Abstract Soil properties were characterised under Chromolaena odorata (the dominant natural fallow in southern Cameroon) on the Typic Kandiudult and Typic Kandiudox using nutrient concentrations, particulate organic matter (POM) status and C mineralization in vitro. POM (53–4000 μm) status was assessed by weight and C and N contents while C mineralization was determined after 4 weeks of soil incubation in laboratory at 28 °C. POM weight was higher in the Typic Kandiudox. C content in coarse POM (2000–4000 μm) and N content in medium POM (2000–250 μm) were higher in the Typic Kandiudult (30.8% and 1.9%) than in the Typic Kandiudox (28.6% and 1.2% respectively). Soil C mineralization was higher in the Typic Kanduidult than in the Typic Kanduidox.