The Black Earth Project


Terra Char

The Black Earth Project is a two-year research project designed to evaluate the effectiveness of biochar when used as a soil amendment by smallholder coffee and pyrethrum farmers in Rwanda. Biochar is produced through a process called pyrolysis, or the burning of dried biomass in a low or zero oxygen environment.

The process prevents combustion and the usual release of carbon dioxide, black carbon and other greenhouse gases associated with traditional charcoal production methods. When used as a soil amendment, biochar can increase crop yields, reduce nutrient leaching, help retain moisture, reduce soil acidity and improve surrounding water quality while significantly reducing the need for additional irrigation and fertilizer inputs. Biochar has increasingly been cited as an effective approach to carbon sequestration as it can remain stable in the soil for thousands of years.

The Black Earth Project is being conducted in partnership with six coffee cooperatives, located in each of the major coffee growing areas of Rwanda. Six Climate Kilns, provided by project partner re:char, are being utilized to enable farmers to manufacture biochar from agricultural crop residues such as dried corn stalks, grasses, coffee pulp, rice hulls as well as cow manure and wood chips.

Eighteen test plots were planted with bush beans on March 15, 2013 and harvested in late June and early July. Those plots treated solely with an application of biochar realized an average 19% increase in yield, with a 100% decrease in input costs. Plots planted with a mixture of biochar and traditional fertilizer demonstrated an average yield increase of 35%, accompanied by a 50% reduction in input costs.

Our Coffee Radio Network features monthly updates on the Black Earth Project, keeping farmers informed of any challenges encountered and progress made as well as specific outcomes as data becomes available. Participating farmers and cooperative agronomists are featured in a radio magazine format, continuing our efforts to promote farmer-to-farmer mentoring through participatory radio.


The use of biochar could provide small-holder farmers with one of their most significant tools to help increase yields, lower input costs and address the many challenges presented by the effects of continuing climate change. To help evaluate both the short and long term benefits of biochar to coffee farmers, Radio Lifeline undertook a two year series of field trials, using our network of community radio stations to help inform and educate producer communities of the project’s challenges, progress and results.

Early results are very promising, demonstrating an average 35% increase in yield with a 50% decrease in the cost of fertilizer inputs. There have been measurable improvements in soil fertility and water retention, providing farmers with viable alternatives to the increased use of petrochemical fertilizers.

In anticipation of increased farmer interest and industry demand for biochar technologies, we created Terra Char, an organization focused on educating farmers about the benefits of biochar while providing tools and technical expertise for the successful implementation of biochar projects within a wide variety of small-holder farm environments. Upon completion of the Rwanda field trials in 2015, Radio Lifeline will transition all biochar activities to Terra Char.




© Radio Lifeline and 2014