Improving Crop Yields And Fertilisers (T5)

Question 1

Explain how greenhouses provide the correct conditions for plant growth..

Answer 1

The transparency of the glass provides natural light for photosynthesis during summer months and additional lighting provides more light during winter months.

The ‘greenhouse effect’ heats the greenhouse up.

Burning fossil fuels produces carbon dioxide and water. CO2 is required for photosynthesis and the water vapour maintains a moist atmosphere and reduces water loss by transpiration.

The grower can provide the correct balance of nutrients for the crops being grown.

Question 2

What are the two main types of fertiliser?

Answer 2

• organic

- inorganic

Question 3

What are most organic fertilisers made up of?

Answer 3

Animal manure mixed with straw.

Question 4

What are most inorganic fertilisers made up of?

Answer 4

Inorganic compounds such as potassium nitrate or ammonium nitrate

Question 5

Describe how growing legumes can replace lost nitrates in the soil..

Answer 5

Eg: growing clover in one year out of four

Legume crops contain nitrogen fixing bacteria in their root nodules which convert nitrogen gas in the soil into ammonium ions.

Some of these ammonium ions are used by the plants to make proteins.

At the end of the crop cycle the plants are ploughed into the soil where the proteins which contain nitrogen are decayed to ammonia.

The ammonia is then oxidised to nitrates by nitrifying bacteria.