WAEC Agricultural Science questions: Soil fertility, manures and fertilisers

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

1. Question 1· Soil fertility, manures and fertilisers· WAEC

   Single superphosphate fertiliser supplies mainly

   • Apotassium
   • Bnitrogen
   • Cphosphorus
   • Dcalcium only

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2. Question 2· Soil fertility, manures and fertilisers· WAEC

   Which nutrient do crops need in the largest amount for leafy growth?

   • Aphosphorus
   • Bnitrogen
   • Cpotassium
   • Dcalcium

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3. Question 3· Soil fertility, manures and fertilisers· WAEC

   Fertiliser placed in a ring round a tree crop such as cocoa is applied by

   • Afoliar spraying
   • Bbroadcasting
   • Cring application
   • Ddrilling with seed

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4. Question 4· Soil fertility, manures and fertilisers· WAEC

   In the nitrogen cycle, lightning helps to

   • Akill nitrifying bacteria
   • Bremove nitrogen from soil
   • Cmake soil acidic only
   • Dfix atmospheric nitrogen as oxides that rain brings to the soil

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5. Question 5· Soil fertility, manures and fertilisers· WAEC

   Organic manure includes

   • Afarmyard manure
   • Burea
   • CNPK
   • Dammonium sulphate

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6. Question 6· Soil fertility, manures and fertilisers· WAEC

   Farmyard manure improves soil by

   • Amaking it saline
   • Badding nutrients and improving structure
   • Ckilling earthworms
   • Dincreasing erosion

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7. Question 7· Soil fertility, manures and fertilisers· WAEC

   Green manure is

   • Agreen plants ploughed into the soil while still fresh
   • Banimal dung
   • Ca chemical fertiliser
   • Dcompost made from refuse

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8. Question 8· Soil fertility, manures and fertilisers· WAEC

   Soil fertility is reduced by

   • Acrop rotation
   • Bcontinuous cropping without fertiliser
   • Cmanuring
   • Dfallowing

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9. Question 9· Soil fertility, manures and fertilisers· WAEC

   The bacteria in the root nodules of legumes that fix nitrogen belong to the genus

   • AClostridium
   • BNitrosomonas
   • CRhizobium
   • DPseudomonas

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10. Question 10· Soil fertility, manures and fertilisers· WAEC

    Crop rotation helps to maintain soil fertility by

    • Agrowing one crop every year
    • Bgrowing crops with different nutrient needs in sequence
    • Cburning the farm
    • Dremoving all residues

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11. Question 11· Soil fertility, manures and fertilisers· WAEC

    Leaching reduces soil fertility by

    • Aincreasing organic matter
    • Badding nutrients
    • Cwashing nutrients down beyond the reach of roots
    • Dimproving soil structure

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12. Question 12· Soil fertility, manures and fertilisers· WAEC

    Which practice helps to maintain soil fertility?

    • Abush burning
    • Bcontinuous cropping of maize
    • Ccrop rotation that includes legumes
    • Dovergrazing

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13. Question 13· Soil fertility, manures and fertilisers· WAEC

    A farmer applies 100 kg of NPK 15-15-15 fertiliser. How much nitrogen does it supply?

    • A5 kg
    • B45 kg
    • C100 kg
    • D15 kg

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14. Question 14· Soil fertility, manures and fertilisers· WAEC

    Adding lime to an acidic soil raises its

    • Aorganic matter
    • Bsalt content
    • CpH
    • Dnitrogen content

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15. Question 15· Soil fertility, manures and fertilisers· WAEC

    Muriate of potash supplies

    • Apotassium
    • Bnitrogen
    • Cphosphorus
    • Dsulphur

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16. Question 16· Soil fertility, manures and fertilisers· WAEC

    Yellowing of older leaves (chlorosis) is a sign of

    • Atoo much sunlight
    • Bexcess water only
    • Cnitrogen deficiency
    • Dphosphorus excess

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17. Question 17· Soil fertility, manures and fertilisers· WAEC

    Phosphorus deficiency in crops shows mainly as

    • Apoor root growth and purplish leaves
    • Byellowing of older leaves
    • Cscorched leaf margins
    • Dwhite spots on fruits

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18. Question 18· Soil fertility, manures and fertilisers· WAEC

    NPK 15-15-15 contains

    • Aequal proportions of nitrogen, phosphorus and potassium
    • B15 kg of each nutrient
    • Conly nitrogen
    • Dno potassium

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19. Question 19· Soil fertility, manures and fertilisers· WAEC

    Nitrogen in fertilisers helps plants to

    • Aripen fruits only
    • Bform roots only
    • Cproduce healthy green leaves
    • Dresist drought only

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    Explanation and discussion