What I do, because like you there are lots of corn and beans close is concentrate on the times of year those food sources aren't around. Late fall through early spring.
I've found that even the clovers are second choice for deer anytime soybeans are green, so I don't plant soys, there are plenty in the ag fields. I have clover which gets a good chance to get established because it doesn't get heavy use during the summer. Once the beans turn yellow the deer just hammer the clover, next in line is Brassicas like Rape and turnips, once they get some good frosts they start getting hit which is about the time the clover fields stop producing and start running out of forage. with a good rape/turnip crop the deer will have a good protien source (along with the soybeans left in the ag fields) deep into winter.
The clover/Alfalfa also tends to green up pretty quickly in the spring also filling the gap before most forage plants and ag plantings are available. (That's why deer are in mowed ditches so much right away in the spring, the fresh green growth)
I also plant some corn and leave it standing, giving a good food source if we happen to get a deep snow winter, and the location of the corn also keeps deer more concealed from passersby and harsh winter winds than they would be out in open fields.
In Iowa with all the grain available almost every winter I don't see calories as being the main issue for our deer but keeping protien levels up is a challenge, one that Brassicas and clover do nicely.