Food Production and Food Production and the Environmentthe Environment

The Carbon CycleThe Carbon Cycle

Carbon dioxide in the air

Carbon dioxide in the air

Green plants use carbon dioxide to make their food

Carbon dioxide in the air

Green plants use carbon dioxide to make their food

Green plants are eaten by animals

Carbon dioxide in the air

Green plants use carbon dioxide to make their food

Green plants are eaten by animals

respiration

carbon dioxide in the air

green plants use carbon dioxide to make their food

green plants are eaten by animals

respiration

dead remains of plants and animals

carbon dioxide in the air

green plants use carbon dioxide to make their food

green plants are eaten by animals

respiration

dead remains of plants and animals

decay by fungi and bacteria

DecayDecay

Fungi and bacteria Fungi and bacteria are responsible for are responsible for the decay of dead the decay of dead organisms.organisms.

DecayDecay

In order to be able In order to be able to carry out decay, to carry out decay, fungi and bacteria fungi and bacteria need:need:

1.1. OxygenOxygen

2.2. MoistureMoisture

3.3. The correct The correct temperaturetemperature

The Nitrogen CycleThe Nitrogen Cycle

nitrogen in the air

nitrogen in the air

fertilizersfertilizers

nitrogen in the air

fertilizersfertilizers

waste substances e.g. faeces

nitrogen in the air

fertilizersfertilizers

waste substances e.g. faeces

lightning

nitrogen in the air

fertilizersfertilizers

waste substances e.g. faeces

lightning

Nitrogen-fixing bacteria in the soil

nitrogen in the air

fertilizersfertilizers

waste substances e.g. faeces

lightning

Nitrogen-fixing bacteria in the soil

Nitrogen-fixing bacteria in the root nodules of clover

nitrogen in the air

fertilizersfertilizers

waste substances e.g. faeces

lightning

Nitrogen-fixing bacteria in the soil

Nitrogen-fixing bacteria in the root nodules of cloverdead remains of

plants and animals

nitrogen in the air

fertilizersfertilizers

waste substances e.g. faeces

lightning

Nitrogen-fixing bacteria in the soil

Nitrogen-fixing bacteria in the root nodules of cloverdead remains of

plants and animals

nitrates in the soil

fertilizersfertilizers

waste substances e.g. faeces

lightning

Nitrogen-fixing bacteria in the soil

Nitrogen-fixing bacteria in the root nodules of cloverdead remains of

plants and animals

nitrates in the soil

denitrifying bacteria in the soil break down nitrates

The nitrogen cycleThe nitrogen cycle

Living things need Living things need nitrogen to make nitrogen to make protein.protein.

They can not use the They can not use the nitrogen in the airnitrogen in the air

The nitrogen in the The nitrogen in the air must be changed air must be changed to to nitratesnitrates before before plants can use it.plants can use it.

The nitrogen cycleThe nitrogen cycle

Animals get their Animals get their nitrogen by eating nitrogen by eating plants.plants.

The nitrogen cycleThe nitrogen cycle

The roots of some The roots of some plants (e.g. clover, plants (e.g. clover, pea & beans) have pea & beans) have swellings called swellings called root root nodules nodules on them.on them.

Nitrogen-fixing Nitrogen-fixing bacteria living in bacteria living in these nodules these nodules change nitrogen in change nitrogen in the air into nitrates.the air into nitrates.

The nitrogen cycleThe nitrogen cycle

The nitrogen-fixing The nitrogen-fixing bacteria are essential bacteria are essential to maintain the to maintain the fertility of the soil.fertility of the soil.

Without them food Without them food yields would rapidly yields would rapidly fall.fall.