Conservation agriculture (CA) has been suggested as a means of makingintensification of agriculture sustainable. The purpose of this study was tounderstand and quantify long-term individual and combined effects of keyconservation practices on soil physical properties and topsoil C content.Field experiments were conducted in 11- to 12-yr-old experiments on twoDanish sandy loams at Foulum and Flakkebjerg. Three crop rotations/residuemanagement treatments were compared and tillage was included as a splitplotfactor. The tillage systems were moldboard plowing to a depth of 20 cm(MP), direct drilling (D) and harrowing to a depth of 8 to 10 cm (H). Soilsampling and in-field measurements were performed in autumn 2013 andspring 2014. In the field, soil structure was visually evaluated and penetrationresistance (PR) measured. Soil C, wet stability (clay dispersion and wetaggregate stability), and soil strength were determined in the laboratory. TheMP soil had a uniform soil organic carbon (SOC) content in the 0- to 20-cmdepth of topsoil, whereas H and D resulted in SOC accumulation near thesoil surface. Plowing resulted in the best visually assessed topsoil structureand had the lowest PR. However, H and D in combination with residueretention gave the best structural stability. Residue retention alleviatednegative effects of reduced tillage on PR and improved wet stability in theMP treatment at the Foulum site. Clay and SOC correlated well with soilphysical parameters, confirming their important role in soil structureformation and stabilization. Our study showed benefits of combining key CAelements, although longer-term studies are most likely needed to reveal thefull potential.