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What is an Ion?

• A negatively charged molecule

• A positively charged molecule

• A charged molecule due to the loss or gain of electrons

• An extremely small soil particle

What is a cation?

• A positively charged ion

• A type of fertiliser used for plant growth

• A negatively charged ion

• A type of layer in a soil profile

Which of the following is a chemical property of soil?

• Earthworm activity

• soil texture

• water content

• cation exchange capacity

Which of the following is a cation?

• K-

• Al

• Cl-

• H+

• Mg

Cation exchange is best described as....

• The exchange of negative ions between soil and soil water

• The removal of positively charged ions from a soil

• The ability of a soil to attract, retain and release clay particles

• The ability of a soil to attract, release and retain cations

pH is a measure of the concentration of which ions in a solution

• Aluminium

• Calcium

• Hydrogen

• Potassium

What is the normal pH range for agricultural land?

• 5 - 8

• 4 - 7.5

• 6 - 7

• 5.5 - 8.5

Which of the following has the lowest cation exchange capacity?

• Sandy loam

• Organic soil

• Loam

• Clay

What is meant by the cation exchange capacity of a soil

• The capacity of a soil to exchange cations between the soil surfaces and the water

• The ability of a soil to exchange cations

• The capacity of water a soil can hold

• The time when a soil is no longer able to exchange cations

What is the result of having an inadequate soil pH?

• A very low / high pH can reduce the availability of nutrients to plants

• A low pH will allow for optimum growth of most crops

• A very high pH will allow for maximum uptake of soil nutrients