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Q75 (NDA-I/2024) Geography › Indian Physical Geography Official Key

Consider the following statements regarding soils : 1. Soils having a very high content of sodium and calcium and pH of more than 7·0 are alkaline soils. 2. Black cotton soil had developed on the Deccan basaltic lava under hot and humid conditions. 3. Laterite soils are characterised by a deep weathered layer from which silica has been leached. Which of the statements given above is/are correct ?

Explanation

All three statements regarding soil characteristics are correct:

  • Statement 1: Alkaline soils (also known as Usar soils) contain high proportions of sodium, magnesium, and calcium. Due to the presence of these salts, their pH value is greater than 7.0, often reaching 8.5 or higher, making them unproductive for most crops without treatment.
  • Statement 2: Black cotton soil, or Regur soil, is derived from the weathering of Deccan basaltic lava. Geologically, its formation is linked to hot and humid/sub-humid conditions that facilitated the chemical decomposition of volcanic rocks into fine-grained clayey soil.
  • Statement 3: Laterite soils are formed under conditions of high temperature and heavy rainfall. This leads to intense leaching, where silica is washed away (desilication), leaving behind a deep weathered layer rich in iron and aluminum oxides.
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SIMILAR QUESTIONS

CDS-II · 2016 · Q45 Relevance score: 2.17

Which of the following statements regarding soil is/are correct? 1. Alluvial soils are rich in nitrogen content. 2. Black soils are rich in iron and lime but deficient in nitrogen. 3. Laterite soils are rich in iron and aluminium but deficient in nitrogen and potassium. Select the correct answer using the code given below.

IAS · 2018 · Q82 Relevance score: 1.99

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CDS-I · 2016 · Q7 Relevance score: 1.01

Consider the following statements regarding laterite soils of India : 1. Laterite soils are generally red in colour 2. Laterite soils are rich in nitrogen and potash 3. Laterite soils are well developed in Rajasthan and UP 4. Tapioca and cashew nuts grow well in this soil Which of the statements given above is / are correct?

CDS-I · 2011 · Q86 Relevance score: 0.33

Consider the following statements about black soil of India : 1. Black soil becomes sticky when it is wet. 2. Black soil contains adequate nitrogen as well as phosphorus required for the growth of plants. Which of the statements given above is/are correct?