A loamy soil is the best-suited for plant growth. Answer: 1 → b, 2 → c, 3 → a, 4 → e, 5 → d Question 4: Explain how soil is formed. all rights reserved. The particles present in clay are very fine and bind very well. It is also constantly being eroded. The nature of any soil depends upon the rocks from which it has been formed and the type of vegetation that grows in it. This process is called weathering. These components constantly … Over long periods of time, thousands and millions of years, the rocks at or near the surface of the Earth are broken down by various physical, chemical and some biological processes. Mineral Riches in the soil But do you know what exactly it is and how it is formed. On the sloping areas in hills, strip cropping should be practiced, thereby reducing the steepness of the slopes and checking soil erosion. When put together, these layers form a soil profile. Organisms. These “residual” soils have the same general chemistry as the original rocks. Water and minerals to the plants, and water for various human needs, irrigation and industry. Soil formation is influenced by organisms (such as plants), micro-organisms (such as bacteria or fungi), burrowing insects, animals and humans. Inspite all measures pesticides and weedicides should be used in limited quantity only when they are required. Laterite soil – rich in clay (which is porous and rich in iron and aluminium hydroxides); rich in organic matter and fertility. It results in the formation of soil. The methods would thus be follows: A-1, Acharya Nikatan, Mayur Vihar, Phase-1, Central Market, New Delhi-110091. Explain how soil is formed. During night, the rocks cool and contract. Here on AglaSem Schools, you can access to NCERT Book Solutions in free pdf for Science for Class 7 so that you can refer them as and when required. Worksheet in 3 sections: 1. Soil is made of layers, which are sometimes termed horizons. The bigger pieces of rocks get converted into small pieces of soil. Soil formation takes place in the following ways: Big rocks break down into smaller rocks by continuous action of wind and rain.It takes many years for these rocks to break down into smaller rocks. All NCERT textbook questions have been solved by our expert teachers. Since all the parts of the rocks do not expand and contract at the same time, cracks appear in the rocks and ultimately the large rocks break up into smaller pieces. As soil forms, plants … Question 7 What are the biological methods of weathering of soil? Explain the Formation of Soil in Detail. The following factors help in the weathering of rocks: Sun- Sun rays heat the rocks during the day time which causes the rocks to expand. The formation of soil happens over a very long period of time and is majorly formed by the weathering of rock. It involves a variety of chemical processes such as hydrolysis,hydration,oxidation,reduction. Answer4: The soil is formed by the breaking down of rocks by the action of wind, water and climate. NCERT Solutions Class 7 Science Chapter 9 Soil. Question 4 How Water causes weathering of soil? Copyright © 2020 Entrancei. Soil is not formed to rocks. Check out CBSE Class 9 Science Chapter 14 Natural Resources. Wind:Strong wind also erode rocks down.The wind also carries sand from one place to the other. How is clayey soil … Quality of soil is decided by amount of humus and microscopic organism found in it.Humus is a major factor in deciding the soil structure because it causes the soil to become more porous and allows water and air to penetrate deep underground. Proper drainage and irrigation arrangements should be made in the fields. Type of soil is decided by average size of particles found in it. The process of soil formation is so slow that the soil is regarded as a non-renewable resource. Toggle navigation. 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