6.5 to 7.5—neutral.over 7.5—alkaline.less than 6.5—acidic, and soils with pH less than 5.5 are considered strongly acidic.
How can you tell if soil is acidic or basic?
- Place 2 tablespoons of soil in a bowl and add ½ cup vinegar. If the mixture fizzes, you have alkaline soil.
- Place 2 tablespoons of soil in a bowl and moisten it with distilled water. Add ½ cup baking soda. If the mixture fizzes, you have acidic soil.
Which soils are basic?
Alkali, or Alkaline, soils are clay soils with high pH (greater than 8.5), a poor soil structure and a low infiltration capacity. Often they have a hard calcareous layer at 0.5 to 1 metre depth.
