Soil - Biology Jamb Past Questions and Answers

Question 16 :

• JAMB 1984

The process of soil erosion is usually from

A. Rill → sheet → gully
B. Gully → rill → sheet
C. Sheet → guly → rill
D. Sheet → rill → gully
E. Rill → gully → sheet

Question 17 :

• JAMB 1985

Soil erosion CANNOT be controlled by

A. Planting cover crops
B. Contouring of sloping ground
C. Terracing of slopes
D. Laying of mulch
E. Burning of bush

Question 18 :

• JAMB 1985

Water retention is highest in soils which are rich in

A. Sand, poor in humus and devoid of clay
B. Clay and sand, but poor in humus
C. Clay and humus, but poor in sand
D. Clay, poor in humus and devoid of sand
E. Sand and humus, but poor in clay

Question 19 :

• JAMB 1985

The origin of mineral particles in the soil is

A. Humus
B. Water
C. Micro-organisms
D. Weathered rock
E. Organic matter

Question 20 :

• JAMB 1985

Atmospheric nitrogen is directly replenished in nature through

A. The activities of denitrifying bacteria
B. The breakdown of ammonium salts in the soil
C. The activities of nitrifying bacteria
D. The activities of nitrogen-fixing bacteria in root nodules
E. Egestion, death and decay