Due to acid rain, the pH of soil decreases, meaning the soil becomes more acidic. Acid rain, which contains sulfuric and nitric acids formed from atmospheric pollutants like sulfur dioxide and nitrogen oxides, lowers soil pH below normal levels (below 5.6 is considered acidic rain) and increases soil acidity
. This increased acidity leads to several effects on soil chemistry and biology:
- Nutrient depletion: Acid rain causes essential nutrients such as calcium and magnesium to leach out from the soil, reducing their availability for plants
- Increased solubility of toxic elements: Aluminum and other potentially harmful elements become more soluble in acidic conditions, which can damage plant roots and hinder nutrient uptake
- Disruption of microbial activity: Acidic soils can suppress beneficial soil microorganisms responsible for nutrient cycling, further reducing soil fertility
- Changes in soil physical properties: Acid rain can alter soil particle structure, reduce soil strength, and affect water retention and permeability
Overall, acid rain causes soil acidification by lowering soil pH, which negatively affects soil nutrient levels, microbial health, and plant growth
. The severity of these effects depends on the soil's buffering capacity; soils rich in calcium carbonate can neutralize some acidity, while others are more vulnerable
. In summary, acid rain decreases soil pH, making the soil more acidic, which leads to nutrient leaching, toxic metal mobilization, impaired microbial functions, and altered soil physical properties, ultimately harming plant health and ecosystem stability.
