In gardening guides you see them talking about testing the acidity of your soil so that your plants will do well. So you, then, want to run out and buy a kit to test your soil. Right? Then you have to learn how to use it. Make this simple test for pennies. Take a cup of soil from the area you want to plant in and mix it with two cups of water. Stir in a 1/4 cup of baking soda. If there is an eruption of effervescence you have a very acid soil. If there is very little effervescing your soil has little acidity. You can now treat your soil to raise or lower your soil to the proper level.