Traditionally scuffles were used after ploughing for breaking the land down further. Depending how 'strong' the land was it was ploughed, scuffled, sometimes rolled with Cambridge rolls (if very cloddy) and sometimes harrowed as well. Mostly replaced these days now by the power harrow. Sometimes scuffles are used just to break up the top few inches of land rather than ploughing. They are a halfway house btween a plough and a harrow really.