SB9l: The Nitrogen Cycle

Question 1

Crop rotation

Answer 1

Where a different crop is planted in the same field each year in a 3- or 4-year cycle, such as potatoes, oats, beans and cabbages. This helps to control the build-up of soil pests for each crop.

Question 2

Manure

Answer 2

A mixture containing animal waste that is added to soil to improve its fertility.

Question 3

Nitrate

Answer 3

A compound that contains nitrogen in the form of a nitrate ion.

Question 4

Nitrogen cycle

Answer 4

A sequence of processes by which nitrogen moves from the atmosphere through living and dead organisms, into the soil and back to the atmosphere.

Question 5

Nitrogen-fixing bacteria

Answer 5

Bacteria that can take nitrogen from the atmosphere and convert it to more complex nitrogen compounds such as ammonia.