Five-year field experiments with barley-canola rotation were conducted at Star City and Birch Hills in Saskatchewan to determine the effects of tillage (ZT – zero tillage, CT – conventional tillage) and crop residue burning (B – residue burnt and NB – residue not burnt) on soil total organic C (TOC), total organic N (TON), light fraction organic matter (LFOM), light fraction organic C (LFOC), light fraction organic N (LFON) and dry aggregation. After five crop seasons, mass of TOC and TON in 0-15 cm soil tended to be greater, whereas mass of LFOM, LFOC and LFON was significantly greater in NB than B treatments at both sites. Mass of TOC, TON, LFOM, LFOC and LFON in soil was greater under ZT than CT, in both B and NB treatments, and was highest in ZT-NB and lowest in CT-B treatment. The ZT-NB treatment usually had lowest proportion (22.6%) of fine aggregates (< 0.83 mm diameter) and greatest proportion (47.1%) of large aggregates (> 6.4 mm diameter) compared to highest (34.9%) and lowest proportion (35.6%) of these aggregates, respectively, in CT-B treatment. This indicated reduced potential for wind erosion when tillage was omitted (ZT) and crop residues were returned to the soil (NB). In conclusion, returning crop residues along with ZT improved soil organic C and N, and aggregation, while burning in combination with CT resulted in the deterioration of these soil properties.