Efficient food production

Lesson objectives

• All will know how energy is transferred through a food chain

• Most will know methods to reduce energy wastage during food production

• Some will be able to independently develop their own argument for/against intensive farming

What are the benefits of eating plants?

Your friend is at university and has phoned you to complain that all she can afford to eat is beans on toast.

What are the energy arguments for eating a plant-based diet?

A luxury item?

An 800g loaf of bread costs £0.80.

A 400g steak costs £4.00.

This equals £1.00 per 100g. This equals £0.10 per 100g.

Why is meat more expensive than bread?

1. What is a food chain and a pyramid of biomass?

2. What two things become less as you move along the food chain?

3. How are these factors lost?

4. Why is it more efficient for humans to eat herbivores and producers rather than carnivores?

25/03/2013 By K.Abrey

25/03/2013 By K.Abrey

How energy efficient is it to eat meat?Which of these chains is the most efficient?

The first food chain is the most efficient because it contains fewest trophic levels, so less energy will be lost.

Is eating meat less energy efficient?

If a one-acre field of corn is used to feed cows, it can support one person.

If the same area is used to feed humans directly, it can support 10 people.

Why is maximizing yields important?Many farmers use intensive farming methods to maximize their yields. Why?

Increased energy efficiency.

Lower costs for farmers.

Cheaper food for consumers.

More food produced in the same amount of space.

How do they do this…..

Intensive farming

• Farmers apply the principle of food chains/pyramids of biomass .

• Intensive farming looks at maximising biomass in animals without feeding them anymore i.e. maintain room temps/limiting their movement

What are the problems of livestock

farming/cramped conditions?

To help prevent these problems, farmers must comply with EU regulations, but some people do not think these regulations are strict enough.

• Animals are more likely to catch diseases.

• Abnormal behaviour e.g. chickens may pluck out each other’s feathers.

Your task

• Using the information you have learnt, the textbook p.166-167 (old) and p.228-229 (new) develop a table for and against intensive farming (i.e. free range versus factory)