I found this interesting tidbit on another website, and thought it would be worth posting here. (I remember...my dad used to do this sometimes) This soil test is for the truly adventurous. But it is also very inexpensive and will give you a rough estimate of the pH level of your soil. Gather two samples of soil and place them in separate glass jars. You should fill the jars about 1/3 full of soil. Next add water to both to create mud. Next, add a tablespoon of baking soda to one jar and a tablespoon of vinegar to the other. If the jar with the vinegar begins to fizz, then you have acidic soil. If the jar with the baking soda begins to fizz, then you have alkaline soil. If neither jar begins to fizz, then you have neutral soil.