Previous Year Question
Which of the following statements regarding laterite soils of India are correct?
They are generally red in colour.
They are rich in nitrogen and potash.
They are well-developed in Rajasthan and Uttar Pradesh.
Tapioca and cashew nuts grow well on these soils.
Select the correct answer using the codes given below.
1, 2 and 3
2, 3 and 4
1 and 4
2 and 3
Correct Answer: C
Detailed Solution
They are generally red in colour—Correct
Laterite soil develops through intense leaching under conditions of high temperature and heavy rainfall. Rainwater carries silica, lime and other soluble substances downward from the upper soil layers. The relatively insoluble oxides of iron and aluminium remain behind. Iron oxide imparts a red or reddish-brown colour to the soil.
They are rich in nitrogen and potash—Incorrect
Intense leaching caused by heavy rainfall removes nutrients such as nitrogen, potash, phosphorus, lime and magnesia. Laterite soil is therefore generally:
deficient in nitrogen, potash and phosphorus;
low in humus;
acidic in nature; and
relatively rich in iron and aluminium oxides.
It can be made productive through the proper application of manure and fertilisers.
They are well-developed in Rajasthan and Uttar Pradesh—Incorrect
High temperature, heavy rainfall and intense leaching are necessary for extensive laterite formation. The arid and semi-arid conditions of Rajasthan are unsuitable for its widespread development. Uttar Pradesh is also not a major laterite-soil region of India.
Laterite soils are mainly found in Karnataka, Kerala, Tamil Nadu, Madhya Pradesh, Maharashtra, the hilly areas of Odisha and parts of Assam. They also occur extensively in several parts of the Western and Eastern Ghats.
Tapioca and cashew nuts grow well on these soils—Correct
Although naturally poor in fertility, laterite soils are suitable for crops such as tapioca and cashew when supported by proper manuring, irrigation and nutrient management. Tapioca, cashew, coconut, arecanut, pepper and pineapple are cultivated on laterite soils in Kerala and other parts of the western coastal region.
Additional facts
The word laterite is derived from the Latin word later, meaning brick.
On exposure to air and drying, the soil may become hard and is used in several regions as brick-like blocks for construction.
Its fertility varies according to the parent rock, intensity of leaching and vegetation cover.
At higher elevations, laterite soils can support crops such as tea and coffee with appropriate fertiliser management.
Therefore, statements 1 and 4 are correct.