PLANT PHYSIOLOGY
PLANT GROWTH
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The weathering of rocks or parent material
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From the eruption of volcanoes
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From the dust in the air as it settles on the earth
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From material brought down from the mountains
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Detailed explanation-1: -Rocks are the source of all soil minerals. The parent material is chemically or physically weathered and transported which then deposits to form layers of soil. Usually, the bedrock is the parent material but there have been cases wherein soil gets transported due to factors like the wind and water.
Detailed explanation-2: -Soil is the thin layer of material covering the earth’s surface and is formed from the weathering of rocks. It is made up mainly of mineral particles, organic materials, air, water and living organisms-all of which interact slowly yet constantly.
Detailed explanation-3: -Alluvial soils are formed due to the weathering of various rocks or gravel or sometimes due to clay particles. These soils are loosened particles.
Detailed explanation-4: -When parent rock material is exposed to the atmosphere or when organic matter and/or minerals are deposited on the earth’s surface, soil formation begins.
Detailed explanation-5: -Laterite soil is rich in iron and aluminium. The red colour is due to iron oxide present in the laterite soil. Laterite soils are formed under typical monsoonal conditions. The alternation of wet and dry seasons leads to the leaching away of the siliceous matter of the rocks and the formation of laterite soils.