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1. In a waterlogged , concentration of • Total soluble salt content is more than ______is high. 0.1%. it is high enough to interfere A. Methane B. Ethane with normal growth of most plant C. Carbon dioxide D. carbon monoxide species. E. None of these • Saline remain in a flocculated Ans. A condition (granulated). It is permeable to water and air. Solution: • Saline soils usually have a surface Wetlands are characterized by water- crust of white salts, especially in the logged soils and distinctive communities season when the net movement of of plant and animal species that have is upward. Salts evolved and adapted to the constant dissolved in the move up to presence of water. This high level of the surface, where they are left as a water saturation as well as warm weather crust when the water evaporates. is the cause of the high levels of methane production. 3. How does ploughing help in retaining sub- soil water? 2. Which soil occurs for the most part in regions of arid and semi -arid areas. A. Improving the character of the sub- soil. A. Saline soils B. Karewas soils B. By breaking capillaries C. Red Soil D. Black Soil C. Enabling the roots of plants to E. None of these penetrate deeper Ans. A D. All of the above Solution: E. None of these Salt affected soil or saline soil are found Ans. D in arid and semi-arid regions. When the soil contains excess of sodium salts and Solution: complex contains exchangeable Ploughing helps in retaining sub-soil calcium, the soil is known as saline soil or water by breaking capillaries which white alkali or brown alkali soil. The enables the roots of plants to penetrate process of accumulation of salts leading deeper in search of nutrients thereby to the formation of soils is known as improving the character of sub-soil. salinization. 4. What is the estimated extent of salt • Saline soils contain usually chloride, affected soils in India? sulphate, bicarbonates and nitrates of A. More than 7 less than 8 sodium. B. More than 8 less than 9 • The presence of chloride and sulphate C. More than 6 less than 7 of sodium gives a white colour on D. More than 5 less than 6 the soil surface. When nitrates are in E. None of these excess they give a brown colour to Ans. C the soil. Solution: • Exchangeable sodium percentage According to report the estimated extent (ESP) is very low, being less than of salt affected soils in India is approx. 15% of the total cation exchange 6.72 million hectares. Out of which 1.71 capacity (C.E.C.). As a consequence million ha is saline soil and 1.24 million of low ESP, generally pH varies ha is coastal salinity. between 7.5 and 8.5.

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B. movement of weathered rock and regolith toward the base of a slope C. disintegration and decomposition of rocks and at the surface D. the combined processes of , eluviation, and mass wasting E. None of the above Ans. A Solution: 1. is a naturally occurring process that affects all landforms. In , soil erosion refers to the wearing away of a field's by the natural physical forces of water and

wind through forces associated with 5. of soil depends on farming activities such as tillage. A. Property of porous medium only 2. Erosion, whether it is by water, wind B. Void ratio of soil or tillage, involves three distinct C. Property of Porous medium and fluid actions – soil detachment, movement D. Both B and C and deposition. Topsoil, which is high E. None of these in organic matter, fertility and , Ans. D is relocated elsewhere "on-site" where Solution: it builds up over time or is carried "off- Hydraulic conductivity, symbolically site" where it fills in drainage channels. represented as, is a property of vascular Soil erosion reduces cropland plants, soils and rocks, that describes the productivity and contributes to the ease with which a fluid (usually water) pollution of adjacent watercourses, can move through pore spaces or wetlands and lakes. fractures. 8. Sum of specific yield and specific 6. The process of removing soluble retention is equal to the constituents from the soil layer by action A. B. Void ratio of percolating water is known as: C. Degree of saturation A. Diffusion B. Percolation D. Storage coefficient C. Leaching D. E. None of these. E. None of these Ans. A Ans. C Solution: Solution: • Porosity-The amount of pore space is known as porosity. Leaching refers to the depletion of soluble materials from the upper soil by • Specific yield-The actual volume of downward-percolating water. water that can be extracted by the force of gravity from a unit volume 7. Which one of the following statements is known as specific yield. best describes erosion? • Specific retention- The fraction of A. the process by which weathered rock water held back is known as and particles are removed specific retention. from one area and transported • Thus, Porosity = specific yield + elsewhere specific retention

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9. The drainable porosity of soil is important • Group A is , loamy sand or sandy parameter for designing types of soils. It has low runoff A. Surface drainage system potential and high infiltration rates even B. Surface system when thoroughly wetted. They consist chiefly of deep, well to excessively C. Drip irrigation system drained or gravels and have a high D. Sub-surface drainage system rate of water transmission. E. All of the above • Group B is loam or loam. It has a Ans. D moderate infiltration rate when Solution: thoroughly wetted and consists chiefly or The drainable porosity is one of the most moderately deep to deep, moderately well important parameters for sub-surface to well drained soils with moderately fine drainage design. At present time in most to moderately coarse textures. drainage formulas the specific yield is • Group C soils are sandy clay loam. taken to be a constant value. As the They have low infiltration rates when existing concepts of specific yield differ thoroughly wetted and consist chiefly of greatly, the methods for estimating this soils with a layer that impedes downward parameter also vary. movement of water and soils with 10. Permeability is measure of moderately fine to fine structure. A. Available soil moisture • Group D soils are clay loam, silty clay loam, sandy clay, silty clay or clay. This B. Porosity HSG has the highest runoff potential. C. Water holding and transmitting They have very low infiltration rates when capacity thoroughly wetted and consist chiefly of D. Ability to transmit water clay soils with a high swelling potential, E. None of these soils with a permanent high-water table, Ans. D soils with a or clay layer at or Solution: near the surface and shallow soils over Soil permeability is the property of the nearly impervious material. soil to transmit water and air and is one 12. The main cause of sheet erosion is of the most important qualities A. Raindrop splash 11. A soil is characterised as Group C soil if it B. Strong winds has: - C. Tillage A. Very low infiltration rate D. Cultivation of cereal crops B. Low infiltration rate E. None of these C. Moderate infiltration rate Ans. A Solution: D. High infiltration rate Rainfall and the surface run-off which E. None of these may result from rainfall, produces four Ans. B main types of soil erosion: splash erosion, Solution: sheet erosion, rill erosion, and gully Soils are classified by the Natural erosion. Splash erosion is generally seen Resource Conservation Service into four as the first and least severe stage in the Hydrologic Soil Groups based on the soil's soil erosion process, which is followed by runoff potential. The four Hydrologic Soils sheet erosion, then rill erosion and finally Groups are A, B, C and D. Where A's gully erosion (the most severe of the generally have the smallest runoff four). Sheet erosion is the transport of potential and Ds the greatest. loosened soil particles by overland flow.

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13. Consider the following statement about erosive agents to transport the particles, badlands/ravines then the third phase called as 'deposition' I. They are formed because of rill takes place. Thus, soil erosion may be erosion. defined as detachment, transportation II. In India, ravines are found in and deposition of soil particles from one Chambal region. place to another under the influence of wind, water or gravity forces. III. Badlands are fit for the cultivation of crops. 15. Gully erosion is the: A. Only I B. Only II A. First stage of soil erosion C. Both I and II D. Both II and III B. Last stage of soil erosion E. All of the above C. It is the third stage of soil erosion Ans. C D. It is the second stage of soil erosion Solution: E. None of these. Badlands are a type of dry terrain where Ans. B softer sedimentary rocks and clay-rich Solution: soils have been extensively eroded by Rainfall and the surface run-off which wind and water. Badlands are partially may result from rainfall, produces four characterized by their thin to nonexistent main types of soil erosion: splash erosion, regolith layers. The regolith profiles of sheet erosion, rill erosion, and gully badlands in arid climates are likely to erosion. resemble one another. In these regions, 16. The sequence of soil erosion is the upper layer is typically composed of A. Splash, Sheet, Rill, Gully silt, shale, and sand (a byproduct of the B. Sheet, Splash, Gully, Rill weathered shale). The formation of badlands is a result of two processes: C. Sheet, Gully, Rill deposition and erosion. The process of D. Gully, Rill, Splash, Sheet deposition describes the accumulation, E. None of these over time, of layers of mineral material. Ans. A Different environments such as seas, Solution: rivers, or tropical zones, deposit different Rainfall and the surface run-off which sorts of clays, , and sand. may result from rainfall, produces four 14. Soil erosion is three phase phenomena: main types of soil erosion: splash erosion, I. Detachments sheet erosion, rill erosion, and gully II. Transportation erosion. III. Deposition 17. The ideal/preferred ratio of primary A. Only I B. Only II nutrient NPK in Soil for our country is C. Both I and III D. All of the above A. 4:2:1. B. 2:4:1 E. None of these. C. 6:3:1 D. 2:2:1 Ans. D E. 1:1:1 Solution: Ans. A Soil erosion is three phase phenomena, Solution: consisting of the detachment of individual The existing Nitrogen - Phosphorous - soil particles from the soil mass and their Potassium (NPK) consumption ratio in the transport by erosive agents such as country is skewed at 8.2:3.2:1 (2012-13) running water and wind. When sufficient as against the preferred ratio of 4:2:1. A energy is no longer available with the great variability is observed in fertilizer

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consumption among States from 250 kg / 20. Why is organic matter (humus) an hectare (ha) in Punjab, 212 kg / ha in important part of soil? Bihar, 207 kg / ha in Haryana to 4.8 kg / A. It helps to improve water infiltration ha in Nagaland and 2 kg / ha in Arunachal B. It can break down organic pollutants Pradesh, during 2012-13. However, C. It converts nitrogen in the air into imbalanced application of fertilizers has nitrates used by plants caused deficiency of primary nutrients (i.e. NPK), secondary nutrients (such as D. It is rich in nutrients, which is Sulphur), and micronutrients (boron, zinc, important for fertility copper etc.), in most parts of country. E. None of the above 18. Percolation rate of water is the least in Ans. D A. Sandy Soil B. Clayey Soil Solution: C. Loamy Soil D. All of the above Humus significantly affects the bulk E. None of these density of soil and contributes to its Ans. B retention of moisture and nutrients. Solution: Humus is the dark organic matter that forms in soil when dead plant and animal Soil acts as a sponge to take up and matter decays. Humus has many retain water. Movement of water into soil nutrients that improve the health of soil is called infiltration, and the downward and fertility. movement of water within the soil is called percolation, permeability or 21. Which of the following is NOT a common hydraulic conductivity. Pore space in soil reason why soil maps are used? is the conduit that allows water to I. To determine the land drainage infiltrate and percolate. It also serves as capabilities of an area the storage compartment for water. II. To determine the suitability of soils Percolation rate (mL/min) = Amount of for particular crops water in mL/Time taken to percolate. The III. To identify soils and their properties percolation rate of water in sandy soil is A. Only I B. Only II fastest and in clayey soil is slowest. C. Both I and II D. Both II and III 19. can be defined as E. All of the above A. A factor influencing how soil is formed Ans. E B. A layer parallel to soil surface Solution: C. An organism found within the soil Soil mapping or soil maps are generally D. A technique used to map soils used to simply identify soils and their E. None of these properties, but are sometimes required Ans. B for more specific purposes, such as Solution: determining the suitability of a soil for A soil horizon is a layer parallel to the particular crops, or the land drainage soil surface, whose physical capabilities of an area. characteristics differ from the layers 22. Which of the following is NOT a threat above and beneath. Each commonly faced by soils? usually has three or four horizons. A. Soil erosion B. Percolation Horizons are defined in most cases by C. Deforestation D. Climate change obvious physical features, chiefly colour and texture. E. None of the above Ans. B

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Solution: Ans. C Percolation is the process of a liquid Solution: slowly passing through a filter. It's how The red colour is mainly due to ferric coffee is usually made. Percolation oxides occurring as thin coatings on the comes from the Latin word percolare, soil particles while the iron oxide occurs which means "to strain through." as hematite or as hydrous ferric oxide, Percolation happens when liquid is the colour is red and when it occurs in the strained through a filter, like when hydrate form as limonite the soil gets a someone makes coffee. yellow colour. 23. Which of the following is the part of 25. Which of the following affects both the Micro-Nutrient? kind of soil and its rate of formation? A. Calcium B. Nitrogen A. climate (precipitation and temperature) C. Magnesium D. Zinc B. slope angle and direction E. None of the above C. biota (plants and animals) Ans. D D. parent material Solution: E. All of the above Zinc is the part of Micronutrients. Major Nutrients Ans. E • pH (Soil Reaction; acidity / alkalinity of Solution: the soil) All soils initially come from rocks, this is • Total Dissolved salts termed the ‘parent material’. The Parent • Organic Carbon Material may be directly below the soil, or • Phosphorous great distances away if wind, water or glaciers have transported the soil. In • Potash addition to the soil parent material, soil Minor Nutrients formation is also dependent upon other • Sulphur prevailing processes affecting soil • Magnesium formation. The soil formation process is • Calcium termed ''. Climatic conditions Micro-nutrients are important factors affecting both the • Zinc form and rate of physical and chemical • Ferrous weathering of the parent material. The • Manganese formation of soils can be seen as a • Copper combination of the products of 24. When you travel to Tamil Nadu, you will weathering, of structural development of notice red soil. What is the main reason the soil, of differentiation of that structure for this colour? into horizons or layers, and lastly of its A. Abundance of magnesium movement or translocation. In fact, there B. Accumulated humus are many ways in which soil may be C. Presence of ferric oxides transported away from the location where it was first formed. D. Abundance of Phosphates

E. None of these

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