Soil organic carbon changes at the plot level in hillside systems

▶ Changes in soil organic carbon in hillside systems resulting from direct measurements over the period 2000-2004 were higher than those reported in the literature. ▶ There were differences in bulk density that occur naturally in successive measurements of this characteristic at different points of the same micro-site. ▶ It is important to standardize the removal of organic residues from the samples and to reduce the effects of spatial variability in measuring bulk density. ▶ RothC simulations did not reproduce the standard deviations of the measured SOC, however, reproduce SOC trends over a short period of assessment in the hillside systems studied.