Based on a long-term field experiment,the effects of conventional tillage(T),no-tillage without wheat stubble mulching(NT) and no-tillage with wheat stubble mulching(NTS) on soil aggregates size distribution and stability of winter-wheat field were studied.The results showed that NTS significantly increased the soil bulk density of plough layer and the organic matter of top layer.Compared with the background values in 2004,macro-aggregates significantly increased in NTS,was 14.88% and 6.40% higher than that...