Agriculture & crops

Answer: (b) Neem coating slows down the rate of dissolution of urea in the soil

A thin coat of neem oil makes urea release its nitrogen into the soil slowly, so more of it is taken up by the crop and less is lost; this raises nitrogen use efficiency and cuts the quantity of urea needed. Neem coating also makes subsidised urea hard to divert to industrial uses. The Centre made neem coating compulsory for all domestic urea from 1 September 2015 and for imported urea from 1 December 2015.

• ✓ (b) Neem coating slows the release of nitrogen from urea to the soil, which the Department of Fertilizers credits for higher nitrogen use efficiency and lower urea consumption.
• ✗ (a) Neem compounds act by slowing the conversion and release of nitrogen already supplied by urea; they are not promoted for boosting biological nitrogen fixation by soil microbes.
• ✗ (c) Slower release can reduce nitrogen losses, but no coating stops nitrous oxide emission from fields altogether; 'not at all released' overstates the effect.
• ✗ (d) Neem-coated urea is a fertiliser only; it contains no weedicide.

Remember · Neem-coated urea (100% mandatory from 2015): slow nitrogen release, higher nitrogen use efficiency, lower urea use, and no diversion of subsidised urea to industry.

Question and answer: UPSC's official GS Paper I (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (b) 2 only

FAO's GIAHS programme exists to recognise and protect living traditional farming systems, together with their landscapes, agro-biodiversity and local knowledge, through 'dynamic conservation'. It does not aim to modernise these systems for higher output, and it has nothing to do with granting Geographical Indication tags.

• ✗ 1. Replacing traditional practice with modern technology to maximise yields runs against the programme's purpose, which is to conserve heritage farming systems while keeping them viable.
• ✓ 2. FAO states the overall goal as identifying and safeguarding these heritage systems with their landscapes, agricultural biodiversity and knowledge systems.
• ✗ 3. Geographical Indications are granted under national law (in India, the Geographical Indications of Goods Act, 1999), not by FAO; a GIAHS listing confers no GI status.

Remember · GIAHS (FAO, launched 2002): dynamic conservation of traditional agricultural systems, their landscapes, agro-biodiversity and knowledge; it is recognition, not modernisation or GI tagging.

Question and answer: UPSC's official GS Paper I (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (c) 1 and 3 only

Drip irrigation reduces weeds and soil erosion, but it does not reduce soil salinity; salt tends to build up at the edge of the wetted zone. Water goes only to the plant's root zone, so the rest of the field stays dry and there is little surface flow to wash soil away.

• ✓ 1. Water is placed at the plants, not spread over the whole field, so the soil between rows stays dry and fewer weeds grow. FAO lists reduced weed control among the advantages of drip irrigation, and ICAR notes that it reduces weed pressure.
• ✗ 2. Drip does not cut soil salinity: FAO notes that the dissolved salts accumulate at the periphery of the wetted soil mass, and salt accumulation at the wetting front is listed as a demerit of drip irrigation. (Drip does let farmers use saline water, and it spares leaves from salt burn, which is a different point.)
• ✓ 3. Water is delivered slowly through emitters with no flooding or heavy surface flow, so soil structure is disturbed least. A field study in a peer-reviewed journal measured suspended soil loss of 5.26 t per ha under furrow irrigation, 2.53 t per ha under subsurface drip at 120% of crop evapotranspiration, and none under deficit subsurface drip.

Remember · Drip irrigation: saves water, fertiliser and labour, keeps weeds down and spares soil structure; drawbacks are clogged emitters and salt build-up at the wetting front.

Question and answer: UPSC's official GS Paper I (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink · Report an error