Question map
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.
Explanation
Statement 1 is incorrect because alluvial soils in India are generally deficient in nitrogen, phosphorus, and humus, though they are rich in potash and lime. Statement 2 is correct; black soils (Regur) are formed from volcanic rocks and are rich in iron, lime, calcium, and magnesium, but they are notably deficient in nitrogen, phosphorus, and organic matter [2]. Statement 3 is correct; laterite soils develop under high temperature and heavy rainfall conditions leading to intense leaching. They are rich in iron and aluminium oxides but are poor in nitrogen, potassium (potash), lime, and organic matter [1]. Since most Indian soils are inherently deficient in nitrogen, the presence of nitrogen in alluvial soil is a common misconception. Therefore, only statements 2 and 3 are accurate regarding the chemical composition of these soil types.
Sources
- [2] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 6: Soils > Table 6.1 > p. 7
- [1] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 6: Soils > Table 6.1 > p. 8