Smallholder agriculture land use systems have profoundly influenced soil organic carbon stock. The study was conducted in Abuja, the Federal Capital Territory (FCT) of Nigeria, to determine the effect of smallholder agriculture land use on soil organic carbon stock. Cashew plantation, maize farm and maize-cowpea mixed cropping farm were studied. Cashew plantation significantly had the highest soil organic carbon stock (24.84±0.225 t ha-1) followed by maize-cowpea mixed cropping farm (21.98±0.283 t ha-1) and maize farm recorded the lowest (13.87±0.089 t ha-1). The significant difference in soil carbon stock among these smallholder agriculture land use types may be due to the differences in overall soil management practice, cropping system and their outdated agronomic practices. Also, the fact is, these smallholder farmers prefer supplying the crop stovers to livestock rather than leaving them in the field to decay and consequently increase the soil organic carbon stock and soil productivity. However, maintenance of high soil carbon stock and soil productivity under intensive cultivation and changing climate could be possible only through the use of innovative technologies in farming.