The analysis of water-stable aggregates was carried out using the wet sieving method (Elliott, 1986). In brief, 100 g air-dried soil on the top of 2mm sieve was submerged in deionized water for 5 min at room temperature to promote disintegration of the sam-ple (Kemper et al., 1985). Water-stable aggregates were separated by moving the sieve up and down for 50 times within 2 min. The dried weight of the soil remaining on the 2mm sieve (>2 mm aggre-gates) was large macro-aggregates. Soil passing through the 2mm sieve was transferred into a 0.25 mm sieve to determine the small macro-aggregates (0.25–2 mm) using the same sieving procedure. Finally with a 0.053 mm sieve and the same sieving procedure, the fractions of micro-aggregates (0.053–0.25 mm) and silt-and-clay micro-aggregates (