Roots modify the properties of soil in their immediate vicinity. Individually, fine roots (<1 mm in diameter) have little effect on soil properties, but this is offset by the fact that they make up most of a plant’s total root length. Roots growing near the soil surface may influence soil detachment. Slope conditions are also known to influence root growth. A field study conducted in a small watershed of Northern Lao People’s Democratic Republic (PDR) during the 2005 rainy season assessed putative interactions between shallow fine roots, slope angle and soil detachment under three land uses: shifting cultivation, fallow and tree plantations. We used auger sampling and root windows to measure root length density and 1-m2 microplots to monitor water infiltration, runoff and soil detachment. Annual crops and plantation trees did not explore shallow soil horizons as thoroughly as fallow species. Under both crop and fallow, RLD in the top 5 cm decreased as slope increased. This pattern could be linked, either as a cause or a consequence, to slope-related changes in infiltration regimes. In contrast, no clear relation between fine root development and soil detachment was found.