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: Concept Definition:
Eutrophication describes the enrichment of a water body with nutrients, triggering excessive growth of algae and other aquatic flora (algal blooms). The inquiry seeks the primary nutrients driving this phenomenon.

Step 3: Comprehensive Elaboration:
Algal growth in most aquatic environments is constrained by the availability of specific essential nutrients. The two most critical limiting nutrients are nitrogen (N) and phosphorus (P). Agricultural runoff containing fertilizers high in nitrates (a nitrogen compound) and phosphates (a phosphorus compound) introduces these nutrients into lakes and rivers, alleviating the limitation. This rapid nutrient influx provokes a surge in algal proliferation. The subsequent decomposition of this abundant algal biomass by bacteria depletes dissolved oxygen, resulting in hypoxia or anoxia (diminished or absent oxygen levels), which can be fatal to fish and other aquatic life.

Step 4: Conclusive Determination:
Nitrogen and Phosphorus are the principal nutrients implicated in eutrophication.