UPPSC 2025 Prelims GS Paper-I · Question 142 of 150

Correct — B, Both 1 and 2. Before anything else, look at where the other options sit on this booklet: 'Only 2' is at (a) and 'Only 1' is at (d), the exact reverse of the layout most candidates have drilled. The correct answer here happens to be the 'both' option, which is safe from that trap, but the reflex of scanning for 'Only 1' at (a) is what wrecks the neighbouring questions on this paper, so break it now. Statement 1 is correct. The Delhi government has run the spray programme on the city's non-basmati paddy fields since 2020, and the farmer pays nothing: the administration procures the decomposer and also bears the cost of preparing and spraying it, so both the input and the labour are free at the point of use. Its stated purpose is exactly what the statement says — to rot the paddy stubble left standing after harvest into manure in the field, so that the farmer has no reason to set fire to it. Statement 2 is also correct. The product is the Pusa decomposer, developed by scientists at the Indian Agricultural Research Institute at Pusa in New Delhi, and it is not a single organism but a consortium of fungal strains supplied as capsules. Those fungi secrete the enzymes that break down the cellulose and lignin in paddy straw, which is the tough, silica-rich residue that ordinarily rots too slowly to be ploughed back in the fortnight or so a farmer has before wheat sowing. The capsules are fermented with jaggery and gram flour into a liquid culture over several days and then sprayed on the standing stubble. Both statements are therefore correct — option (b).

• (a)Only 2 — This accepts the microbiology and rejects the delivery, but the delivery is the whole point of the Delhi programme. The decomposer is supplied to farmers free of cost, and the government also pays for the spraying itself rather than merely handing over capsules — a design choice made precisely because a paid input would not be taken up in the narrow window between paddy harvest and wheat sowing. Note where this option sits, too: on a conventional paper 'Only 2' would be at (b), and on this booklet it has been moved to (a).
• (c)Neither 1 nor 2 — Both statements are in fact correct, so this option fails twice over. It is sometimes marked by a candidate who has read the sceptical commentary on the programme — that adoption has been patchy, or that the decomposer needs longer to work than the gap between harvest and sowing allows. Those are arguments about how well the scheme has performed, and they are worth knowing. They are not arguments that the solution is charged for, or that it is not made from fungi, which is all the two statements assert.
• (d)Only 1 — This accepts that the spray is free but denies that it is made from fungi, which is the one thing about the Pusa decomposer that is beyond dispute — it is a microbial consortium of fungal strains, isolated and formulated at the Indian Agricultural Research Institute, whose enzymes digest paddy straw. Candidates sometimes reject the second statement because they assume any farm input in a capsule must be a chemical, or because they are thinking of bacterial biofertilisers such as Rhizobium and Azotobacter. This option also carries the paper's structural trap: 'Only 1' has been moved from its usual position at (a) to (d) here.

In the rice-wheat belt of Punjab, Haryana and western Uttar Pradesh, the combine harvester leaves a thick mat of paddy stubble in the field, and the farmer has only two to three weeks before wheat must be sown. Paddy straw is high in silica and low in feed value, so it neither rots quickly nor sells easily, and burning it is the cheapest way to clear the field. The smoke from those fires, trapped under the winter inversion, is a major seasonal contributor to the severe air pollution of Delhi and the National Capital Region. The bio-decomposer is one attempt at an in-situ answer: a consortium of fungi developed at the Indian Agricultural Research Institute (ICAR-IARI) at Pusa in New Delhi, sprayed on the standing stubble so that it decomposes into manure in the field instead of being set alight.

Two-statement scheme questions are usually decided by asking who runs the scheme, who pays, and what the technology actually is. Here all three are unambiguous: the Delhi government runs the spray programme, the government pays for both the solution and the spraying, and the technology is a fungal consortium from ICAR-IARI. Be careful with the arithmetic of praise and criticism, though, because the two are often confused in the examination hall. The programme's real-world impact has been argued over — critics point to limited uptake, to the time the fungi need against a tight sowing window, and to the fact that Delhi itself has very little paddy area compared with Punjab and Haryana — but none of that touches either statement in this question. Learn the design of a scheme separately from the debate about its results. Finally, the option layout. On this paper 'Only 2' sits at (a) and 'Only 1' at (d), a straight inversion of the conventional arrangement. The answer here is the 'both' option and so is unaffected, but the habit of reading the printed option text rather than trusting the position is the single most valuable thing a candidate can carry through this booklet.

• The Pusa decomposer was developed at the Indian Agricultural Research Institute (ICAR-IARI), Pusa, New Delhi, and is supplied as capsules that are fermented with jaggery and gram flour into a liquid spray
• It is a consortium of fungal strains, not a single organism — the fungi secrete enzymes that break down the cellulose and lignin of paddy straw; sources differ on the exact number of strains, so the safe formulation is 'a mix of several fungi', which is what the question says
• The Delhi government has sprayed it on the city's non-basmati paddy fields since 2020, providing both the solution and the spraying free of cost to farmers
• The purpose is in-situ management: the stubble is decomposed into manure in the field, with the government and the institute reporting decomposition within roughly a fortnight to three weeks and improvements in soil organic carbon and nitrogen
• The problem it targets is the two-to-three week gap between the paddy harvest and wheat sowing in the rice-wheat belt, which is why speed rather than cost is the binding constraint on any alternative to burning
• Mechanical alternatives to burning include the Happy Seeder and the Super Straw Management System, which sow wheat directly through the residue; ex-situ uses include fodder, biomass power, compressed biogas and co-firing in thermal plants
• The regulatory architecture for the region includes the Commission for Air Quality Management in the National Capital Region and Adjoining Areas, given statutory form by an Act of 2021, and the Graded Response Action Plan for winter pollution episodes

• The option layout on this booklet — 'Only 2' at (a) and 'Only 1' at (d), the reverse of the conventional arrangement
• Confusing criticism of the scheme's results with a defect in the statements. Debates about uptake and effectiveness do not make the spray paid-for, nor make it non-fungal
• Assuming the decomposer is a chemical or a bacterial biofertiliser. It is a fungal consortium developed at ICAR-IARI
• Asserting a precise number of fungal strains. Published descriptions vary, so say 'a consortium of fungal strains' rather than committing to a figure

UPPSC likes the two-statement format for government schemes — who runs it, who pays, what it does — and has a long-standing appetite for air-pollution questions, from the chemistry of smog in 2019 to biological indicators of pollution in 2021. UPSC approaches the same territory obliquely, asking about decomposer organisms in a food chain, about crop residue retention as a conservation-agriculture practice, or about the components of a national clean-air effort, rather than naming a state scheme.

• practice — not a real PYQ

  The 'Pusa decomposer', used to convert paddy stubble into manure in the field, was developed by

  • (a)the Indian Institute of Technology, Delhi
  • (b)the Indian Agricultural Research Institute (ICAR-IARI), New Delhi
  • (c)the Central Pollution Control Board
  • (d)the National Institute of Plant Health Management, Hyderabad

  Answer(b) the Indian Agricultural Research Institute (ICAR-IARI), New Delhi — the institute at Pusa developed the fungal consortium, supplied as capsules that are fermented into a liquid spray.

• practice — not a real PYQ

  Consider the following statements with reference to crop residue burning in north-western India : 1. Paddy straw is difficult to use as cattle fodder mainly because of its high silica content. 2. The Happy Seeder allows wheat to be sown directly into a field that still carries paddy residue. Which of the statements given above is/are correct ?

  • (a)1 only
  • (b)2 only
  • (c)Both 1 and 2
  • (d)Neither 1 nor 2

  Answer(c) Both 1 and 2 — the high silica content of paddy straw limits its value as fodder, which is one reason farmers burn it, and the Happy Seeder is a tractor-mounted machine that cuts through the residue and sows wheat without any need to clear the field.