Question

Which of the following would be one way a farmer could increase the amount of available nitrogen in his fields without adding a synthetic fertilizer?

Grow a legume crop to support the development of root nodules.
Flush the field with water.
Burn unwanted plants on the field.
Add nitrogen gas to the fields.

Answer 1

The best way that a farmer could increase the amount of nitrogen in his fields without adding synthetic fertilizer is to grow a legume crop to support the development of root nodules. This is because legumes have a symbiotic relationship with bacteria found in the soil. 

Answer 2

The correct answer is:

Grow a legume crop to support the development of root nodule

The best way that a farmer could increase the amount of nitrogen in his fields without adding synthetic fertilizer is to grow a legume crop to support the development of root nodules. This is because legumes have a symbiotic relationship with bacteria found in the soil.

Step-by-step explanation:

Legumes use nitrogen fixing bacteria, specifically symbiotic rhizobia bacteria, within their root nodules to counter the limitation.The plant root cells convert sugar into organic acids which then supply to the rhizobia in exchange, hence a symbiotic relationship between rhizobia and the legumes.