Soil Types and Formation Quiz

Soil and Agriculture

• Soil is a renewable natural resource
• Soil consists of organic (humus) and inorganic materials
• Important factors for soil formation include parent material, climate, relief, and time
• Soil can be classified based on factors like color, thickness, texture, age, and chemical/physical properties
• Parent material determines soil's color, texture, chemical properties, mineral content, and permeability
• Climate affects weathering rates and humus content
• Relief influences soil accumulation
• ICAR (Indian Council of Agricultural Research) categorizes Indian soils into 8 types
• Indian soils often lack nitrogen (N₂), phosphorus (P), and humus (organic matter)
• Major soil types in India include alluvial (40%), red (18%), black (15%), laterite (4.3%), arid, montane, marshy/peaty, and saline/alkaline soils
• Alluvial soils are widely spread, fertile, and found in northern plains and deltas
• Black soils (Regur) are ideal for cotton cultivation
• Red and yellow soils form from metamorphic rocks and are often found in low rainfall areas
• Laterite soils result from intense leaching in high-temperature, high-rainfall regions
• Arid soils are sandy, saline, and found in low-precipitation regions
• Marshy/peaty soils have high organic matter, high humidity, and high rainfall
• Desert soils are found in extremely low rainfall areas
• Montane soils have high humus content

Soil Erosion and Conservation

• Soil erosion is the washing away of topsoil
• Soil erosion can happen due to sheet and gully erosion, and is influenced by water
• Gully erosion, a permanent process, cuts deeply into soil along drainage lines
• Soil conservation methods include counter bunding/ploughing, mulching, shelter belts, terrace farming, and strip farming
• Counter bunding/ploughing is a land management practice for hilly and sloping land
• Mulching covers topsoil with plant materials to retain moisture
• Shelter belts use rows of trees to prevent wind erosion
• Terrace farming creates flat areas on hillsides for agriculture
• Strip farming divides fields into strips and rotates crops
• Soil conservation helps prevent the loss of fertile topsoil and maintain soil's productivity

Types of Farming

• Primitive subsistence farming uses basic tools, family/community labor, and small land plots
• Intensive subsistence farming uses high doses of inputs (biochemical, irrigation) for high yields
• Commercial farming focuses on single crops grown on large areas, often using high-yielding varieties (HYVs), fertilizers, and pesticides
• Important commercial crops include tea, coffee, rubber, sugar cane, and bananas

Mixed and Intercropping

• Mixed farming combines crop production with livestock rearing
• Intercropping involves growing two or more crops closely together on the same land
• Similarities exist between mixed and intercropping as both involve growing multiple crops in one field
• Kṛṣi, broadly defined as farming and agriculture, has different cropping patterns
• Kharif crops are sown in the monsoon season, and harvested in the autumn
• Rabi crops are sown in the winter, harvested in the spring
• Zaid crops are short-season crops

Major Crops

• Wheat requires 50-70 cm of rain
• Sugarcane needs 75-100 cm of rain, and a temperature range of 21-27°C
• Tea cultivation requires well-drained acidic soils rich in humus
• Leguminous crops like pulses, rajma, and soyabeans have nitrogen-fixing bacteria in their roots
• Major millets include bajra, ragi, and jowar
• India is a significant producer of oilseeds such as groundnuts, coconuts, mustard, sesame, and cotton
• Fruits, vegetables, and coffee are also important crops.

Agricultural Revolutions

• Different agricultural revolutions, such as the Green Revolution, focus on increasing crop yields
• The Green Revolution, that started in the 1960s, used high-yielding varieties (HYVs) of crops, leading to increased agricultural output
• Drawbacks of the green revolution include groundwater depletion and soil alkalinity.