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Answer- (b)

Explanation:

• • About Red Soil: It develops on crystalline igneous rocks in areas of low rainfall in the eastern and southern part of the Deccan Plateau. 
    • Along the piedmont zone of the Western Ghat, a long stretch of the area is occupied by red loamy soil. The soil develops a reddish colour due to a wide diffusion of iron in crystalline and metamorphic rocks. 
    • The fine-grained red soil is normally fertile, whereas coarse-grained soils found in dry upland areas are poor in fertility. It is generally poor in nitrogen, phosphorus and humus.
• Hence option (b) is the correct answer.

SOURCE:

https://ncert.nic.in/ncerts/l/kegy106.pdf

Answer: (c)

Explanation:

•  Mars has polar ice caps and signs of subsurface water/ice, which makes it a key candidate in the search for extraterrestrial life. Hence statement I is correct.
• The current atmosphere of Mars is too cold and thin to support liquid water, an essential ingredient for life, on its surface for lengthy periods.
• However, various NASA and international missions have found evidence that water was abundant on the Martian surface billions of years ago during a more clement era, such as features that resemble dried-up rivers and lakes, and minerals that only form in the presence of liquid water.
• However, its atmospheric pressure is less than 1% of Earth’s and surface temperatures are extremely low (average −60 °C), making liquid water unstable on the surface. Hence statement II is incorrect.

Therefore, only Statement-I is correct.

Answer: (b)

Explanation:

The Sun is the closest star to the Earth. Among the stars beyond the solar system, Proxima Centauri, part of the Alpha Centauri star system, is the nearest at a distance of about 4.24 light years.

• Sirius, though the brightest star in the night sky, lies about 8.6 light years away.
• Polaris (the North Star) is ~323 light years away.

Hence option (b) is correct.

Correct Answer: (c) 1, 3 and 4 only

Fertigation is a farming technique where fertilizers are dissolved in water and applied to crops through an irrigation system, like drip irrigation. 

1. Controlling the alkalinity of irrigation water is possible

Correct

• Fertigation allows precise adjustment of irrigation water pH using additives like urea phosphate or acids.
• This mitigates soil alkalinity, improves nutrient solubility, and prevents clogging in drip systems.
• Example: Urea phosphate releases H⁺ ions, lowering pH and enhancing nutrient uptake in alkaline soils.

2. Efficient application of Rock Phosphate and all other phosphatic fertilizers is possible

Incorrect

• Rock Phosphate is insoluble in water and cannot be applied via fertigation.
• Fertigation requires water-soluble fertilizers (e.g., urea, potassium nitrate).
• Phosphatic fertilizers like DAP or MAP are used instead of Rock Phosphate in fertigation.

3. Increased availability of nutrients to plants is possible

Correct

• Nutrients are delivered directly to the root zone via drip irrigation, enhancing absorption.
• Fertilizer use efficiency increases to 80–90% compared to 30–40% in traditional methods.
• Ensures optimal growth and higher yields (25–50% increase).

4. Reduction in the leaching of chemical nutrients is possible

Correct

• Precise application minimizes excess fertilizer, reducing nutrient runoff and groundwater contamination.

Correct Answer: (c) 1 and 4 only

Explanation:

Statement 1: A substantial saving in seed material is made when ‘bud chip settlings’ are raised in a nursery and transplanted in the main field.

Correct

• Bud chip technology reduces seed material requirements by up to 80% compared to conventional methods.
• Nursery-raised settlings ensure healthier plants and better field establishment.

Statement 2: Germination percentage is better with single-budded setts.

Incorrect

• Multi-budded setts have higher germination due to greater nutrient reserves. Single-budded setts lack sufficient energy for reliable sprouting.

Statement 3: Single-budded setts survive better in bad weather.

Incorrect

• Larger setts (with multiple buds) survive better in adverse conditions due to stored moisture and nutrients.

Statement 4: Sugarcane can be cultivated using tissue culture settlings.

Correct

• Tissue culture produces disease-free, uniform settlings for transplantation, enhancing crop quality.