Winter frosts can lift soil over the winter leaving the roots of young grass and legume plants explosed and vulnerable to winter kill. Rolling these fields in late winter will consolidate the soil around the roots and promote the health of the ley.

Rolling should be done when the crop is still relatively small so the plants are not damaged. It can be done when the soil is damp - but not too wet - and must take place when there is no imminent frost risk. Either a flat or Cambridge (ring) roller can be used to good effect.

Leys of all types can benefit from this type of rolling, including those containing grasses, clovers and vetches.

After an autumn or spring planting, some farmers also roll leys to press in stones and flatten soil mounds so that they are below the mower bar. This is to protect mower blades and conditioners and also, vitally, to prevent raised soil contaminating silage.