you can test the run-off or make a slurry, and test it. Take a soil sample from a couple inches down, and mix it with distilled water. Shake the crap out of it, and wait for the soil to settle to the bottom. (I have a small test tube for this) after the soil has settled you can test the water. This is not 100% accurate, but will give you a general idea of where your soil pH is.