Turnips are cheap- and a good plot for a late summer planting - on a spot that you want to put to corn or soybeans the next year.
In our program - the deer have ample food in the summer/fall and ignore the turnips (and brassicas) until Jan/Feb. Right now, our deer are pawing through 2ft of snow to get to turnips. They eat everything green - and nibble into the bulb - but usually leave them 3/4 whole. Its winter food for us, same as soilman, and a good field transition from Summer sod, to easily planted beans or corn in the Spring.
For us, turnips is a plot that serves a purpose - but its not a primary plot -
January Pictures - This plot was completely ignored October, November & December.
FH