JAMB Agricultural Science questions

306 questions with answers and explanations. Tap an option to check yourself.

1. Question 261· Soil fertility, manures and fertilisers· JAMB

   Leaching is the

   • Aburning of vegetation
   • Baddition of nutrients
   • Cwashing down of soluble nutrients below the root zone
   • Dcompaction of soil

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2. Question 262· Soil fertility, manures and fertilisers· JAMB

   Phosphorus is needed by crops mainly for

   • Agreen leaf colour only
   • Broot development and seed formation
   • Cabsorbing water
   • Ddrought resistance only

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3. Question 263· Soil fertility, manures and fertilisers· JAMB

   Deficiency of nitrogen in crops is shown by

   • Apurple leaves only
   • Byellowing of older leaves and stunted growth
   • Cleaf scorch at the margins only
   • Dexcessive vegetative growth

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4. Question 264· Soil fertility, manures and fertilisers· JAMB

   Potassium deficiency in plants is shown by

   • Adeep roots
   • Bdark green leaves
   • Cfast growth
   • Dscorching of leaf margins

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5. Question 265· Soil fertility, manures and fertilisers· JAMB

   Potassium deficiency in crops shows mainly as

   • Ascorching of leaf margins
   • Bpurple colouring of leaves
   • Cstunted roots only
   • Ddark green leaves

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6. Question 266· Soil fertility, manures and fertilisers· JAMB

   Which of these fertilisers supplies only nitrogen?

   • Asingle superphosphate
   • Burea
   • Cmuriate of potash
   • DNPK 20:10:10

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7. Question 267· Soil fertility, manures and fertilisers· JAMB

   Which of these elements is a micronutrient?

   • Azinc
   • Bnitrogen
   • Cpotassium
   • Dcalcium

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8. Question 268· Soil fertility, manures and fertilisers· JAMB

   Yellowing of the older leaves of maize most likely shows a shortage of

   • Airon
   • Bcalcium
   • Cboron
   • Dnitrogen

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9. Question 269· Soil fertility, manures and fertilisers· JAMB

   Rhizobium bacteria live in the root nodules of

   • Atubers
   • Bcereals
   • Clegumes
   • Dgrasses

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10. Question 270· Soil fertility, manures and fertilisers· JAMB

    Which of these practices reduces soil fertility?

    • ACrop rotation
    • BContinuous cropping without fertiliser
    • CBush fallowing
    • DAdding compost

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11. Question 271· Soil formation and properties· JAMB

    Liming acidic soil helps by

    • Aadding nitrogen
    • Blowering soil pH
    • Craising soil pH
    • Dkilling earthworms

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12. Question 272· Soil formation and properties· JAMB

    A soil with pH 4.5 is

    • Astrongly alkaline
    • Bneutral
    • Calkaline
    • Dstrongly acidic

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13. Question 273· Soil formation and properties· JAMB

    The soil water that plants can readily absorb is mainly

    • Agravitational water
    • Bhygroscopic water
    • Ccapillary water
    • Dcombined water

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14. Question 274· Soil formation and properties· JAMB

    A soil profile is

    • Aa soil sample bag
    • Ba soil map
    • Ca vertical section showing the soil horizons
    • Da fertiliser type

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15. Question 275· Soil formation and properties· JAMB

    A soil pH of 5.0 shows that the soil is

    • Aneutral
    • Bacidic
    • Calkaline
    • Dsaline

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    Explanation and discussion

16. Question 276· Soil formation and properties· JAMB

    Which instrument is used to measure the pH of a soil sample?

    • Aa rain gauge
    • Ba hygrometer
    • Ca pH meter
    • Dan anemometer

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17. Question 277· Soil formation and properties· JAMB

    Loamy soil is best for most crops because it

    • Acontains no air spaces
    • Bis very sticky when wet
    • Cdrains water too quickly
    • Dhas a good mixture of sand, silt and clay with humus

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18. Question 278· Soil formation and properties· JAMB

    Which of these is NOT a factor of soil formation?

    • Atime
    • Bclimate
    • Cparent material
    • Dcrop yield

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19. Question 279· Soil formation and properties· JAMB

    A soil that holds water well but is poorly aerated and sticky when wet is

    • Aclay soil
    • Bsandy soil
    • Cgravel
    • Dsandy loam

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20. Question 280· Soil formation and properties· JAMB

    The deposition in the B horizon of materials washed down from the A horizon is

    • Aerosion
    • Beluviation
    • Cweathering
    • Dilluviation

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    Explanation and discussion