Yield of soybean and red gram could be increased by employing the following as biofertilizer
(I) Glomus (II) Azospirillum
(III) Cyanobacteria (IV) Rhizobium

Options

A. I only
B. I and II
C. I, II and IV
D. I & IV

Answer

To determine which biofertilizers can increase the yield of soybean and red gram, we need to analyze each option provided:

1. **Understanding the Plants**:
- Soybean and red gram belong to the family Fabaceae (also known as Leguminosae), which are leguminous plants. These plants have a symbiotic relationship with nitrogen-fixing bacteria.

2. **Identifying the Biofertilizers**:
- **(I) Glomus**: This is a genus of fungi known as arbuscular mycorrhizal fungi. They help in nutrient uptake, particularly phosphorus, and can enhance plant growth but do not directly fix nitrogen.
- **(II) Azospirillum**: This is a free-living nitrogen-fixing bacterium found in the soil. It does not form nodules but can fix atmospheric nitrogen, which benefits the plants.
- **(III) Cyanobacteria**: These are photosynthetic bacteria that can fix nitrogen but are typically found in aquatic environments. They are not commonly associated with soybean and red gram in terrestrial settings.
- **(IV) Rhizobium**: This is a well-known nitrogen-fixing bacterium that forms nodules on the roots of leguminous plants, including soybean and red gram, facilitating nitrogen fixation.

3. **Evaluating Each Option**:
- Glomus (I) helps with nutrient uptake but does not fix nitrogen.
- Azospirillum (II) can fix nitrogen and is beneficial for soybean and red gram.
- Cyanobacteria (III) are not suitable for these plants in a terrestrial environment.
- Rhizobium (IV) is essential for nitrogen fixation in leguminous plants.

4. **Conclusion**:
- The biofertilizers that can effectively increase the yield of soybean and red gram are Azospirillum and Rhizobium. Glomus also contributes to plant health but is not a nitrogen fixer. Therefore, the correct options are (II) Azospirillum and (IV) Rhizobium.

5. **Final Answer**:
- The yield of soybean and red gram could be increased by employing the following biofertilizers: (I) Glomus, (II) Azospirillum, and (IV) Rhizobium.