Question

Which one of the following is non-symbiotic bio fertilizer ?

• A. Rhizobium
• B. Azotobacter
• C. VAM
• D. Mycorrhiza

Answer 1

The Correct Option is B

To determine which one of the options provided is a non-symbiotic biofertilizer, we need to understand what non-symbiotic biofertilizers are and how they differ from symbiotic ones.

Non-symbiotic biofertilizers are free-living microorganisms that can fix nitrogen independently in the soil without a direct association with plants. In contrast, symbiotic biofertilizers require a partnership with plant roots to fix nitrogen.

Let's examine each option:

1. Rhizobium: Rhizobium is a symbiotic nitrogen-fixing bacterium. It forms nodules on the roots of leguminous plants, establishing a symbiotic relationship. Therefore, it is not a non-symbiotic biofertilizer.
2. Azotobacter: Azotobacter is a non-symbiotic nitrogen-fixing bacterium. It lives freely in soil and fixes nitrogen independently. Therefore, this option is a non-symbiotic biofertilizer.
3. VAM (Vesicular Arbuscular Mycorrhiza): VAM forms a mutualistic association with plant roots, helping with nutrient absorption. As such, it is a symbiotic biofertilizer.
4. Mycorrhiza: Generally, mycorrhizae develop symbiotic relationships with plants, aiding in water and nutrient absorption. Thus, they are symbiotic rather than non-symbiotic.

Based on the explanation above, the correct answer is Azotobacter, as it is capable of fixing nitrogen in the soil independently, without forming a symbiotic relationship with plants.