Which one of the following is found in appreciable amount in Laterite soil in India ?

The correct answer is C, Potash. Indian laterite soils are poor in organic matter, nitrogen, phosphate and calcium, while iron oxide and potash are present in excess.

Laterite soils form in areas of high temperature and heavy rainfall with alternating wet and dry seasons. Heavy rain leaches away lime and silica, leaving behind oxides of iron and aluminium, which give these soils their red colour and make them hard like brick when dried; the name comes from the Latin word "later", meaning brick. They are found in Kerala, Karnataka, Tamil Nadu, Madhya Pradesh and the hilly parts of Odisha and Assam. With manure and fertilisers they are used for tea, coffee, cashew and rubber, and they are cut into blocks for building.

A is wrong because calcium (lime) is washed out of laterite soils by heavy rain. B is wrong because laterite soils are poor in phosphate. D is wrong because their low humus content leaves them poor in nitrogen.

Exam tip: laterite = leaching; rich in iron oxide and potash, poor in nitrogen, phosphate, calcium and humus; good for cashew, tea and coffee.