To do a quick test for excess alkalinity in the soil in your yard, place a handful of earth in a container and then pour in 1/2 cup white vinegar. If the soil fizzes or bubbles, it’s definitely alkaline. Similarly, to see if your soil has a high acidity, mix the earth with 1/2 cup water and 1/2 cup baking soda. This time, fizzing would indicate acid in the soil. To find the exact pH level of your soil, have it tested or pick up a simple, do-it-yourself kit or meter.