Agronomic Assessment of Biochar-Enriched Compost in the Southern Sudanian Zone of Burkina Faso for Yam Production

Biochar production requires large quantities of pyrolysable materials, posing challenges for producers to mobilize. The addition of reduced quantities of biochar during composting of organic residues could be an alternative for better promoting the use of biochar in agriculture. This study was carried out in the southern Sudanian zone of Burkina Faso with the aim of improving the agronomic value of composts via addition of biochar during composting for sustainable soil management. The first phase of the experiment involved a composting trial with three replicates and two treatments (sole compost and biochar-enriched compost). The composts which were produced were then evaluated for yam production in a completely randomized block design with four replicates. The parameters studied involved the changes in temperature and dry matter content during composting, as well as the chemical characteristics of the composts, yam tuber yield and soil organic C content. The composts were statistically similar in terms of temperature evolution, dry matter content, total N, P, K content and C:N ratio. The sole compost had a pH-H2O of 8.6 which was statistically higher than that of biochar-enriched compost (8.3). The available organic C, labile C, N and P contents of the biochar-enriched compost were 27%, 27%, 28% and 21% higher respectively than those of sole compost. The two composts were similar in terms of their effect on yam tuber yield but statistically higher than the control treatment. They did not significantly improve soil organic C compared to the control treatment. Co-composting with biochar could improve the agronomic performance of composts.