Soil - 2

Bags (A) are not made of soil - they are typically made from materials like plastic, paper, cloth, or jute. Surahis (B), Matki (C) - traditional clay pots, and likely 'Statues' (D, appears to be a typo for 'Statues') are typically made from clay or soil. The question tests knowledge of materials used for different items.

Silt deposition occurs in river beds and subsoil areas (D). Silt particles are fine enough to be carried by water and settle in areas where water flow slows down, such as river beds, floodplains, and subsoil layers. Grasslands (A) are surface vegetation areas, bedrock (B) is the solid rock beneath soil, and the C-Horizon (C) is the weathered rock layer below subsoil but not the primary deposition site.

Silt particles are intermediate in size between sand (larger) and clay (smaller) particles. Sand particles range from 0.05mm to 2mm, silt from 0.002mm to 0.05mm, and clay particles are smaller than 0.002mm. This makes 'Sand, clay' (B) the correct answer, as silt fills the size gap between these two types. Rocks (A) are much larger, humus (C) is organic matter not a particle size category, and gravel (D) is larger than sand.

Rate of percolation = Volume of water ÷ Time taken = 200 ml ÷ 30 min = 6.67 ml/min (approximately). Option C (6.66 ml/min) is the closest and most accurate answer, using the exact calculation 200 ÷ 30 = 6.666... ml/min. Option A (7) is too high, B (10) is incorrect, and D (6) is too low.

Evaporation (B) is the correct answer - it is the process by which water changes from liquid to vapor, removing moisture from soil. Condensation (A) is the opposite process (gas to liquid). Precipitation (C) is water falling from atmosphere to ground. Transpiration (D) is water loss from plants, not directly from soil.

To calculate moisture percentage, divide the moisture weight by total soil weight and multiply by 100. Here: (10 gm / 100 gm) × 100 = 10%. This is straightforward division - 10 is one-tenth of 100, which equals 10%.

Rice requires water-retentive soil and can grow in clayey, fertile soils that hold moisture. Cotton needs well-drained sandy/loamy soil, while pulses and lentils prefer lighter soils. Rice paddies specifically use clayey soils that retain standing water.

This analogy tests contrasting properties: sandy soil has high percolation (water drains quickly), while clayey soil has high absorption/retention capacity (water stays in soil). The parallel is about how each soil type handles water movement and retention.

The density of water is 1 gram per milliliter at standard conditions. This means 1 ml of water weighs exactly 1 gram. This is a fundamental property used in many calculations involving water volume and mass.

The soil absorbed water that didn't pass through. Starting with 200 ml total and only 70 ml collected means the soil retained: 200 - 70 = 130 ml. This is straightforward subtraction - what went in minus what came out equals what stayed.

Wheat and gram (chickpea) are crops that prefer well-drained soils with good moisture retention. Clayey-loamy soils provide this balance - clay holds moisture while loam ensures drainage. Pure sandy soil drains too quickly; pure clayey soil can become waterlogged.

The odd one is wheat because it's a cereal grain, while cotton, pulses, and lentils are all legume or fiber crops. Wheat belongs to the grass family (Poaceae) and is a cereal, whereas the others are either legumes (pulses, lentils) or fiber crops (cotton).

Cotton requires well-aerated, loamy soil that allows good drainage and prevents waterlogging. Loamy soil provides the right balance of sand, silt, and clay. Cotton cannot grow in waterlogged clayey soil and needs proper aeration for root development.

Sandy soil has large particles with large pore spaces, so it retains the LEAST water but percolates the MOST. Clayey soil has small particles, retains MORE water but percolates LESS. The question asks which retains LEAST (sandy) and which percolates LEAST (clayey).

Soil moisture is the term for water held in soil. This water is available for plant uptake and exists in the pore spaces between soil particles. Soil profile refers to soil layers, percolation rate is drainage speed, and soil capacity is not a standard term.

Water and wind are the primary natural agents that cause soil erosion by carrying away soil particles from one location to another. Water erosion occurs through rainfall and runoff, while wind erosion happens in dry areas with loose soil. The other options list factors that influence soil but are not the primary agents of erosion.

Soil erosion is defined as the removal or transportation of topsoil by natural forces like water and wind. Soil pollution refers to contamination, not removal. Soil profile refers to soil layers, and soil moisture is about water content - none of these mean removal of topsoil.

Lack of vegetation is a major cause of soil erosion because plant roots hold soil in place and prevent water and wind from carrying it away. Areas with excess vegetation actually have less erosion, while rocks don't directly cause erosion and less rainfall means less water erosion.

Loam soil is a mixture of sand, silt, and clay particles, combining the beneficial properties of all three soil types. It has good drainage, water retention, and nutrient-holding capacity, making it ideal for agriculture. The other options describe single soil types rather than the characteristic mixture that defines loam.