Correct Option
The correct option is 1 and 3 only.
Explanation
Laterite soils are derived from the Latin word 'later', meaning brick. These soils are typical of the tropical regions and are the result of intense leaching processes driven by specific climatic conditions.
Statement-wise Analysis
- Statement 1 is Correct: Lateritic soils are formed under conditions of alternate wet and dry seasons. This climatic alternation is crucial for the leaching process, where heavy rains wash away soluble substances, and dry periods facilitate the hardening of the soil.
- Statement 2 is Incorrect: These soils develop mainly in areas of high temperature and heavy rainfall, not low rainfall and low temperature. High temperatures allow microorganisms to rapidly consume humus, while heavy rainfall causes the leaching of lime and silica.
- Statement 3 is Correct: Due to the removal of silica and lime through leaching, laterite soils are generally rich in iron oxide and aluminium. The abundance of iron oxide is responsible for the reddish colour often associated with these soils.
Key Takeaway: Laterite soils are formed by intense leaching in tropical areas with high temperature and heavy rainfall. They are chemically characterized by an excess of iron and aluminium oxides and a deficiency in nitrogen, potash, and organic matter.