I have been dumping corn for around 10 years now and have never had a problem with corn plants growing up. Occassionaly the corn will rot on the ground though and you have to remove it but that is as bad as it gets. Looks like a great plan to me. Really, any plan is usually a good plan b/c it means that you will be improving things at least somewhat. I am not sure that the deer will care about switchgrass versus weeds, but it will help any quail or pheasant around plus rabbit, etc. Sounds like you are going to be doing a lot of enjoyable work this year. Best of luck!