I own a trailer house and the land lord is making new rules not in the rental agreement book.?

Okay I'm stuck untill I can move my trailer house of this property.The problem that now exists is that the owner of the park say's i cant store my own lawn mower trailer on my property and I cant own an atv. I pay my rent EARLY and am a respectful, yet these so called rules are not stated in the rental book. What can I legally do to stop this harassment.