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The complexities of nutrient cycling in grazing systems are influenced by management practices and soil characteristics. Grazed land accounts for approximately 71% of the total land area in the Great Barrier Reef (GBR) catchment and plays an important role in soil organic carbon storage and cycling. This study investigates the effect of vegetative ground cover and soil properties on the export of carbon fractions in runoff from grazed land in the Fitzroy and Burdekin Basins of the GBR catchment under simulated rainfall. Particulate organic carbon (POC) in runoff was driven by fluctuations in ground cover, where POC increased as ground cover declined. Soil type and texture, specifically clay fractionation, also contributed to the export of POC. In contrast, dissolved organic carbon (DOC) exports were independent of ground cover condition and instead linked with soil type; these being Dermosols, Sodosols, and Vertosols. Clay content less than 50% in the parent soil influenced DOC load, especially as an interaction with ground cover. The enrichment of DOC in runoff as clay increased and ground cover decreased suggests soil type, and associated texture properties, facilitate DOC mobilisation, and is enhanced by the disaggregation of soil particles as driven by the erosive action of raindrops and overland flow. Raindrop impact, runoff, and entrainment of sediment are the primary drivers for POC losses, particularly where ground cover is scarce. However, the presence of DOC in runoff is influenced by the inherent characteristics of the surface soil. Interestingly, the organic matter content of the surface soil had little influence on the carbon fractions in this study. These findings highlight the importance of vegetative management in reducing POC losses from hillslopes through runoff. The lateral movement of soil organic carbon because of depletion in POC and DOC is an important aspect of the terrestrial carbon budget.