In my food plot im going to make its really clayey. should i do a ph test? and how do you do a ph test?

Get soil samples from several areas in the plot and call your county extension agent, they probably will do it for you. If not you can go online to a company who specializes in seeds for deer plots and several of them have test kits.

You could do the pH test yourself with a soil pH meter. You can get one at any hardware/feed store or BassPro or a store like that. Do some research about the seed you're going to plant to see what pH value is preferrable for what seed you're going to plant. About 1,000 lbs. of lime is needed per acre to bring the pH up one point on the scale. You might want to add some sod/seed starter soil or planting soil and some sand to the soil to give the plants a better chance to have good root structure. Clay gets really hard and hinders the ability of the plants to have extensive root structures which are crucial for the plants to extract nutrients from the soil. With a little hard work and a couple of dollars, you can get great results.

so if i just call the dnr in my area, theyll do it for me?

Nope. It's not that easy. You just have to collect a soil sample yourself and send it to the extension office. They'll do all of the analysis for you. You're probably out of luck if you wanted it done to help you plant for this summer, but they should have it done before it's time to plant for the fall. Here's a link to help you find your local extension office. http://www.csrees.usda.gov/Extension/
I think you just have to get a little bag from them, collect your sample, and send it in. It might take a month or so to get it done. Hope this helps. Good luck to you.

I agree and make sure you take soil from 3 or 4 different spots so you can get an average and don't put anything on the soil at all before you take it up. It's only like ten bucks to get it tested at the extension office or you can call local farm supply co-ops since they do all the field testing for farmers and get it back in a week. You can buy pelletized gypsum too that will help break down the clay and give you better soil to plant on but like I say you will wanna wait until you get the soil samples pulled.