From human waste to fertilizer to fuel: rice yields green charcoal in Senegal

Inadequate management of human waste is a dire problem in much of the developing world. Swelling urban populations can make matters worse by exposing increasingly dense populations to illnesses carried by human waste.

Some, however, are making good use of the surplus sewage. Rather than allow the urine and fecal matter to lie fallow, some have taken to utilizing it for agricultural purposes in lieu of synthetic or inorganic fertilizers.

This practice not only makes fertilizer more readily available to farmers who might not have easy access to it in conventional forms, it is also significantly less expensive than using inorganic and synthetic fertilizers, which are often imported. Furthermore, the use of human fertilizer can sometimes be a crop-saving tactic when water is in short supply.

It is with these benefits in mind that groups like AgriDjalo, a small limited liability company focused on rice cultivation, are looking to start projects in Senegal that use urban biomass (primarily human waste) to fertilize rice fields. With over 40 percent of Senegal’s almost 13 million inhabitants living in urban areas, there is an abundant supply of human fertilizer.

AgriDjalo’s project could have the added benefit of decreasing reliance on rice imports. In 2012 alone, Senegal imported 820,000 metric tons of rice, accounting for more than 6 percent of its total imports and presenting a considerable strain on the nation’s trade balance. As the second-largest rice importer in Sub-Saharan Africa, and one of the top 10 worldwide, Senegal has much to gain, both in terms of income generation and decreased import dependency, from an increase in domestic rice production.

The project also seeks to use leftover rice husks and straw in the production of green charcoal. In this way, the unused byproducts of rice cultivation can be utilized to create an alternative to the wood charcoal, firewood, and butane gas traditionally used to generate energy.

In Senegal, where deforestation for purposes of collecting fuel wood has been an issue and 70 percent of the urban population relies on imported butane, green charcoal from rice represents a sustainable and affordable fuel source.

Combating both import dependency and deforestation while utilizing readily available fertilizer, projects such as this demonstrate that sustainable agricultural practices have the potential to improve food and income security for many in less developed countries.

• Andrew Alesbury is a former administrative assistant at the Worldwatch Institute.

• This article first appeared at Nourishing the Planet, a blog published by the Worldwatch Institute.