JAMB Agricultural Science Past Questions & Answers - Page 37

181.

Crop rotation has the following effects on the soil except

A.

Maintenance of soil fertility

B.

Reducing concentration of soil pests

C.

Improving soil structure

D.

Predisposing soil to leaching

Correct answer is D

Crop rotation is the growing of different crops in succession on a piece of land to avoid exhausting the soil and to control weeds, pests, and diseases.

182.

Which of the followings is not an advantage of Introduction?

A.

It enhances greater productivity

B.

It leads to the absence of pests and diseases

C.

It may not perform maximally

D.

Breeds may perform better in terms of quality and quantity

Correct answer is C

Disadvantages of introduction is that it may not perform maximally while others are advantages of introduction.

183.

Which of the following will be responsible for the poor yield of fertile soil in a high rainfall area?

A.

Leaching of soil nutrients

B.

Very low pH value of land

C.

Lack of soil microbes

D.

High alkalinity of soil

Correct answer is A

Leaching is the loss of water-soluble plant nutrients from the soil, due to rain and irrigation.

184.

A soil with pH2 can be described as

A.

Moderately acidic

B.

Moderately alkaline

C.

Highly acidic

D.

Highly alkaline

Correct answer is C

PH scale is number 1-14.1-6.9 is acidic ,the close it is to 1 the more acidic it becomes and the closer it is to 6.9 the less /slightly acidic it becomes ,while 7 is neutral ,8-12 is alkaline and the closer it is to 12 the highly it gets and the closer it is to 8 the less/slightly alkaline it is.

185.

One of the followings is not a type of pond

A.

Metallic pond

B.

Earthen pond

C.

Concrete pond

D.

Plastic pond

Correct answer is A

It is a confined body of water where fishes are raised under controlled conditions. Fish can also be raised in plastics, fiber stars and wooden rafts.
There are three types of pond: Earthen pond, Concrete pond and Plastic pond.