Acidic soils have a pH level below 6.0, indicating a higher concentration of hydrogen ions. These soils can affect plant growth by limiting nutrient availability, particularly essential elements like calcium, magnesium, and phosphorus. Many crops prefer neutral to slightly acidic conditions for optimal growth. Common causes of soil acidity include rainfall, which leaches away basic nutrients, and the presence of organic matter that decomposes to release acids. Acidic soils are often found in regions with high rainfall or in areas with certain types of parent rock, such as granite or sandstone.