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Understanding the effects of long-term traditional and alternative agricultural management practice effects on carbon (C) and nitrogen (N) cycling and storage within particulate organic matter (POM) and light fractions (LF) within various soil aggregate-size classes can be illuminated by isotopic 13 C/ 12 C (δ 13 C) and 15 N/ 14 N (δ 15 N) differences. The objective of this study was to evaluate the effects of residue level, residue burning, tillage, and irrigation on δ 13 C and δ 15 N values of the bulksoil, macro-(>250 μm) and micro-aggregate-(53-250 μm), coarse-(>250 μm), and fine-(53-250 μm) POM, and coarse-and fine-LF in the top 10 cm following 13 yr of consistent management in a wheat (Triticum aestivum L.)-soybean [Glycine max (L.) Merr.] double-crop system on a silt-loam soil in eastern Arkansas. Various treatment combinations affected (p < .05) δ 13 C values within the bulk-soil and fine-POM, as well as δ 15 N values within the bulk-soil, macro-aggregate, coarse-LF, and fine-LF fractions. Averaged across all other field treatments, macro-aggregate δ 15 N was greater (p < .01) in the no-tillage (NT)-low-(3.23%) compared with NT-high-residue (3.05%) and CT-high-and low-residue combination, which did not differ and averaged 3.11%, indicating that more labile residue can be achieved in the NT-highresidue treatment combination. Results showed significant variations in aggregateassociated δ 13 C and δ 15 N, as affected by long-term residue and water management practices that would otherwise not have been evident from simple, bulk-soil analysis or a short-term field study.