What goes round: Vermicomposting as a cyclic system to manage coffee waste

Ethiopia is widely reputed to have gifted the world with one of its most beloved beverages – coffee. Today, Ethiopian coffee, specifically Coffea arabica, is one of the world’s most sought-after, with the country ranked among the top 10 global exporters of the commodity. Coffee production is spread across the country, covering an approximate 400,000 hectares of land.

Tainting the beautiful picture of coffee in Ethiopia, is the coffee waste challenge. Coffee is processed through the removal of layers of skin, pulp, mucilage and the parchment that surrounds the beans. The major solid residues from this process are coffee husks and pulp, which amount to 50% of total coffee weight. It is estimated that 235,296 tonnes of such coffee waste are produced every year. These residues contain phenolic toxic poisonous substances that are low in pH, high in organic load, caffeine, tannins, polyphenols and inorganic nutrients.  Coffee processing takes place around river banks and this affluent is pumped directly into the water with great impact on the biodiversity, people’s health and livestock the ecosystem.

Science, innovation and enterprise

In 2018, Burqitu (Bio-chain) Bio-waste Processing and Integrated Agriculture Enterprise, an initiative supported by BioInnovate Africa Programme, commenced activities to develop a cyclic process known as vermicomposting. This strategy involves the use of earthworms to convert coffee affluent into nutrient-rich fertilisers that are then applied to coffee and other crops. The project is based in Shoye, a village located in Yirgalem, southern Ethiopia. A fertile, idyllic landscape sitting at altitudes of around 1776 metres above sea level, Shoye is an epicentre of coffee production, with coffee fields nestled in lush vegetation, forming part of the diverse flora.

Supported by the Swedish International Development Cooperation Agency (Sida) and managed by the International Centre of Insect Physiology and Ecology (icipe), BioInnovate Africa Programme assists scientists and innovators in eastern Africa to link biological based research ideas, inventions, and technologies to business and the market.

The Burqitu (Bio-chain) bio-waste initiative is being led by Prof. Gezahegn Degefe of Debre Berhan University, Ethiopia, and it is based on a pilot project that demonstrated the potential of coffee waste vermicomposting.  

“Not all earthworms can vermicompost. Only a few members of this family have such capacity. Our earlier studies demostrated that three earthworm species: Eisenia fetida and E. andrie and Dendrobanae veneta, can manage various organic wastes. This research also revealed the  levels of their performance and the time it takes to manage various wastes,” he explains.

He adds: “We also established the substrates that provide the most efficient growth and reproductivity in earthworms. This knowledge is highly essential in rearing  cocoons under laboratory conditions for sustainable vermicomposting.” 

The support from Bioinnovate Africa is enabling the team and partners that include the International Livestock Research Institute (ILRI), Selian Agricultural Research Institute (SARI), Tanzania, Wondo Genet College of Forestry and Natural Resources, Ethiopia, to scale up the ideas.

As part of its community service mandate, the University is providing the vermicomposting technology, training and initial earthworm colonies to the Burqitu Enterprise. The Enterprise members, who, were previously either unemployed or underemployed, now have the capacity and skills to implement all vermicomposting activities. Using locally available materials, they have constructed a vermicompositing system that consists of a light-proof unit – because worms do not like light – and bedding trays.

“We collect the coffee waste from 15 villages. We spread the waste on the bedding trays and mix it with soil according to the ratios provided by the scientists. We then introduce the worms into the mixture. We regularly water and turn the mixture. The ferlitizer is ready in two months,” explains Mathewos Abebe, Burqitu Enterprise member. The water aids the disintegration process by creating a suitable medium for microbial action, while the turning helps to oxiginate the mixture.

The vermicomposting beds are fitted with a drainage and collection system connected to cylinders to tap the liquid run-off from the vermicompost mixture. Known as leachate  or “vermi tea)”, this liquid contains significant amounts of plant nutrients and humic acids, which are known to increase plant growth by regulating many processes for plant development including macro- and micronutrients adsorption.

Thus, the Burqitu (Bio-chain) Enterprise is producing two types of biofertilizers: solid and liquid, both of them popular with farmers. The solid fertiliser is  packaged in 100 kilogrammes bags and sells at 350 ETB (approximately 7.6 USD).  Five litres of the liquid fertiliser goes for 60 ETB (approximately 1.3USD). Coffee farmers are the major customers of solid fertilizer, while the liquid fertilizer is in high demand for urban agriculture.

Benefits

“Farmers have reported that the solid biofertiliser keeps the fertility of the soil, increases the water holding capacity, and has superior performance than commercial synthetic brands and traditional compost,” explains Prof. Degefe.“The liquid fertiliser is sprayed onto the soil and on the leaves of plants. The liquid fertiliser leaves a very deep green, which is a sign of health and strength, and improves the performance of biomass of coffee and other plants.”

“Previously, I was using the traditional compost, but after trying vermicompost produced from Burqitu (Bio-chain) enterprise, I have switched completely. Within a short time, I have noticed that the condition of my coffee has improved, it has become very green. And it looks much healthier. To me this is a sign of better performance and I anticipate a better yield,” says Mengistu Dubar, Coffee Union Representative, Burqitu village.

“The Burqitu bio-waste project demonstrates the potential of biological sciences as a path to viable green and inclusive businesses in Africa,” observes Julius Ecuru, Manager, BioInnovate Africa Programme. “Although vermicomposting is a popular technology in many parts of the world, hitherto it has not been widely used in eastern Africa and to this scale. This partnership has created an integrated project where most components result in high quality products.”

Earthworms are  hermaphrodites, they are self-sustaining, they reproduce quickly and they have a long shelf life. Therefore, colonies soon exceed the requirements of vermicomposting. The Burqitu Enterprise members are employing the surplus earthworms to start poultry and fish farming, using them as feed for broiller chicken and fish fingerlings. In turn, the effluent from the fish pond, which is enriched with fish and chicken waste, become an additional  source of agricultural nutrient. Earnings from these activities are allocated three ways: to operations, a savings account in a cooperative society, and to the beneficiaries.

“Before I joined this initiative, I was  striving to eke a living and not earning much money. Now, I obtain enough income to support my family. I have also been able to enrol for a Diploma in Business Management, and to pay my own tuition fee,” states Abebe.

“We now have good experience on how to create job opportunities and generate income. We plan to expand our business by opening retail outlets for chickens, fish and also other products in town centres.”

“Before, the coffee waste used to be pumped into the river, which is our main source of water including for domestic consumption. This was a great challenge for us as the water was highly polluted, and we had no idea how to treat the solid waste,” says Dubar.

Inspiration

The Burqitu Bio-waste Processing and Integrated Agriculture Enterprise recently benefitted from a visit by icipe Director General, Dr Segenet Kelemu, who provided inspiration, ideas and recommendations on how to diversify activities to boost income of the members, ensure viability of the project, and elevate its value in environment improvement and job creation strategies.

The Director General observed that the region’s diverse flora is ideal for beekeeping, an element that would form a synergetic relationship with coffee growing. Moreover, the group would tap into’s icipe extensive experience and capacity in beekeeping.

She added: “icipe’s experience in Kenya shows the growing value of insects like black soldier flies as alternative animal feed protein and how they can unlock the full potential of the fast-growing fish, poultry and piggery sectors. For instance, 4% of Kenya’s annual animal feed protein is currently being met through insect proteins, with projections that in two to three years time, such integration could go up to 40%.

“This model can be integrated into the vermicomposting initiative. This would enable the Enterprise members to also include egg-laying chicken,” She noted.

These goals will require the right policies and an enabling environment. Thus, it is vital to create awareness among government actors on the value of the waste management especially in urban areas, improving agriculture, maintaining the of the environment and people and creating jobs.