Contribution of soil macro-fauna to soil fertility improvement in cocoa-based (Theobroma cacao) agroforestry systems in the Littoral Region of Cameroon: Examining cocoa farmers indigenous knowledge

Soil macro-fauna play an important role in soil fertility improvement in different agricultural systems. However, limited research has been done to assess the role played by soil macro-fauna to soil fertility enhancement in cocoa-based agroforestry systems. This study was therefore initiated to fill this knowledge void. A mixed research approach was used during data collection, and data analysis was done using descriptive and analytical statistics. Findings showed that the main indicators of soil fertility perceived by cocoa farmers in cocoa-based agroforestry systems were cocoa yield (100%), soil colour (90%) and presence of soil macro-organisms (80%). Cocoa farmers identified earth worms (100%), ants (100%), termites (70%), millipedes (50%), and centipedes (50%) as the main soil macro-fauna found in cocoa-based agroforestry systems. With respect to the contribution of soil macro-fauna to soil fertility improvement, cocoa farmers perceived that earth worms, ants, and termites (62, 47.7, 57.6, and 52.4, respectively) contributed highly to soil fertility improvement in cocoa-based agroforestry systems while crickets, woodlice, snails and slugs were perceived by cocoa farmers (61.7, 60, 45.6, and 58.9%, respectively) to contribute only averagely to soil fertility improvement in cocoa-based agroforestry systems. Through correlation and regression analysis, it was found that the main soil macro-fauna contributing significantly (p<0.05), to soil fertility improvement in cocoa-based agroforestry systems were earth worms, ants, termites, beetles, snails and slugs. On the basis of these findings, it is recommended that appropriate measures be taken to ensure the sustainability of soil macro-fauna in cocoa-based agroforestry systems owing to the great role they play role in soil fertility improvement.