The present study investigated the effect of different combinations of tillage and residue management on carbon sequestration in different sized soil aggregates and also on crop yield after 4 years of continuous rice–wheat cropping system (RWCS) on a sandy loam soil of north India. Compared to conservation tillage (CT), combined with RWCS and residues retention resulted in a higher proportion of macro-aggregates. In the 0–5cm layer, plots raised beds transplanted rice (W Bed-TPR) combined with zero tillage on raised beds in wheat (with residue) (W Bed ZT-DSW+ 100%SR) had the greatest proportion of large stable macro-aggregates(12.9%) and highest mean weighted diameter (MWD) (1.80mm). 50% surface residue retention caused a significant increment of 15.65% in total aggregates in surface soil (0–5cm) and 7.53% in sub-surface soil (5–10cm).In surface soil, the maximum (13.5%) and minimum (4.3%) proportion of total aggregated carbon was retained with>2-<0.053mm size fractions, respectively. W Bed-TPR; W Bed ZT-DSW+100%SR treatment (T9) had the highest capability to hold the organic carbon in surface(10.73g kg-1 soil aggregates).A considerable proportion of the total SOC was found to be captured by the macro-aggregates (>2–0.25mm) under both surface (35.5%) and sub-surface layers (28.1%) leaving rest amount in micro-aggregates and <0.53mm sized particles. From the study, it has been proved that W Bed-TPR WBedZT-DSW+100% SR treatment (T9) has the highest potential to secure sustainable yield increment (8.4%) and good soil health by improving soil aggregation (26.5%) and SOC sequestration (36.7%) with respect to the conventional tillage puddle transplanted rice (T10) after four years of continuous RWCS in light textured soil of North India.

Keywords: Conservation tillage, Carbon sequestration, Residue management, Aggregate stability