Answer:
1. Answer: (b) Weathering of rocks
Explanation: Weathering of rocks is a step in the formation of soil because the basis of the formation of soil is soil minerals which are produced from the rocks.
2. Answer: (a) A
Explanation: Topsoil that is the A horizon is the layer of soil that is located just below the O Horizon. This layer consists of minerals and decomposed organic matter.
3. Answer: (a) Clay
Explanation: Clay soil will form a colloidal solution when suspended in water.
4. Answer: (d) All of these
Explanation: Formation of soil is called pedogenesis. Soil formation is the process of soil formation from its parental material. In addition to the soil parent material, soil formation is also dependent upon other prevailing processes like climate, relief, etc.
5. Answer: (b) texture
Explanation: Texture refers to the size of the particles that make up the soil. The terms sand, silt, and clay refer to relative sizes of the soil particles. The combined portions of sand, silt, and clay in a soil determine its textural classification.
6. Answer: (b) Forest
Explanation: In the forest, plenty of plants and trees are grown. Because of plants and trees, in the forest moisture and nutrients are sufficient. It helps to promote the expansion of micro-organisms.
7. Answer: (b) Topsoil
Explanation: The soil conservation measures are mainly aimed at protecting the topsoil. It is the nutrient-rich soil with humus and is fertile in nature that helps the plants to grow.
8. Answer: (c) surface
Explanation: Soil is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Earth's body of soil, called the pedosphere, has four important functions: as a medium for plant growth. as a means of water storage, supply and purification.
9. Answer: (b) Solid wastes
Explanation: Soil erosion occurs when the weathered soil particles are dislodged and carried away by wind or water. Deforestation, agricultural development, temperature extremes, precipitation including acid rain, and human activities contribute to this erosion. Humans speed up this process by construction, mining, cutting of timber, over cropping and overgrazing. It results in floods and cause soil erosion.
10. Answer: (b) loamy soil
Explanation: The best topsoil for growing plants is loam. Loam is a mixture of sand, silt, clay and humus. It has the right water-holding capacity for plant growth.
11. Answer: (a) soil
Explanation: The mixture of rock particles and humus is called the Soil.
12. Answer: (b) silty soil
Explanation: Silty is not a type of soil. Sand, clay, silt, and humus in the proper amounts make up loamy soil.
13. Answer: (c) Clay
Explanation: Clay has the smallest size of particles, less than 0.002 mm in diameter.
14. Answer: (a) black soil
Explanation: Black Soil covers the Deccan plateau along the Godavari and Krishna valleys. This soil is rich in calcium carbonate, potash, magnesium, and lime making it ideal for growing cotton.
15. Answer: (b) Deforestation
Explanation: Deforestation causes soil erosion. Deforestation causes soil erosion.
16. Answer: (c) deserts
Explanation: In the desert, there are few plants to hold soil in place and little water. Instead, wind is the main way that the rock pieces are moved around. The wind cannot move all the pieces though, just the small lighter ones, so sand is left behind. Over a long time the deserts become mostly sand.
17. Answer: (b) Volcanic soil
Explanation: They are often very rich in nutrients and hold water well because of their volcanic ash content. These soils are called Andisols, and they are often very young, and acidic depending on which type of volcano they come from.
18. Answer: (d) All of the above
Explanation: The soil is a mixture of fine rock particles and organic matter. Chemical processes involve the weathering of rocks by chemical reactions. Organic or biological processes involve the weathering of rocks by biological agents such as lichens and mosses.
19. Answer: (c) minerals, organic matter, air and water
Explanation: Soil composition refers to the nutrients and various other substances present in the soil. The basic components of soil are minerals, organic matter, water, and air. The typical soil consists of approximately 45% mineral, 5% organic matter, 20-30% water, and 20-30% air.Hence In addition to the rock particles, the soil contains Minerals, organic matter, air, and water.
20. Answer: (a) Alluvial soil
Explanation: Alluvial soils are ideal for the growth of sugarcane, paddy, wheat and other cereal and pulse crops.
21. Answer: (c) rotting dead matter in soil
Explanation: The dark black upper layer of the soil is known as humus. It is the dead remains of plants and animals that have been decomposed by bacteria and fungi. This humus-rich soil increases the aeration capacity of soil and also helps in the penetration of roots of plants. The decomposition of organic matter helps in bringing the plant and animal residues back to the soil.
22. Answer: (d) Less than 0.002 mm
Explanation: Starting with the finest, clay particles are smaller than 0.002 mm in diameter. Some clay particles are so small that ordinary microscopes do not show them. Silt particles are from 0.002 to 0.05 mm in diameter.
23. Answer: (a) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
Explanation: The roots of the plants bind the soil together, and interweave with other roots, forming a more solid mass that is less susceptible to both water and wind erosion. The removal of vegetation increases the rate of surface erosion.
24. Answer: (c) Kerala
Explanation: Laterite has been derived from the Latin word ‘later’ which means brick. The laterite soil develops in areas with high temperature and heavy rainfall. These soils are mainly found in Karnataka, Kerala, Tamil Nadu, Madhya Pradesh, and the hilly areas of Orissa and Assam. This soil is very useful for growing tea and coffee.
25. Answer: (c) Plastics
Explanation: necessary throw waste also contain food with plastic, when cattles hunt for their food they eat food along with plastic which can led to their death. plastic also cause soil pollution as plastic is not burn completely and it leaves residue.
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