Different tillage systems affect labile organic matter and carbon management in purple paddy soil. No-tillage and ridge culture increase organic matter in the surface soil but decrease labile organic matter in deeper layers. Rotation of paddy and upland decreases organic matter in all layers but only labile organic matter in the surface layer. No-tillage and ridge culture increase all labile organic matter fractions in the surface soil and oxidative organic matter in deeper layers. Rotation of paddy and upland increase oxidative organic matter in all layers but decrease some fractions. Carbon management index increases with no-tillage and ridge culture in all layers but decreases in the surface layer with rotation of paddy and upland. Agricultural practices have a significant impact on soil organic matter, labile organic matter, and carbon management index.