Tap to Read ➤

Acid Rain Effects on Plants

Megha Tiwari
Precipitation of rainwater in an acidic form is known as acid rain. It has many harmful effects on the flora and fauna of our planet. Read the following story to gain more information about the same.
During rainfall, the water droplets dissolve certain chemicals, and carry small particles present in the air. The pH value of rainwater is neutral i.e., 7. In a clean atmosphere, the rain washes down certain particles like dust, CO2, and other chemicals present in it.
The presence of these compounds makes it a little acidic, and hence, the pH valve decrease below 7.

When the rain carries harmful chemicals like sulfur dioxide (SO2), nitrogen oxide (NO), hydrochloric acid, phosphoric acid, gases and effluents released by industries and vehicles, etc., its acidic nature increases.
This acid content reduces the pH value, which ranges between 5.6 to 3.5; and sometimes, it even goes below 2.


In the natural process of bacterial decomposition of sulfur and nitrogen oxides, increase and decrease of gas content, volcanic eruptions, and forest fires, the atmosphere naturally attains an equilibrium.
However, examples like industries, vehicles, burning of coal, power plants, and many other appliances have added loads of chemicals in the surroundings, and have caused a lot of environmental pollution.
Gases like sulfur dioxide and nitrogen oxide react with water vapors in the presence of sunlight, and form sulfuric acid and nitric acid mist. This reaction takes place in the following manner.

Chemistry of Acid Rain
SO2 + H2O = H2SO3 (Sulfurous acid)

SO2 + O3 (Ozone) = SO3 + O2; SO3 + H2O = H2SO4 (Sulfuric acid)

2NO + O2 = 2NO2; 2NO2 + H2O = HNO3 (Nitric acid) + HNO2 (Nitrous acid)
The sulfuric and nitric acid remain in a vapor state when the temperature is high. Condensation begins with the fall of temperature, and it mingles with the rain, fog, or snow; this increases its acidity.
Effects on Plants

Acid rain affects all kinds of vegetation including crops. It not only damages the plant roots, but also stops the plant growth above the surface.
The nutritive value of soil is reduced to a great extent. Acid rain effects can also be seen on the useful microorganisms, which convert the decayed organic matter into essential nutrients for the soil. The consequence is that the microbes are killed resulting in reducing the availability of nutrients for the soil and plants.
Also, the waxy layers of the leaves are damaged, which make the plant more susceptible to diseases. These ill effects make it difficult for the flora to survive under extreme climatic conditions like storms, drought spells, and heavy rainfall. It even effects the productivity and the germination process in plants.
The acidity of the rain also leads to soil erosion by dissolving the soil substrate, which is essential for the plant growth. Acid rain also damages the forests and other vegetation. It takes away the essential nutrients of the soil and releases aluminum, which disables trees from sucking water from the soil.
The direct impact of acid rain can be seen in the production of carrot, radish, broccoli, and beet roots. Their yield has reduced to a great extent because of this rain, which damages the protective layer of leaves, and interrupts the evaporation process, thereby not allowing the plant to breathe and survive.
It also stops the process of conversion of nutrients into energy for the plants, and hence, the yield is affected.

We all know that this is not the only end; acid rain has not even spared animals, aquatic life, and non-living beings.
Of course, how can we forget that we humans, are ourselves responsible for this problem. But nothing is impossible, as we can control and solve it by conserving energy, reducing the fossil fuel usage, decrease the release of chemicals and gasses in the environment, and cutting down the use of vehicles by walking, as much as possible.
It has now become essential to focus on undertaking solutions to protect our planet, and the forthcoming generations from the harmful effects of such phenomenon like acid rain.