There were 17 Questions from Environment in 2020, of which

• 4 Questions were related to Climate Change
• 5 Questions were related to  Environmental Ecology
• 8 Questions were related to Bio-Diversity

The examiner covered areas such as the Basics of Biodiversity and distribution of biodiversity Basics of Environmental Ecology and Basics of Climate Change.

The level of the questions was moderate.

Questions were aimed  to test the basic understanding of the subject and map based knowledge. 

Previous Year UPSC Environment Questions (PYQs) With Explanation 2020

1. Which of the following are the reasons/factors for exposure to benzene pollution?

1. Automobile exhaust

2. Tobacco smoke

3. Wood burning

4. Using varnished wooden furniture

5. Using products made of polyurethane

Select the correct answer using the code given below :

(a) 1, 2 and 3 only

(b) 2 and 4 only

(c) 1, 3 and 4 only

(d) 1, 2, 3, 4 and 5

1. Ans: a

Explanation:

Benzene is a naturally occurring colourless liquid at room temperature (25 oC) and pressure (760 mm Hg). It has a characteristic aromatic odour, a relatively low boiling point (80.1oC) and high vapour pressure, which causes it to evaporate rapidly at room temperature. 

Benzene is released into the environment from both natural and man-made sources, although the later is the most significant source. 

Benzene in air exists predominantly in the vapour phase, with residence time varying between few hours to a few days depending on the environment and climate.

Degradation of benzene in air occurs mainly by reaction with hydroxyl, alkoxy and peroxy radicals. Toluene and Xylene are also present in most of the sources along with Benzene.

Benzene is a highly volatile aromatic compound usually component of mineral oil, petrol, coking plant and other products. Benzene is extensively utilized as industrial solvent in manufacturing of lacquers varnishes and paint. 

Benzene escapes from mineral oil and petrol during storage, transport, loading, unloading or during filling of petrol in motor vehicles. High concentration of Benzene are encountered in the vicinity of petrol filling stations, fuel tank storage sites, coking plant in the vicinity of refineries. 

Major Benzene emission originates from the motor vehicles . 

Sources of BTX Emission 

Transport : 

• (I) Vehicular Pollution : a) Vehicular exhaust b) Fuel filling station c) Fuel adulteration 
• (II) Railways 
• (III) Airways

 Industries 

• (I). Major industrial units (Refinery, Petrochemical etc ) 
• (II). Industrial estates 
• (III). Medium scale chemical industries 

Domestic Emissions 

• (I). Domestic combustion units 
• (II). Commercial combustion units

Emissions from combustion sources:

• Medical waste incinerators 
• Sewage sludge incinerators 
• Hazardous waste incinerators
• External combustion solid, liquid and gaseous fuels in stationary sources heat and power generation Stationery internal combustion 
• Secondary lead smelting Iron and Steel foundries 
• Portland cement production Hot-mix ashalt production 
• Open burning of biomass, scrap tires

About 50% of benzene is absorbed by inhalation & absorption of it via skin is limited. The high lipophilicity and low water solubility of benzene favour its distribution to fat-rich tissues. Benzene distributed by blood accumulates in fat-rich tissues like adipose tissue bone marrow & liver. 

Polyurethane is a plastic material, which exists in various forms. It can be tailored to be either rigid or flexible, and is the material of choice for a broad range of end-user applications such as:

• insulation of refrigerators and freezers
• building insulation
• cushioning for furniture
• mattresses
• car parts
• coatings
• adhesives
• rollers and tyres
• composite wood panels
• shoe soles
• sportswear

Hence, option a is correct.

2. With reference to Indian elephants, consider the following statements :

1. The leader of an elephant group is female.

2. The maximum gestation period can be 22 months.

3. An elephant can normally go on calving till the age of 40 years only.

4. Among the States in India, the highest elephant population is in Kerala.

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 and 4 only 

(c) 3 only

(d) 1, 3 and 4 only

2. Ans: a

Explanation:

Elephants are the largest land mammals on earth and have distinctly massive bodies, large ears, and long trunks. Two genetically different African species exist: the savanna elephant and the forest elephant, with a number of characteristics that differentiate them both. The African savanna elephant is the largest elephant species, while the Asian forest elephant and the African forest elephant are of a comparable, smaller size.

About Indian Elephant:

• Both female and male may live 55-60 years in wild and 70 years in captivity. The mean age of first calving ranged between 18 and 20 years and the females are known to breed up to an age of 55 years. The active reproductive phase in cow elephants is about 40 years. 
• Gestation usually lasts 18-22 months, the longest of any mammal, with a minimum of 17 months and maximum of 24 months. Normally one calf is born, though there are occasional records of twins and rarely triplets.  
• In Indian elephants, the family groups are the basic social units, and they vary in number from two to seven. These family groups are formed along matriarchal lines and are usually led and coordinated by an older cow. Several groups may join to form a herd, several herds a clan and several clans a population 
• In wild it is known to occupy a variety of vegetation types. In India, they are distributed from thorn scrub to dry and moist deciduous forests in the south, sal forests in the north, alluvial flood plains in West Bengal and Assam and evergreen forests in the northeast and south.
• Within Asia, although elephants occur in 13 countries, India holds more than 60% wild elephant populations of the globe. 
•  Karnataka with 6,399 elephants in its forest the highest population of elephants in the wild in India.

Hence, statements 1 and 2 are correct and 3 and 4 are incorrect.

3. Which of the following Protected Areas are located in the Cauvery basin ?

1. Nagarhole National Park

2. Papikonda National Park

3. Sathyamangalam Tiger Reserve

4. Wayanad Wildlife Sanctuary

Select the correct answer using the code given below:

(a) 1 and 2 only

(b) 3 and 4 only

(c) 1, 3 and 4 only

(d) 1, 2 , 3 and 4

3. Ans: c

Explanation:

The Cauvery River is one of the major rivers of the peninsular India. It rises at an elevation of 1,341 m at Talakaveri on the Brahmagiri range near Cherangala village of Kodagu district of Karnataka and drains into the Bay of Bengal.

Its important tributaries joining from left are the Harangi, the Hemavati, the Shimsha and the Arkavati whereas the Lakshmantirtha, the Kabbani, the Suvarnavati, the Bhavani, the Noyil and the Amaravati join from right.

• The Cauvery basin extends over states of Tamil Nadu, Karnataka, Kerala and Union Territory of Puducherry, 
• The river Kaveri makes the second biggest waterfall in India, known as Shivasamudram Falls

Sathyamangalam Tiger Reserve – Tamil nadu

• Sathyamangalam Tiger Reserve is at the the critical intersection of the Western and Eastern Ghats. It is bordered on the north by the state of Karnataka and on the west by the Nilgiris, which serves as a buffer for the Mudumalai Tiger Reserve. 
• Moyar river flows through this which is a perennial water source because the eastern portion of the sanctuary is in the rain shadow region of the Western Ghats and receives little rainfall. 
• The Nilgiri-Eastern Ghats Elephant Reserve includes this area as well. The Billigiri Ranganatha Swamy Temple Wildlife Sanctuary, Mudumalai National Park, and Bandipur National Park are four more protected sites connected genetically via SMTR. 
• Moyar River is a tributary of the Bhavani River which then is tributary of Cauvery river.

Nagarhole National Park – Karnataka 

• The national park is named after the ‘Nagarahole’ (meaning “snake stream” in Kannada), a tiny river that flows through the ecosystem before entering Kabini (tributary of Cauvery river.). 
• The reserve has incredible floral and faunal diversity. It is bounded on the southeastern side by the Bandipur Tiger Reserve and the southwest by the Wayanad Wildlife Sanctuary of Kerala. The Nilgiri Biosphere Reserve also protects the habitat.

 Papikonda National Park- Andhra pradesh

• The Papikonda National Park (PNP) is spread in the Eastern Ghats. Its on the banks of the river Godavari and cuts through the Papikonda hill range of Eastern Ghats with an elevation ranging from 150-1,350 m. 
• Varied and multifarious streams emanating from PNP make the Papikonda forest vegetation luxuriant. All these constitute to make the area into a typical ecological and geomorphological zone. 

Wayanad Wildlife Sanctuary- Kerala 

• Wayanad wildlife sanctuary is contiguous to the protected areas of Nagarhole and Bandipur of Karnataka on the north-east.Mudumalai of Tamilnadu on the south –east. Rich in biodiversity, the sanctuary is an integral part of the Nilgiri Biosphere Reserve,
• Bio diversity: The major tree species are Tectona grandis, Terminalia sp, Dalbergia latifolia, Anogeissus latifolia, Grewia tiliaefolia, Adina cordifolia Cirmamum zeylanicum, Pterocarpus marsupium, Vateria indica, Largerstroemia lanceolata, Artocarpus hirsute, Macranga peltata etc.
• Elephant, Gaur, Tiger, Panther,Sambar, Spotted deer, Barking deer, Wild boar, Sloth bear, Nilgiri langur, Bonnet macaque, Common langur, Wild dog, common otter, Malabar giant squirrel etc are the major mammals 
• It falls in cauvery Basin drained by Cherupuzha, Bavali puzha, Kabani river, Kannaram puzha, Kurichiat puzha, Chedalathu puzha etc

Hence, option c is correct.

4. With reference to India’s biodiversity, Ceylon frogmouth, Coppersmith Barbet, Gray-chinned minivet and White-throated redstart are:

(a) Birds

(b) Primates

(c) Reptiles

(d) Amphibians

4. Ans: a

Explanation:

Ceylon frogmouth, Coppersmith Barbet, Gray-chinned minivet and White-throated redstart  are included as SCHEDULE — I  species in Section B (Birds) of  Wildlife Protection Act.

Hence, option a is correct.

5. Which one of the following protected areas is well-known for the conservation of a sub-species of the Indian swamp deer (Barasingha) that thrives well on hard ground and is exclusively graminivorous?

(a) Kanha National Park

(b) Manas National Park

(c) Mudumalai Wildlife Sanctuary

(d) Tal Chhapar Wildlife Sanctuary

5. Ans: a

Explanation:

About Barasingha:

• Barasingha in Hindi means twelve-pointer, indicating a characteristic antler pattern in adult stages. Barasingha is a large, graceful deer, similar in shape and general body plan to other deer species such as red deer and sambar.
• Two distinctly different subspecies of Barasingha have been recognised: R.d. duvaucelii, from the alluvial plains on the foot of the Himalaya, and R.d. branderi from central India. The latter subspecies has also been known as ‘hard ground barasingha’.
• Barasingha’s historic range to extend along marshy areas in the foothills of the Himalaya, all along the Brahmaputra, ganga and Indus basins, from upper Assam to Rohri, along riverbeds in the Sal forests areas of central India, between Ganga and Godavari rivers.
• Now the barasingha is only found in three relatively small areas: one in Kheri, philibhit and Bahraich divisions, including Dudhwa National Park in Uttar Pradesh, and the adjacent divisions in southwestern Nepal; another in Kaziranga and Manas Naitonal Parks in Asssam few in Laokhowa Sanctuary(Asssam ); and the other in Kanha National Park in Madhya Pradesh.
• The barasingha has a distinct preference for swampy grassland areas. It subsist on grass for their diet showing clear preference for coarse grasses.
• It has a gestation period of 240-250 days and give birth to single young.

Kanha National Park:

• Kanha National Park is nestled in the Maikal range of Satpuras in Madhya Pradesh, the heart of India that forms the central Indian highlands. The national park is also a Tiger reserve. 
• The Kanha National park also supports an endemic population of the hard ground barasingha (Cervus duvauceli branderi), whose commendable resurrection over the years has become a very inspiring success story in wildlife conservation. 
• The lush green forests of Kanha, composed majorly of Sal (Shorea Robusta) and other mixed forest trees, supports the growth of rich and varied flora and fauna. 

Tal Chhapar Wildlife Sanctuary:

• Tal Chhapar is located on the fringe of the Great Indian Thar Desert and is a unique refuge for the most elegant antelope encountered in India “The Black Buck”.
• Tal Chhapar sanctuary, with its almost flat tract and interspersed shallow, low-lying areas, has open grassland with scattered Acacia and Prosopis trees, which give it an appearance of a typical savanna.
• The sanctuary lies in Sujangarh Tehsil of Churu district in the North-East of Rajasthan. 

Manas National Park:

• Manas Wildlife Sanctuary is located in the State of Assam in North-East India, a biodiversity hotspot. Covering an area of 39,100 hectares, it spans the Manas river and is bounded to the north by the forests of Bhutan.
• The site’s scenic beauty includes a range of forested hills, alluvial grasslands and tropical evergreen forests. 
• The site provides critical and viable habitats for rare and endangered species, including tiger, greater one-horned rhino, swamp deer, pygmy hog and Bengal florican. Among these pygmy hog, hispid hare and golden langur as well as the endangered Bengal florican are endemic to Manas National Park.
• The property,  has six national and international designations (i.e. World Heritage Site, National Park, Tiger Reserve (core), Biosphere Reserve (national), Elephant Reserve (core) and Important Bird Area).
• The Manas-Beki system is the major river system flowing through the property and joining the Brahmaputra river further downstream. These and other rivers carry an enormous amount of silt and rock debris.
• The monsoon and river system form four principal geological habitats: Bhabar savannah, Terai tract, marshlands and riverine tracts.
• The Manas Wildlife Sanctuary provides habitat for 22 of India’s most threatened species of mammals.

Mudumalai National Park

• Located in the western side of Tamil Nadu, the national park lies on the North eastern and North Western slopes of Nilgiris, descending to the Mysore plateau, at the tri-junction of Kerala, Karnataka and Tamil Nadu. 
• A part of the Nilgiri Biosphere Reserve, the sanctuary is crusted with other national parks including Bandipur, Nagarhole, Wayanad, Mukurthi and Silent Valley national parks. These parks and reserve forests together are spread across a whopping area of 3300 sq.km of forest land. 

Hence, option a is correct.

6. Steel slag can be the material for which of the following?

1. Construction of base road

2. Improvement of agricultural soil

3. Production of cement

Select the correct answer using the code given below:

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

6. Ans: d

Explanation:

Steel Slag:

• The slag produced at blast furnace during pig iron manufacturing is called blast furnace slag.  The slag produced at steel melting shop is known as steel slag. To produce steel, removal of excess silicon and carbon from iron is achieved through oxidation by adding limestone and coke. 
• Lower grade ores yield much higher slag fractions, sometimes as high as one tonne of slag per tonne of pig iron produced.
• The iron content is the major  basic difference between BF slag and steel slag. In BF slag, FeO is around 0.70%, whereas, in case of steel slag, total iron content varies from 16  to 25%.
• Ferro Scrap Nigam Ltd (FSNL), a wholly owned subsidiary of MSTC Ltd (public sector company) undertakes the recovery and processing of scrap from slag and refuse dumps in the nine steel plants.

Uses of Steel Slag:

• Slag based on their types, has different uses. The air-cooled BF slag is crushed, screened and used mainly as road metal and bases, asphalt paving, track ballast, landfills and concrete aggregate.
• The expanded or foamed slag binds well with cement and is used mainly as aggregate for light weight concrete. 
• Granulated BF slag is used as a pozzolanic material for producing portland slag cement. 
• It is also used for soil conditioning. BF slag is used in making mineral wool for insulation purposes.
• Steel slag has found use as a barrier material remedy for waste sites where heavy metals tend to leach into the surrounding environment. Steel slag forces the heavy metals to drop out of solution in water run off because of its high oxide mineral content. 
• Steel slag has been used successfully to treat acidic water discharges from abandoned mines. 
• It has shown potential for use as a raw mix component up to 10% in the manufacture of cement clinker. 
• Steel slag can also replace granulated blast furnace slag up to 10% in the manufacture of Portland Slag Cement. 

Hence, option d is correct.

7. Which of the following are the most likely places to find the musk deer in its natural habitat?

1. Askot Wildlife Sanctuary

2. Gangotri National Park

3. Kishanpur Wildlife Sanctuary

4. Manas National Park

Select the correct answer using the code given below:

(a) 1 and 2 only

(b) 2 and 3 only

(c) 3 and 4 only

(d) 1 and 4 only

7. Ans: a

Explanation:

About Musk Deer: 

• Musk deer are small solitary forest ruminants that inhabit the forested and alpine scrub habitats of mountains in Asia. It is shy, cryptic and nocturnal or crepuscular.
• Musk deer differ from other deer in not having antlers and facial glands. They have a gall bladder, caudal gland and musk gland which other deer does not possess. The musk has been in use in indigenous medicine since ancient times.
• They have only one pair of teats wheres other have two.
• In India, the musk deer inhabits forests areas between 2500m and the tree line on the southern side of the Greater Himalayas. It is reported to occur in and around 23 Protected Areas located in the states and UT of Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh.
• The musk deer are relatively sedentary animals, meeting their requirements for food and cover within their small home ranges in all seasons.

 Askot Wildlife sanctuary 

• Askot Wildlife Sanctuary (WLS) in Pithoragarh district of Uttarakhand lies at the junction of the Western and Central Himalayas.
• The Sanctuary was notified in July 1986, and covers three major watersheds: Kali, East Dhauli and Goriganga.
• The Sanctuary harbours the typical fauna of Himalayan forests as well as alpine pastures. Some of the rare and endangered species found in the Sanctuary are Musk Deer, Snow Leopard, Himalayan Tahr, Bharal or Blue Sheep, Goral, Serow, Asiatic Black Bear and Brown Bear.

Gangotri national park

• It is the largest (2,390 km²) Protected Area in the state of Uttarakhand, it lies in the upper catchments of River Bhagirathi.
• The Gangotri glacier lies at the centre of the Park and gives rise to River Bhagirathi. The Park has a relatively good forest cover and the vegetation types vary from Himalayan Moist Temperate Forests to the Alpine scrub and pastures. The GNP also forms a corridor between Govind National Park in the west and the Kedarnath Wildlife Sanctuary in the south.
• So far, 15 species of mammal and 150 bird species have been documented from the park which includes Snow leopard, Black bear, Brown bear, Musk deer , Blue sheep or Bharal, Himalayan tahr, Himalayan monal, Koklass and Himalayan Snowcock.

Kishanpur Wildlife Sanctuary (WLS) 

• It is part of the Dudhwa Tiger Reserve near Mailani in Uttar Pradesh.  Spread in a compact area of 200 sq Km, it is part of Dudhwa Tiger Reserve, covering terai forest and meadows. It is home to Tigers, Leopards, Pythons, Barking Deer, Ghariyal, Wild Boar and Swamp Deers. 
• Kishanpur has one of the most important terai grasslands left in northern India. 
• It is not the natural habitat for Musk Deer.

Manas National Park

• The Manas National Park has four principal geological habitats: Bhabar savannah, Terai tract, marshlands and riverine tracts, therefore Musk Deer is not naturally found in Manas National Park.
• For more Information Refer Question No-6

Hence, option a is correct.

8. In rural construction, the use of which of the following is preferred for ensuring environmental sustainability or to reduce carbon footprint?

1. Copper slag

2. Cold mix asphalt technology

3. Geotextiles

4. Hot mix asphalt technology

5. Portland cement

Select the correct answer using the code given below:

(a) 1, 2 and 3 only

(b) 2, 3 and 4 only

(c) 4 and 5 only

(d) 1 and 5 only

8. Ans: a

Explanation:

Copper slag is a by-product obtained during smelting and refining of copper. The waste copper slag can be used as abrasive tools, road construction, and ballast. One of the greatest potential applications for reusing copper slag is in cement and concrete production.

Asphalt is a mixture of aggregates, binder and filler, used for constructing and maintaining roads, parking areas, railway tracks, ports, airport runways, bicycle lanes, sidewalks and also play- and sport areas. Aggregates used for asphalt mixtures could be crushed rock, sand, gravel or slags. Nowadays, certain waste and by-products, such as construction and demolition debris, are being used as aggregates, which increases the sustainability of asphalt.

Hot Mix Asphalt (HMA)

Hot asphalt mixes are generally produced at a temperature between 150 and 180 °C. (more energy is involved and, consequently, more fumes are produced)

Warm Mix Asphalt (WMA)

A typical WMA is produced at a temperature around 20 – 40 °C lower than an equivalent Hot Mix Asphalt. Significantly less energy is involved and, consequently, less fumes are produced (as rule of thumb, a reduction of 25ºC produces a reduction of 75% of fumes emission). In addition, during the paving operations, the temperature of the material is lower, resulting in improved working conditions for the crew and an earlier opening of the road.

Cold Mix Asphalt

Cold mixes are produced without heating the aggregate. This is only possible, due to the use of bitumen emulsified in water, which breaks either during compaction or during mixing. Producing the coating of the aggregate. Over the curing time, water evaporates and strength increases. Cold mixes has the least emissions among all.

Geotextiles are permeable fabrics made from synthetic or natural fibers. They are designed to be placed in contact with soil or rock to improve their strength and stability. Moreover, they are commonly used to prevent soil erosion, filter water, and separate different layers of soil or rock.

Portland cement is a fine powder, gray or white in color, that consists of a mixture of hydraulic cement materials comprising primarily calcium silicates, aluminates and aluminoferrites.

Particulate matter (PM and PM-10), nitrogen oxides (NOx), sulfur dioxide (SO2), carbon monoxide (CO), and CO2 are the primary emissions in the manufacture of portland cement. Small quantities of volatile organic compounds (VOC), ammonia (NH3), chlorine, and hydrogen chloride (HCl), also may be emitted. Emissions may also include residual materials from the fuel and raw materials or products of incomplete combustion that are considered to be hazardous.

Hence, option a is correct.

9. Consider the following statements:

1. Coal ash contains arsenic, lead and mercury.

2. Coal-fired power plants release sulphur dioxide and oxides of nitrogen into the environment.

3. High ash content is observed in Indian coal.

Which of the statements given above is/are correct?

(a) 1 only

(c) 2 and 3 only

(b) 3 only

(d) 1, 2 and 3

9. Ans: d

Explanation:

Coal-based Thermal Power Plants (TPPs)  are better responsible for a disproportionately higher share of emissions than the industrial sector (60 per cent of PM, 45 per cent of SO₂, 30 per cent of NO₂ and 80 per cent of mercury (Hg)). 

Hence, statement 2 is correct.

Coal ash, also referred to as coal combustion residuals or CCRs, is produced primarily from the burning of coal in coal-fired power plants.Coal ash contains lead, arsenic, mercury, cadmium, and uranium. Coal ash includes a number of by-products produced from burning coal, including:

• Fly ash, a very fine, powdery material composed mostly of silica made from the burning of finely ground coal in a boiler.
• Bottom ash, a coarse angular ash particle that is too large to be carried up into the smokestacks so it forms in the bottom of the coal furnace.
• Boiler slag, molten bottom ash from slag tap and cyclone type furnaces that turn into pellets that have a smooth glassy appearance after it is cooled with water.
• Flue gas desulfurization material, a material leftover from the process of reducing sulphur dioxide emissions from a coal-fired boiler that can be a wet sludge consisting of calcium sulfite or calcium sulphate or a dry powdered material that is a mixture of sulphites and sulphates.

Hence, statement 1 is correct. 

Coal / Lignite based Thermal Power Generation has been the backbone of power capacity addition in the country. Indian coal is of low grade with ash content of the order of 30-45 % in comparison to imported coals which have a low ash content of the order of 2-15 %.  A large quantity of ash is, thus being generated at Coal / Lignite based Thermal Power Stations in the country, which not only requires a large area of precious land for its disposal but is also one of the sources of pollution of both air and water.  

Hence, statement 3 is correct. 

10. What is the use of biochar in farming?

1. Biochar can be used as a part of the growing medium in vertical farming.

2. When biochar is a part of the growing medium, it promotes the growth of nitrogen-fixing microorganisms.

3. When biochar is a part of the growing medium, it enables the growing medium to retain water for a longer time.

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 only

(c) 1 and 3 only

(d) 1, 2 and 3

10. Ans: d

Explanation:

Biochar is a charcoal-like product that contains no petroleum. It is made by heating biomass such as herbaceous or woody crop residues, non-salvageable timber and slash, or animal manure, in a contained system.

There are many potential uses for biochar including water treatment, land reclamation, and carbon sequestration. 

Biochar may also be used as a soil amendment for two purposes – to improve plant health and to store carbon. It is predicted that at least 50% of the carbon in any piece of waste turned into biochar becomes stable, locking away that carbon for a period of several to hundreds of years, offsetting its contribution as a greenhouse gas in the form of carbon dioxide.

Biochar provides several benefits to the soil by increasing its nutrient contents and water retention capacity. This is due to the cation exchange capacity and porous nature of the biochar, which is essential in promoting plant growth and development

Incorporation of biochar into growing medium has been found to enhance crop yield, increase populations of plant growth-promoting microbes and promote disease suppression.

Inoculating a peat medium with biochar with Rhizobia and mycorrhizal fungi may serve as a potential microbe activator. 

Vertical farming generally refers to the growing of crops mostly vegetables, ornamentals, and herbs on stacks of indoor shelves using artificial light and nutrient solutions, without much sunshine and soil. Such farms are not dependent on seasons/controlled environment and have ability to enhance production round the year with little risk of crop failure.

The usage of biochar can be also interesting for the urban farming industry. In fact, green roofs are seen as “privileged areas” for retaining rainwater and reducing the effects of urban heat islands and it is  also a part of vertical farming. 

The reported benefits of biochar include: 

• Greater uptake of nitrogen (N) stimulating plant growth 

• Stimulation of beneficial soil life, including mycorrhizal fungi

• Increased cation exchange capacity (ability the soil’s ability to retain nutrients) 

• Increased nutrient availability 

• Reduced nutrient leaching 

• Improved soil porosity

• Greater water retention in soil

Hence, option d is correct.

11. If a particular plant species is placed under Schedule VI of The Wildlife Protection Act, 1972, what is the implication?

(a) A license is required to cultivate that plant.

(b) Such a plant cannot be cultivated under any circumstances.

(c) It is a Genetically Modified crop plant.

(d) Such a plant is invasive and harmful to the ecosystem

11. Ans: a

Explanation:

Section 17C of The Wildlife Protection Act  –Cultivation of specified plants without licence prohibited.—

(1) No person shall cultivate a specified plant except under and in accordance with a licence granted by the Chief Wild Life Warden or any other officer authorised by the State Government in this behalf: 

(2) Every licence granted under this section shall specify the area in which and the conditions, if any, subject to which the licensee shall cultivate a specified plant. 

Hence, option a is correct.

12. What is/are the advantages/advantages of zero tillage in agriculture?

1. Sowing of wheat is possible without burning the residue of the previous crop.

2. Without the need for the nursery of rice saplings, direct planting of paddy seeds in the wet soil is possible.

3. Carbon sequestration in the soil is possible.

Select the correct answer using the code given below:

(a) 1 and 2 only

(b) 2 and 3 only

(c) 3 only

(d) 1, 2 and 3

12. Ans: d

Explanation:

Tillage is an agriculture land preparation through mechanical agitation which includes digging, stirring and overturning.

Zero tillage is the process where the crop seed will be sown through drillers without prior land preparation and disturbing the soil where previous crop stubbles are present. Zero tillage not only reduce the cost of cultivation it also reduces the soil erosion, crop duration and irrigation requirement and weed effect which is better than tillage. Zero Tillage (ZT) also called No Tillage or Nil Tillage.

Zero tillage proves better for direct-seeded rice, maize, soybean, cotton, pigeonpea, mungbean, clusterbean, pearlmillet during kharif season and wheat, barley, chickpea, mustard and lentil during rabi season. 

Wheat sowing after rice can be advanced by 10-12 days by adopting this technique compared to conventionally tilled wheat, and wheat yield reduction caused by late sowing can be avoided.

ZT provides opportunity to escape wheat crop from terminal heat stress. 

Zero tillage reduces cost of cultivation by nearly Rs 2,500-3,000/ha through reduction in cost of land preparation, and reduces diesel consumption by 50-60 litres per hectare.

Zero tillage reduces water requirement of crop and the loss of organic carbon by oxidation.

Zero tillage reduces Phalaris minor problem in wheat.

The carbon status of soil is significantly enhanced in surface soil (0-5 cm), particularly under crop residue retention with zero tillage 

Advantages of zero tillage

1. Reduction in the crop duration and thereby early cropping can be obtained to get higher yields.
2. Reduction in the cost of inputs for land preparation and therefore a saving of around 80%.
3. Residual moisture can be effectively utilized and number of irrigations can be reduced.
4. Dry matter and organic matter get added to the soil.
5. Environmentally safe – Greenhouse effect will get reduced due to carbon sequestration.
6. No tillage reduces the compaction of the soil and reduces the water loss by runoff and prevent soil erosion.
7. As the soil is intact and no disturbance is done, No Till lands have more useful flora and fauna.

Hence, option d is correct.

13. According to India’s National Policy on Biofuels, which of the following can be used as raw materials for the production of biofuels?

1. Cassava

2. Damaged wheat grains

3. Groundnut seeds

4. Horse gram

5. Rotten potatoes

6. Sugar beet

Select the correct answer using the code given below:

(a) 1, 2, 5 and 6 only

(b)  1, 3, 4 and 6 only

(c) 2, 3, 4 and 5 only

(d) 1, 2, 3, 4, 5 and 6

13. Ans:  a

Explanation:

Biofuels’ are fuels produced from renewable resources and used in place of or in blend with, diesel, petrol or other fossil fuels for transport, stationary, portable and other applications . 

The Union Cabinet, chaired by the Prime Minister Shri Narendra Modi has approved National Policy on Biofuels – 2018.

The Policy expands the scope of raw material for ethanol production by allowing use of Sugarcane Juice, Sugar containing materials like Sugar Beet, Sweet Sorghum, Starch containing materials like Corn, Cassava, Damaged food grains like wheat, broken rice, Rotten Potatoes, unfit for human consumption for ethanol production.

The Policy categorises biofuels as “Basic Biofuels” viz. First Generation (1G) bioethanol & biodiesel and “Advanced Biofuels”- Second Generation (2G) ethanol, Municipal Solid Waste (MSW) to drop-in fuels, Third Generation (3G) biofuels, bio-CNG etc. to enable extension of appropriate financial and fiscal incentives under each category.

Hence, option a is correct.

14. Which one of the following statements best describes the term ‘Social Cost of Carbon’?

(a) It is a measure, in the monetary value of the long-term damage done by a tonne of CO2 emissions in a given year.

(b) the requirement of fossil fuels for a country to provide goods and services to its citizens, based on the burning of those fuels.

(c) efforts put in by a climate refugee to adapt to live in a new place.

(d) contribution of an individual person to the carbon footprint on the planet Earth.

14. Ans:  a

Explanation:

The social cost of carbon dioxide (SC-CO2) measures the monetized value of the damages to society caused by an incremental metric tonne of CO2 emissions and is a key metric informing climate policy. Used by governments and other decision-makers in benefit–cost analysis .

Hence, option a is correct.

15. With reference to India’s Desert National Park, which of the following statements are correct ?

1. It is spread over two districts.

2. There is no human habitation inside the Park.

3. It is one of the natural habitats of the Great Indian Bustard.

Select the correct answer using the code given below:

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

15. Ans: c

Explanation: 

The Desert National Park covering an area of 3,162 sq km was notified in 1980 to conserve the unique biological diversity of this desert ecosystem. It is the largest protected area of the state, spread over Jaisalmer and Barmer districts. 

Hence, statement 1 is correct.

The great Indian bustard inhabits dry grasslands and scrublands on the Indian subcontinent; its largest populations are found in the Indian state of Rajasthan.

The Desert National park is the most important site for the long-term survival of the Globally Threatened Great Indian Bustard and other endemic fauna and flora.

Hence, statement 3 is correct.

There are 73 villages and also settlements or Dhanis existing within the Park. These communities have inhabited this area for hundreds of years and with their rich culture and tradition they are an integral part of this ecosystem.

Hence, statement 2 is incorrect.

16. Consider the following statements :

1. 36% of India’s districts are classified as “overexploited” or “critical” by the Central Ground Water Authority (CGWA).

2. CGWA was formed under the Environment (Protection) Act.

3. India has the largest area under groundwater irrigation in the world.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 and 3 only

(c) 2 only

(d) 1 and 3 only

16. Ans: b

Explanation:

The Central Groundwater Board of India estimates that about 17% of groundwater blocks are overexploited (meaning the rate at which water is extracted exceeds the rate at which the aquifer is able to recharge) while 5% and 14% , respectively, are at critical and semi-critical stages. The situation is particularly alarming in three major regions – north-western, western, and southern peninsular.

Hence, statement 1 is incorrect.

ABOUT CENTRAL GROUND WATER AUTHORITY

Central Ground Water Authority has been constituted under Section 3 (3) of the Environment (Protection) Act, 1986 to regulate and control development and management of groundwater resources in the country.

Hence, statement 2 is correct.

The agriculture sector is the largest consumer of groundwater resources, accounting for 87% of the total annual groundwater extraction, which amounts to 213.29 bcm. 

India is the largest user of groundwater in the world. It uses an estimated 230 cubic kilometers of groundwater per year – over a quarter of the global total.

Groundwater resources  serve 85% of domestic water supply in rural areas, 45% in urban areas, and over 60% of irrigated agriculture.

Hence, statement 3 is correct. 

17. Among the following Tiger Reserves, which one has the largest area under “Critical Tiger Habitat”?

(a) Corbett

(b) Ranthambore

(c) Nagarjunsagar-Srisailam

(d) Sunderbans

17. Ans: c 

Explanation:

Tiger Reserves:

Project Tiger was launched by the Government of India in the year 1973 to save the endangered species of tiger in the country. 57 Tiger reserves have been notified  until as on January 2025 

Tiger reserves with largest area

Tiger reserves with largest core / critical tiger habitat 

Hence, option c is correct.