Which of the following factors is both a physical and a chemical agent of rock weathering?

A. temperature

B. animal

C. water

D. oxygen

Physical properties of clay soil include

A. low porosity and low capillarity

B. high porosity and high capillarity

C. low porosity and high capillarity

D. high porosity and low capillarity

Streak disease of maize is caused by

A. virus

B. nematode

C. fungus

D. bacterium

In the carbon cycle, atmospheric carbon dioxide is replenished by

A. respiration

B. transpiration

C. lightening

D. dentrification

The following farming practices expose the soil to agents of erosion except

A. bush burning

B. land clearing

C. crop rotation

D. overgrazing

Which of the following effects is not due to water-logging?

A. inhibition of crop development

B. enhancement of leaching

C. inhibition of the activities of soil microorganisms

D. wilting of crop roots

An advantage of sprinkler irrigation is that

A. it assists farmers to raise a greater varity of crops

B. it is easy to instal

C. large areas of land can be irrigated

D. it can be afforded by peasant farmers

The main sources of farm power in West Africa are

A. wind,solar and mechanical

B. human,animal and mechanical

C. mechanical,solar and human

D. electrical,mechanical and solar

The function of the mouldboard in a mouldboard plough is to

A. cut a horizontal line in the soil

B. give support to the share

C. invert the furrow slice

D. keep the equipment steady during operation

The objectives of farm mechanization include the following except to

A. obtain higher farm yield

B. carry out farm operation quickly

C. improve the quality of farm produce

D. produce disease-resistant crop varieties