Research was conducted in two, long-term (23 yr) tillage experiments in the piedmont region of North Carolina to assess the impact of sharply contrasting tillage on compaction, micro- and macroporosity, aggregation, and organic matter. In one experiment, nine different tillage systems have been maintained in place since the inception of the study. These tillage systems vary in the intensity and timing of tillage and include: fall or spring moldboard plowing, fall or spring chisel plowing with or without disking, spring disking only, no-tillage, and no-tillage with shallow ripping. The other experiment examined the consequences of alternating, on an annual basis, conventional and no-tillage, and no-tillage with shallow cultivation compared to continuous conventional and no-tillage systems. Corn was planted in both studies the first six years and thereafter maintained in a corn/soybean rotation until 2005. Results have shown that differences in infiltration, evaporation, and runoff associated with differences in surface residue cover have influenced productivity in the systems more than bulk density, micro- and macroporosity, and C accumulation.