1. Alfalfa

2. Amaranth

3. Chickpea

4. Clover

5. Purslane (Kulfa)

6. Spinach

Select the correct answer using the code given below:

(a) 1, 3 and 4 only

(b) 1, 3, 5 and 6 only

(c) 2, 4, 5 and 6 only

(d) 1, 2, 4, 5 and 6

10. Ans: a

Explanation:

Nitrogen fixation is a process that implies the transformation of the relatively non-reactive atmospheric N2 into its more reactive compounds (nitrates, nitrites, or ammonia).

The list of nitrogen-fixing plants for agriculture is quite versatile and includes:

1. Beans: fava (aka faba), alfalfa, green beans, runner beans, field beans, sweet beans, peanuts (aka groundnuts), soybeans, cream beans, black-eyed beans, or purple-hulled beans, lupins, lentils, cowpeas, chickpeas.
2. Vetches: hairy, American, wood, tufted.
3. Clovers: white, red, crimson, Silver River.

Hence, option a is correct.

Read: Previous Year UPSC Environment Questions (PYQs) With Explanation 2022