Soil aggregates and organic matter are considered to be important indicators of soil quality. The objective of this review study was to determine agricultural practices effects on the distribution of soil organic carbon (SOC) associated with aggregate-size fractions. Depth distribution of soil organic carbon (SOC) fractions depends on the efficiency of agro‐technical managements. The SOC stocks to 1-m depth were 172.3 Mg C ha⁻¹ under Forest and the lowest 89.3 Mg C ha⁻¹ under home-garden. No significant differences were noted in SOC within the silt + clay fraction (< 53 µm) beyond 60 cm depth under Forest and other shaded AFS. Moreover, depth, aggregate size and treatment had significant interaction effects on SOC stocks. The reports show that deep rooted, crop-based systems, have higher total soil C stocks and more C in the smallest (< 53 µm) soil fractions indicating the recalcitrant (longer-term storage) nature of C and implying consequent ecosystem benefit of reduced chances for soil C release back to the atmosphere. Moreover, the mean stratification ratio (SR) (i.e. a ratio of the concentrations of SOC in the soil surface to those in a deeper layer) of SOC for 0–5:5–10, 10–15, 15–20, 20–25 and 25–30 cm were found higher (> 2) under CA practices compared to intensive tillage-based conventional agricultural practice. The fractions of aggregates, aggregate SOC and aggregate EOC in grassland and forestland were generally higher than those in farmland. Furthermore, because conventional cultivation destroyed aggregates, the dominant aggregate size fractions were < 0.5 mm for farmland and > 0.5 mm for other land uses. Compared to the corresponding values in farmland, the mean weight diameter (MWD) in forestland and grassland increased by 808%–417%, and the stability ratio of water-stable aggregate (WSAR) increased by 920%–553%. Aggregate formation and its dominant size fraction were associated closely with its carbon fractions. SOC and EOC in farmland tended to be concentrated in smaller-sized aggregates, whereas SOC and EOC under other land uses tended to concentrate in larger-sized aggregates. The MBC concentration was the highest in minimum tillage (MT) system, at 15 to 30‐cm depth and PMC concentration was highest with MT at 45–60 cm. The highest DOC was at 0 to 15‐cm depth. The highest stratification ratio (SR) of PMC was under MT with at 0–15:15–30 and POC was under tine cultivator (TC) and moldboard plow (MP) at depths of 0–15:45–60 cm. The highest SR for DOC was under MP at 0–15:45–60 cm and HCl insoluble C was under MT at 0–15:45–60. In broad‐spectrum, labile organic fractions revealed differential sensitivity, and POC stocks are also a sensitive indicator to detect the short-management effects.

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