Pulse crop which does not fix atmospheric nitrogen is

Gram
Pea
Raj ma
Moong

The correct answer is (c) Rajma.

Rajma is a pulse crop that does not fix atmospheric nitrogen. This means that it does not have the ability to convert nitrogen gas from the air into a form that plants can use. Other pulse crops, such as gram, pea, and moong, do have this ability.

Nitrogen fixation is an important process in agriculture because it helps to increase the amount of nitrogen available for plants. Nitrogen is a key nutrient for plant growth, and it is essential for the production of proteins, nucleic acids, and other important compounds.

There are several ways to fix nitrogen. One way is through the use of legumes, which are plants that have a symbiotic relationship with bacteria that can fix nitrogen. Another way is through the use of chemical fertilizers, which are often made from ammonia or urea.

Rajma is a legume, but it does not have the ability to fix nitrogen. This means that it must rely on other sources of nitrogen, such as chemical fertilizers or manure. This can be a disadvantage, as it can make rajma more expensive to grow. However, it also means that rajma is not as likely to contribute to the problem of nitrogen pollution.

Nitrogen pollution is a serious problem in many parts of the world. It can cause eutrophication, which is the excessive growth of algae in water bodies. This can lead to the death of fish and other aquatic life. Nitrogen pollution can also contribute to climate change.

By choosing to grow pulse crops that do not fix nitrogen, farmers can help to reduce the problem of nitrogen pollution. This is a good thing for the environment, and it can also save farmers money.