Thanks everyone for clearing that up for me. I planted soybean and corn last year after spraying, disking, harrowing and spraying again over a 4 week period. My plants grew beautifully for the first month and then the ragweed started and it took over both food plots. The land had laid fallow for 12 years after many years of being farmed for corn. I limed and fertilized the soil and everything in that regard is optimal, I just need to get these weeds taken care of this year so my plants yield food. I considered a controlled burn folowed by spraying repeatedly because the ragweed seed bed is so thick.