1. Organic and Intensive Farming

2. Recycling elements
Nitrogen is very important for all plant life! Animals eat plants.
When plants and animals die,
they decompose (rot) and the
nitrogen returns to the soil.
Microbes also break down
animal waste so that it can be
used by plants again (manure).

3. Nitrogen Cycle
(play animation)

4. The Nitrogen cycle

5. Harvesting crops When crops are harvested
(taken for food), the elements
(e.g. nitrogen) are taken away instead of being returned to the soil by dying and rotting.
If the elements are not replaced (put back), the next crops will not grow
well.

6. Intensive Farming - chemicals
Many different chemicals are used to make plants and animals grow faster
Intensive farmers use artificial fertilizers to put elements nitrogen, phosphorus, potassium back into the soil.
It is easier to use than manure and smaller quantities are needed, because it contains more of the elements.
Artificial fertilizers are spread on the
ground or sprayed on the crops.

7. Intensive Farming - chemicals
Problems:
They do not just disappear but stay in the plants that we eat, so our food is contaminated with chemicals.
Soil used to grow the plants will also be contaminated and have chemicals in it for a very long time.
Animals eat the grass , which has had
chemicals sprayed on to it, so the chemicals
get into their blood and therefore the meat
that we eat.
Chemicals run off the land into rivers
and kill plants and fish.

8. ORGANIC farming Artificial fertilizers are banned in Organic farming.
Organic farmers use animal manure, compost and human sewage, (which has been heated to destroy any harmful microbes) to make their crops grow.
‘Green manure’ is grown – plants are grown,
then ploughed in and left to rot.
Worms, insects and bacteria underground are
always working on making the soil good.
By using a process called CROP ROTATION
(changing the crop grown each year), the farmer
can keep a good soil for many years.

9. Organic farming
It is illegal to sell produce as organic if it hasn’t been produced that way.
Farmers must keep to National Standards.
Artificial chemicals are banned.
Artificial fertilizers and pesticides in the soil have to be below a certain level.
Animals must be allowed to move freely, given organic feed but no artificial hormones.

10. Pest and disease control
Pests e.g. aphids, are insects that eat crops.
Diseases e.g. potato blight, can kill crops.
Pests and diseases can mean that the yield from the crop is small – but pests and diseases can usually be controlled.
aphids
Potato blight

11. Intensive farms – Pests and Diseases
The crops are sprayed with man-made chemicals to get rid of pests (pesticides or insecticides) and diseases (fungicides)– this means bigger yields and plants that look good.
Other chemicals (herbicides) are used to kill weeds (plants not wanted).
But the chemicals stay on the
plants and could be eaten by
humans as well as the pests.

12. Organic farms-pests and diseases
Organic farmers are not allowed to use man-made chemicals for this.
Farmers introduce natural predators e.g. ladybirds to eat aphids (biological control).
Hedges and grass are left around fields to
encourage other natural predators e.g. birds.
Crop rotation prevents diseases of a
particular crop building up.
Natural pesticides may be used.
Pest and disease-resistant (stronger) varieties of plants are planted.

13. Compare these two farms

14. Advantages Intensive farming Organic farming
Bigger yields from land available
Fewer workers needed
Animals lead happier lives
Soil structure is better
Fewer blemishes on crops
Use of hormones increases meat production
Intensive farming
Organic farming
Produce is cheaper
Large numbers of animals kept in ideal conditions
More birds and insects
Less harmful to environment
Antibiotics use keeps animals healthy
No harmful chemicals – healthier?

15. Disadvantages More expensive More blemishes on crops
Chemicals stay in soil
Man-made chemicals used
Intensive farming
Organic farming
Animals live in crowded conditions
Smaller yields
Natural predators destroyed
Chemicals wash into rivers
More farm workers needed
Hedgerow habitats destroyed