Home Technology Safeguarding food security by composing waste into fertiliser-NEPAD

Safeguarding food security by composing waste into fertiliser-NEPAD


The application of fertiliser can enhance agricultural productivity and food security in Africa.

Also read: Support for smallholder farmers key to ending hunger in Africa-AGRA President

Reportedly, African farmers progressively applied fertilisers from an average of 8.5 kg per hectare of land in 2006 to an average of 17 kg of fertiliser per hectare of cropland in 2018. The progressively incremental utilisation of fertilisers in Africa to ensure food security places the commodity at the apex of modern technologies to ensure the production of fertilisers.

The leading causes of food insecurity in Africa have recently included pandemics that can disrupt the food value chains. Since the Russian invasion, global food prices have increased significantly. The Food Price Index of the United Nation’s Food and Agriculture Organization (FAO) increased 12.6% from February to March 2022, when the Russia-Ukraine conflict commenced. The March index was the highest since the measure’s inception in the 1990s.[4]

In Africa, the conflict between Russia and Ukraine in 2022 has equally exacerbated food insecurity, placing more Africans at risk of acute starvation. Ukraine’s key food exports, such as wheat, barley, and sunflower oil, provide calories to supply approximately 400 million people worldwide. Together, Russia and Ukraine provide over 40% of Africa’s wheat supply.[6] Yet, Ukraine’s key ports, such as Odesa, through which 98% of the grain exports typically pass, are being blockaded by Russia.

Currently, Africa is encountering grain shortages, cooking oil and essential organic fertilisers that can be utilised in food production. The price of inorganic fertiliser is also continually escalating. For example, the price of urea fertiliser has risen by up to 32%, while that of diammonium phosphate increased by 13% by March 2022.[9] Can African countries establish autonomous systems to provide fertilisers for their farming activities to nurture the agricultural potential of the African continent sustainably?

Inorganic fertilisers containing a variety of nutrients, including nitrates, magnesium, phosphorous and potassium, are essential for improving the soil quality and crop yield, thereby ensuring food security in Africa.[10] Due to land degradation in some parts of Africa, fertilisers can replenish the nutrients the crops have removed from the soil. Thus, crop yields and agricultural outputs would be markedly lowered if fertilisers were not applied.[11]

Some farmers often utilise fertilisers containing 19% potassium, 15% nitrogen, and 14% phosphorus. However, the disadvantage of these inorganic fertilisers is that the nitrogen, phosphate, and potassium-based synthetic fertilisers can leach into groundwater bodies. This can, in turn, escalate their toxicity, causing substantial water pollution. Such fertilisers that leach into streams, rivers, lakes, and other bodies of water can upset and unsettle the aquatic ecosystems.

Additionally, even though inorganic fertilisers produce remarkably quick results on commercial farms, where growth equals profit, the substantial and unrestrained use of these synthetic compounds can result in fertiliser pollution. Inorganic fertilisers can also increase the nitrate levels of soil, which can, in turn, produce nitrites that can react with the haemoglobin in the bloodstream. Consequently, this could lead to the production of methemoglobinaemia, which can potentially damage the vascular and respiratory systems. Such complications may result in suffocation and even death in extreme cases, especially when the blood methaemoglobin level is 80% or more. In addition, plants that grow in overly fertilised soil are deficient in iron, zinc, carotene, vitamin C, copper, and protein.

Between the pollution caused by fertiliser and the limited supply across the continent, African farmers are encouraged to explore organic fertiliser alternatives to apply to their crop production. This can be accomplished by using already existing food waste to create compost fertiliser containing organic matter. Notably, the food waste fertiliser is processed by simply breaking down food waste in the presence of air and water, using microorganisms and small insects present in nature. The food waste composite fertilisers can decrease the solidity of soil and bulk density by enhancing the soil’s porosity and aeration. It can also improve saline water leaching and decrease soil acidity, as well as soil’s humus content and allows for beneficial microbes to grow. The food waste fertiliser is also environmentally friendly and cost-effective.

The African Union High-Level Panel on Emerging Technologies (APET) notes that generating compost fertiliser from waste in Africa is not necessarily new. Nevertheless, an emergent circular economy is responsible for linking entrepreneurs with smallholder farmers in Africa to manufacture fertiliser as a value-added product to support agricultural activities. For example, young Ghanaian entrepreneurs founded a Sabon Sake project to develop a small bio-compost fertiliser plant in the South Volta region in 2018.[13] These young entrepreneurs are using biotechnology to generate bio-compost fertiliser from sugarcane waste. Notably, this fertiliser is improving the soil quality as well as crop yields and competing with a market that utilises a lot of chemical fertilisers.

In most cases, Ghanian farmers turn to burn their crop waste in the fields immediately after their harvest. Consequently, this causes pollution, and this subsequently damages the soil quality. Thus, through capacity strengthening, Ghana has brought a network of 30 sugarcane farmers to produce organic fertiliser for their fields using sugarcane waste. The plan is to scale up the project to support vertical and urban farmers as well. Moreover, the Ghanaian people are known to grow a lot of fruits and vegetables in the backyards of their homes, and they can potentially turn the waste from their fruits and vegetables into bio-compost fertiliser for more farming activities.

The Moroccan Compost Systems specialises in the biological treatment of waste. As a result, Compost Systems have built a composting plant for organic agricultural waste to serve as the pilot phase for a regional composting project.[15] This project is utilising the regional composting platform to add value to the organic agricultural waste in the Sous-Massa region of Morocco. Notably, this region generates approximately 1.87 million tonnes of organic agricultural waste annually. Even though the project is still in an experimental phase, the future facility is anticipated to generate up to 100,000 tonnes of fertiliser per year from the waste.[16] Remarkedly, improving the agricultural yields through bio-compost fertiliser can strategically strengthen the 12% of the GDP and the 15,000 people employed in the agricultural sector of Morocco.[17] Thus, the small venture in the Sous-Massa plant will decrease organic agricultural waste and contribute to Morocco’s socio-economic development.

In July 2021, Gambia’s Kanifing Municipal Council (KMC) inaugurated a project to decrease the size of the organic waste usually dumped into the local landfills. In this project, the waste is converted into fertiliser and biomass briquettes.[18] The current arrangement is that the waste gets collected from the Kanifing and then deposited into an unregulated landfill located near Serekunda. This is the largest city in the Gambia. However, under the KMC project, the organic waste is collected from crops and vegetable markets and subsequently converted into fertiliser. Female vendors then sell the fertiliser for profit to farmers across the country. As such, APET is encouraging other African countries to effectively replicate this model in their context to supply fertiliser to their local farmers. Young African entrepreneurs can be supported to scale up such projects for their local communities.

Furthermore, deforestation remains a severe challenge in the Gambia, as the country lost over 100,000 hectares of forest between 1998 and 2008.[19] This loss was attributable to commercial logging and firewood. Entrepreneurs are manufacturing biomass briquettes from municipal organic waste to address this deforestation challenge. Local households utilise such biomass briquettes for cooking instead of using wood. APET observes that this biomass reclamation project is mitigating deforestation and reducing carbon dioxide (CO2) emissions.

With the assistance of development partners such as the Japan International Cooperation Agency (JICA) and the United States of America-based company known as Sanergy, Kenya has invested about US$2.5 million into the circular economy.[20] Within this circular economic activity, a factory was built in 2021 in Nairobi to produce one of the largest insects’ feeds in East Africa. This factory collects human excreta and organic waste from slums. Subsequently, this waste is transformed into insect feed, organic fertiliser, and biofuel.[21] This is undertaken in collaboration with the Black Soldier Flies (BSF). The Black Soldier Fly Larvae (BSFL) are utilised to compost and alter waste into animal feed.[22] The fly larvae are efficiently converting the biomass into feed. The global market for BSF is envisaged to expand at an annual rate of 34.7% over the next 10 years, reaching approximately US$3.4 billion.[23]

The population of Kenya’s capital, Nairobi, is envisaged to reach approximately 5.94 million by the year 2030.[24] Waste volumes in the city are expected to increase to approximately 3,990 tonnes per day by 2030.[25] Notably, approximately half of Nairobi’s waste is illegally dumped into unauthorised and sometimes undesignated landfills. For example, about 1.8 million cubic metres (m3) of waste is brought into the waste disposal sites that can only process only about 500,000 m3.[26] On the other hand, only 12% of Nairobi is linked to the Kenya sewer grid system, and human waste is substantially challenging the city.[27] This results from the limited sanitation capacity, negatively impacting the health of the Kenyan people in slums such as Kibera. However, repurposing the waste from these communities can improve sanitation, create wealth, and enhance fertiliser production for agricultural purposes.

In some African villages, approximately a third of the population is hungry because over a quarter of the harvested food is lost due to spoilage. Besides, hundreds of millions of livestock across the African continent are responsible for degrading approximately half of the cropland, making up over one-third of overgrazed lands worldwide. However, the uneaten food, manure, and other forms of waste can be utilised by farmers to produce fertiliser, fuel, and food. For example, South Africa is diverting about 2% of organic matter from its landfills generated in Cape Town, and 15% in Johannesburg, through composting.[28] Notably, some municipalities in South Africa are operating smaller-scale composting facilities. Then again, Uganda has nine (9) municipalities that have established composting plants through the support of the World Bank.[29]
APET observes that composting food waste reduces the pressure on landfills while generating a cost-effective nutrient-rich soil amendment that farmers can utilise to enhance their soil fertility. This is because the compost complements the soil’s organic matter, enhances the soil’s water-holding capacity, facilitates root penetration, and makes soil nutrients available for crops over time. Notably, subsistence farmers have conventionally depended on composting and livestock manure to improve soil nutrition. For example, the Ibo tribe of Nigeria has traditionally utilised branches from trees for mulching, employed goat dung to individual plants, and composted human waste.[30] Alternatively, the Zimbabwean, South African, Mozambiquan, and Eswatini subsistence farmers have customarily grazed their cattle during the day and confined them in pens at night so to collect the manure and scatter it over their farms.

To strengthen capacity for compositing, various projects across the continent are being implemented to enhance farmers’ capacity for composting and improving the quality of compost being generated. For example, a participatory radio show in the Zégoua region of Mali has resulted in a 64% incremental household adoption of composting.[31] Conversely, Kenya has established a demonstration project to turn waste from households, vegetable markets, and an avocado processing plant into compost that farmers can utilise to boost their crop yields and profits. Further to this, Pelungu farmers in Ghana are constructing goat shelters with sloppy floor surfaces to transport the goats’ dung into a central location using gravity. The resultant manure is subsequently composted for farming purposes.

APET observes that some African farmers use manure and agricultural waste for fish food. For example, Tanzania established an “integrated fish management” system in 2005 that could generate fish from farm waste and fertiliser from fish waste.[33] This was accomplished by incorporating the production of catfish and tilapia with poultry, corn, rabbit, and vegetable production. The chickens are made for walking on stalks, enabling their nitrogen-rich excreta to fall directly into the fishpond.[34] Subsequently, the enriched fishpond water is then utilised to irrigate crops. These crops can then be utilised to feed livestock as well.

APET is challenging African countries to upscale compost fertiliser production from food waste. Such projects can help repurpose food wastage and develop small-scale fertiliser production for local farmers within African communities. Furthermore, African governments can upscale these fertiliser projects together with capacity strengthening programmes of fertiliser production for African farmers. This can help enhance the quality of the compost production. Most importantly, APET underscores the critical importance of resiliently and sustainably transforming Africa’s food systems using food waste as fertiliser. African communities can utilise mechanisms that will ensure that Africa accomplishes food self-sufficiency”