Soil aggregation and aggregate-associated carbon affected by long-term crop residues incorporation in rice-wheat cropping system

Crop residue management is one of the options for enhancing soil organic carbon stabilization by improving soil aggregation in semi-tropical soil. We studied the influence of different levels of crop residue incorporation on aggregation and carbon stabilization in different soil aggregates after 23 years of continuous rice-wheat cropping system on sandy loam calcareous soil. Residue incorporation (100%) caused a significant increment of 49.09% in total water-stable aggregates (>0.25 mm) in surface soil. Carbon content in both macro- and micro aggregates was increased, but the increment was greater in macroaggregates (33.47%) than in microaggregates (16.23%). These results show that the long-term application of organics in combination with inorganic fertilizers helped in carbon accumulation in macroaggregates, thereby improving soil carbon status.