Food Production

What does an increasing human population require

An increased food yield

What may be used to increase food yield

Fertilisers and pesticides

What are fertilisers

Fertilisers provide chemicals such as nitrates, which increase crop yield

What are pesticides

Plants and animals which reduce crop yield can be killed by pesticides.

Nitrates dissolved in…

Soil water are absorbed into plants

What are nitrates used to do

Nitrates are used to produce amino acids, which are synthesised into plant proteins

Why do animals eat plants or other animals

To obtain amino acids for protein synthesis

How to increase the nitrate content of the soil

fertilisers can be added to the soil

Fertilisers can leach…

Into fresh water, adding extra unwanted nitrates

What does this do

Increase algal populations which can cause algal blooms

Whag happens in an algal bloom

Algal blooms reduce light levels, killing aquatic plants

• these dead plants, as well as algae, become food for bacteria, which increase greatly in number.

• The bacteria use up large quantities of oxygen, reducing oxygen availability for other organisms

What can be used to reduce the use of fertilisers

Genetically modified crops

What can happen when pesticides are sprayed onto crops

can accumulate in the bodies of organisms over time.

• as they are passed along food chains, toxicity increases and can reach lethal levels

What is bioaccumulation

The build up to toxic substances in living organisms

Alternatives to the use of pesticides

The use of biological control and genetically modified crops