'System of Rice Intensification' of cultivation, in which alternate wetting and drying of rice field

Q: What is UPSC Prelims?

UPSC Prelims is a competitive examination conducted in India. This question is from the 2022 UPSC Prelims Environment & Ecology paper.

Q: How can I prepare for UPSC Prelims Environment & Ecology?

To prepare for UPSC Prelims Environment & Ecology, practice previous year questions (PYQs), understand concepts thoroughly, and solve mock tests regularly. This 2022 question covers Biogeochemical Cycles – Carbon, Nitrogen, Water & Phosphorus topic.

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This UPSC Prelims 2022 Environment & Ecology question has a easy difficulty level and is marked as an important question.

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Question

'System of Rice Intensification' of cultivation, in which alternate wetting and drying of rice fields is practised, results in:Reduced seed requirementReduced methane productionReduced electricity consumptionSelect the correct answer using the code given below:

Accepted Answer

Correct Answer: D — 1, 2 and 3Step-by-step Solution:The System of Rice Intensification (SRI) was developed in Madagascar in the 1980s and promotes sustainable rice cultivation through several changes in agronomic practices — including transplanting younger seedlings, wider spacing, alternate wetting and drying (AWD) of fields, and organic soil enrichment.Statement 1 — Reduced seed requirement: This is correct. Traditional rice cultivation requires approximately 5 kg of seed per acre for nursery preparation. Under SRI, only about 2 kg of seed per acre is required — a reduction of 60%. This is because SRI uses very young seedlings (8–12 days old, with only 2 leaves) planted singly at wider spacings, allowing each plant to develop into a robust multi-tillered plant. ✓Statement 2 — Reduced methane production: This is correct. Traditional paddy cultivation involves continuous flooding — creating anaerobic soil conditions ideal for methane-producing bacteria. SRI uses Alternate Wetting and Drying (AWD), where fields are periodically dried between waterings. The aerobic periods disrupt methane production by methanogenic bacteria. Studies have confirmed that SRI with AWD can significantly reduce methane emissions from rice paddies. ✓Statement 3 — Reduced electricity consumption: This is correct. SRI saves approximately 15–20% of irrigation water compared to traditional flooded rice cultivation. Less water pumped = less energy consumed for irrigation. Studies in Vietnam demonstrated that applying SRI methods can save around 23% of total energy inputs. Reduced pumping of water translates directly into lower electricity consumption, especially important in areas with electric pumps for irrigation. ✓Why other options are incorrect:Options A, B, and C: Incorrect because all three statements are correct.Key Concept: SRI principles: Transplant young seedlings (8–12 days old) singly; wider spacing (25×25 cm); alternate wetting and drying (not continuous flooding); use of organic matter/compost; mechanical weeding to aerate soil. Benefits: 25–50% yield increase; 15–20% water saving; 60% seed reduction; reduced methane emissions; lower energy use. Challenges: Initially more labour-intensive; requires precise water management; cultural resistance among farmers used to traditional methods.

'System of Rice Intensification' of cultivation, in which alternate wetting and drying of rice fields is practised, results in:Reduced seed requirementReduced methane productionReduced electricity consumptionSelect the correct answer using the code given below:

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'System of Rice Intensification' of cultivation, in which alternate wetting and drying of rice fields is practised, results in:Reduced seed requirementReduced methane productionReduced electricity consumptionSelect the correct answer using the code given below:

Master UPSC Prelims with Our Test Series

More Questions from Biogeochemical Cycles – Carbon, Nitrogen, Water & Phosphorus

Frequently Asked Questions