Question

Nitrogen fertilization of rice fields can be low in the presence of one of the following types of organisms. Which one?

• A. Water fern
• B. Green algae
• C. Brown algae
• D. Mosses

Answer 1

The correct option is A

Water fern

The correct option is A.
Explanation of the correct option:

1. The Azolla plant is an aquatic fern that usually grows with the rice crop.
2. It spreads very quickly and decays in the hot summer which results in the enrichment of soil with nitrogen.

Explanation of the incorrect option:

Option B:
Green algae are found both in the sea and freshwater. They cover most of the surfaces on land that receive sunlight and stay damp.

Option C:
Brown algae are commonly found in cool seawater and are dominant on rocky shores.

Option D:
Mosses are dense green clumps or mats found in damp and shady locations.

Final answer:
Nitrogen fertilization of rice fields can be low in the presence of aquatic fern.