Previous Year Question

Excessive and imbalanced use of fertilizers can affect soil, water and air—all three.

Soil Pollution: Continuous excessive use of Nitrogenous fertilizers can disturb the soil nutrient balance. It may result in excess of some nutrients and deficiency of others. Long-term imbalanced fertilizer application can also adversely affect soil health and crop productivity.

Water Pollution: Nitrates and Phosphates that are not taken up by plants may reach groundwater through leaching or rivers, lakes and ponds through runoff during rainfall or irrigation. Excess nutrients can cause excessive growth of algae and aquatic plants, known as Eutrophication. Their decomposition may reduce Dissolved Oxygen and adversely affect aquatic organisms.

Air Pollution: A portion of Nitrogen from fertilizers may volatilize into the atmosphere as Ammonia (NH₃). Soil microbial processes can also release Nitrous Oxide (N₂O), which is a powerful Greenhouse Gas.

Long-term fertilizer experiments in India have also indicated that continuous use of Nitrogenous fertilizers alone can adversely affect soil health and productivity, while excessive use can increase the possibility of nitrate contamination in groundwater.