Hello RG,
Now that Tabdog, the Aristotle of Arkansas has weighed in with his wisdom, I'll put in my 2c...
Seems like you have an excellent spot. Don't let anyone tell you different.
(You'll learn!)
Since the property is controlled by you, you've got no worries, and can do this at your leisure without concern for competition.
Don't bother to plant a test garden... you already got one!
Now here's my thoughts on a detector...
The smallest investment you can make, on the purchase of a quality machine, with a lifetime warranty, is the Tesoro Compadre.
Brand new, cost is $151.
If you are able to find a few interesting old relics, you could recover that much money, fairly easily, if you chose to sell them.
You will learn in a short time if relic hunting is really something you're interested in, AND, if there are possibilities of GOOD finds.
I see your chances ARE pretty good!
You can tell the nice fellow at work you are buying a Compadre to search it yourself, and watch his reaction...
Read all the favorable posts about the Compadre here on the forum, if you haven't already... It's highly thought of. A real sleeper!
My guess is you shall more than pay for it with nice relics and keep it forever with warm feelings, even when you eventually get a more expensive machine just to see if they perform better. Some do! At four or five times the money, and more! Many won't.
I should caution you of a couple things...
Until you learn more, don't clean anything you find with anything but water and maybe a bit of soap.
If you discover a coin, resist the temptation to rub the muck off it with your thumb, to see what it might be... Scratches put on it in that instant COULD ruin it's value, and we're talking about possibly hundreds of dollars!
If you discover any ordnance, let it be! Just STOP.
Post a message here on the forum and ask advice before even removing it from the ground.
None of us want to read about a mishap in the newspaper like the most recent one.
Wow! An old city dump?
There's more than a few fellows here who have searched many years for such a place.
Friends are priceless.
Be cautious and selective who you chose!
HH