Question

Given below are two statements:
Statement (I): The use of Rhizobium culture in cereals is most promising among different kinds of biofertilizers fixing atmospheric nitrogen.
Statement (II): The performance of biofertilizers is highly unpredictable due to their biological nature and susceptibility to biotic and abiotic stresses.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are correct.
• B. Both Statement (I) and Statement (II) are incorrect.
• C. Statement (I) is correct but Statement (II) is incorrect.
• D. Statement (I) is incorrect but Statement (II) is correct.

Hint:

Remember the host specificity:
- Rhizobium is exclusively for legumes.
- Azotobacter and Azospirillum are used for cereals and non-legume crops.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Biofertilizers are preparations containing living cells of latent or active strains of microorganisms that facilitate plant growth by increasing nutrient availability.

Step 2: Detailed Explanation:
Let us evaluate both statements:

• Statement (I): Rhizobium forms a highly specific symbiotic relationship with leguminous crops (like pulses, groundnut, soybean) by forming root nodules. It does not establish productive symbiotic associations with non-legumes like cereals (wheat, rice, maize). For cereal crops, other biofertilizers such as Azotobacter, Azospirillum, or blue-green algae are used. Thus, Statement (I) is incorrect.

• Statement (II): Biofertilizers contain living cells of micro-organisms whose survival, colonization, and functional activity are highly dependent on native soil microflora, soil moisture, pH, temperature, and organic matter. This biological dependency makes their field performance highly variable under different stress conditions. Thus, Statement (II) is correct.

Step 3: Final Answer
Statement (I) is incorrect, but Statement (II) is correct.