If you DO plant any spruce there, I'd plant them on the north and west sides of the field to block the worst of the winter winds and make your field more sheltered. Then whatever you plant in the field might be a little more attractive in cold weather - whether it's NWSG, crabapples, rye, clover - or a combination of those things. If I was doing that field, I'd plant the spruce on north & west edges, then the NWSG next to the spruces ( bedding in the sun ), then a few crabapples in the center surrounded by rye/clover. Having the spruce blocking wind for any deer that wanted to bed in the switch might be a good match. Rye/clover in spring & summer would be good for does & fawns for milk production - and switch to lay in.