Which of the following statements is not true, with respect to 'Laterite soils' in India?
- (a)They are deficient in lime and nitrogen.
- (b)They provide good building materials.
- (c)They are affected by leaching process.
- (d)They are moisture retentive with large clay factor.
Correct — D, They are moisture retentive with large clay factor..
The official key marks They are moisture retentive with large clay factor as the statement that is not true, and it is right. That sentence describes black (regur) soil. Regur is made of extremely fine clayey material, holds moisture for a long time, swells and turns sticky when wet, and cracks deeply when dry.
Laterite is the opposite in texture. It forms where high temperature and heavy rain leach silica and lime out of the profile, leaving iron and aluminium oxides behind. The result is typically coarse, porous and free-draining, which is why it dries out fast and needs manure and fertiliser before it will grow crops.
The idea to carry away: leaching makes laterite; clay makes regur. Options (a), (b) and (c) each state a real property of laterite, so the odd one out is the clay-and-moisture claim, which belongs to the black soil of the Deccan.
- (a)They are deficient in lime and nitrogen. — This statement is true of laterite, so it cannot be the odd one out. Heavy tropical rain washes lime (calcium) out of the profile, and humus is broken down quickly by bacteria that thrive in the heat, so nitrogen stays scarce. NCERT lists laterite as poor in organic matter, nitrogen, phosphate and calcium.
It is the right answer to which bases and nutrients laterite lacks. Regur, by contrast, is rich in lime, though it too is short of nitrogen.
- (b)They provide good building materials. — This statement is true. The name comes from the Latin later, meaning brick. Laterite is soft enough to be cut into blocks when freshly quarried and hardens on exposure to air, which is why NCERT notes that it is widely cut as bricks for house construction.
It is the right answer to the building use that gives laterite its name. A soil can be poor for crops and still be a good building stone; the two properties are unrelated.
- (c)They are affected by leaching process. — This statement is true; leaching is what creates laterite. Under high temperature and heavy rainfall, soluble silica and lime are carried downward and away, leaving iron oxide and aluminium compounds behind, which is also the source of the reddish colour. NCERT calls laterite the result of intense leaching due to tropical rains.
It is the right answer to the process that forms laterite. The same leaching explains option (a): the lime is gone because it was leached.
Laterite is a soil of the humid tropics. Where temperatures are high and rain is heavy, water percolating through the profile dissolves and carries away the more soluble constituents, silica and the bases such as lime, and leaves behind the insoluble oxides of iron and aluminium. This selective removal is called leaching.
The leftover material is typically coarse, porous and reddish, with little humus because organic matter decomposes fast in the heat. Such a soil drains quickly and holds little water.
A clay-rich soil behaves the opposite way: fine particles pack tightly, hold moisture, and swell and shrink with wetting and drying. That is the signature of black regur soil.
Indian soils are grouped for the exam into major types such as alluvial, black, red and yellow, laterite, arid, saline, peaty and forest soils, each tied to a parent material, a climate and a set of crops.
Laterite sits at the high-rainfall, high-temperature end of that spread, in the higher parts of the peninsular plateau and the western coastal belt. It matters in two ways: as the textbook example of leaching, and as the natural contrast to regur.
Regur is clayey and moisture-retentive; laterite is leached and free-draining. A statement that attributes clay and moisture retention to laterite has taken a black-soil property and moved it across that line.
- The word laterite comes from the Latin later, meaning brick.
- Laterite develops under high temperature and high rainfall; NCERT describes it as the result of intense leaching due to tropical rains.
- Leaching removes lime and silica and leaves behind soils rich in iron oxide and aluminium compounds.
- Laterite soils are poor in organic matter, nitrogen, phosphate and calcium, while iron oxide and potash are in excess — NCERT gives both halves of that sentence together.
- Humus content stays low because bacteria that thrive at high temperature break organic matter down quickly.
- Laterite is widely cut as bricks for house construction; quarried blocks harden on exposure to air.
- In India laterite is found in Karnataka, Kerala, Tamil Nadu, Madhya Pradesh and the hilly areas of Odisha and Assam.
- Red laterite soils of Tamil Nadu, Andhra Pradesh and Kerala suit tree crops such as cashew nut.
- Black (regur) soil is clayey and impermeable, swells and turns sticky when wet, shrinks and cracks when dry, and retains moisture for a long time.
- Regur is rich in lime, iron, magnesia and alumina but lacks phosphorus, nitrogen and organic matter.
The highlighted row is the one the keyed option gets wrong: clay and moisture retention belong to regur, while laterite is the leached, free-draining soil. Nitrogen deficiency is shared by the two, so it does not separate them.
- Nitrogen deficiency is true of laterite and of regur alike, so it cannot be used to tell the two apart; lime content and clay content can.
- 'Deficient in lime' can look inconsistent with 'rich in iron and aluminium', but they are the same leaching story: the soluble bases leave, the insoluble oxides stay.
- The brick in the name suggests a clayey soil; laterite is brick-like because quarried blocks harden in air, and its texture is coarse and porous.
- A 'not true' stem reverses the task: three options are correct descriptions, and 'good building materials' is one of them even though the soil is poor for crops.
In the two linked laterite statement-sets, HPSC 2021 and UPSC 2013, the item mixes a climate clue, a nutrient clue, a brick clue and a location clue. The false statements there each contradict one of those clues: low rainfall, a claim of richness in nitrogen and potash, and a Rajasthan-and-Uttar-Pradesh location.
On the nutrient clue, read carefully: it is the nitrogen half that is wrong. Potash is actually in excess in laterite, so a statement pairing the two is only half false.
This UKPSC item is the single-property version of the same task, with one regur property, clay and moisture retention, set among three genuine laterite properties. The linked NDA 2024-I item takes a third shape: one leaching statement on laterite placed beside statements on other soils.
HPSC_2021_PRE_GSII_Q132021Same soil, statement-set form: it tests the climate of formation, nutrient status, brick-cutting and plateau location. Its nutrient statement (rich in nitrogen, phosphate and calcium) is option (a) here stated from the false side, and its brick statement matches option (b). It differs in probing climate and location rather than the clay-and-moisture contrast with regur.
UPSC_2013_GS1_Q622013Country-level statement set on laterite keyed (c): red colour and cashew/tapioca are accepted, while 'rich in nitrogen and potash' and 'well-developed in Rajasthan and UP' are rejected. It shares the nitrogen-deficiency point with option (a) here; it differs by testing colour, crops and distribution instead of texture and moisture.
NDA_GAT_2024_I_Q752024Its third statement, that laterite has a deep weathered layer from which silica has been leached, is the leaching idea behind option (c) here, and the item is keyed with statements 1, 2 and 3 correct. It differs in pairing laterite with alkaline-soil and black-soil statements rather than asking which laterite property is false.
- practice — not a real PYQ
Which one of the following soils of India is clayey, retains moisture for a long time, and develops wide cracks in the dry season that produce a kind of self-ploughing?
- (a)Laterite soil
- (b)Black (regur) soil
- (c)Red soil
- (d)Alluvial soil
Answerb — Regur is made of fine clayey material, swells when wet, shrinks when dry, and the resulting cracks aerate it, which NCERT calls self-ploughing.Laterite (a) is leached, coarse and free-draining. Red soil (c) forms on crystalline rocks and is typically loamy to sandy rather than swelling clay. Alluvial soil (d) is river-deposited and varies from sandy to loamy without the swell-shrink behaviour.
- practice — not a real PYQ
Consider the following statements about laterite soils: 1. They develop in areas of high temperature and heavy rainfall. 2. Their name is derived from a Latin word meaning brick. 3. They are rich in lime and humus. Which of the statements given above is/are correct?
- (a)1 and 2 only
- (b)2 and 3 only
- (c)1 and 3 only
- (d)1, 2 and 3
Answera — Statement 1 is correct: laterite is a product of intense leaching under tropical heat and rain. Statement 2 is correct: later is Latin for brick.Statement 3 is wrong twice over: lime is leached away and humus is broken down fast in the heat, so laterite is poor in calcium and organic matter. Options (b), (c) and (d) each include statement 3.
- practice — not a real PYQ
The red laterite soils of Tamil Nadu, Andhra Pradesh and Kerala are considered most suitable for which one of the following crops?
- (a)Cotton
- (b)Wheat
- (c)Cashew nut
- (d)Jute
Answerc — NCERT states that the red laterite soils of Tamil Nadu, Andhra Pradesh and Kerala are more suitable for tree crops like cashew nut.Cotton (a) is the crop of black regur soil. Wheat (b) is grown on the alluvial plains of the north. Jute (d) is a crop of the wet alluvial deltas of West Bengal and neighbouring areas.
- practice — not a real PYQ
Which one of the following processes is chiefly responsible for the formation of laterite soils?
- (a)Deposition of silt by rivers
- (b)Leaching under heavy tropical rainfall
- (c)Weathering of Deccan basalt
- (d)Deposition of wind-blown sand
Answerb — Laterite forms when heavy rain in a hot climate leaches silica and lime out of the profile and leaves iron and aluminium oxides behind. River deposition (a) gives alluvial soil. Weathering of Deccan basalt (c) gives black regur soil. Wind-blown sand (d) builds the arid soils of western Rajasthan.