soil science Mcqs
251. Source of negative charges on silicate clays is/ are________?
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A. Isomorphous substitution

B. All of these

C. Anion exchange

D. Exposed crystal edges

252. There are twelve soil orders found in the world of which six soil orders have been recognized at various locations are________?
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A. Andisols, Gelisols, Histosols, Spodosols, Oxisols, Ultisols

B. The above statement is wrong

C. Andisols, Aridisols, Histosols, Vertisols, Regosols, Libosols

D. Entisols, Inceptisols, Aridisols, Alfisols, Mollisols, Vertisols
253. Following are types if erosion:
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A. All of these

B. Rill & Gully erosion

C. Normal (geological) erosion & Accelerated erosion

D. Rain splash & sheet erosion

254. According to a latest research, Pakistan is predominantly a dryland country; 80% of its land area is arid and semi arid, 12% sub-humid and 8% under humid climate. Thus , soils of arid & semi-arid regions are vulnerable to a wide range of degradation process. As the case in arid and semi-arid climates elsewhere in south-central/southern Asia and Sub-Saharan Africa; _________________ are among the major causes of soil degradation and desertification?
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A. Accelerated erosion & salinization

B. All of the above

C. Drought stress

D. Depletion of soil fertility and SOM

255. Which one of the following techniques is used for assessing available P in soil and does not include growing plants:
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A. a-Value

B. A-Value

C. E-Value

D. L-Value

256. Surface removal of ice or snow from a glacier or snowfield by melting, sublimation, and/ or calving:
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A. Bank-Caving

B. Ablation

C. Abrasion

D. Backplain

257. The movement of water through a column of soil is called:___________?
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A. Leaching

B. Percolation

C. Infiltration

D. hydraulic conductivity

258. An intrazonal group of dark calcareous soils high in clay and having mainly montmorillonitic type clay are called as:________?
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A. Regur

B. Montmorillosol

C. Regosol

D. Ragour

259. Which chemical used to prevent evaporation from surface of water in water bodies?
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A. Cetyle alcohol

B. Methyle alcohol

C. both A and B

D. None of these

260. The planned development, distribution and use water resources:
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A. Water distribution

B. Water management

C. both A & B

D. None of the above

261. Organic matter in Pakistani soils is generally:_________?
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A. less than 1 %

B. 3%

C. 5%

D. less than 10 %

262. The evolution of new species is known as_____________?
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A. Speciation

B. None of these

C. Smog

D. Specialization

263. According to the Soil survey of Pakistan, the total waterlogged summer-rain area in the country is:_________?
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A. 22.5 mha

B. 4.11 mha

C. The above statement is wrong

D. 5.16 mha

264. The water diffusivity has the units of:__________?
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A. cm2

B. s/cm

C. cm2/s

D. cm/s

265. Fossils are found in__________type of rocks:
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A. Sedimentary rocks

B. Metamorphic rocks

C. Aqueous rocks

D. both A & C
266. In Pakistan, The following igneous rocks are found over considerable areas:
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A. Slate, Shist

B. Marl, gypsum

C. Dolomite shale, gneiss

D. None of the above
267. Which element is found highest in earth crust?
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A. None of the above

B. Aluminum

C. Sodium

D. Silicon

268. Which type of soil is found near the canal banks:
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A. Alkaline

B. Acidic & Alkaline

C. Calcareous

D. Acidic

269. Depending on the percentage of sand, silt, clay, soils are divided into _______ textural classes:
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A. 12

B. 14

C. 13

D. 9

270. Decomposition of the organic matter in submerged soil is carried out by?
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A. Algae

B. None of the above

C. Actinomycetes

D. Fungi

271. Which of the following is a component of nucleic acid and protein:
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A. Ca

B. None of the above

C. N

D. Mg

272. Soil Organic Matter (SOM) which consists of about _______ % organic carbon plays a vital role by providing macro & micro nutrients:
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A. 72%

B. 62%

C. Al of the above

D. 58%
273. The process by which nutrients chemicals or contaminants are dissolved and carried away by water, or are moved into a lower layer of soil:
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A. Percolation

B. Infiltration

C. Leaching

D. Seeping

274. The soil samples are dried at _______________, for gravimetric soil analysis?
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A. 110 <sup>0</sup>C

B. 120 <sup>0</sup>C

C. both A and B

D. 105 0C
275. Most abundant organic compound in nature?
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A. Lignin

B. Hemicellulose

C. Cellulose

D. All of these

276. Select the water soluble phosphatic fertilizer from the following__________?
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A. All of these

B. SSP

C. DSP

D. TSP

277. The maximum amount of water which a soil can hold after free drainage has ceased is called as_______?
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A. Water harvesting

B. Water use efficiency

C. Water potencial

D. Water holding capacity
278. Aridisols cover the largest in Pakistan_______?
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A. 278,910 km<sup>2</sup>

B. 259,710 km2

C. 269,810 km<sup>2</sup>

D. None of these

279. Wind transported materials if it is silt dominated is__________?
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A. Colluvial

B. Eolian

C. Alluvial

D. Loess
280. Clay and humus particles are referred to as colloids and are less than 0.002mm. Due to their small size, colloids have ________________ surface area which provides surface for adsorption, catalysis, precipitation and microbial colonization:
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A. Very little

B. None of these

C. Extremely high

D. Extremely low

281. Combination of soil genesis and classification is collectively called_________?
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A. Pedology

B. Poly pedology

C. Edaphology

D. None of the above

282. Organic Soils are classified as ____________ and are also known as ____________ soils:
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A. Alfisols. fine & coarse textured

B. Ultisols, Fe & Al rich

C. None of the above

D. Histosols, peat & muck
283. Which leaf of rice is sampled for tissue nutrient analysis?
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A. Mature leaf

B. Lower leaf

C. Both A & B

D. None of these
284. Weathering is the natural process of__________?
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A. Disintegration

B. Sedimentation

C. Decomposition

D. both A & C
285. Conservation agriculture improves the water use efficiency of dryland systems. It has components:
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A. Residue return to keep at least 30% of soil covered

B. all of the above

C. Reduced soil disturbance through no-till or minimum till

D. Crop rotations for better utilization of available water & nutrients

286. The instrument used for measuring the photosynthetically active radiations (PAR) is:________?
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A. Pyrheliometer

B. Pyrgeometer

C. Quantom sensor

D. Both A & C

287. Element responsible pollen grain of plant__________?
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A. P

B. N

C. B

D. K

288. According to one estimate, wind and water erosion over ______ % of the Pakistans total area?
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A. None of the above

B. 76%

C. 46%

D. 36%

289. The seventieth element included in the list of essential nutrient element is:__________?
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A. Cobalt

B. Vanadium

C. Nickle

D. Sodium

290. The availability of essential nutrients from soil to the plants is controlled by the ________ properties of soil:
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A. Physical

B. chemical

C. Biological

D. both A & B

291. Organic matter influences:_________?
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A. Cation exchange capacity

B. Aggregate stability

C. All of the above

D. Water holding capacity

292. The configuration of a surface and the relations among its man-made and natural features is called:________?
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A. All of the above

B. topograpy

C. Topography

D. Tofography

293. Potassium (K) fixation capacity is maximum in:____________?
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A. Illite

B. Montmorillonitic

C. Vermiculite

D. Amorphous clay

294. Humus generally refers to the decomposed organic residues which have undergone a series of degradation and synthesis cycles. The humic substances consist of a series of highly acidic, yellow to black coloured, high molecular weight compounds __________________, which can be separated using different extraction procedures:
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A. Hymatomelanic acid & Humin

B. Humic acid & Fulvic acid

C. both A & B

D. None of these

295. Loss of nitrogen in the form of NH3 in alkaline medium is known as_________?
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A. None of these

B. Leaching

C. Denitrification

D. Volatilization
296. In cation exchange, 18 mg of Ammonium ion can be exchanged for__________?
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A. 6 mg of Al

B. 12 mg of mg

C. 46 mg of Na

D. 40 mg of Ca

297. If the chlorophyll content in plant increases, the solar radiation transmitted:
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A. None of these

B. Decreases

C. Increases

D. Constant

298. The unique soil environment under the influence of plants roots is called rhizosphere and this term was given by__________?
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A. Helium. S. Denial

B. A.Q khan

C. Aristotle et al.

D. Hiltner
299. World biodiversity day is celebrated on:_________?
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A. 2-Mar

B. 22-Apr

C. May-22

D. 21-Mar

300. Which chemical used to prevent evaporation from surface of water in water bodies?
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A. Cetyle alcohol

B. Methyle alcohol

C. both A and B

D. None of these