I'm bring my horses home soon :) the pasture is less then 2 acres so I will be feeding hay year around 24/7. There is "some" grass but of course that will be LONG gone by the time the horses get to it. I know there is some poison ivy in the pasture and I have looked lots of stuff up and everything I have read said most horses aren't effect by poison ivy. Also there is a lots of weeds around all the big trees. What can I use to kill the weeds and some of the poison ivy that's safe for the horses?