Question

Most of the agricultural runoff and chemical fertilizers used in farming end up in water bodies, which leads to eutrophication. The nutrients responsible for eutrophication are

• A. Nitrogen and Potassium
• B. Nitrogen and Phosphorus
• C. Phosphorus and Potassium
• D. Nitrogen and Boron

Hint:

Remember the acronym "N-P-K" for common fertilizers. While Potassium (K) is a key plant nutrient for land plants, it is Nitrogen (N) and Phosphorus (P) that are the main culprits for causing algal blooms and eutrophication in water bodies.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Eutrophication is the process of nutrient enrichment of a water body, which leads to excessive growth of algae and other aquatic plants (algal blooms). The question asks for the primary nutrients that cause this process.

Step 3: Detailed Explanation:
In most aquatic ecosystems, the growth of algae is limited by the availability of certain key nutrients. The two most important limiting nutrients are nitrogen (N) and phosphorus (P). When agricultural fertilizers, which are rich in nitrates (a form of nitrogen) and phosphates (a form of phosphorus), wash into lakes and rivers, they remove this limitation. This sudden influx of nutrients causes an explosive growth of algae. When this large amount of algae dies, its decomposition by bacteria consumes a large amount of dissolved oxygen in the water, leading to hypoxia or anoxia (low or no oxygen), which can kill fish and other aquatic organisms.

Step 4: Final Answer:
The primary nutrients responsible for eutrophication are Nitrogen and Phosphorus.