Shrub-derived mulching enhances sorghum performance and weed suppression in Sahelian cereal-based agroforestry systems

Abstract

Cereals are central to food security and livelihoods in the West African Sahel. However, their productivity is limited by poor soil fertility, erratic rainfall, and increasing weed pressure. Given the limited availability of mineral fertilizers and the declining efficacy of herbicides, there is an urgent need for sustainable strategies that can enhance crop productivity and soil resilience. This study evaluated the potential of shrub-pruning mulches to improve sorghum yields, suppress weeds and buffer the cereal systems against rainfall variability. A total of thirteen treatments replicated four times were implemented using a randomized complete block design. Field experiments assessed prunings from three shrub species (Gliricidia sepium, Guiera senegalensis and Piliostigma reticulatum), applied with or without mineral fertilizer over three consecutive years (2021–2023) in Katibougou, Mali. Two controls, with the locally recommended fertilisation dosage and without any fertilisation were included. Mulched treatments produced significantly higher sorghum grain yield than the unamended control and yields comparable to the mineral-fertilized control. Among mulched treatments, sorghum amended with G. sepium mulch produced the highest grain yields consistently across years. Mulched treatments showed a significantly lower weed pressure than the control without mulch. These results demonstrate the potential of shrub-pruning mulches to enhance the productivity of sorghum in Sahelian cereal-based systems. Future research should refine combinations of multiple species of mulch and quantify the optimal application rates of biomass.