Thats kinda of a strange problem, I grow oats every year and most of the time they do great. The only time I have had problems is with very low rainfall. I havent planted any of mine this year because of low rainfall, planning on planting mine the 2nd weekend in sept. I could understand the deer eating it down, but that shouldnt have turned it brown. Do you have someone close by who doesnt like you? Sounds like someone might have sprayed it with roundup for you.