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Vertical distribution of soil nematode communities under conventional tillage (CT),no-tillage (NT) and fallow field (FF) treatments in the Lower Reaches of the Liaohe River was investigated at six soil depths (0-5 cm,5-15 cm,15-30 cm,30-50 cm,50-75 cm and 75-100 cm).The results show that total nematode abundance gradually decreases with depth,and the highest number of total nematodes is observed at 0-5 cm depth under NT and FF treatments.The number of fungivores and plant parasites is significantly higher under FF and NT treatments than under CT treatment at the 0-5 cm depth.There is significant soil depth effect on the abundances of bacterivores and omni-vores-predators,which exhibits a similar trend to that of total nematodes; whereas,no significant tillage effect is found.Tillage effect on soil nematode communities can be reflected by values of relative tillage response of index V.Results of index V indicate that total nematodes,bacterivores,fungivores and plant parasites are mildly inhibited,and omni-vores-predators is moderately inhibited under CT treatment; while,under FF treatment total nematodes is mildly,and fungivores and plant parasites are moderately stimulated,respectively.