Question

Which of the following usually have less dependency on nitrogenous fertilizer for its commercial cultivation?

• A. Wheat
• B. Chickpea
• C. Rice
• D. Maize

Hint:

Remember: Legumes (Beans, Peas, Pulses) = Nitrogen Fixers. Cereals (Rice, Wheat, Maize) = Nitrogen Consumers. This is the logic behind traditional crop rotation.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Biological Nitrogen Fixation (BNF) is the process where atmospheric dinitrogen (\(N_2\)) is converted into ammonia by the enzyme nitrogenase. Leguminous plants can form a symbiotic relationship with nitrogen-fixing bacteria (like Rhizobium).

Step 2: Detailed Explanation:
Cereal crops like Wheat, Rice, and Maize are non-legumes. They are incapable of fixing atmospheric nitrogen and are highly dependent on the application of synthetic nitrogenous fertilizers (like urea) to achieve high yields. These crops are "nitrogen-hungry."
Chickpea (Cicer arietinum), on the other hand, is a pulse or legume. It develops specialized root nodules containing Mesorhizobium ciceri. These bacteria fix atmospheric nitrogen and provide it directly to the plant in exchange for carbohydrates. Because of this natural internal source, chickpea crops require significantly less (or sometimes zero) nitrogenous fertilizer from external sources compared to cereals. This makes legumes essential for crop rotation to restore soil fertility.

Step 3: Final Answer:
Chickpea, being a legume, fixes its own nitrogen and thus depends less on chemical fertilizers. Option 2 is correct.