Abstract:In order to explore soil aggregates stability of sedimentation zone in front of hedgerows in purple soil area, taking purple soil under these zones as the research object, this article set 10° blank control (T1), 10° Leucaena leucocephala hedgerows (T2), 10° Vetiveria zizanioides hedgerows (T3), 15° blank control (T4) and 15° Vetiveria zizanioides hedgerows (T5). The composition of air-dried aggregates and water-stable aggregates was measured by the Savinov method. Using a series of evaluation indicators (save probability, stability index, percentage of aggregate destruction, mean weight diameter, geometric mean diameter, mean weight soil specific area, bias coefficient, peak convex coefficient), this article analyzed soil aggregates stability characteristics of sedimentation zone in front of hedgerows on different slopes and different hedgerow types. The results indicated that: (1) The number of water-stable aggregates in T2 and T3 was significantly larger than that of T1, and the T5 was slightly larger than that of T4. There was a pre-process that hedgerows could produce effect in soil conservation of steep slopes. (2) In the same slope position, the stability index of soil aggregates in sedimentation zone in front of hedgerows was: T3>T2>T1, T5>T4, while PAD showed T1>T2>T3, T4>T5. Compared with blank control, hedgerows showed that it can enhance effect on anti-erodibility of soil aggregates. (3) At the same slope position, the MWD, GMD and CS of air-dried aggregates and water-stable aggregates showed T3>T2>T1, T5>T4, whereas the MWSSA showed opposite trend. Vetiveria zizanioides hedgerows were more beneficial to enhance the stability of aggregates than that of Leucaena leucocephala hedgerows. (4) PAD could well describe the stability of aggregates before and after wet and sieve treatment. The CS of air-dried aggregates could be used as the best index to evaluate the mechanical stability of aggregates. The MWD and GMD of water-stable aggregates could better express the water stability of the aggregates.