Fields with heaving 1 inch or less are likely to have unbroken taproots and may be salvageable for at least the current year. They will likely green up later than normal. Do not go over the field with a roller or cultipacker in early spring to push the crowns back into the soil. This will likely to do more damage than good. Natural settling should occur during the year and if plants are reseated stands should survive until next year.
Stands entering the winter with elevated crowns are likely to suffer above average winterkill.
Heaving in future years can be minimized by having good internal and surface drainage. Tiling may reduce heaving problems depending on the depth of the tile. Residue on the surface over winter will reduce heaving because it insulates the soil and reduces the amount of freezing and thawing. This means that fields not harvested last fall will have less heaving that those with fall growth removed. Planting a grass with the alfalfa has not been shown to reduce heaving of the alfalfa in the stand.