The temperature has soared to well over 30 degrees, but Kwasi Asare and Samuel La show no signs of slowing down.
With each heavy scoop of their shovels, steam rises from the mound of waste and organic material they are turning. It's hard work but it is vital to kick-start a scientific process that could hold the key to increasing agricultural productivity in sub-Saharan Africa.
It is all part of the 'Fertilizer Pellet Fertilization Project', an innovative effort led by the Resource Recovery and Reuse team at the West Africa office of the International Water Management Institute (IWMI).
The project is looking to harness human waste and turn it into safe, hygienic fertilizer pellets that are suitable and safe for application by farmers.
If successful, this fertilizer will help farmers increase the organic content and nutrient levels of their poor soils, which in turn can increase the water-holding capacity and crop yields of their farming land.
As project leader Josiane Nikiema, explains, Asare and La's hard work is an important part in the early phase of the project.
"This material being turned by Kwasi and Samuel is a combination of human waste and other natural products such as sawdust and organic food scraps," says Nikiema. "That is why you can see they take precautions with their equipment and their clothes. By constantly turning and resting the materials, we help create a natural heat treatment during the composting process that will assist in removing pathogens while minimizing nutrient losses."
The use of human waste or fecal sludge in agriculture is not a new concept. It has been used effectively in Asia for centuries. However, its use in sub-Saharan Africa is relatively new, and the West Africa office of IWMI has been exploring the potential it could hold for agriculture in the region since 2001.
Adding organic waste to the soil makes sense in a region particularly vulnerable to climate variability and changes. Most agriculture in West Africa is rain-fed so crop yields are highly dependent on climate fluctuations. Human waste will help improve the water holding capacity of the soil, reducing drought risk.
Climate change scenarios developed by the Intergovernmental Panel on Climate Change indicate that the cropping season in the Sahel and Sudano-Sahelian zones could be reduced by over 20 percent by 2050.
Rainfall may become far more unpredictable. Providing smallholder farmers with support to improve water and soil management will be a key strategy to increase their resilience to adverse climatic conditions and hence reduce poverty in a changing climate.
"Unlike animal manure or farm residue traditionally, the use of human manure in agriculture has been met with some opposition in sub-Saharan Africa," says Nikiema. "However, this was more at the regulatory level than at the farmer's end. Farmers appreciate the material."
Nikiema understands that cultural resistance to the use of human waste in food production is a confounding factor that needs to be addressed.
"It's understandable that there are concerns when dealing with this product. That's why the project puts significant emphasis on controlling or eliminating the possibility of disease incidence," she explains. "These options have been researched and verified by IWMI and partners, and now need to be explained to farmers and the authorities to support the safe use of this important nutrient source."
Human waste is an abundant, inexpensive resource and research indicates that, if treated effectively and applied correctly, it can hold numerous benefits for farmers.
Pelletizing the materials and mixing it with other nutrients, which is the current objective of the study, will make the product more marketable, easier to handle and easier to transport.
Nikiema hopes the project will lead to the creation of a rich and valuable product that will have a prolonged shelf life and can be transported over long distances.
"This will help immensely in exploring options to make this form of resource recovery profitable for private investors," says Nikiema.
And there is a further potential benefit. If converting human waste can become a profitable business, then badly needed investments in sanitation could follow. For the burgeoning cities of Africa and Asia, that could be an incalculable boon.
Lee Davelaar works for the International Water Management Institute(IWMI) in West Africa. IWMI is part of the CGIAR Consortium of International Agricultural Research Centres, a co-sponsor of Agriculture, Landscapes and Livelihoods Day being helf on 3rd December in parallel with the climate negotiations in Doha.