Soil Science

Red soil gets its characteristic color from iron oxide (Fe2O3) content, which forms through extensive leaching in tropical and subtropical regions. The iron accumulates in the soil profile, creating the reddish hue. Ascorbic acid is vitamin C, not a soil component. Ferrite is a magnetic iron compound but not the coloring agent. Potash is potassium, unrelated to soil color.

This is the correct matching.  

Lichens are pioneer organisms that secrete acids to break down rocks into soil particles, initiating soil formation in barren landscapes. Animals like snakes, lions, and deer live in developed ecosystems but do not contribute to creating soil from parent rock material.

This is the correct answer as this statement is incorrect. The Ganga Brahmaputra basin consists of alluvial soil deposits.

This is the correct answer as both statements are correct.

Alluvial soil is ideal for wheat and rice because it's formed by river deposits rich in nutrients like potash, phosphoric acid, and lime. It has excellent water retention capacity - crucial for rice - and is found extensively in Indo-Gangetic plains where these crops are primarily grown.

This is the correct option. A-horizon is the uppermost dark-colored layer of soil consisting mainly of partly disintegrated organic debris. B-horizon is composed of mineral soil (subsoil). C-horizon contains the unconsolidated parent material.

This is the correct option. Sandy soil is found in desert areas and cannot hold much water. Clayey soil is compact and can hold water, but cannot trap air. Loamy soil has good water holding capacity and is porous to allow aeration of roots. This option is wrong. Sandy soil is found in desert areas and cannot hold much water. Loamy soil has good water holding capacity and is porous to allow aeration of roots.

This is the correct option. Alluvial soil is layered and consists of smooth round particles and contains gravel, sand and clay. Desert soil is coarse, sandy and porous, is greyish brown in colour and is rich in minerals. Mountainous soil consists of sand, stones, clay, shales and limestones and also contains a good amount of humus.

Red soil gets its color from the presence of iron oxide compounds, particularly hematite and limonite. These iron compounds give the soil its characteristic reddish or reddish-brown appearance. The color indicates iron content, not potash, nitrogen, or humus.

Loam soil, which is a balanced mixture of sand, silt, and clay, provides ideal conditions for wheat cultivation. It offers good drainage, adequate water retention, proper aeration, and easy root penetration. Gravel is too coarse, sandy soil doesn't retain enough water or nutrients, and sandy loam is acceptable but not as optimal as true loam for wheat.

This is the correct option. Plants grow in the topsoil. This layer of Earth's crust supports the growth of plants in many ways.

This is the correct option, as this is not a property of B-horizon. This layer is not rich in humus.

This is the correct option. All of the above factors influence the nature of soil. Plants affect soil development by supplying upper layers with organic matter, recycling nutrients from lower to upper layers, and helping to prevent erosion. Deep rooted plants contribute more to soil development than shallow rooted plants. Animals living in the soil also affect decomposition of waste materials.

This is the correct option, as this is not a property of the A-horizon.