Farming

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World population (billions)

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Human Population Growth

Pop Clock

How does this huge human population affect the environment?

• Habitat destruction

incl. deforestation, building, quarrying, etc.

• Farming farms are not natural environments!

• Pollution of land, water and air

We’ll look at all these issues in the next few lessons, starting with farming.

The human population is over 7 billion. We can feed all these humans due to intensive farming, which maximises the farm yield i.e. the mass of food produced per area of farmland per year (kg/m2/y). This is also known as productivity.

How do farmers increase their productivity (try comparing a modern industrial farm with an African subsistence farm)?

Intensive Farming

Intensive farming filmfrom Home

Intensive Farming• Selective

breeding for fast-growing crops and animals

• Fertilisers to increase plant growth

• Pest control to kill animals who might eat our crops

• Greenhouses to increase growth of certain crops

• Factory farming

to increase growth of farm animals

• Mechanisation to increase efficiency of all aspects of farming and reduce labour costs

• Fish farming To conserve fish stocks

Work in groups of four, each person to study a different topic:

1. Glasshouses

2. Fertilisers

3. Pest control

4. Fish farming

Put a subheading for your topic in your book and use p165-169 of your textbook to write notes that answer the questions on the worksheet.

Then teach the rest of your group about that topic, so you all end up with lovely notes.

Intensive Farming

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via sew age .

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cycle broken here

Farming breaks the nitrogen cycle, so farmers need some form of fertiliser to replace the lost nitrates.

Fertilisers

Fish Farming

Fish farmclip from BBC