Valorizing staple crop residues through mushroom production to improve food security in eastern Democratic Republic of Congo

Food security is challenged by low agricultural productivity in eastern Democratic Republic of Congo (DRC). This study aimed at contributing to food security of rural households in South-Kivu by valorizing residues of four staple crops, including cassava, maize, banana, and common bean. The study was conducted in two steps: (1) monitoring of farmers' fields throughout the cropping season to record weight of crop residues and yields, and (2) assessment of the potential of staple crop residues for mushroom (Pleurotus ostreatus) production. Results showed that the four major staple crops had low yields and low biomass productivity in the study area. Residues of these staple crops were mainly used by farmers as fodder, compost, incinerated, or left on the farm for nutrient recycling. In addition to target plant parts (tubers or grains), cassava and common bean leaves were harvested for household consumption (as vegetables) or traded at local markets for income generation. Substrates based on maize residues, combined with cow manure as additive, gave the highest yield of P. ostreatus (2.4 kg kg−1) compared to residues of other three staple crops. In contrast, substrates from banana leaves had consistently lowest yields, regardless of used additives (1.1 and 1.2 kg kg−1 with soybean flour and cow manure, respectively). This study showed that valorizing residues of staple crops could help improve households’ food security and income in rural areas of eastern DRC. This practice should, therefore, be encouraged and scaled across the country and other parts of the world facing food shortages and poverty.