indian soils — BSSC Geography

The ICAR (headquartered in New Delhi) has classified Indian soils into 8 major categories.

• These include Alluvial, Black, Red, Laterite, Montane, Arid, Saline/Alkaline, and Peaty/Marshy soils.

• Classification is based on soil formation, color, thickness, texture, age, and chemical/physical properties.

• 4, 6, and 10 are incorrect numbers as per the official ICAR agricultural taxonomy.

• Always remember the number "8" for ICAR soil types; it's a very frequent direct question in SSC exams.

• The largest geographical area among these is covered by Alluvial soil (approx. 40-43%).

• ट्रिक: ICAR के अनुसार भारतीय मिट्टी को 8 प्रमुख श्रेणियों में बांटा गया है — यह SSC परीक्षाओं में बहुत सामान्य प्रश्न है।

Soil is composed of 45% Minerals, 25% Air, 25% Water, and 5% Organic Matter.

• Organic matter primarily consists of humus, which is formed by decomposing plants and animals.

• Air and water occupy the pore spaces between the mineral particles in the soil.

• Other percentage breakdowns do not match the standard pedological composition of ideal soil.

• Remember the ratio 45:25:25:5 (Minerals:Air:Water:Organic) to quickly eliminate wrong options.

• Soil is considered a renewable natural resource, but its formation takes thousands of years.

• ट्रिक: 45:25:25:5 (खनिज:हवा:पानी:कार्बनिक) — इस अनुपात को याद करें।

Black soil is an example of Vertisol, which swells when wet and shrinks upon drying.

• Inceptisol is a recently formed soil with weakly developed horizons and covers the largest area in India.

• Oxisols are highly weathered soils found in tropical areas, while Gelisols contain permafrost.

• Any other matching combination misidentifies the US Soil Classification System terminology.

• 'Vert' means 'to invert' (self-ploughing black soil); 'Gel' relates to cold/freezing (Permafrost).

• Alfisols are clay/mineral-rich soils found in humid/semi-arid regions, and Histosols are peat/muck in wetlands.

• ट्रिक: 'Vert' = पलटना (स्व-जुताई काली मिट्टी); 'Gel' = ठंड/जमना (परमाफ्रॉस्ट)।

Laterite soil develops in areas with high temperature and heavy rainfall, causing intense leaching.

• Leaching washes away soluble minerals (silica, calcium), making the soil acidic and low in fertility.

• Because of the concentration of iron oxides, the soil is deeply red and hardens like a brick when dry.

• The reason perfectly explains why the assertion (low fertility) is true, so B, C, and D are invalid.

• 'Later' means 'brick' in Latin. Remember: High Rain = Intense Leaching = Laterite Soil.

• Despite low natural fertility, with manure and fertilizers, it is highly suitable for growing Cashew nuts, Tea, and Coffee (e.g., in Kerala, Karnataka).

• ट्रिक: 'Later' = लैटिन में 'ईंट'। भारी वर्षा = तीव्र लीचिंग = लेटराइट मिट्टी।

Black soil is naturally deficient (poor) in phosphorus, nitrogen, and humus. Thus, Statement 1 is wrong.

• It is rich in iron, calcium carbonate, magnesium, potassium, and alumina.

• Formed by the weathering of volcanic rocks (Deccan Traps), it is highly clayey and retentive of moisture.

• Any option including Statement 1 is incorrect because black soil lacks phosphorus.

• Indian soils in general are mostly deficient in Nitrogen and Humus. Black soil is specifically poor in Phosphorus too.

• It is internationally known as 'Tropical Chernozems' and is best suited for Cotton cultivation.

• ट्रिक: काली मिट्टी = नाइट्रोजन, फास्फोरस और ह्यूमस में कमजोर; लेकिन लोहे, कैल्शियम और मैग्नीशियम में समृद्ध।

Laterite soil is formed due to intense leaching caused by high temperature and heavy rainfall.

• The name is derived from the Latin word 'later', which means 'brick', and it becomes very hard when dry.

• During leaching, silica washes away, leaving behind a concentration of iron and aluminum oxides.

• Black soil is formed from volcanic rocks, while Alluvial is deposited by rivers.

• Remember the connection: 'Heavy Rain + Leaching = Laterite Soil (Brick)'.

• Despite being slightly acidic and less fertile, it is excellent for growing Cashew nuts, Tea, and Coffee when treated with manure.

• ट्रिक: 'Later' = लैटिन में 'ईंट' — लेटराइट मिट्टी सूखने पर ईंट जैसी कठोर हो जाती है।

Saline soil (excess salts) is treated with Gypsum (CaSO4.2H2O).

• Acidic soil (low pH) is neutralized by adding Lime (Calcium Carbonate/Oxide).

• Saline soils are widely found in Gujarat, UP, and Bihar, locally known as Reh, Usar, or Kallar.

• Option A reverses the treatments. Fertilizers like Potash/Phosphorus do not neutralize pH levels directly.

• Remember 'Acid-Lime' (like a sour lemon) to associate acidic soil with lime treatment.

• Saline soils have high accumulation of chlorides and calcium, making them largely unproductive without treatment.

• ट्रिक: खट्टे नींबू की तरह 'Acid-Lime' याद रखें — अम्लीय मिट्टी को चूने से, लवणीय को जिप्सम से उपचारित करें।

Iron is a Micronutrient, whereas Nitrogen, Phosphorus, and Calcium are Macronutrients.

• Macronutrients (required in larger amounts) include N, P, K, Sulfur (S), Calcium (Ca), and Magnesium (Mg).

• Micronutrients include Chlorine, Iron, Boron, Manganese, Zinc, Copper, and Molybdenum.

• A, B, and D belong to the same category (Macronutrients).

• 'NPK' (Nitrogen, Phosphorus, Potassium) are the primary macronutrients found in standard agricultural fertilizers.

• Soil is the major natural source for these essential elements determining crop yield.

• ट्रिक: लोहा (Iron) एक सूक्ष्म पोषक तत्व (Micronutrient) है, बाकी तीन — N, P, Ca — वृहत पोषक तत्व (Macronutrients) हैं।

Both statements have swapped definitions. 'Khadar' is NEW alluvium, while 'Bhangar' is OLD alluvium.

• Khadar is highly fertile, found within floodplains, and varies from light grey to ash grey.

• Bhangar is found on elevated terraces away from floodplains, is dark brown, and contains calcareous concentrations (Kankar).

• Since the definitions are interchanged, neither statement is factually accurate.

• Trick: 'Khadar' sounds like 'Khaad' (fertilizer) = New and highly fertile. 'Bhangar' sounds like 'Bangar' (scrap/old) = Old alluvium.

• Alluvial soil is mostly found in the Northern Plains and river deltas, formed by the Indus, Ganga, and Brahmaputra rivers.

• ट्रिक: 'खादर' = 'खाद' जैसा = नई और उपजाऊ। 'भांगर' = 'कबाड़' जैसा = पुरानी जलोढ़।

Black soil (Regur) develops deep cracks during dry weather, which helps in the oxygenation of the soil (self-ploughing).

• It is clayey in nature, meaning it is made of extremely fine materials that can hold moisture for a long time.

• It becomes very sticky when wet, making it difficult to plough immediately after the first shower.

• Arid soil is sandy and cannot hold moisture. Laterite soil becomes hard like a brick when dry but does not self-plough.

• Black Soil = Deccan Trap = Self Ploughing = Cotton Cultivation.

• It is highly rich in iron, calcium carbonate, magnesium, and alumina, but poor in phosphorus and nitrogen.

• ट्रिक: काली मिट्टी = दक्कन ट्रैप = स्व-जुताई = कपास की खेती।