The place where I board my horses fertilized the pasture my horses usually go in about 3 weeks ago. The owner thinks it's safe now to put them back on it. I don't think it is but I am not knowledgable in that either so i thought I would ask here. We were in a drought and it has rained some the past couple of days but not a whole lot other than that. He wants to move them on Sunday. Is it safe?