SOIL - Jamb Biology Past Questions and Answers

Question 6:

• JAMB 1980

Leguminous plants, e.g Mucana, are usually planted in cultivated farmlands because they

A. Enrich the soil with phoshates
B. Provide animals with food
C. Enrich the soil with organic nitrogen
D. Protect the soil from being over-heated
E. Protect the micro organisms in the soil

Question 7:

• JAMB 1980

A few grams of dried soil were first heated until red hot and then further heated until no more smoke was released. This experiment was to determine

A. Amount of water in soil
B. Percentage of water in soil
C. Presence of humus in soil
D. Resistance of laterities to heat
E. Release of smoke from the soil

Question 8:

• JAMB 1981

Nitrification means

A. Conversion of nitrates to nitrogen
B. Fixing nitrogen into plants
C. Conversion of nitrates to nitrites
D. Changing of ammonia to nitrities, then nitrates
E. Nitrogen cycle

Question 9:

• JAMB 1981

Soil is said to be fertile if

A. It is black
B. It can supply usable nutrients to plants
C. The oxygen content is very high
D. Artificial manure is added to it
E. It is not waterlogged

Question 10:

• JAMB 1982

If a farmer left his land uncultivated for five years before returning to it, he must be practising

A. Modern agriculture
B. Strip cropping
C. Contour ridging
D. Crop rotation
E. The bush fallow system