The most active agent of physical weathering in arid regions is

A. wind

B. water

C. temperature

D. ice

Soils in forest areas would normally have

A. low moisture content

B. high proportion of sand

C. high proportion of humus

D. low microbial activity

Clay particles hold cations because they

A. are negatively charged

B. become hardened when dry

C. are very small in size

D. have definite shapes

Under which of the following conditions will organic matter in the soil decompose fastest?

A. optimum pH

B. low temperature

C. anaerobic conditions

D. waterlogged condition

Which of the following materials can be applied to the soil in order to correct yellowing of leaves?

A. lime

B. urea

C. gypsum

D. bone meal

One importance of cover crops is that they

A. provide shade for crops

B. protect crops from pests

C. increase soil acidity

D. suppress weed growth

The appropriate irrigation method for upland rice field is

A. sprinkler

B. drip

C. flooding

D. underground

Drainage refers to

A. removal of excess water from the soil

B. removal of nutrients from the soil

C. addition of water to the soil

D. protection of soil from erosion

Energy in fossil materials may be harnessed as

A. water energy

B. wind energy

C. electrical energy

D. fuel energy

A decorticator is useful in the processing of

A. maize

B. cotton

C. cocoa

D. groundnut