Which one of the following crops would be preferred for sowing in order to enrich soil with nitrogen? A. Wheat B. Mustard C. Sunflower D. Gram

The correct answer is D. Gram.

Gram is a legume, which means that it has the ability to fix nitrogen from the atmosphere. This process is done by bacteria that live in nodules on the roots of legumes. The bacteria convert nitrogen gas into ammonia, which the plant can then use to make proteins and other compounds.

Wheat, mustard, and sunflower are not legumes. They do not have the ability to fix nitrogen from the atmosphere. Therefore, they would not be as effective at enriching soil with nitrogen as gram.

In addition to fixing nitrogen, gram is also a good source of protein and other nutrients. It is a staple food in many parts of the world.