Soil Science MCQs

Soil Science MCQs Multiple Choice Question


1. Soils having pHs > 8.5 are known  as

a) Alkaline soils                   b) Sodic soils                         c) Saline-sodic soils


2. Accumulation of Na+ on exchange complex of the soils is the process of

a) salinization                       b) calcification             c) sodication


3. Land which has never been cultivated is classified as

a) Thur kohna                      b) thur tirk                    c) thur juzvi


4. 10 me L-1 of Ca2+ is equal to

a) 10 mmol L-1 of Ca2+            b) 5 mmol L-1 of Ca2+   c) 20 mmol L-1 of Ca2+


5. Percentage of irrigation water that must pass through root zone to control salinity/sodicity at some pre-determined level is called as

a) Leaching requirement      b) leaching fraction               c) reclamation requirement


6. SAR is measure of hazard of

a) soluble Na+                       b) exchangeable Na+             c) adsorbed Na+


7. RSC of water fit for irrigation should be

a) less than 3.0            b) less than 3.25           c) less than 2.25


8. Immediate effect of waterlogging on plant growth is

a) deficiency of oxygen       b) deficiency of nutrients     c) deficiency of light


9. Increasing ion concentration will

a) not affect ion activity      b) enhance ion activity         c) decrease ion activity


10. The Ca2+ concentration (mmolc L-1) of saturated gypsum solution should be >

a) 15                                      b) 86                             c) 28


11. Soil redox potential (Eh) is the measure of

 a) oxygen in the soil            b) nitrogen in the soils                   c) carbon in soils


12. Permanent layer charge on soil clays develops due to

a) broken edges           b) interlayer bonding            c) isomorphic substitution


13. An ion which exist in the coordination sphere of central ion is called as

a) chelate                     b)complex ion                       c)ligand


14. Avogadro Number is

a)6.2 × 1023                                  b) 6.20 × 10-23                       c) 6.02 × 1023


15. The SI unit of CEC is

 a) cmolc kg-1                          b) me 100g-1                          c) mmolc 100 g-1



16.           Hydrolysis is the reaction in which

a) water molecule is added to the compound b) water molecule splits and attach with other compounds         c) Both

17.           De-calcification is the reaction in which

a) CaCO3 is removed from soil profile   b) Ca(OH)2 is removed from soil profile   c) Both

18.   One of the following element is essential for osmoregulations

a) sulpher                      b) Iron                           c) Potassium  

19.   Upon dilution, pH of the soil will

a) Increase                              b) Decrease                            c) remain unchanged

20. Acid rain is due to

a) NO2 in the air                    b) SO2 in the air           c) Both a & b

21. Sorption includes

a) Physical adsorption          b) Chemical adsorption        c) Both

22. Anaerobic decomposition of OM leads to the formation of

a) CO2­ and H2O           b) CO2­                                    c) CH4­ and H2O

23. Ion exchange reactions in the soil are

a) Spontaneous and non stiochiometeric b) Non- spontaneous and stiochiometeric

c) Spontaneous and stiochiometeric

24. The nutrient-holding ability of the soil pertains to

a) Alkalinity                          b) Available water capacity c) Cation exchange capacity

25. Salinity problems are most likely to occur in

a) Arid environments            b) Tropical rainforests          c) Humid areas

26. Saline soils can be ameliorated with

a) Application of gypsum      b) heavy irrigation good quality water c) deep ploughing

27. Reclamation of sodic soils is

a) easier than saline soils      b) difficult than saline soils  c) impossible

28. In saline-sodic soils which practice proves better

a) direct seeding of crops      b) transplanting of nursery   c) both

29. Which soils are well structured?

a) saline soils                         b) sodic soils                          c) both

30. The osmotic potential of soil water is affected by

a) salt content                        b) barometric pressure          c) clay content

31. High RSC waters can cause

a)                Soil flocculation          b) dispersion                          c) aggregation

32.           High pH of soils adversely affects the availability of

a) macronutrients                   b) micronutrients                   c) both

33. A liming material neutralizes acidity by producing

a) H+ ions                     b) OH- ions                            c) Al3+ ions

34. Principal source of charge in 2:1 and 2:1:1 type silicate mineral is

a) Isomorphic substitution   b) pH – dependent charges   c) none

35. The term alkali reflect the hazard of

a) Salinity                     b) Sodicity                             c) both a & b

36. Which one is more tolerant to salinity

a) barley                        b) bean                          c) corn

37. Rice is tolerant to

a) salinity                      b) sodicity                    c) both a & b

38. Acceptable yield reduction on salt affected soil is

a) 10%                                    b) 40%                                   c) 50%

39. For a wide range of texture the saturation percentage is approximately how many times the moisture present at PWP.

a) 2                                b) 4                                c) 6

40. Plants those accumulate heavy metals in higher concentration are called

a) excluders                            b) halophytes                         c) hyperaccumulators

41. One of the following is not available at low pH

a) Cu                             b) Mn                                     c) Mo

42. Silicate clays are also called as

a) oligosilicates            b) tentosilicates            c) phylosilicates

43. At high pH P precipitates with

a) Calcium hydroxide           b) Calcium silicate                c) Calcium carbonate

44. The property of a mineral to transmit light is called

a) diaphareity                         b) luster                        c) streak

45. A horizon of soluble salts other than gypsum is called

a) salic                                    b) gypsic                       c) calcic

46. H2PO4- form of phosphorus is dominant at pH:

a) acidic                        b)      basic                    c) neutral


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