Surface horizons of Rhodic Paleudults in the Tennessee Valley region of Alabama contain large amounts of clay (<2 μm) composed of quartz, kaolinite, hydroxy-interlayered vermiculite, and iron oxides. Similar clay mineralogical suites have been shown to be dispersive, which can lead to the degradation of soil physical properties. Furthermore, some studies have suggested mineralogical enrichment in dispersed colloids versusin situsoil, which can effect transport of sediment-attached pollutants. The historical utilization of conventional tillage practices without cover crops has degraded soil quality in this region; however, reduced tillage systems are becoming common. We evaluated clay dispersibility and mineralogical partitioning for fine, kaolinitic, thermic Rhodic Paleudults cropped to cotton (Gossypium hirsutumL.) in: (i) a no-till system without a cover crop (NT), (ii) a no-till system with a rye (Secale cerealeL.) cover crop (NTC), (iii) a no-till system with a rye cover crop and fall paratilling (NTCP), and (iv) a conventional tillage system (disking and chisel plowing in the fall followed by disking in spring) (CT). Water dispersible clay (WDC), extractable Fe, and soil organic carbon (SOC) were evaluated for surface (0–1 cm) samples. Particle size distribution (PSD) and clay mineralogy ofin situsoil, runoff sediment, and WDC were also determined. Data indicated Fe oxides play a more significant role in clay aggregation than soil organic matter (SOM) in these high Fe systems. Higher clay amounts were recovered with dithionite extractable Fe removed (Fed) compared with SOM removal (33 ± 3% vs 25 ± 4%). The WDC quantities were related to SOC (r2= 0.65) and negatively correlated with Fed(%) and water stable aggregates (%). Particle size and mineralogy of runoff sediment and WDC mineralogy were similar toin situsoil, suggesting models depicting erosion and sediment-attached pollutant transport can be developed usingin situsoil as a surrogate for sediment characterization in these soils.