Agriculture & crops

Answer: (b) Rice

Paddy is grown in standing water, and bacteria decomposing organic matter in that oxygen-free soil release methane; the heavy nitrogen fertiliser used on rice, poorly taken up by the plant, adds nitrous oxide. No other field crop contributes so much of both gases.

• ✓ (b) Flooded paddy fields are one of the largest human-made sources of methane (about a tenth of global methane emissions), and fertiliser applied to rice releases nitrous oxide as well.
• ✗ (d) Wheat is grown on drained, aerated soil, so it produces little methane; its fertiliser gives some nitrous oxide but not both gases on rice's scale.
• ✗ (c) Sugarcane is a heavy user of water and fertiliser, but it is not grown under continuous flooding, so it is not a major methane source.

Remember · Flooded rice = anaerobic soil = methane; nitrogen fertiliser = nitrous oxide. Alternate wetting and drying, SRI and direct-seeded rice cut paddy methane.

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) 1, 2 and 3

SRI transplants young seedlings singly at wide spacing and keeps the field moist rather than flooded. Fewer seedlings means far less seed; drying the soil between irrigations curbs methane-producing bacteria; and less irrigation means less pumping, so less electricity. All three follow.

• ✓ 1. Because one young seedling is planted per hill at wide spacing, SRI needs only a small fraction of the seed used in conventional transplanted rice.
• ✓ 2. Methane forms in oxygen-free, waterlogged soil. Alternate wetting and drying lets air into the soil, so methane emission falls; ICAR lists SRI among its methane-mitigation technologies for rice.
• ✓ 3. SRI uses roughly a fifth to a third less water than flooded paddy. Where fields are irrigated by electric pumps, less water pumped means lower electricity use.

Remember · SRI: young single seedlings, wide square spacing, moist (not flooded) soil, weeding that aerates the soil — less seed, less water, less methane, similar or higher yield.

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (c) 1 and 2

Statements 1 and 2 are correct. Gucchi is the morel mushroom (genus Morchella), an edible fungus that grows wild in Himalayan forests such as those of Jammu & Kashmir and Himachal Pradesh. It is gathered from the forest; Indian research describes commercial cultivation as unsuccessful, and it is not farmed in north-eastern India.

• ✓ 1. Gucchi is a mushroom of the genus Morchella, which belongs to the fungal group Ascomycota (family Morchellaceae).
• ✓ 2. Gucchi grows on the ground in coniferous and mixed coniferous forests; in J&K and Himachal Pradesh it is collected from forests.
• ✗ 3. Gucchi is a wild-collected forest produce of the western Himalaya. ICAR's Mushroom Research journal notes that commercial cultivation of Morchella has not succeeded, and no source shows it being farmed in north-eastern India.

Remember · Gucchi = morel (Morchella), a wild Himalayan forest fungus from J&K and Himachal; hand-collected, not commercially farmed.

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (a) 1, 3 and 4 only

Only alfalfa, chickpea and clover fix nitrogen, because they are legumes. Legume roots carry nodules housing Rhizobium bacteria that turn nitrogen from the air into a form the plant can use. Amaranth, purslane and spinach are not legumes.

• ✓ 1. Alfalfa (lucerne) is a legume with its own Rhizobium partner, Rhizobium meliloti, in nodules on its roots.
• ✗ 2. Amaranth is a leafy green and grain crop, not a legume, so it has no Rhizobium root nodules.
• ✓ 3. Chickpea (gram) is a pulse and a legume crop, so its root nodules host nitrogen-fixing Rhizobium.
• ✓ 4. Clover is a legume; its roots form nodules with Rhizobium bacteria (the clover group).
• ✗ 5. Purslane (kulfa) is a leafy vegetable, not a legume, and does not fix nitrogen.
• ✗ 6. Spinach is a leafy vegetable, not a legume, and does not fix nitrogen.

Remember · Nitrogen fixers here are legumes: alfalfa, chickpea, clover. Rhizobium in root nodules does the fixing. Leafy greens such as spinach, amaranth and purslane are not legumes.

📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 5 (practise this chapter)

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) All four States

All four States grow tea. Kerala is one of the major tea-producing States, and Himachal Pradesh, Andhra Pradesh and Tripura are named among the other tea-producing States.

• ✓ 1. Andhra Pradesh is listed among the other tea-producing States.
• ✓ 2. Kerala is one of the major tea States, along with Assam, West Bengal (Darjeeling and Jalpaiguri) and Tamil Nadu.
• ✓ 3. Himachal Pradesh is also named among the tea-producing States.
• ✓ 4. Tripura is also named among the tea-producing States.

Remember · Major tea States: Assam, West Bengal, Tamil Nadu, Kerala. Also tea-growing: Himachal Pradesh, Uttarakhand, Meghalaya, Andhra Pradesh, Tripura.

📘 Read it in NCERT: Class 10 Contemporary India – II, Ch 4 (practise this chapter)

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error