Question

If farmers wanted to increase the amount of naturally occurring nitrate in their farm fields so that they would have to apply less of it as fertilizer, what would be the best thing for them to do?

Answer 1

I would say that the answer is C, since variations in crop restore the nitrogen in the soil from certain bacteria growing on the root of beans, including legumes.

Answer 2

Alternate their normal crops with crops of legumes.

Step-by-step explanation:

Certain plants, known as nitrogen fixing plants, can draw nitrogen from the air and store it in their roots. They do so through a bacteria called rhizobium. This bacteria infects legume plants in particular, and converts nitrogen gas to store it in the roots of these plants. In this way, a farmer could increase the amount of naturally occurring nitrate in his farm field.