How Zanzibar scientists managed to convert waste to organic fertiliser

26Dec 2017
Gerald Kitabu
The Guardian
How Zanzibar scientists managed to convert waste to organic fertiliser

ONE of the most social problems facing many cities like Dar es Salaam and other urban areas is the dilemma of how to dispose the garbage.

Dr Said Bakari, a lecturer at the State University of Zanzibar (SUZA) explains on how waste is being converted to organic fertilizer for sustainable vegetable farming. Photo: Gerald Kitabu

Zanzibar as of the urban areas is facing similar problems and so far establishing a proper solid waste management system is an uphill task. Gerald Kitabu reports on how researchers from State University of Zanzibar (SUZA) in collaboration with University of Dar es Salaam Institute of Marine Sciences have managed to convert waste to organic fertiliser for sustainable vegetable farming and household waste management in Zanzibar suburb.

Watering, sun and direct light for at least six to eight hours per day had always convinced Mohamed Yusufu to think that he would have bumper harvest, however, at the end of every harvesting season, he could not post high yield due to lack of other necessary factors such as fertilisers and fast-draining and loamy soil.

Yusufu, a tomato farmer from Shakani area in Zanzibar repesents many farmers in Zanzibar who had similar methods of traditional agriculture but now, they have changed following discovery of the new technology of  converting households organic wastes into reusable by-product (compost) by using effective micro-organisms (EM) consortium.


With the help of reserchers from State University of Zanzibar (SUZA), Yusufu opened up his tomato field in an open area before moving on to green houses for productive tomato farming.

By using converted waste to organic fertiliser, Yusufu has doubled production and currently struggling to look for more markets following expansion of his farming area.


Suleiman Mumbi, a farmer from Kibele area said that just like any other vegetable agriculture, tomato agriculture has many challenges such as diseases and pests. However, this new technology has, at least will help the farmers do away with expensive fertlizers.

”Because the organic wastes which are being converted into reusable by-product (compost) are easily accessible, will help reduce fertilizer costs and increase productivity,”he explained.


While Dar es Salaam city has no strategy to solve the problem of wastes, The great potential of organic wastes available in Zanzibar suburb are being converted into reusable by-product (compost) by using effective micro-organisms (EM) consortium.


According to scientists, effective micro-organisms (EM) consortium (EM) refers to the specific mixed cultures of known beneficial micro-organisms that are being used effectively as microbial inoculants. They help to hasten the process of composting biodegradable waste, preventing development of foul odors and fly nuisance.


Co-Principal investigator Dr Mohamed Maalim from State University of Zanzibar said that the produced compost was applied as a source of organic fertiliser to the growing sector of vegetable farming in Zanzibar suburb.


The results show that management of household solid waste have been improved at the study areas for 60 percent. The data also show that tomato yield cultivated with EM compost was increased for 20 percent compared to mineral fertilizer.


Similarly, the nutrient level (Beta-carotene and Vitamin C) of tomato was increased in soil treated with EM compost than mineral fertilizer. Through this technology, 150 peoples were engaged in different jobs activities; Whereas three M.Sc. students were supported financially by this research, he explained.


Composting of household waste is now being encouraged as a means of reducing the organic waste being discarded and sent to the landfills in many part of world.


Raw organic materials such as crop residues, animal wastes, food garbage, and some municipal wastes, enhance their suitability for application to the soil as a fertilizing resource, after having undergone composting. The decomposition can be carried out naturally or enhanced using effective micro-organisms (EM).


”EM contain selected species of micro-organisms, commonly found in all ecosystems, namely Lactic Acid Bacteria, Yeast, Actinomyces and Photosynthetic bacteria. They have a high ability to decompose organic matters into the finished product (compost) within a short range of time. EM has been used by farmers and demonstrated beneficial effects,” he said.


Studies have suggested that EM may have a number of applications, including agriculture, livestock, gardening and landscaping, composting, bioremediation, cleaning septic tanks, algal control and household uses.


He explained that composting of household waste is now being encouraged as a means of reducing the organic waste being discarded and sent to the landfills in many parts of world.


He said that the technology is a simple technology that can be used by ordinary farmers to increase vegetable production like incresaing tomato productivity and human health  with very low cost.


”Im optimistic that this technology will ensure sustainable vegetable agriculture, change farmers life in Zanzibar and reduce poverty,” he said.


For his part, Dr Said Bakari also a lecturer from State University of Zanzibar exlained that apart from increasing food production in Zanzibar, the project has benefited University students and farmers in Zanzibar.


”During the first phase the crops were planted in an open environment and the second phase, we planted in green house. In the first phase, we involved two University Students at the level of Masters degree and another student at the level of undergraduate. In the second phase we have one participating resercher student  who looks after the quality of the potatoes,” he said.


He said that apart from University students, six farmers were involved. They were from Shakani, Kibele and Mwela.  In the second phase, there are two participating farmers in the research.


A masters degree student at State University of Zanzibar (SUZA) Sheikha Salum explained that her research is to examine the nutrients contained in the tomato produced by reusable by-product as fertilizers.


”The tomatoes produced through this way are far better than ordinary ones, they are smooth, sweet and red compared to other tomatoes,” she said.


The Deputy Vice Chancellor of the State University of Zanzibar, Dr Zakiya Abubakar commended Tanzania Commission for Science and Technology (COSTECH) for funding the project saying it will help many farmers increase vegetable production in Zanzibar.


She said that the research on converting waste to organic fertilizer for sustainable vegetable farming and household waste management in Zanzibar suburb was funded by the Tanzania commission for Science and Technology (COSTECH).

She said that COSTECH is the Parastatal organization with the responsibility of coordinating and promoting research and technology development activities in Tanzania. The commission is the chief advisor to the government on all matters pertaining to science and technology and their application to the socio-economic development of the country.

Acting Director General for Costech, Dr Dugushilu Mafunda said that the government has managed to build capacity in different research areas including academic institutions and Universities. Citing an example, he explained that through SIDA he said the institutions have been equipped with modern infrastructures to carry out fruitful research.

“The Swedish International Development Agency (SIDA), has been very instrumental for building capacity in terms of training students, funding researches, innovation and ICT systems among many other fields,” he said.

“A good research is that which has impact in our communities. We would like to see more researches that direct reflect the nation’s plans and priorities,” he said.

The Permanent Secretary in the Ministry of Education, Science and Technology Dr Leonard Akwilapo commended the researches saying  any research conducted in the country should be result oriented and contribute to the development of the nation.

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