Farming to save biomass
Definition
Intensive farming
Farming that produces as much food as possible from the land or animals available, often by restricting animals' movement and controlling their temperature.
- Farmers can produce more meat by reducing the biomass that farm animals lose.
- Restricting the animals' movement means they use less energy in respiration for their muscles.
- Controlling their temperature in heated barns means they lose less biomass keeping their bodies warm.
- So more of the food the animals eat is turned into biomass that people can eat.
Common Mistake
- Do not say intensive farming gives the animals more energy.
- It reduces the energy they lose, so more of their food becomes biomass we can eat.
Eating lower down the food chain
- Because only about 10% of biomass passes up each level, biomass is lost at every step of a food chain.
- Eating plants rather than animals wastes less biomass, so it can feed more people from the same land.
- This is why a plant-based diet is a more efficient use of the land's biomass.
Key Idea
Eating plants instead of animals skips a trophic level, so less biomass is wasted and more people can be fed.
Ethical objections
- Keeping animals in small pens and heated sheds raises ethical objections about animal welfare.
- The animals cannot behave naturally and may suffer stress or health problems.
- Some people therefore choose free-range food or a plant-based diet instead.
Self review
- Give two ways intensive farming reduces the biomass that animals lose.
- Why does restricting movement mean more of the food becomes meat?
- Why is eating plants a more efficient use of land than eating meat?
- Give one ethical objection to intensive farming.
