried out on a daily basis. Every morning animal waste, mostly from cattle, is mixed with water and fed into a mixing tank in a 1: 1 ratio. After feeding into the mixing tank it is stirred to promote its movement by gravity to the digester. In the digester there exists an anaerobic condition that leads to the formation of methane gas and other gases. The produced methane (biogas) is collected in an inverted drum above the digester. The walls of the drum extend down into the slurry to provide a seal. The drum is free to move to accommodate more or less gas as needed. The weight of the drum provides the pressure on the gas system to create flow. The produced biogas flows through a small hole in the roof of the drum. A non-return valve here is a valuable investment to prevent air being drawn into the digester, which would destroy the activity of the bacteria and provide a potentially explosive mixture inside the drum. The drum is slightly smaller than the tank, but the difference is small to prevent loss of gas. The biogas is transferred through the pipes to the kitchen where it is used to prepare food and to the poultry where it is used for heating.

Biogas plant Biogas mixing tank with fresh cow dung
Inverted drum on digester with no biogas Biogas by-product (slurry) tank
Inverted drum on digester raised by the presence of biogas
The daily feeding of animal waste through the mixing tank pushes the old animal waste in the digester out by gravity to the discharge tank. The biogas by-product in the discharge tank (called slurry) is collected and used as fertilizer in the crop areas and also to act as a natural pesticide. This fertilizer is better than other organic manure in that mineralization has occurred and nutrients are directly available to crops. The biogas by-product contains no infectious bacteria as they are unable to pass through the digester without being killed.

Use of biogas slurry for soil fertility and pest control
Cow dung is mostly used for biogas production. Slurry resulting from cow dung anaerobic digestion in the biogas plant is composed of 1.8 - 2.4% nitrogen (N2), 1.0 - 1.2% phosphorus (P2O5), 0.6 - 0.8% potassium (K2O) and 50 - 75% organic humus. The anaerobic condition involved in biogas production mineralizes organic matter through the increased incubation period. The application of slurry improves the physical, chemical, and biological characteristics of the soil. The anaerobic digestion decreases the C:N ratio and increases the concentration of immediately accessible plant nutrients. The slurry could be sold as fertilizer, used in crop fields to improve soil fertility, be sprayed on pastureland as liquid fertiliser, or used as a nutrient medium for aquaculture.
The slurry is used on vegetable (huckleberry and cabbage) plots to increase soil nutrients needed by these crops to do well. High yields have been recorded in these areas due to the application of slurry as manure. The presence of nitrogen, phosphorus and potassium in slurry, highly needed by plants for growth in various concentrations, is responsible for the high crop yields.
The slurry that is produced by the biogas plant in the BIOFARM Centre is collected in another tank. This tank containing this slurry is always free from flies and insects while in the tank where the mixed cow dung with water is present, many flies are always seen present. This slurry has been noticed by the farm staff to contain some special characteristics that could be used to fight pests in crop fields. The huckleberry fields were seen at one time to be affected by a certain pest and the staff of the farm decided to continuously water it with slurry which they had discovered to be free from flies. After some time it was discovered that the pest had disappeared. Since then, the staff of the Biofarm have been using slurry for pest management in the vegetable fields. There is still need for more research on the possibility of producing a natural pesticide from this slurry. This will provide an opportunity for it to be sold to other farmers.

Use of biogas energy in the Centre
Cow dung is used to produce biogas in the Centre. About one cubic foot of gas may be generated from one pound of cow manure at around 28°C. This has been known to be enough gas to cook a day's meal for 4-6 people in India. About 1.7 cubic metres of biogas has the energy equivalent of one litre of gasoline. The manure produced by one cow in one year can be converted to methane which is the equivalent of over 200 litres of gasoline. The energy value of biogas varies between 4.5 and 8.5 kWh/m3, depending on the relative amounts of methane, carbon dioxide and other gases present. Both methane and carbon dioxide are odourless.
The biogas is used for cooking food for the course participants and staff - usually about 50 people. The biogas is connected to the kitchen where food is prepared. It is the only source of energy used for cooking at the Centre except for staff who prepare their own food using cooking gas from fossil fuel.

Course participants line up for food prepared using biogas
The biogas is also used for heating the poultry. Bamdzeng in Kumbo where the Biofarm is located, is at the top of a hill and is very cold for the survival and proper growth of poultry. Biogas has been used to provide the birds with the heat that is necessary for their growth and well being.
Poultry heated with energy from biogas
Biofarm self reliant programme
The Centre is far from the national energy grid system and now uses biogas for cooking and heating. Energy for lighting the Centre comes partially from fossil fuel to run the generator. The Centre has the vision of becoming self reliant in biogas, wind and solar energy in the future thus contributing to the fight against climate change. The Centre has two windmills that provide energy for lighting the administrative block, classrooms and some residential areas. Energy from the windmill is also used to charge the telephones of participants and staff. There are plans to install more windmills to meet the lighting needs of the Centre. The wind speed in the locality is strong enough to produce much energy.

Wind energy used for lighting and charging telephones
There are also plans to make use of a solar system to get more energy. The available small rivers in the vicinity will be dammed for irrigation purposes and feasibility studies will also be carried out to see the possibility of developing small hydropower systems.

Other activities
During the period of internship in the nine months organic agriculture course participants present their theses in front of the various assessment boards at the Centre in partial fulfillment for the award of a diploma in organic farming. The participants do research on various agricultural domains like fishery, goat and sheep rearing, cattle rearing, Solanum potatoes cultivation and many other topics.

A course participant presents her thesis in front of the Assessment Board
Radio programme on integrated organic agriculture
The internship period fell in a time that SHUMAS needed to visit the Kumbo Community Radio to sensitise the public on SHUMAS's integrated organic agriculture activities especially on its importance in promoting food security, fighting economic and environmental crises, and serving as a demonstration and training centre to peasant farmers. This programme was carried out successfully and it created an impact in communities. A lot of feedback and comments followed the programme and were positive and encouraging. The programme was recorded and copies are available.

The above report has been based on the experience and writing of one of the participants, Wirsiy Emmanuel Binyuy, who concluded that "It was a great experience doing internship in SHUMAS and its Biofarm Centre. It created a positive impact in my life and built my capacity on integrated organic farming, biogas production, project writing, team spirit, participatory approach methods, being result focused in all work done and using a bottom-top approach in making things work for communities while protecting the environment. There are a lot of opportunities for internship and research for students interested in renewable energy, organic agriculture, agro-forestry, auditing, biodiversity conservation, anthropology, sociology etc to exploit in SHUMAS. From all work done with SHUMAS there is much potential that could be better exploited if more collaboration, networking and partnership is created with all farmers, agricultural researchers, university students and policy makers in this sector. This will make organic farming and natural pest management a success in the North West Region and the rest of Cameroon. This success story will then be replicated all over the nation".