UPSC Static Quiz – Environment : 30 April 2026

Solution: C

• Soil is a non-renewable resource that is increasingly under threat.
• Statement 1 is correct; in states like Punjab and Haryana, excessive canal irrigation without proper drainage causes the water table to rise. As water evaporates from the surface, it leaves behind dissolved salts, leading to salinization, which renders the soil unproductive.
• Statement 2 is incorrect; intensive tillage actually depletes soil organic carbon (SOC). By breaking up soil aggregates and exposing organic matter to oxygen, tillage accelerates decomposition and the release of CO2, reducing the soil’s capacity to act as a carbon sink.

Statement 3 is correct; tree roots act as a biological anchor for the soil. Their removal, combined with the loss of the protective leaf litter layer, exposes the soil to wind and water erosion, which can reduce soil depth by up to 50% in hilly regions. Transitioning to Zero Tillage and Agroforestry is essential to restore soil health and sequester carbon.

Solution: A

• Row I is correctly matched; nutrient runoff from farms into water bodies causes cultural eutrophication, leading to hypoxic “dead zones” where aquatic life cannot survive.
• Row II is correctly matched; many older synthetic pesticides are lipophilic and resistant to degradation. They accumulate in the fat tissues of organisms and their concentration increases as they move up the trophic levels (e.g., from insects to birds to humans).
• Row III is correctly matched; as discussed, the absence of oxygen in waterlogged paddy fields triggers methanogens to produce methane, which has a warming potential roughly 28 times that of carbon dioxide over a century.

Solution: B

IPM is an ecological approach to crop protection.

Statement 1 is correct; the goal is suppression, not eradication, to maintain ecological balance.

Statement 2 is correct; it represents the “multi-faceted strategy” that integrates various tactics.

Statement 3 is incorrect; while traps are part of IPM, they are classified as mechanical or physical control methods, not biological control. Biological control specifically refers to the use of natural enemies like predators (e.g., ladybugs), parasitoids, or pathogens (e.g., Bt) to suppress pests.

Solution: B

• ZBNF is a movement aimed at reducing farmer debt and restoring soil health.
• Statement 1 is correct; it draws inspiration from natural ecological processes to eliminate external input costs.
• Statement 2 is correct; the model relies on poly-cropping. The income generated from short-duration “intercrops” is intended to cover any costs associated with the long-duration “main crop,” effectively making the production cost for the main crop “zero”.
• Statement 3 is incorrect; Subhash Palekar specifically opposes the use of vermicompost (which he claims uses non-indigenous earthworms) and instead recommends reviving local deep-soil earthworms through organic matter and “Jivamrita”.
• Furthermore, ZBNF discourages intensive irrigation, promoting the concept of “Whapasa” (soil moisture/aeration balance) to reduce water consumption.

Solution: D

• The “color” of hydrogen is determined by the source of energy and the carbon management involved in its production.
• Statement 1 is correct as Green Hydrogen uses renewable electricity (solar/wind) to split water into H2 and O2 through electrolysis, resulting in zero emissions.
• Statement 2 is correct because Blue Hydrogen is derived from fossil fuels (primarily natural gas through steam methane reforming), but it incorporates Carbon Capture and Storage (CCS) to prevent the CO2 from entering the atmosphere.
• Statement 3 is correct as Brown (or Black) Hydrogen is produced from the gasification of coal (or lignite), and it is the most carbon-intensive form because the emissions are typically released unabated.
• The National Green Hydrogen Mission specifically aims to shift India’s current dependence from brown/grey hydrogen (produced from fossil fuels) to green hydrogen to help achieve Net Zero 2070.