Agriculture: UPSC Previous Year Questions (Geography)

Explanation

Statement 1 is correct: Coffee plant requires a hot and humid climate of tropical areas whereas tea can be cultivated in both tropical and subtropical areas. Coffee thrives in a hot and humid tropical climate, requiring temperatures between 15°C and 28°C with well-distributed rainfall. Traditional coffee producing regions include the southern states of Karnataka (largest producer), Kerala, and Tamil Nadu. Non-traditional regions consist of Andhra Pradesh and Odisha, located in the Eastern Ghats of India. Tea can grow in both tropical and subtropical with temperaturerange 20-30°C requiring high humidity and well-distributed rainfall (100-200 cm) areas. For example, it is cultivated in Assam (tropical) and Darjeeling (subtropical) regions. Assam is the largest producer of tea in the country.

Statement 2 is incorrect: Coffee is propagated by seeds but tea is not propagated by stem cuttings only. Coffee is primarily propagated by seeds, but vegetative propagation methods like cuttings and grafting are also used. Tea is propagated both by seeds and vegetative methods, including stem cuttings and grafting, depending on the desired plant characteristics. In tea cultivation, cuttings are planted either upright or at a slight angle, ensuring that the leaves do not come into contact with the soil. After developing roots, they are transferred to the field approximately 12 months later. Seeds, on the other hand, are sown at a depth of 1.5 to 2.5 cm.

Explanation

Soil conservation techniques aim to prevent soil erosion, improve soil fertility, and maintain ecological balance.

Option 1 is correct: Rotating crops helps maintain soil fertility by alternating nutrient-exhausting crops with nitrogen-fixing ones, reducing soil degradation and pest infestations. Legumes are rotated with cereals to fix nitrogen in the soil in states like Punjab and Haryana.

Option 2 is correct: Sand fences are barriers made of wood or other materials to trap sand and stabilize soil in areas prone to wind erosion, such as coastal or desert regions. It is practised in arid regions like Rajasthan, where wind erosion is a problem.

Option 3 is correct: Terracing involves creating step-like structures on slopes, which slows down water runoff, prevents soil erosion, and conserves moisture, making it highly effective in hilly areas.

Option 4 is correct: Wind breaks are rows of trees or shrubs planted to reduce wind speed and protect soil from erosion, especially in open fields. It is commonly used in hilly regions like the Himalayas and Western Ghats.

Explanation

The National Development Council (NDC) in 2007 adopted a resolution to launch a Food Security Mission comprising rice, wheat and pulses to increase the annual production of rice by 10 million tonnes, wheat by 8 million tonnes and pulses by 2 million tonnes by the end of the Eleventh Plan (2011-12). Accordingly, a Centrally Sponsored Scheme, ‘National Food Security Mission’ (NFSM), was launched in October 2007. Initially, NFSM (2007-08) focused on rice, wheat, and pulses only. The objectives of NFSM are:

Increase production of specific crops through area expansion and productivity enhancement. Ensure sustainability by focusing on improved technologies and efficient resource use. Enhance farm profitability and rural livelihoods.

Explanation

Statement 1 is correct: Paddy fields are typically flooded, creating anaerobic (oxygen-deprived) conditions. Soil saturation in wetland rice fields restricts oxygen transport, creating anaerobic conditions due to submergence. This environment supports the activity of methanogenic bacteria, which produce methane (CH₄), a potent greenhouse gas. Rice cultivation is a significant source of methane emissions globally.

Statement 2 is correct: Nitrogen-based fertilizers, which enhance crop yield, stimulate soil microbes to convert nitrogen into nitrous oxide (N₂O), another potent greenhouse gas. Microbial processes like nitrification and denitrification in the soil release nitrous oxide, especially in poorly drained, waterlogged soils. Nitrous oxide has a global warming potential 265 times greater than CO₂ over 100 years.

Explanation

Energy crops, also called agroenergy or bioenergy crops, are cultivated specifically to generate biomass for renewable energy production. These crops can thrive on degraded, waste, saline, or waterlogged lands. In addition to providing a sustainable energy source, energy crops contribute to reducing greenhouse gas emissions. They also play a role in enhancing water quality and supporting wildlife habitats.

Option (a) is incorrect: Jatropha is primarily cultivated for biodiesel, as its seeds contain oil that can be converted to biodiesel. It is not used for ethanol production.

Option (b) is correct: Maize (corn) is a major crop used for ethanol production. It is rich in starch, which is fermented by yeast into ethanol.India is expanding maize-based ethanol production as part of the Ethanol Blending Program (EBP) to reduce petrol imports.

Option (c) is incorrect: Pongamia (Indian beech) is mainly used for biodiesel production due to the oil content in its seeds. It is not used for ethanol production.

Option (d) is incorrect: Sunflower, with very low sugar content, is primarily grown for edible oil production. It is not a significant crop for ethanol production.