Atmospheric nitrogen is directly replenished in nature through
the activities of denitrifying bacteria
the breakdown of ammonium salts in the soil
the activities of nitrifying bacteria
the activities of nitrogen-fixing bacteria in root nodules
egestion, death and decay
Correct answer is A
The nitrogen in the soil is converted to atmospheric nitrogen by the process of DENITRIFICATION. This is done by the action of denitrifying bacterias eg several species of Pseudomonas.
The origin of mineral particles in the soil is
humus
water
micro-organisms
weathered rock
organic matter
Correct answer is E
No explanation has been provided for this answer.
Water retention is highest in soils which are rich in
sand, poor in humus and devoid of clay
clay and sand, but poor in humus
clay and humus, but poor in sand
clay, poor in humus and devoid of sand
sand and humus, but poor in clay
Correct answer is C
Clay Soil can hold more total water than most other soil types.
Soil erosion CANNOT be controlled by
planting cover crops
contouring of sloping ground
terracing of slopes
laying of mulch
burning of bush
Correct answer is E
No explanation has been provided for this answer.
Tsetse fly is harmful to man because it is associated with the spread of
river blindness
malaria
sleeping sickness
leprosy
dysentry
Correct answer is C
No explanation has been provided for this answer.