4.5 is tough - Even rye/wheat will have a tough time until ph is around 5.0-5.5. It will start OK, but will begin to yellow, and grow very spindly. It may not head out. When the ph is this low, plants are unable to use the nutrients in the soil, or that you apply, effectively, so fertilizing may not help until the Ph is corrected. 3 tons of lime/acre ought to get you up to a Ph good enough for rye, and maybe wheat. Buckwheat is an option too. Depending on your equipment, you may want to lime/fertilize and spring plant an annual, then do it again in the fall according to your test results. If the land has been fallow for some time, it could be important to build up the organic matter in your soil as well, and this helps for a first plot. I would wait a year for a clover/alfalfa plot. When you plant a perenial, you want it to last a few years, and you need to work the land a bit.