The increasing population in Ontario is straining the agricultural lands in the South. To alleviate some of this pressure, conversion of boreal forest in the Great Clay Belt of Northern Ontario has been proposed. Such conversions have the potential for deleterious impacts to soils and their ability to sequester atmospheric carbon and provide crucial ecosystem services. The purpose of this research is to assess the impact that land use conversion has on several soil properties and organic matter dynamics along a chrono sequence of up to >30-years. Results from deforestation and reforestation chrono sequences show promise for the sustainable implementation of pastoral lands and their rejuvenation should degradation occur. Interesting trends were also highlighted regarding the storage of carbon in the soil’s composite organic matter fractions. The information provided by this study highlight the potential of expanding agricultural activities to Northern Ontario while maintaining sustainability.