I'm looking for a strong perennial seed to seed down a 1 acre field I just bush hogged. The field was previously all poison ivy, weeds, etc and other nasty stuff. Im getting the top layer scraped off tomorrow with a bobcat, and want to seed it down with something that will be prolific and crowd out the nasty stuff.

Since it is a field, it will be mowed maybe twice a year, so im not looking for lawn grasses, more something taller that wont look too bad not being cut. I can put down a lot of seed, but it need to be able to survive without being watered during the year, or any maintenance really since it is just a field.

Any recommendations on something that will take in a hostile environment, be hardy, and spread fast?

The soil environment is very sandy, and im located in zone 7