Which of the following statements regarding laterite soils of India are correct? 1. They are generally red in colour. 2. They are rich in nitrogen and potash. 3. They are well-developed in Rajasthan and UP. 4. Tapioca and cashew nuts grow well on these soils. Select the correct answer using the codes given below:
1 and 4
Understanding Laterite Soils in India: Characteristics and Distribution
Laterite soils are a type of soil formed in areas with high temperatures and high rainfall. This combination leads to intense leaching of bases, leaving behind oxides of iron and aluminum. Let's examine the given statements about laterite soils in India to determine which ones are correct.
Analyzing Statements on Laterite Soils
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Statement 1: They are generally red in colour.
This statement is correct. Laterite soils are typically red or reddish-yellow due to the presence of iron oxides left behind after the leaching of other minerals. This is a defining characteristic of laterite soil.
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Statement 2: They are rich in nitrogen and potash.
This statement is incorrect. Due to the intense leaching process occurring in the formation of laterite soils, soluble nutrients like nitrogen, potash, and phosphorus are washed away. Therefore, laterite soils are generally poor in these nutrients.
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Statement 3: They are well-developed in Rajasthan and UP.
This statement is incorrect. Laterite soils require conditions of high temperature and high rainfall for their formation (through the process of laterization). Rajasthan is largely an arid or semi-arid region, and while parts of Uttar Pradesh receive moderate rainfall, the intense leaching required for widespread laterite formation is not typical there. Laterite soils are commonly found in the Western Ghats, Eastern Ghats, parts of Maharashtra, Karnataka, Kerala, Odisha, and Assam, where these climatic conditions prevail.
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Statement 4: Tapioca and cashew nuts grow well on these soils.
This statement is correct. Despite being low in nutrients, laterite soils can support certain crops, particularly plantation crops and those adapted to acidic conditions. Crops like tapioca (cassava), cashew nuts, tea, and coffee are often cultivated on laterite soils, especially with proper management like adding manures and fertilizers.
Summary of Statement Analysis
Based on our analysis:- Statement 1 is correct.
- Statement 2 is incorrect.
- Statement 3 is incorrect.
- Statement 4 is correct.
Revision Table: Key Characteristics of Laterite Soils
Here's a quick summary of the important points about laterite soils:
| Characteristic | Description |
|---|---|
| Formation | Formed under conditions of high temperature and high rainfall through intense leaching (laterization). |
| Colour | Generally red due to high iron oxide content. |
| Nutrient Status | Poor in major nutrients like nitrogen, phosphorus, and potash due to leaching. |
| Distribution in India | Found in areas like Western Ghats, Eastern Ghats, parts of Maharashtra, Karnataka, Kerala, Odisha, and Assam. |
| Suitability for Crops | Not very fertile, but suitable for specific crops like tapioca, cashew, tea, and coffee with proper management. |
Additional Information: Soil Formation Process (Laterization)
Laterization is the process responsible for the formation of laterite soils. It occurs in tropical and subtropical regions experiencing alternating wet and dry seasons, though continuous high rainfall is a key driver. Here's a simplified look:
- During the wet season, water percolates deeply into the soil.
- This water dissolves soluble minerals and bases (like silica, lime, magnesia, potash, and soda).
- These dissolved materials are then leached downwards or removed from the soil profile.
- Insoluble oxides of iron and aluminum are left behind near the surface.
- During the dry season, capillary action may bring some dissolved substances upwards, but the overall effect is the enrichment of the surface layers with iron and aluminum oxides, giving the soil its characteristic red colour and often a hard, brick-like consistency when dry.
This process results in soils that are typically acidic and poor in plant nutrients, requiring careful agricultural practices.
Important Questions from Rocks and Soils
Soil, in which nearly all our food grows, is a living resource that takes years to form. Yet it can vanish in minutes. Each year 75 billion tonnes of fertile soil is lost to erosion. That is alarming — and not just for food producers. Soil can trap huge quantities of carbon dioxide in the form of organic carbon and prevent it from escaping into the atmosphere.
On the basis of the above passage, the following assumptions have been made :
1. Large scale soil erosion is a major reason for widespread food insecurity in the world.
2. Soil erosion is mainly anthropogenic.
3. Sustainable management of soils helps in combating climate change.
Which of the above assumptions is/are valid ?
With reference to agricultural soils, consider the following statements :
1. A high content of organic matter in soil drastically reduces its water holding capacity.
2. Soil does not play any role in the sulphur cycle.
3. Irrigation over a period of time can contribute to the salinization of some agricultural lands.
Which of the statements given above is/are correct ?
Which of the following adds/add nitrogen to the soil?
1. Excretion of urea by animals
2. Burning of coal by man
3. Death of vegetation
Select the correct answer using the codes given below:
When you travel in certain parts of India, you will notice red soil. What is the main reason for this colour ?
Which one of the following is the appropriate reason for considering the Gondwana rocks as most important of rock systems of India?
