Fig. 4. Annualized soil organic C differences related to experiments duration from experiments conducted in the Argentine Pampa Region. (a) SOC calculated for fixed depth, (b) SOC calculated on an equivalent mass basis. SOC NT – PT (solid circles) denotes SOC differences between no-till and plow till. SOC NT – RT (open circles) denotes SOC differences between no-till and reduced till (chisel and disk till).