What practice can help in replenishing the soil with nitrogen?a)Continuous cultivation of the same cropb)Using synthetic fertilizers exclusivelyc)Growing legumes in rotationd)Leaving the field uncultivatedCorrect answer is option 'C'. Can you explain this answer?

Question

Answer

One of the biological methods to replenish nitrogen is the process of crop rotation
In crop rotation farmers grow cereals for one season and legumes for another.
Legumes fix nitrogen from the atmosphere in the soil with the help of a bacteria called rhizobium.
This process is an effective way to fix nitrogen in soil
So option C is the correct answer

Answer

Continuous plantation of crops makes the soil poor in nutrients. This result in lack of required nutrients such as nitrogen phosphorus and potassium further resulting in a decline in crop output. Since these nutrients are required by plants for their proper growth and functioning, farmers need to replenish the soil by fertilizers and manure.

Answer

Growing legumes in rotation
Legumes have a unique ability to fix atmospheric nitrogen into the soil through a symbiotic relationship with nitrogen-fixing bacteria in their root nodules. This process helps replenish the soil with nitrogen, making it available for other plants to use. Here's how growing legumes in rotation can help in replenishing the soil with nitrogen:

Nitrogen fixation:
- Legumes such as peas, beans, and clover have the ability to fix atmospheric nitrogen into the soil.
- This nitrogen fixation process is carried out by specialized bacteria called rhizobia, which form a symbiotic relationship with the legume plants.

Enhanced soil fertility:
- The nitrogen fixed by legumes enriches the soil, making it more fertile for other crops to grow.
- This reduces the reliance on synthetic fertilizers, which can have negative environmental impacts.

Diversified crop rotation:
- Rotating legumes with other crops helps break pest and disease cycles, improving overall soil health.
- Different crops have different nutrient needs, and rotating legumes helps maintain a balance of nutrients in the soil.

Sustainable farming practices:
- Growing legumes in rotation is a sustainable farming practice that helps improve soil quality over time.
- It reduces the need for chemical inputs and promotes a more environmentally friendly approach to agriculture.
In conclusion, growing legumes in rotation is an effective practice for replenishing the soil with nitrogen, improving soil fertility, and promoting sustainable farming practices.

Answer

Growing Legumes in Rotation for Soil Nitrogen Replenishment :
Answer: (c) Growing legumes in rotation

Explanation:
Nitrogen Fixation by Legumes: Legumes (e.g., peas, beans, clover, alfalfa) have a symbiotic relationship with specific bacteria called Rhizobium. These bacteria reside in nodules on the roots of legume plants. Rhizobium bacteria have the unique ability to convert atmospheric nitrogen gas into ammonia, a form of nitrogen that plants can readily use. This process is known as biological nitrogen fixation.
Benefits of Crop Rotation with Legumes: When legumes are grown, they enrich the soil with fixed nitrogen, making it available for subsequent crops. Incorporating legumes into a crop rotation cycle naturally replenishes soil nitrogen, reducing the need for synthetic nitrogen fertilizers. This practice improves soil fertility and structure, benefiting overall agricultural sustainability.

Why other options are incorrect:

(a) Continuous cultivation of the same crop: This practice depletes specific nutrients from the soil, including nitrogen, as the same crop consistently draws the same nutrients without replenishment.

(b) Using synthetic fertilizers exclusively: While synthetic fertilizers provide nitrogen, relying on them exclusively can lead to environmental issues like water pollution and can neglect the benefits of natural soil enrichment.

(d) Leaving the field uncultivated: While leaving a field fallow can help in some aspects of soil recovery, it doesn't actively replenish nitrogen in the same efficient and targeted way as growing legumes. Nitrogen fixation by free-living bacteria might occur, but it's generally less significant than that by symbiotic Rhizobium in legumes.

Answer

C

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