herbicide

I am new to food plot management. I planted about 1// acre of clover last spring and it can in pretty sparse after following the fertilizer requirements for my plot and liberally spreading of clover. It was over run by Japanese Siltgrass this spring and so I mowed it for the first time and...

Sorry if there is already a similar post...I looked before posting but couldn't find one. Short version...what is the best/cheapest spray to kill all grass and weeds (leaving basically just dirt) for my food plot? P.S. I am unable to do a controlled burn.